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The goal of this project was to determine if standardized ileal digestible (SID) lysine provided at 40% above estimated requirements, with the concomitant increase in protein intake, from days 90 to 110 of gestation would stimulate mammary development in gilts. From day 90 of gestation, Yorkshire × Landrace gilts were fed 2.65 kg of either a conventional diet (CTL, control, n = 19) providing 18.6 g/d of SID Lys or a diet providing 26.0 g/d of SID Lys via additional soybean meal (HILYS, n = 19). Both diets were isoenergetic. Jugular blood samples obtained on days 90 and 110 of gestation were used to measure concentrations of insulin-like growth factor-1 (IGF-1), metabolites, and amino acids (AA). Gilts were necropsied on day 110 ± 1 of gestation to obtain mammary glands for compositional analyses, immunohistochemistry, and analysis of mRNA abundance for AA transporters and markers of cell proliferation and differentiation. The HILYS gilts gained more body weight (P < 0.01) during the experimental period compared with CTL gilts, and had greater fetal weights (1.29 vs. 1.21 ± 0.03 kg, P < 0.05). There was no difference in circulating IGF-1, glucose, or albumin (P > 0.10) between HILYS and CTL gilts on day 110 of gestation, whereas concentrations of urea and free fatty acids were greater (P < 0.01), and those of Trp and Ala were lower (P < 0.05), in HILYS than CTL gilts. The provision of lysine at 40% above estimated requirements increased total mammary parenchymal mass by 44%, as well as total parenchymal fat, protein, DNA, and RNA (P < 0.01). The mRNA abundance of ACACA was greater (P < 0.05) in HILYS than CTL gilts, while only the AA transporter SLC6A14 tended (P < 0.10) to be greater. Results demonstrate that providing dietary Lys above current National Research Council recommendations in late gestation increases mammary development in gilts. Results also indicate that Lys may have been limiting for protein retention. These data suggest that the use of a two-phase feeding strategy during gestation, whereby dietary Lys is increased from day 90, could benefit potential sow milk yield in the subsequent lactation.

Piglets with low birth weight present low vitality after farrowing, often leading to impaired weight gain during lactation. A recessive missense variant (C >T) for increased appetite and fatness in the porcine leptin receptor gene (rs709596309) causes a negative maternal effect on the weight of piglets at weaning. However, it is not known whether this variant already exerts an effect on the birth weight and vitality of newborn piglets and on their growing capacity during lactation. An experiment was conducted using 668 purebred Duroc piglets (131 CC, 311 CT, and 226 TT) from 74 multiparous sows (9 CC, 43 CT, and 22 TT) and 14 boars (1 CC, 10 CT, and 3 TT). All piglets were individually weighed at birth and tested for vitality, which was assessed on a scale from 1 (low vitality) to 3 (high vitality) based on behavioral observations, including the status of the piglet immediately before the test. Only non-adopted piglets were considered for piglet performance at weaning. Inferences on the effect of the genotype on birth and weaning traits were done on a Bayesian setting based on 2-trait bivariate models including the effects of the piglet and the litter, as well as the genotype of the sow and the piglet, the sex of the piglet, and the parity number. Vitality and the status of the piglet before the test were analyzed using a liability threshold (probit) model. As compared to other genotypes, TT newborn piglets were 28 g heavier, were more vital (the probability of being scored as highly vital was 6.5% higher) and were more often found suckling before the test (the probability of being suckling at test was 6.5% higher). As a result, they grew more during lactation (153 g) and were heavier at weaning (169 g) than littermates of the two other genotypes, thus partly compensating for the limited maternal capacity of TT sows. Our findings provide evidence that appetite-influencing genes, such as the leptin receptor gene, have developmental implications from very early life stages. [ABSTRACT FROM AUTHOR]

Feeding a Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V, Cedar Rapids, IA) during periods of metabolic stress is beneficial to the health of dairy cows partially through its effect on the gut microbiota. Whether SCFP alters the ileal microbiota in lactating cows during intestinal challenges induced by feed restriction (FR) is not known. We used 16S rRNA sequencing to assess if feeding SCFP during FR to induce gut barrier dysfunction alters microbiota profiles in the ileum. The mRNA abundance of key genes associated with tissue structures and immunity was also detected. Multiparous cows (97.1 ± 7.6 days in milk (DIM); n = 7 per treatment) fed a control diet or the control plus 19 g/d NutriTek for 9 wk were subjected to an FR challenge for 5 d, during which they were fed 40% of their ad libitum intake from the 7 d before FR. All cows were slaughtered at the end of FR. DNA extracted from ileal digesta was subjected to PacBio Full-Length 16S rRNA gene sequencing. High-quality amplicon sequence analyses were performed with Targeted Amplicon Diversity Analysis and MicrobiomeAnalyst. Functional analysis was performed and analyzed using PICRUSt and STAMP. Feeding SCFP did not (P > 0.05) alter dry matter intake, milk yield, or milk components during FR. In addition, SCFP supplementation tended (P = 0.07) to increase the relative abundance of Proteobacteria and Bifidobacterium animalis. Compared with controls, feeding SCFP increased the relative abundance of Lactobacillales (P = 0.03). Gluconokinase, oligosaccharide reducing-end xylanase, and 3-hydroxy acid dehydrogenase were among the enzymes overrepresented (P < 0.05) in response to feeding SCFP. Cows fed SCFP had a lower representation of adenosylcobalamin biosynthesis I (early cobalt insertion) and pyrimidine deoxyribonucleotides de novo biosynthesis III (P < 0.05). Subsets of the Firmicutes genus, Bacteroidota phylum, and Treponema genus were correlated with the mRNA abundance of genes associated with ileal integrity (GCNT3, GALNT5, B3GNT3, FN1, ITGA2, LAMB2) and inflammation (AOX1, GPX8, CXCL12, CXCL14, CCL4, SAA3). Our data indicated that the moderate FR induced dysfunction of the ileal microbiome, but feeding SCFP increased the abundance of some beneficial gut probiotic bacteria and other species related to tissue structures and immunity [ABSTRACT FROM AUTHOR]

Periods of decreased feed intake may disrupt function of the intestinal barrier. Feeding NutriTek® (NTK; Diamond V, Cedar Rapids, IA), a postbiotic from S. cerevisiae fermentation (SCFP), improved health and supported anti-inflammatory functions. We investigated the effects of feeding NTK to cows before and during a period of feed restriction (FR) designed to model periods of intestinal barrier dysfunction. In total, 16 multiparous cows (97.1 ± 7.6 DIM; n = 8/group) were fed a control diet (CON) or CON plus 19 g/d NTK for 9 wk (Phase 1; P1) and then were subjected to an FR challenge for 5 d, during which they were fed 40% of their ad libitum intake from the 7 d prior to FR. Milk yield (MY) and DMI were collected daily. During FR, milk was collected daily for composition, blood daily to measure plasma biomarkers and to measure monocyte and neutrophil phagocytosis and oxidative burst on d 1, 3, and 5. Data were analyzed using a mixed model in SAS 9.4. All data were subjected to repeated measures ANOVA. Dietary treatment (TRT), Day, and their interaction (TRT × Day) were considered as fixed effects and cow as the random effect. For analysis of P1, data collected during a 7-d adaptation phase were used as a covariate. During P1, NTK cows tended to have greater DMI and had greater fat, ECM and FCM yields, and feed efficiency (ECM/DMI and FCM/DMI). Protein yield tended to be greater in NTK compared with CON cows. A tendency for greater monocyte phagocytosis was detected with NTK. However, during FR, feeding NTK led to lower MY and lactose yield and tended to lower solids percentage. While NTK cows tended to have reduced neutrophil oxidative burst than CON cows during FR (NTK: 26.20%, CON: 36.93%), there was no difference in phagocytosis (NTK: 7.92%, CON: 6.31%). Plasma biomarkers of energy metabolism, liver function, inflammation, and oxidative stress during the FR period did not differ. Overall, results suggested that feeding NTK increased the yield of FCM, ECM, feed efficiency and milk components prior to FR. [ABSTRACT FROM AUTHOR]

Stressors such as lack of access to feed, hot temperatures, transportation, and pen changes can cause impairment of ruminal and intestinal barrier function, also known as “leaky gut”. Despite the known benefits of some nutritional approaches during periods of stress, little is understood regarding the underlying mechanisms, especially in dairy cows. We evaluated the effect of feeding a Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V, Cedar Rapids, IA) on the ileal transcriptome in response to feed restriction (FR), an established model to induce intestinal barrier dysfunction. Multiparous cows [97.1 ± 7.6 days in milk (DIM); n = 5/group] fed a control diet or control plus 19 g/d SCFP for 9 wk were subjected to an FR challenge for 5 d during which they were fed 40% of their ad libitum intake from the 7 d before FR. All cows were slaughtered at the end of FR, and ileal scrapping RNA was used for RNAseq (NovaSeq 6000, 100 bp read length). Statistical analysis was performed in R and bioinformatics using the KEGG (Kyoto Encyclopedia of Genes and Genomes) and GO databases. One thousand six hundred and ninety-six differentially expressed genes (DEG; FDR-adjusted P ≤ 0.10) were detected in SCFP vs. control, with 451 upregulated and 1,245 downregulated. “Mucin type O-glycan biosynthesis” was the top downregulated KEGG pathway due to downregulation of genes catalyzing glycosylation of mucins (GCNT3, GALNT5, B3GNT3, GALNT18, and GALNT14). An overall downregulation of cell and tissue structure genes (e.g., extracellular matrix proteins) associated with collagen (COL6A1, COL1A1, COL4A1, COL1A2, and COL6A2), laminin (LAMB2), and integrins (ITGA8, ITGA2, and ITGA5) also were detected with SCFP. A subset of DEG enriched in the GO term “extracellular exosome” and “extracellular space”. Chemokines within “Cytokine-cytokine receptor interaction pathways” such as CCL16, CCL21, CCL14, CXCL12, and CXCL14 were downregulated by SCFP. The “Glutathione metabolism” pathway was upregulated by SCFP, including GSTA1 and RRM2B among the top upregulated genes, and GSTM1 and GPX8 as top downregulated genes. There were 9 homeobox transcription factors among the top 50 predicted transcription factors using the RNAseq DEG dataset, underscoring the importance of cell differentiation as a potential target of dietary SCFP. Taken together, SCFP downregulated immune-, ECM-, and mucin synthesis-related genes during FR. Homeobox transcription factors appear important for the transcriptional response of SCFP [ABSTRACT FROM AUTHOR]

Preweaning piglet growth is tied to milk quality and consumption. To determine the relationship of milk traits from parity 1–4 dams and piglet growth, early- and mid-lactation (day 2 and day 16) milk samples were collected from 48 litters and analyzed for protein, fat, somatic cell count (SCC), lactose, other solids (solids excluding protein and fat), total solids, and milk urea nitrogen (MUN). There were no interactions of parity by day therefore only main effects were tested. Milk volume and percent MUN were greatest (P < 0.05) from fourth parity dams. Nulliparous dams had elevated (P < 0.05) SCC. Several milk traits were different by day. Percent milk protein, fat, and total solids were greater (P < 0.05) from day 2 milk, while percent milk lactose and other solids were greater (P < 0.05) from day 16 milk. Each milk trait was categorically identified as high, moderate, or low at ¼, ½, or ¼ distribution, respectively. Mixed models were used to determine the association of individual milk traits with piglet lactation growth (gain calculated from body weights at birth, day 10, and day 25 weaning; WN). Moderate levels of day 2 milk protein were associated with the greatest (P < 0.05) gain during lactation in comparison to low and high levels. High levels of day 2 milk lactose and day 2 other solids were both related (P < 0.05) to piglet gain over the lactation period. Evaluation of day 16 milk traits with piglet gain over lactation indicated high levels of fat, other solids, and total solids had the greatest (P < 0.05) gain in comparison to moderate and low levels of each trait. Within phase of lactation weight gain, association of day 2 or day 16 milk traits with early weight gain (birth to day 10) or late weight gain (day 10 to WN) were performed. The greatest (P < 0.05) early weight gains were associated with moderate levels of day 2 protein, high levels of day 2 lactose and day 2 other solids, and low levels of day 2 MUN. High levels of day 2 milk lactose and day 16 milk fat were associated (P < 0.05) with piglet gain during late lactation (day 10 to weaning). Genetic selection or improved management that allows for favorable milk traits at critical periods of lactation for improved weight gain will improve pig production. [ABSTRACT FROM AUTHOR]

Milk proteins serve as nutrition and affect neonate development and immunity through their bioactivity. Post-translational modifications of proteins affect their bioactivity. Glycosylation is the attachment of sugar moieties to proteins, with attachment of glycans to asparagine indicated as N-linked glycosylation. Our objective was to characterize N-linked glycosylated proteins in homogenate swine milk samples collected from sows (n  = 5/6) during farrowing to represent colostrum and on days 3 and 14 post-farrowing to represent transitional and mature milk, respectively. Glycopeptides were isolated with lectin-based extraction and treated with Peptide N -glycosidase F (PNGase F) to identify N-linked glycosylation sites. Purified glycopeptides were analyzed by label-free liquid chromatography–tandem mass spectrometry (LC–MS/MS). MaxQuant software was used to align spectra to Sus scrofa Uniport database to identify proteins and measure their relative abundances. Analysis of variance and Welch's t -test analysis identified glycoproteins differentially abundant between colostrum, transitional, and mature milk (false discovery rate <0.05). Shotgun proteome analysis identified 545 N-linked and glutamine, Q, -linked, glycosylation (P  > 0.75 for deamidation) sites on 220 glycoproteins in sow milk. Glycoproteins were found across all three phases of swine milk production and varied by number of glycosylation sites (1–14) and in abundance and distribution between colostrum, transitional, and mature milk. Polymeric immunoglobulin receptor was the most glycosylated protein with 14 sites identified. Also highly glycosylated were casein and mucin proteins. These data are described and the relevance of glycosylated milk proteins in neonate development, such as protection against pathogens, is discussed. [ABSTRACT FROM AUTHOR]

CCAAT/enhancer binding protein α (C/EBPα) is the key transcription factor involved in lipid metabolism, however, the role of C/EBPα in milk fat synthesis of dairy goats remains unknown. The objective of the present research was to clarify the function of C/EBPα in goat mammary epithelial cells (GMECs) and its impact on peroxisome proliferator-activated receptor gamma (PPARG) promoter activity. In this study, C/EBPα overexpression increased its mRNA and protein levels by 42-fold and 6-fold, respectively. In contrast, transfecting siRNA targeting C/EBPα decreased its mRNA level to 20% and protein abundance to 80% of the basal level. The contents of lipid droplets, triacylglycerol (TAG), and cholesterol were increased (P < 0.05) in C/EBPα-overexpressing GMECs, and knockdown of C/EBPα led to the opposite results. Overexpression of C/EBPα significantly increased the expression levels of genes involved in TAG synthesis (AGPAT6 , DGAT2 , P < 0.01), lipid droplet formation (PLIN2 , P < 0.01), and fatty acid synthesis (FADS2 , P < 0.05; ELOVL6 , P < 0.01). Knockdown of C/EBPα decreased (P < 0.05) the expression levels of AGPAT6 , DGAT1 , DGAT2 , PLIN2 , FADS2 , and ELOVL6. C/EBPα upregulated the expression level of PPARG (P < 0.05), and four C/EBPα binding regions were identified in the PPARG promoter at −1,112 to −1,102 bp, −734 to −724 bp, −248 to −238 bp, and −119 to −109 bp. Knockdown of C/EBPα reduced (P < 0.05) the PPARG promoter activity when the C/EBPα binding regions were mutated at −1,112 to −1,102 bp, −734 to −724 bp, and −248 to −238 bp locations of the promoter. However, the promoter activity did not change when the mutation was located at −119 bp. In conclusion, our results suggest that C/EBPα can promote TAG synthesis in GMECs through its effects on mRNA abundance of genes related to lipid metabolism and regulation of the PPARG promoter activity via C/EBPα binding regions. [ABSTRACT FROM AUTHOR]

A total of 91 sows (Line 241, DNA Genetics) were used to evaluate the effects of supplemental fat sources and essential fatty acid intake on sow farrowing performance, litter growth performance, and essential fatty acid composition of colostrum, milk, and adipose tissue. At approximatelyday 107 of gestation, sows were blocked by body weight and parity, then allotted to 1 of 5 experimental treatments as part of a 2 × 2 + 1 factorial arrangement. Experimental diets were corn-soybean meal-based with a control diet that contained no added fat or diets with 3% added fat as either beef tallow or soybean oil, with consumption of the added fat diets starting on day 107 or 112 of gestation and fed until weaning. Thus, sows were provided low essential fatty acids (EFA; as linoleic and α-linolenic acid) without supplemental fat or with beef tallow or high EFA with soybean oil. Sows were provided approximately 2.8 kg/d of their assigned lactation diet pre-farrow and then provided ad libitum access after parturition. Sows consuming diets with beef tallow had greater lactation ADFI (fat source, P  = 0.030), but lower daily linoleic acid (LA) and α-linolenic acid (ALA) intake than sows that consumed diets with soybean oil (fat source, P  < 0.001). Supplemental fat sources providing either low or high EFA did not influence litter growth performance (fat source, P  > 0.05). Sows fed diets with beef tallow did not influence the LA composition of colostrum; however, lactation diets with high EFA provided by soybean oil on day 107 of gestation increased colostrum LA concentration compared to providing diets on day 112 of gestation (fat source × time, P  = 0.084; time, P  < 0.001). Additionally, regardless of pre-farrow timing, ALA concentration of colostrum increased when sows consumed diets with soybean oil compared to beef tallow (fat source, P  < 0.001). Both LA and ALA concentrations of milk at weaning were greater for sows that consumed diets with soybean oil compared to beef tallow (fat source, P  < 0.001). Furthermore, concentrations of LA and ALA within adipose tissue were greater at weaning when sows consumed diets with high EFA compared to low EFA (fat source, P  < 0.05). These responses suggest that providing dietary fat sources with high concentrations of EFA can increase backfat, colostrum, and milk LA and ALA. However, in this experiment, changes in colostrum and milk composition did not influence litter growth performance. [ABSTRACT FROM AUTHOR]

Although in vitro data with mixed ruminal fluid demonstrated positive effects of posbiotic diet (POS) from lactobacilli on measures of fermentation and microbial profiles, there is a paucity of in vivo data with lactating ruminants. The aim of the study was to evaluate the effects of incorporating POS into diets of lactating goats on energy (E) partitioning, carbon (C) and nitrogen (N) balance, and performance. Ten late-lactation Murciano-Granadina goats were used in a crossover design with 26-d periods. Goats in the control diet (CON) were fed daily at the rate of 1 kg alfalfa hay and 1.5 kg concentrate, and the treatment group (POS) was fed CON with the addition of 3.75 g/d of Probisan Ruminants (PENTABIOL S.L. Navarra, Spain). No differences in DMI were detected. However, ruminal fluid propionate and apparent total tract digestibilities of NDF and ADF were greater (18%, 4.7%, and 5.2%, respectively; P  < 0.05) in POS compared with the CON diet. Daily partitioning of E to milk and efficiency of ME intake for milk production greater (11% and 3.0%, respectively; P  < 0.05) in POS compared with CON. The nonprotein RQ was greater in POS compared with CON due to greater (P  < 0.05) oxidation of carbohydrate (213 vs. 115 kJ/kg of BW0.75 per day) compared with fat (362 vs. 486 kJ/kg of BW0.75 per day). Although no differences were found in C balance, goats in POS had lower (P  < 0.05) amounts of C in CH4 (1.1 vs. 1.3 g/kg BW0.75 per day) compared with CON. There were no differences in N intake or N in feces or urine, but N in milk was greater (P  < 0.05) in POS compared with the CON diet (0.8 vs. 0.7 g/kg BW0.75 per day). Yield of fat-corrected milk (FCM) (3.20 vs. 2.72 kg/d; P  < 0.05) and concentration of true protein (3.4 vs. 3.3 kg/d; P  < 0.05) and lactose (4.7 vs. 4.5 kg/d; P  < 0.05) were greater in POS compared with CON. These responses were accompanied by lower (P  < 0.05) urea (12.3 vs. 16.6 mM/L) and ammonia-N (6.6 vs. 8.8 mg/L) without changes in fat concentration (6.1% vs. 6.0%; P  > 0.05) in POS compared with the CON diet. Daily amount of CH4 emission did not differ P  > 0.05 between diets. However, when expressed relative to unit of edible product, feeding POS reduced (P  < 0.05) the amount of CH4 by 46 g/kg of milk fat, 97 g/kg of milk protein, and 3 g/kg of milk compared with CON. Overall, data indicated that feeding a postbiotic in late-lactation increased energy efficiency for milk production partly by reducing CH4 emission. [ABSTRACT FROM AUTHOR]

Eighty-eight gilts [initial body weight (BW) 49.8 ± 0.8 kg] were recruited to determine the effects of moderate energy and protein restriction during the development period on changes in BW and backfat depth (BF) and subsequent lactation performance. Gilts were randomly assigned to one of four feeding programs: 1) standard commercial diet fed ad libitum (CON), 2) standard commercial diet fed 10% or 3) 20% below ad libitum, or 4) a high–fiber diet fed ad libitum [2.5 times more fiber (neutral detergent fiber) than the commercial diet to dilute net energy and crude protein by approximately 20% and 13%, respectively; FIB ]. The gilts were housed individually and received the feeding programs between 90 and 190 (breeding) d of age and standard gestation and lactation diets thereafter. Litters were standardized to 12 ± 1 pigs within 48 h of farrowing; weaning occurred at 20.0 ± 0.4 d of age. Gilts that received the 20% restricted program had lower overall average daily feed intake (ADFI) during the development period (2.64 ± 0.04 kg; P < 0.05) versus all other feeding programs and gilts that received the 10% restricted program had lower ADFI than FIB and CON, which were not different (2.96 vs. 3.44 and 3.47 ± 0.04 kg for 10%, FIB and CON, respectively; P < 0.05). Plasma free fatty acid (FFA) concentrations on day 180 of age were lower for gilts that received the 10% and 20% restricted programs compared to gilts that received the FIB and CON programs, which were not different (97 and 86 vs. 220 and 149 ± 29 µEq/L, respectively; P < 0.05). Plasma concentrations of glucose, urea, prolactin, and IGF-1 were not different among feeding programs on day 180 of age. At breeding, gilts that received the FIB and 10% programs had lower BW and BF versus CON (145.7 and 144.8 vs. 155.2 ± 0.9 kg and 14.4 and 14.8 vs. 16.5 ± 0.2 mm for BW and BF, respectively; P < 0.05) but greater BW than gilts that received the 20% restricted program (137.9 kg; P < 0.05). The BW and BF of gilts did not differ at the end of gestation or at weaning. The ADFI of sows during lactation and offspring birth weight and growth rate during lactation and the 5-wk nursery period were not influenced by gilt development feeding program. Therefore, a high-fiber feeding program could be used in group-housing gilt-development scenarios, where feed is offered ad libitum, to control BW and BF prior to breeding without influencing milk production in the subsequent lactation period. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effects of dietary grape seed polyphenols (GSP) supplementation during the late gestation and lactation period on reproductive performance, antioxidative status in serum, nutrient composition, and Ig content in colostrum of multiparous sows. On day 80 of gestation, a total of 64 sows with similar body condition were allocated to a completely randomized block design with 4 dietary treatments (n = 16 sows per treatment): 1) basal diet (CON, control group); 2) basal diet supplemented with 200 IU/kg vitamin E (200VE, positive control group); 3) basal diet supplemented with 200 mg/kg GSP (200GSP); and 4) basal diet supplemented with 300 mg/kg GSP (300GSP). The trial lasted 56 d until the piglets were weaned on day 21 of lactation. Reproductive performance, parameters of antioxidative status, and levels of progesterone (P4) and estradiol (E2) in serum, nutrient composition, and Ig content in colostrum of sows were determined. The number of dead fetuses was reduced, and farrowing survival was significantly improved in the litters from 300GSP-fed (P < 0.05). Preweaning survivability significantly increased in the litters from sows fed 200GSP and 200VE (P < 0.05). The activity of superoxide dismutase and glutathione peroxidase (GSH-Px) in the serum was significantly increased in sows fed 200GSP and 300GSP (P < 0.05). The activity of GSH-Px in the serum also significantly increased in sows fed 200VE (P < 0.05). Sows fed 300GSP had the greatest levels of P4 and E2 in the serum, which was significantly greater than sows fed 200VE and CON (P < 0.05). No significant differences were found among treatments for the content of solids-not-fat, fat, protein, and lactose in colostrum (P > 0.05). However, sows fed GSP had greater IgM and IgG content in colostrum compared with sows fed 200VE and CON (P < 0.05). In conclusion, dietary GSP supplementation during late gestation and lactation improved the farrowing survival and preweaning survivability, enhanced the antioxidant status and hormone levels in serum, and increased the IgM and IgG content in colostrum of sows.

An experiment was conducted to test the hypothesis that productivity of sows fed diets containing canola meal produced from high-protein or conventional varieties of canola seeds is not different from that of sows fed corn-soybean meal (SBM) diets. A total of 180 sows (initial BW: 207.8 ± 29.11 kg) were randomly allotted to 1 of 5 diets with 36 to 40 sows per diet. A 2-phase feeding program was used with gestation diets fed from day 7 of gestation to farrowing and lactation diets fed during the lactation period and from weaning to first estrus. The 5 diets within each phase consisted of a control diet based on corn and SBM, 2 diets were based on corn and high-protein canola meal (CM-HP) that was included to replace 50 or 100% of the SBM in the control diet, and 2 diets contained conventional canola meal (CM-CV) included to replace 50 or 100% of the SBM in the control diet. Soybean hulls were included in diets fed during gestation to standardize the concentration of NDF to approximately 13% in all diets. However, no soybean hulls were used in lactation diets resulting in increased concentrations of NDF as the dietary concentration of CM-HP or CM-CV increased. Results of the experiment indicated that there were no differences in sow BW changes during gestation, in sow BW on day 1 post-farrowing, or at weaning due to dietary treatments. No differences were observed among diets in ADFI during gestation or lactation or in the number of total pigs born, pigs born alive, still-born pigs, or weaned pigs per litter. Likewise, no differences were observed among diets in litter birth weight, live litter birth weight, litter BW at weaning, or litter ADG. As the inclusion level of CM-HP or CM-CV increased, the percentage of pigs surviving during the lactation period increased (linear, P < 0.05), but the wean to first estrus interval also increased as the dietary concentration of CM-CV increased (linear, P < 0.05). Average pig BW at weaning and pig ADG decreased (linear, P < 0.05) as the inclusion level of CM-HP increased. No differences were observed between CM-HP and CM-CV with the exception that pigs born from sows fed CM-CV during gestation had greater (P < 0.05) average live pig birth weight compared with pigs born from sows fed CM-HP during gestation. Results of this experiment indicate that CM-HP or CM-CV may replace all SBM in diets fed to sows during gestation and lactation.

The circadian system is an inbuilt timekeeping mechanism that tracks the 24-h day through the generation of circadian rhythms. Circadian rhythms enable animals to forecast and anticipate regular changes in their environment, and orchestrate biochemical, physiological and behavioral events so that the right process occurs at the right time. The 24 h rhythms generated by circadian clocks are integrated into homeostatic feedback loops and repair pathways. Metabolic and reproductive systems are highly integrated with the circadian timing system and demonstrate reciprocal regulation. Circadian clocks set the timing of circadian rhythms by gathering temporal information from external and internal signals to include light and nutrients. Exogenous and endogenous factors that function as inputs to the circadian clocks can disrupt their timing when applied at unusual and inappropriate times, and are referred to as chronodisruptors. Changes in the natural light-dark cycle perturb the circadian system. Other chronodisrupters include inappropriately timed food intake and physical activity and biological stress. Knowledge of the biology underlying circadian clock timing is critical to understanding how to maximize health and production effciency of cattle. Here we review circadian clocks and their function in the regulation of metabolic and reproductive systems as well as the consequence of circadian disruption on mammary development and lactation with a particular focus on recent research fndings from studies of dairy cows. [ABSTRACT FROM AUTHOR]

Although mammary gland growth and development in females is a lifelong process, it builds on isometric and allometric phases of mammary growth to establish a complex ductal network before and during puberty. Only then can other phases of branching and alveologenesis, differentiation, lactation, and involution proceed. Although the ductal network of various species differs in its histomorphology, all glands undergo a common phase of allometric growth when the mammary ducts penetrate into the supporting stromal microenvironment. Perhaps not surprisingly, different aspects of diet and nutrition can influence this allometric growth, either directly or indirectly. In this review, we outline some of the fundamental aspects of how allometric ductal growth in the mammary glands of various species is influenced by diet and nutrition and identify opportunities and questions for future investigation.

Precision feeding (PF) aims to provide the right amount of nutrients at the right time for each animal. Lactating sows generally receive the same diet, which either results in insufficient supply and body reserve mobilization, or excessive supply and high nutrient excretion. With the help of online measuring devices, computational methods, and smart feeders, we introduced the first PF decision support system (DSS) for lactating sows. Precision (PRE) and conventional (STD) feeding strategies were compared in commercial conditions. Every day each PRE sow received a tailored ration that had been computed by the DSS. This ration was obtained by blending a diet with a high AA and mineral content (13.00 g/kg SID Lys, 4.50 g/kg digestible P) and a diet low in AAs and minerals (6.50 g/kg SID Lys, 2.90 g/kg digestible P). All STD sows received a conventional diet (10.08 g/kg SID Lys, 3.78 g/kg digestible P). Before the trial, the DSS was fitted to farm performance for the prediction of piglet average daily gain (PADG) and sow daily feed intake (DFI), with data from 1,691 and 3,712 lactations, respectively. Sow and litter performance were analyzed for the effect of feeding strategy with ANOVA, with results considered statistically significant when P < 0.05. The experiment involved 239 PRE and 240 STD sows. DFI was similarly high in both treatments (PRE: 6.59, STD: 6.45 kg/d; P = 0.11). Litter growth was high (PRE: 2.96, STD: 3.06 kg/d), although it decreased slightly by about 3% in PRE compared to STD treatments (P < 0.05). Sow body weight loss was low, although it was slightly higher in PRE sows (7.7 vs. 2.1 kg, P < 0.001), which might be due to insufficient AA supply in some sows. Weaning to estrus interval (5.6 d) did not differ. In PRE sows SID Lys intake (PRE: 7.7, STD: 10.0 g/kg; P < 0.001) and digestible P intake (PRE: 3.2, STD: 3.8 g/kg; P < 0.001) declined by 23% and 14%, respectively, and feed cost decreased by 12%. For PRE sows, excretion of N and P decreased by 28% and 42%, respectively. According to these results, PF appears to be a very promising strategy for lactating sows. [ABSTRACT FROM AUTHOR]

Feeding probiotics like live yeast Saccharomyces cerevisiae var. boulardii (SB) in pig diets has been suggested to preserve health and reduce antibiotic use during critical periods like weaning. This study was conducted to determine whether SB added to the diet of sows during the last 2 mo of gestation and the 4 wk of lactation may contribute to support the health and performance of piglets before and after weaning through changes in sow physiology, milk composition, and fecal microbiota. Crossbred sows (n = 45) from parity 1 to 9 were allocated to two dietary treatments: Control (n = 23) and SB (n = 22). Sows in the SB group were fed the same standard gestation and then lactation diet as the Control sows but with the addition of SB at 1 × 109 colony-forming units/kg of feed. Piglets were weaned under challenging conditions consisting of mixing of litters, no pen cleaning, and a 2-h period of nonoptimal temperature exposure. Blood and feces were collected from sows on days 28 and 113 of gestation and days 6 (feces only) and 28 of lactation, and from piglets on days 6 (feces) and 28 of lactation and day 5 after weaning. Colostrum was collected during parturition and milk on day 6 of lactation. Supplementation of sow diets with SB influenced the fecal microbiota of the sows and their piglets. Five days after weaning, the alpha-diversity was lower (P < 0.05) in piglets from SB sows than in piglets from Control sows. Analysis of microbiota with partial least square discriminant analysis discriminated feces from SB sows from that of Control sows at 110 d of gestation (29.4% error rate). Piglet feces could also be discriminated according to the diet of their mother, with a better discrimination early after birth (day 6 of lactation) than after weaning (day 5 postweaning, 3.4% vs. 12.7% error rate). Five days after weaning, piglets had greater white blood cell count, plasma haptoglobin concentration, and oxidative stress than before weaning (P < 0.001). Nevertheless, SB supplementation in sow diets had no effect (P > 0.05) on most of health criteria measured in blood and growth performance of piglets during lactation and the postweaning period. Moreover, dietary supplementation of SB to sows did not elicit any changes (P > 0.05) in their reproductive performance, metabolic and health status, nor in the concentration of immunoglobulins and nutrients in colostrum and milk. In the present experimental conditions, feeding SB to sows influenced sow and piglet microbiota with no consequences on their health and performance. [ABSTRACT FROM AUTHOR]

The first objective was to investigate the effects of feeding rumen-protected methionine (RPM) during a heat stress (HS) challenge on abundance and phosphorylation of mechanistic target of rapamycin (mTOR)-related signaling proteins in mammary gland. The second objective was to investigate how HS and RPM may modulate the response of mammary gland explants to an inflammatory challenge using lipopolysaccharide (LPS). Thirty-two multiparous, lactating Holstein cows (184 ± 59 DIM) were randomly assigned to 1 of 2 environmental treatment groups, and 1 of 2 dietary treatments [TMR with RPM (Smartamine M; Adisseo Inc.; 0.105% DM as top dress) or TMR without RPM (CON)] in a crossover design. There were two periods with two phases per period. In phase 1 (9 d), all cows were in thermoneutral conditions (TN) and fed ad libitum. During phase 2 (9 d), group 1 (n = 16) cows were exposed to HS using electric heat blankets, whereas group 2 cows (n = 16) remained in TN but were pair-fed to HS counterparts to control for DMI decreases associated with HS. After a washout period (14 d), the study was repeated (period 2). Environmental treatments were inverted in period 2 (sequence), whereas dietary treatments remained the same. Mammary tissue was harvested via biopsy at the end of both periods. Tissue was used for protein abundance analysis and also for incubation with 0 or 3 μg/mL of LPS for 2 h and subsequently used for mRNA abundance. Data were analyzed using PROC MIXED in SAS. Analysis of protein abundance data included the effects of diet, environment and their interaction, and period and sequence to account for the crossover design. The explant data model also included the effect of LPS and its interaction with environment and diet. Abundance of phosphorylated mTOR and ratio of phosphorylated eukaryotic translation elongation factor 2 (p-EEF2) to total EEF2 in non-challenged tissue was greater with RPM supplementation (P = 0.04 for both) and in both cases tended to be greater with HS (P = 0.08 for both). Regardless of RPM supplementation, incubation with LPS upregulated mRNA abundance of IL8 , IL6 , IL1B , CXCL2 , TNF , NFKB1 , and TLR2 (P < 0.05). An environment × LPS interaction was observed for NFKB1 (P = 0.03); abundance was greater in LPS-treated explants from non-HS compared with HS cows. Abundance of CXCL2 , NFKB1 , NOS2 , NOS1 , and SOD2 was lower with HS (P < 0.05). Although LPS did not alter mRNA abundance of the antioxidant transcription factor NFE2L2 (P = 0.59), explants from HS cows had lower abundance of NFE2L2 (P  < 0.001) and CUL3 (P  = 0.04). Overall, RPM supplementation may alter mTOR activation in mammary tissue. Additionally, although HS reduced explant immune and antioxidant responses, RPM did not attenuate the inflammatory response induced by LPS in vitro. [ABSTRACT FROM AUTHOR]

Several studies have evaluated the effects of the dietary application of exogenous alpha-amylase preparations (AMA) as a strategy to increase total tract starch digestibility (TTSD) and milk yield (MY) in dairy cows, but the results have been inconsistent. Thus, the objective of this study was to evaluate the effects of the dietary application of AMA on the performance, digestibility, and rumen fermentation of lactating dairy cows using a meta-analytic method. A total of 18 peer-reviewed manuscripts (N = 32 treatment comparisons) from 2003 to 2019 were systematically identified following the PRISMA method. The weighted raw mean differences between dietary AMA and control treatments were compared with a robust variance estimation. Likewise, diet characteristics like crude protein (CP) content, NDF content, starch content, days in milk (DIM), experimental design (Latin square and continuous), and AMA dose (0 to 732 Kilo Novo units [KNU]/kg TMR) were used as covariates in a meta-regression, subgrouping, and dose–response analysis. Compared to the control, dietary AMA increased (P < 0.05) DM digestibility (69.32% vs. 68.30%), TTSD (94.62% vs. 94.10%), milk protein concentration and yield (3.11% vs. 3.08%; 1.14 vs. 1.10 kg/d) and tended to increase (P = 0.09) fat-corrected milk (35.96 vs. 35.10 kg/d), but no effects were observed on DM intake (22.99 vs. 22.90 kg/d) and feed efficiency (1.50 vs. 1.48). Dietary AMA tended (P = 0.10) to reduce rumen pH (6.27 vs. 6.30). Both the enzyme dose and DIM strongly influenced (P < 0.05) the effects of AMA on digestibility and performance. The dose–response analysis revealed that feeding 600 KNU/kg to high-producing early lactation (< 70 DIM) dairy cows increased FCM and milk protein. Accounting for the type of experimental design was associated with a lower between-studies-variance among comparisons. Overall, this meta-analysis supports the hypothesis that dietary AMA supplementation is associated with a better lactational performance in dairy cows. However, these effects are only suitable for high-producing early lactation dairy cows. [ABSTRACT FROM AUTHOR]

The objective was to evaluate increasing standard ileal digestible (SID) lysine (Lys) and metabolizable energy (ME) above recommended inclusion levels fed to young (parity 1-2) and mature (parity 3-5) lactating sows. A total of 741 sows (371 parity 1-2, 370 parity 3-5) were fed in a 2×2 factorial arrangement of treatments in a randomized complete block design. Factors included SID Lys (0.85% vs 1.11%) and ME (3.18 Mcal/kg vs 3.33 Mcal/kg). Diets were formulated to deliver 62 g of SID Lys at 0.85% inclusion and 23.2 Mcal of energy to sows that consume 7.30 kg of complete feed per day. Overall, sows consumed 61 g/d SID Lys and 22.6 Mcal/kg, but because of nutrient intake differences between young and mature sows, outcome variables were analyzed separately and not statistically compared. There were no differences for either SID Lysine or ME treatment in lactation feed intake (P ≥ 0.27) or change in body weight (P ≥ 0.19) for young sows. Young sows fed 3.33 Mcal/kg ME had 0.31 fewer post-cross foster mortalities (P < 0.01) resulting in weaned litters that were 4.06 kg heavier (P < 0.01) than litters from young sows fed 3.18 Mcal/kg ME. Young sows fed 1.11% SID Lys and 3.33 Mcal/kg ME had the fewest (P ≤ 0.03) sows bred by d 7 compared to all other treatments. There was an interaction (P = 0.03) for wean-to-estrus-interval for young sows were young sows fed 1.11% SID Lys and 3.33 Mcal/kg ME were at least 3.27 days longer than young sows fed 0.85% SID Lys and 3.33 Mcal/kg ME or 1.11% SID Lys and 3.18 Mcal/kg ME. Young sows fed 3.33 Mcal/kg ME had a nearly 7% improvement in lactation G:F (0.40 vs 0.43; P < 0.01) compared to young sows fed 3.18 Mcal/kg ME. The percentage of mature sows fed 1.11% SID Lys bred by day 7 was 7.0 percentage units less (P = 0.06) when fed 3.33 Mcal/kg ME compared to 3.18 Mcal/kg ME. Feed efficiency of mature sows fed 1.11% SID Lys (0.38) was 7.89% greater (P < 0.01) than mature sows fed 0.85% SID Lys (0.35). Increasing either SID Lys or ME energy to young and mature sows had little influence on sow or pig performance, but simultaneously increasing both SID Lys and metabolizable energy negatively impacted subsequent breeding performance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs. yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from days 0 to 7, then concentrations were decreased by 50% from days 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P < 0.05) average daily gain (ADG) from days 0 to 24 and days 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased days 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery, there was reduced (P < 0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24; or DFM, 0.10% MicroSaf-S from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From days 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. Although feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2. [ABSTRACT FROM AUTHOR]

A total of 80 sows (Line 241; DNA, Columbus, NE) across three farrowing groups were used in a study to evaluate the effect of feeding live yeast and yeast extracts to lactating sows on sow and litter performance and antimicrobial resistance (AMR) patterns of sow fecal E. coli. Sows were blocked by farrowing group, BW, and parity on day 110 of gestation and allotted to 1 of 2 dietary treatments. Dietary treatments consisted of a standard lactation diet with or without yeast-based pre- and probiotics (0.10% Actisaf Sc 47 HR+ and 0.025% SafMannan; Phileo by Lesaffre, Milwaukee, WI). Diets were fed from day 110 of gestation until weaning (approximately d 19 post-farrow). A tendency (P = 0.073) was observed for increased feed intake through lactation when sows were fed a diet with yeast additives compared with the control diet. There was no evidence (P > 0.10) that treatment influenced any other sow or litter performance measurements. Fecal samples were collected upon entry into the farrowing house and at weaning from the first farrowing group (27 sows) to determine the resistance patterns of E. coli. E. coli was isolated from fecal samples and species confirmed by PCR detection of uidA and clpB genes. Microbroth dilution method was used to determine the minimal inhibitory concentrations (MIC) of E. coli isolates to 14 antimicrobials. Isolates were categorized as either susceptible, intermediate, or resistant based on Clinical and Laboratory Standards Institute guidelines. An interaction (P = 0.026) of diet × sampling day was observed for cefoxitin where fecal E. coli showed no evidence of treatment differences (P = 0.237) in MIC values at entry, but sows fed the control diet had lower (P = 0.035) MIC values at weaning compared with sows fed yeast additives. There were no diet main effects (P > 0.10) on the resistance of fecal E. coli. There was an increased (P < 0.02) toward resistance for 11 of the 14 antimicrobials over time. Fecal E. coli were resistant to tetracycline and ceftriaxone at weaning. Fecal E. coli were susceptible or intermediate in all sampling days to the remaining antimicrobials. In conclusion, feeding live yeast and yeast extracts tended to increase feed intake during lactation but did not influence either sow or litter performance measurements or the resistance of fecal E. coli during lactation except for cefoxitin, which had a higher MIC at the end of lactation when yeast additives were present in the diet. [ABSTRACT FROM AUTHOR]

The physiology during late gestation and the transition period to lactation changes dramatically in the sow, especially during the latter period. Understanding the physiological processes and how they change dynamically as the sow approaches farrowing, nest building, giving birth to piglets, and producing colostrum is important because these processes greatly affect sow productivity. Glucose originating from assimilated starch accounts for the majority of dietary energy, and around farrowing, various organs and peripheral tissues compete for plasma glucose, which may become depleted. Indeed, physical activity increases shortly prior to farrowing, leading to glucose use by muscles. Approximately ½ to 1 d later, glucose is also needed for uterine contractions to expel the piglets and for the mammary gland to produce lactose and fat for colostrum. At farrowing, the sow appears to prioritize glucose to the mammary gland above the uterus, whereby insufficient dietary energy may compromise the farrowing process. At this time, energy metabolism in the uterus shifts dramatically from relying mainly on the oxidation of glucogenic energy substrates (primarily glucose) to ketogenic energy supplied from triglycerides. The rapid growth of mammary tissue occurs in the last third of gestation, and it accelerates as the sow approaches farrowing. In the last 1 to 2 wk prepartum, some fat may be produced in the mammary glands and stored to be secreted in either colostrum or transient milk. During the first 6 h after the onset of farrowing, the uptake of glucose and lactate by the mammary glands roughly doubles. Lactate is supplying approximately 15% of the glucogenic carbon taken up by the mammary glands and originates from the strong uterine contractions. Thereafter, the mammary uptake of glucose and lactate declines, which suggests that the amount of colostrum secreted starts to decrease at that time. Optimal nutrition of sows during late gestation and the transition period should focus on mammary development, farrowing performance, and colostrum production. The birth weight of piglets seems to be only slightly responsive to maternal nutrition in gilts; on the other hand, sows will counterbalance insufficient feed or nutrient intake by increasing mobilization of their body reserves. Ensuring sufficient energy to sows around farrowing is crucial and may be achieved via adequate feed supply, at least three daily meals, high dietary fiber content, and extra supplementation of energy. [ABSTRACT FROM AUTHOR]

Subclinical mastitis is a common intramammary disease in sheep production systems. Expenses associated with compromised animal performance, therapeutic interventions, and decreased ewe longevity make efforts to minimize its prevalence worthwhile. The objectives of this study were to 1) quantify the prevalence of subclinical mastitis throughout lactation, 2) evaluate the impact of bedding treatments on subclinical mastitis during early lactation, 3) evaluate the efficacy of prophylaxis and feed restriction during weaning on subclinical mastitis cure rates, and 4) identify levels and types of antimicrobial resistance in milk-derived bacteria. Ewe milk samples were collected at days 1, 2, and 28 post-partum, weaning, and 3-d post-weaning for bacterial identification via culture-based methods. Staphylococcus spp. and Streptococcus spp. isolates were subjected to in vitro antimicrobial susceptibility testing. The overall prevalence of subclinical mastitis defined by culture growth ranged between 22% and 66% and differences were observed between post-weaning and days 1 and 28 milk samples. Commonly isolated bacteria include coagulase-negative staphylococci (CoNS; 59%), Bacillus spp. (35%), Mannheimia haemolytica (10%), Staphylococcus aureus (8%), Streptococcus spp. (5%), and Corynebacterium spp. (5%). Early milk samples (days 1 and 2) were compared between jug bedding treatment: jugs were recently vacated, cleaned, and dusted with barn lime before adding fresh straw (CLEAN) or jugs were previously vacated and fresh straw was added atop soiled bedding (SOILED). Jug bedding treatment did not affect the prevalence of subclinical mastitis, though CoNS had greater sulfadimethoxine resistance in SOILED isolates than CLEAN isolates (P = 0.03). Three different weaning treatments were used: ewes were injected with penicillin at weaning (PENN), ewes had restricted feed access 48 h prior to and 72 h post-weaning (FAST), or a combination of these treatments (COMBO). Weaning treatment did not affect the prevalence of subclinical mastitis or cure rate from weaning to 3-d post-weaning, though all PENN and no FAST milk S. aureus isolates were resistant against tetracycline (P = 0.08). Subclinical mastitis prevalence tended to decrease from weaning to post-weaning (P = 0.08). These data show that subclinical mastitis is common throughout lactation and the levels of antimicrobial resistance of bacteria isolated from ewe milk are generally low against commonly used antimicrobials. [ABSTRACT FROM AUTHOR]

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn–soybean meal–wheat-based lactation diets that contained 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low LA and ALA in diets with CWG or high LA and ALA in diets that included soybean oil. Sows received their assigned EFA treatments until weaning and were then fed a common gestation and lactation diet in the subsequent reproductive cycle. Average daily feed intake during the lactation period increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. However, daily LA and ALA intakes of sows fed the Combination and SO diets were still greater (P < 0.05) than those of sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P < 0.05) piglet weaning weights and greater (P < 0.05) litter ADG when compared with litters from sows fed diets with CWG that provided low EFA. Despite advantages in growth performance, there was no impact of sow EFA intake on piglet survivability (P > 0.10). Additionally, lactation diet EFA composition did not influence sow colostrum or milk dry matter, crude protein, or crude fat content (P > 0.10). However, LA and ALA content in colostrum and milk increased (P < 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P > 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by soybean oil during lactation increased overall litter growth and pig weaning weights, reduced sow ADFI, but did not affect piglet survivability or subsequent performance of sows. [ABSTRACT FROM AUTHOR]

Due to the large amounts of calcium transferred to milk from mammary glands, periparturient dairy goats face challenges with calcium metabolism disorder and hypocalcemia. Serotonin (5-hydroxytryptamine, 5-HT), the product of 5-hydroxy- l -tryptophan (5-HTP) catalyzed by tryptophan hydroxylase 1, is a multifunctional monoamine thought to be a homeostatic regulator of the animal. The objective of the current study was to investigate the effects and underlying mechanisms of intramuscular 5-HTP injections on calcium homeostasis in the goat mammary glands. In the in vivo experiment, 30 multiparous Guanzhong dairy goats were randomly assigned to 2 groups, one group was injected with 5-HTP intramuscularly and the other group was injected with normal saline. From the first 10 d of the expected date for delivery, 5-HTP or saline was injected into goats through the shoulder muscle every morning before feeding, with a dose of 1 mg/kg per body weight. In the in vitro experiment, goat mammary epithelial cells (GMEC) were treated with 100 μM 5-HT for the evaluation of 5-HT in calcium transportation. The results demonstrated that 5-HTP treatment had no effect on the basic composition of colostrum (P > 0.05) but increased the serum 5-HT concentrations on days −5, −4, −3, and 5 relative to parturition (P < 0.05). The 5-HTP injection group had greater serum calcium concentration on day 4 and greater serum parathyroid hormone-related protein (PTHrP) on days −5, −4, −1, 3, 4, and 5 compared with the saline injection group (P < 0.05). It was further confirmed that 5-HT could increase intracellular calcium levels by increasing PTHrP and decreasing plasma membrane Ca2+-ATPases1 (PMCA1) in GMEC (P < 0.05). In conclusion, 5-HTP treatment in multiparous goats during the transition period from pregnancy to lactation is a feasible way to protect goats from calcium metabolism disorder. [ABSTRACT FROM AUTHOR]

Milk production in dairy cows increases worldwide since many decades. With rising milk yields, however, potential limiting factors are increasingly discussed. Particularly, the availability of glucose and amino acids is crucial to maintain milk production as well as animal health. Limitations arise from feed sources, the rumen and digestive tract, tissue mobilization, intermediary metabolism and transport, and the uptake of circulating nutrients by the lactating mammary gland. The limiting character can change depending on the stage of lactation. Although physiological boundaries are prevalent throughout the gestation–lactation cycle, limitations are aggravated during the early lactation period when high milk production is accompanied by low feed intake and high mobilization of body reserves. The knowledge about physiological constraints may help to improve animal health and make milk production more sustainably. The scope of this review is to address contemporary factors related to production limits in dairy cows from a physiological perspective. Besides acknowledged physiological constraints, selected environmental and management-related factors affecting animal performance and physiology will be discussed. Potential solutions and strategies to overcome or to alleviate these constraints can only be presented briefly. Instead, they are thought to address existing shortcomings and to identify possibilities for optimization. Despite a scientific-based view on physiological limits, we should keep in mind that only healthy animals could use their genetic capacity and produce high amounts of milk. [ABSTRACT FROM AUTHOR]

Heat stress (HS) decreases lactation output in sows due to an attempt to reduce metabolic heat production. However, this negatively affects litter growth performance. Therefore, the study objective was to determine whether electronically controlled cooling pads (ECP) would improve indirect measures of lactation output (e.g., total heat production [THP]) and litter growth performance in HS exposed sows. Over two repetitions, 12 multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg body weight [BW]) and litters were assigned to either an ECP (n = 3/repetition) or a non-functional ECP (NECP; n = 3/repetition) and placed into farrowing crates within indirect calorimeters from days 3.7 ± 0.5 to 18.7 ± 0.5 of lactation. Litters were standardized across all sows (11.4 ± 0.7 piglets/litter), and sows were provided ad libitum feed and water. All sows were exposed to cyclical HS (28.27 ± 0.26 °C nighttime to 33.09 ± 0.19°C daytime). On days 4, 8, 14, and 18 of lactation, indirect calorimetry was performed on each individual sow and litter to determine THP and THP/kg BW0.75. Body temperature (TB) was measured hourly using vaginal implants, and respiration rate (RR; breaths per minute [bpm]) was measured daily at 0700, 1100, 1300, 1500, and 1900 h. Sow feed intake (FI) was assessed daily. Litter weights were obtained at birth, on days 4, 8, 14, and 18 of lactation, and at weaning. Data were analyzed using PROC GLIMMIX with sow and/or litter as the experimental unit. An overall decrease (P < 0.01; 25 bpm) in RR and maximum daily TB (P = 0.02; 0.40 °C) was observed in ECP vs. NECP sows. An increase in THP (P < 0.01; 20.4%) and THP/kg BW0.75 (P < 0.01; 23.1%) was observed for ECP when compared with NECP sows and litters. Litter average daily gain and weaning weight were increased (P < 0.05; 25.0 and 19.2%, respectively) for ECP vs. NECP litters. No FI differences were observed (P = 0.40) when comparing ECP (5.66 ± 0.31 kg/d) and NECP (5.28 ± 0.31 kg/d) sows. In summary, ECPs improve litter growth, thermoregulatory measures, and bioenergetic parameters associated with greater milk production in lactating sows exposed to cyclical HS. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the reliability of using Ca to P ratio measured in spot urine samples to assess P intake adequacy in gestating and lactating sows. A total of 36 sows were fed one of six concentrations of dietary total P (0.40, 0.48, 0.56, 0.64, 0.72, 0.80%) from day 7.5 + 1 after breeding until the end of lactation (day 26.6 + 1). Dietary Ca to P ratio was maintained constant across treatments at 1.25. Total 24-hour urine samples were collected in mid and late gestation (days 77.1 + 2 and 112.4 + 1), and early and late lactation (days 4.5 + 1 and 18.2 + 1). In parallel to 24-hour collections, spot urine samples were collected at three different times (early morning, late morning, and late afternoon) in late gestation and late lactation. Urine Ca and P concentrations were measured and Ca to P ratio was calculated. Sows were classified as P-adequate or P-deficient according to dietary P intake. Urine Ca to P ratio was greater in sows fed P-deficient diets than sows fed P-adequate diets (P < 0.001). Receiver operator characteristic (ROC) curves were used to determine the cut-off values for urine Ca to P ratio to predict P intake adequacy. Three different categories of P intake were defined according to urine Ca to P ratio: deficient, adequate, and excessive. The area under the ROC for Ca to P ratio was 0.88 (95% CI 0.81 – 0.95). Best cut-off value of urine Ca to P ratio was 1.5 (sensitivity 94% and specificity 68%) to identify sows fed P-deficient diets and 0.5 for P-excessive diets (sensitivity 82% and specificity 82%). A strong relationship between Ca to P ratio in 24-hour and spot urine samples was determined (r = 0.93, P < 0.01), independent of physiological state and collection time of spot samples (adjusted-R 2 = 0.86, P < 0.01). The degree of agreement between spot and 24-hour urine for P intake adequacy, assessed by Cohen's weighted kappa analysis, was substantial (0.78, 95% CI 0.69 – 0.88). We conclude that urinary Ca to P ratio provides a reliable prediction of the adequacy of P intake in reproducing sows. Urinary Ca to P ratio measurements in random spot urinary offers a practical method to determine dietary P adequacy. [ABSTRACT FROM AUTHOR]

Multiparous, lactating Holstein cows (n = 32) were randomly assigned to 1 of 2 dietary treatments [TMR with rumen-protected Met (RPM) or TMR without RPM (CON)], and within each dietary treatment group cows were randomly assigned to 1 of 2 environmental treatment groups in a split-plot crossover design. In phase 1 (9 d) all cows were fed ad libitum and in thermoneutral conditions (TN). In phase 2 (9 d), group 1 (n = 16) was exposed to a heat stress (HS) challenge (HSC). Group 2 cows (n = 16) were pair-fed (PFTN) to HSC counterparts and remained in TN. After a 21-d washout period, the study was repeated (period 2) and the environmental treatments were inverted relative to treatments from phase 2 of period 1, while dietary treatments remained the same for each cow. During phase 1, cows in RPM had greater plasma Met concentration compared to cows in CON (59 µ M and 30 µ M, respectively; P < 0.001). Cows in PFTN had a greater decrease (P < 0.05) in plasma insulin than cows in HSC at 4 h (-2.7 µIU/mL vs. -0.7 µIU/mL) and 8 h (-7.7 µIU/mL vs. -0.4 µIU/mL) during phase 2. Compared to cows in PFTN, cows in HSC had an increase (P < 0.05) in plasma serum amyloid A (-59 µg/mL vs. +58 µg/mL), serum haptoglobin (-3 µg/mL vs. +33 µg/mL), plasma lipopolysaccharide binding protein (-0.27 µg/mL and +0.11 µg/mL), and plasma interleukin-1β (-1.9 pg/mL and +3.9 pg/mL) during phase 2. In conclusion, HSC elicited immunometabolic alterations; however, there were limited effects of RPM on cows in HSC. [ABSTRACT FROM AUTHOR]

This study evaluated factors affecting LH release and ovulation in response to a treatment with a conventional dose of gonadorelin (GnRH), in lactating dairy cows on day 7 of the estrous cycle. Factors evaluated were: GnRH preparation (ready-to-use vs. lyophilized), body condition score (BCS), parity, days in milk (DIM), milk yield and dominant follicle (DF) diameter, at the time of GnRH treatment. Seven days after an artificial insemination, preceded by a synchronization protocol, lactating Holstein cows were evaluated by ultrasound and those with a corpus luteum (CL) and a DF =10 mm were randomly assigned to receive 100 μg GnRH ready-to-use solution (Fertagyl; MSD, Brazil) or lyophilized (Profertil; J.A. Animal Health, Brazil) diluted just before its administration. Overall, 106 cows (BCS = 3.1 ± 0.1; DIM = 96.7 ± 4.2; 39.7 ± 0.7 kg of milk/d) were assigned to GnRH treatments. Ovulation was determined by ultrasound examinations 2 d after GnRH treatment, by disappearance of the DF, and confirmed 5 d later by the presence of an accessory CL. In a subset of cows (n = 33), blood samples were collected just before the GnRH treatment, and 2 and 4 h later, to evaluate circulating P4 and LH concentrations. Data were analyzed by GLIMMIX (SAS 9.4). Treatment effect and its interaction were included in the analyses of all other factors. Differences were declared when P = 0.05 and tendency when 0.053.0 (1.4 ± 0.2 vs 0.7 ± 0.1 ng/mL; Table 1). Moreover, cows with DF =12 mm had greater LH peak than cows with DF >12 mm (1.3 ± 0.2 vs. 0.9 ± 0.1 ng/mL; Table 2). However, these factors did not affect ovulation. Neither milk yield nor DIM affected LH peak or ovulation. In conclusion, although no differences were detected on LH peak, primiparous cows on day 7 of the estrous cycle had greater ovulation when treated with Profertil compared with Fertagyl. Moreover, regardless of treatment, greater BCS and larger DF (>12 mm) at the time of GnRH treatment were associated with decreased LH peak, however, without impairing ovulation. [ABSTRACT FROM AUTHOR]

Pre-weaned piglets prefer higher temperatures than lactating sows. To address this, swine producers use heating lamps or pads in combination with maintaining farrowing room macroenvironment temperatures at the upper end of the thermoneutral zone (24-25℃) of the lactating sow. This may inadvertently cause thermal stress for lactating sows resulting in decreased feed consumption, and ultimately, reduced milk production and litter growth. Therefore, the objective was to determine the sow level macroenvironment temperature that would improve both sow and litter productivity. In two repetitions, 37 lactating sows (parity = 3.1 ± 1.7) and their litters (d 1 litter size = 12.0 ± 1.0) were housed within 1 of 3 farrowing rooms set to different macroenvironment temperatures: LOW (n = 12 sows and litters; 15.0 ± 0.4℃), MID (n = 13 sows and litters; 19.3 ± 0.2℃), and HIGH (n = 12 sows and litters; 24.6 ± 0.8℃). Lactating sows and their litters were on trial from the onset of farrowing until weaning (19.8 ± 0.9 d of age). Individual farrowing crate temperatures were recorded throughout the trial in 0.14 s intervals using thermocouples mounted at sow head height. Piglets were provided a 0.34 x 1.52 m heating pad with a verified steady state of 35.0℃. Sow body weight (BW) was recorded at 24 h post-farrowing and at weaning, and piglet weights were measured on d 1, 7, 14 and at weaning to determine average daily BW gain (ADG). Liveborn piglet mortality was recorded throughout the trial. Sow feed intake (FI) was recorded daily from d 1 post-farrowing until weaning. The sow was considered the experimental unit for sow level measures and the litter was considered the experimental unit for piglet measures. Data were analyzed using PROC GLIMMIX in SAS 9.4 and using GLM in JMP 15. Regression models were used to determine the optimal macroenvironment temperature to improve sow FI and piglet ADG. Sow FI was greater (P < 0.01) for LOW (7.91 ± 0.38 kg) and MID (7.32 ± 0.37 kg) versus HIGH (6.37 ± 0.39 kg) sows, but similar for LOW and MID sows. Piglet ADG was greater from d 1 to weaning (P < 0.01) for LOW (0.25 ± 0.01 kg) and MID (0.26 ± 0.01 kg) versus HIGH (0.21 ± 0.01 kg) piglets, but similar for LOW and MID piglets. Pre-weaning mortality was similar (P = 0.32; 15.6%) among all treatments. A quadratic effect was observed (P < 0.01) where sow FI was maximized at a macroenvironment temperature of 17.2℃. A cubic effect was observed (P < 0.01) where piglet ADG was greatest at 17.0℃. In summary, these data have implications towards housing lactating sows and their litters at lower macroenvironment temperatures to improve growth performance. [ABSTRACT FROM AUTHOR]

Within the cattle industry, implementation of timed artificial insemination (TAI) or estrus detection protocols aid in determining the optimal breeding date. However, previous studies utilizing both breeding strategies have found differences between pregnancy rates, further emphasizing pregnancy establishment as a prominent issue in cattle production systems. Recent research has begun to evaluate the role of the female reproductive microbiome as it pertains to pregnancy establishment in cattle. It has been demonstrated that shifts in the female reproductive bacterial communities may alter pregnancy outcomes in cattle. Therefore, the objective of this work was to evaluate vaginal microbiomes on day of artificial insemination (AI) in dairy cattle bred utilizing either TAI or estrus detection and the impacts on subsequent pregnancy outcomes. Lactating Holstein cows (104 days in milk) were classified into two groups based on breeding protocols: 1) TAI (n = 44), and 2) Heat (n = 9). On day of AI, sterile swabs were inserted into the vagina, rotated eight times, and subsequently stored at -80°C in sterile collection tubes for microbiome analysis. For microbiome analysis, the V4 hypervariable region of the 16S rRNA bacterial gene was targeted. Statistical analysis for microbiome data were conducted using PROC TTEST in SAS where equality of variances was performed. Pregnancy rates by TAI versus Heat were 56.8% and 33.3%, respectively. The phylum Firmicutes had greater relative abundance in cows bred by Heat (64.1 ± 2.3% vs. 53.9 ± 2.5%, respectively; P < 0.01) compared with phyla Proteobacteria (7.1 ± 0.8% vs. 13.7 ± 1.7%), Fusobacteria (0.9 ± 0.3% vs. 5.8 ± 1.5%), and Actinobacteria (1.8 ± 0.3% vs. 3.2 ± 0.5%) which had a greater relative abundance in cows bred by TAI (P < 0.01). Within Firmicutes, genera Ruminococcus (13.0 ± 1.0% vs. 8.5 ± 0.6%), Blautia (10.3 ± 0.7% vs. 8.0 ± 0.5%), Clostridium (5.8 ± 0.2% vs. 4.9 ± 0.3%), Oscillospira (2.2 ± 0.2% vs. 1.7 ± 0.1%), and Caloramator (2.1 ± 0.1% vs. 1.7 ± 0.1%) were all greater in relative abundance in cows bred by Heat compared with cows bred by TAI (P < 0.05). Interestingly, within Fusobacteria, genera Sneathia (0.6 ± 0.3% vs. 3.5 ± 1.0%) and Fusobacterium (0.2 ± 0.1% vs. 1.5 ± 0.5%) were greater in relative abundance in cows bred by TAI (P < 0.01). Within phyla Proteobacteria and Bacteroidetes, genera Gallibacterium and Porphyromonas respectively, were both greater in relative abundance in cows bred by TAI (P < 0.05). Collectively these results indicate that the vaginal microbiomes of lactating dairy cows bred via TAI or estrus expression differs. Additionally, a shift in the vaginal microbiome to a prevalence of the phylum Firmicutes on day of AI appears to be negatively impacting pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Fifty multiparous sows (average parity 3.7±0.9 and initial BW 245.6±32.5 kg) were used to evaluate the effects of dietary standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on nitrogen utilization throughout a 24-day lactation period. Sows were randomly assigned to one of five isoenergetic feeding programs that provided equally spaced and increasing Lys-to-NE ratios between 2.79 and 5.50 g SID Lys/Mcal NE. The feeding programs were generated by blending the two extreme diets in varying proportions using a precision feeding system and were provided to sows immediately after farrowing (d1) and until weaning at d 24 ± 1. At farrowing, litters were standardized to 12 piglets. Three nitrogen balances were conducted from d 4 to 7±1 (NB1), 12 to 15 ± 1 (NB2), and 20 to 23 ± 1 (NB3) using total urine collection and fecal grab sampling. Contrast statements were used to determine linear and quadratic effects of increasing Lys-to-NE ratios. Linear (LBL) and quadratic (QBL) broken-line and polynomial quadratic (QPM) models were used to determine the optimum dietary Lys-to-NE ratios for N retention. The Bayesian information criterion was used to assess best fit. Feeding program did not influence sow ADFI (5.96 ± 0.19 kg/d), BW change (-5.4 ± 4.1 kg) or change in backfat thickness (-2.0 ± 1.1 mm) over the entire 24-d lactation period, but piglet ADG increased with dietary Lys-to-NE ratio (linear; P < 0.05). Sow N intake increased with dietary Lys-to-NE ratio in NB2 and NB3 (linear; P< 0.001). Nitrogen retention (N intake - N output in urine and feces) increased with dietary Lys-to-NE ratio in all NB (linear; P = 0.05, P < 0.001, and P < 0.001 for NB1 -to 3, respectively). The QPM showed an inflection point at 3.75 g Lys/Mcal NE during NB1 and the QBL model showed break points at 2.87 and 4.83 g Lys/Mcal NE in NB2 and NB3, respectively. Nitrogen retention in milk increased with dietary Lys-to-NE ratio only in NB1 (linear; P < 0.05) and the QPM showed inflection points at 4.31, 4.37, and 4.90 g Lys/Mcal NE for NB1-to-3, respectively. Maternal nitrogen retention (N intake - N output in urine, feces, and milk) decreased and then increased in NB1 (quadratic; P < 0.01) and increased in NB2 and NB3 (linear; P < 0.01) with dietary Lys-to-NE ratio. The QPM showed inflection points at 4.01 and 3.01 g Lys/Mcal NE for NB1 and NB2, respectively, and the QBL model showed a breakpoint at 4.83 g Lys/Mcal NE for NB3. To optimize N retention, feeding programs with a Lys-to-NE ratio between 3.75 and 4.31, 2.87 and 4.37, and 4.83 and 4.90 g SID Lys/Mcal NE should be considered during early, mid, and peak lactation, respectively. Therefore, precision feeding programs can be developed to match the ideal SID Lys-to-NE ratio more closely at different stages of lactation to improve sow performance and reduce nitrogen excretion to the environment. [ABSTRACT FROM AUTHOR]

Climatic resilience (CR) can be defined as the ability of an animal to maintain euthermia under thermally stressful conditions. However, CR based on longitudinal physiological variables has not been included in current swine genetic selection schemes. This is the first study deriving novel CR indicators using automatically recorded vaginal temperatures (TV) and estimating genetic parameters for them. Therefore, the study objectives were to: 1) derive novel indicators of CR based on automatically recorded vaginal temperature (TV); and 2) estimate (co)variance components and genetic parameters for these indicators. TV of 1,381 lactating sows (parities 2 to 7; Landrace × Large White) were measured automatically every 10 minutes from June 5th, 2021 to July 30th, 2021 using a vaginally implanted thermochron data recorder. A total of 1,639 F1 (Landrace x Large White) sows within the studied population were genotyped using the PorcineSNP50K Bead Chip. A total of 18 HS indicators derived from Tv, their definitions, heritability estimates, and mean genomic estimated breeding value (GEBV) accuracies are shown in Table 1. Multi-trait animal models were fitted for estimating the (co)variance components, considering the effects of week of data collection, parity, and location (barn and room within barn) as fixed. Heritability estimates for these resilience traits ranged from 0.0004 ± 7.16E-6 (SlopeDe) to 0.291 ± 0.047 (HSAB). Most traits derived directly from vaginal temperature (e.g., Duration: 0.201 ± 0.033, MaxTv: 0.203 ± 0.032) are moderately heritable with substantial additive genetic variance. Besides, LnVar(Med) that is derived from the deviation between the real and predicted value had moderate heritability (0.196 ± 0.041) and high mean GEBV accuracy (0.616 ± 0.042). The indicators defined based on the slope of Tv and time had low heritability estimates, which are close to zero, and low mean GEBV accuracy (0.106 ± 0.050 - 0.337 ± 0.065). Among all the CR indicators, Duration, MaxTv, Nor_medvar, Nor_avevar, HSAA, and HSAB outperformed the other indicators with moderate heritability estimates and high average GEBV accuracies. Genetic correlations were estimated among the six indicators with moderate heritability and high mean GEBV accuracy. Moderate to high positive genetic correlations (0.508 ± 0.034 to 0.992 ± 0.025) were estimated among Duration, MaxTv, Nor_medvar, HSAB, and HSAA. LnVar(Med) showed low negative genetic correlations (-0.218 ± 0.028 to -0.039 ± 0.018) with the traits Duration, MaxTv, HSAA, and HSAB, except with Nor_medvar, which was positive (0.156 ± 0.022). Thus, Duration, LnVar(Med), MaxTv, Nor_medvar, HSAB, and HSAA might be promising CR indicator and contribute toward improving lactating sows' resilience to thermal stress through genetic selection. New studies about the relationship between these new indicators and other economic important traits in pigs are required before including them in selection indexes. [ABSTRACT FROM AUTHOR]

Impacts of heat stress (HS) on lactating sows during the summer causes challenges in production. The study objective evaluated the daily patterns of common HS measures on late lactation sows. Sows in a HS environment, on and off electronic cooling pads (ECP), were compared with sows in a cool room (CR). From a sample of six sows, three sows were assigned to a HS environment, (31℃ daytime for 6 h and 26℃ nighttime for 5 h) with an ECP (n = 1) or without an ECP (nECP, n = 2). Three sows were placed in a CR (n = 3) with set temperature of 20℃. The ECP automatically flushed 2.0 L of cool water (18 to 19℃) when one of the three temperature sensors reached 26℃. Flushing occurred for 30 s replacing 1.73L of water in the ECP. All sows were in farrowing crates and provided ad libitum access to feed and water. Internal Temperature (TI) was measured in 10-minute intervals using vaginal implants. Skin temperature (TS) was measured hourly, using an infrared gun 10 cm behind the ear. Respiration rate (RR) was observed in 30-minute intervals from 0600 to 2200 h over 2 days. Mixed model periodic regressions were performed in R 4.2.2 using REML lme4, fitted to the RR, TS, and TI data. Significant treatment and treatment by periodic regression variables (P < 0.05) indicated the need for separate equations for each treatment. The final model for TI included the random effect of sow, effect of room, and single, double, and triple sine/cosine phase variables for each room. For TI, there were also significant (P < 0.001) interactions of the single-phase sine/cosine variables with the ECP treatment in the HS environment. The final model for TS included the random effect of sow, ECP treatment, single, double, and triple sine/cosine and their interactions with room, and the interaction of the single phase with ECP treatment in the HS environment. The final model for RR included the effects of room and ECP within the HS environment (P < 0.001), the single-phase sine/cosine variables, and their interactions of ECP within the HS environment and CR. Daily increases in RR and TI were much greater for sows in the HS environment compared with the CR, or the sow on the ECP. The RR for the ECP sow increased from 18 to 24 bpm from 6000 h to midafternoon (1500 to 1700 h), versus 65 to 108 bpm for the nECP sows. Overall, the ECP reduced TI on average by 0.39℃ with the greatest impact of 0.8 to 0.9℃ from 1500 to 1900 h. As in previous experiments, the sow on the ECP had greater relative reductions in RR and smaller differences in TI. [ABSTRACT FROM AUTHOR]

Essential oils are increasingly being used in the swine industry as an alternative to antibiotics. New areas of research indicate that essential oils may alter milk composition and production in lactating sows with the potential of increasing resistance of piglets to harmful bacteria. The purpose of this preliminary study was to determine the effects of Agolin-Pig, a product containing micro-encapsulated essential oils, on milk composition and production. The treatment group (n = 13) consisted of sows fed 200 ppm of Agolin-Pig mixed in an in-house premix combined with a standard lactation diet (NRC, 2012). The control group (n = 13) consisted of sows fed the same diet without added essential oils. All sows were started on their corresponding diets 14 days before their calculated farrowing date. Sows were induced on day 114 of gestation if they had not already farrowed. Colostrum was collected within 2 hours of the onset of farrowing from all teats and mixed to form a 50 to 100 mL homogenate, representative sample. On days 3 and 14 of lactation, sows were administered 0.5 mL of oxytocin via their ear vein to induce milk ejection. Three teats were selected along the midline of the sow and milked completely into 3 separate, corresponding 50 mL conical tubes. All milk samples were stored at -20°C until analysis. Protein composition of the three teats was averaged by sow before statistical analysis. Weigh-suckle-weigh (WSW), an indirect measure of milk production, was performed on d 10 to 12 of lactation by removing piglets from the sow for 45 minutes before recording a litter weight. The piglets were then returned to the sow to nurse for 30 minutes and weighed again. Colostrum and milk samples were analyzed for protein composition via a Bradford assay using a bovine serum albumin (BSA) standard. The PROC Mixed procedure of SAS v9.4 (Cary, North Carolina) was used to evaluate the effects of Agolin-Pig on the protein composition of milk at day 0, day 3, and day 14 of lactation along with WSW data. Treatment and parity (P1 vs P = 2) were main effects with day of collection as a repeated measure and the random effect of sow. There was a significant decrease for both groups in protein composition from day 0 to 3 (P = 0.0001) and day 0 to 14 (P < 0.0001) with no significant change between day 3 to 14, which is expected as colostrum transitions into whole milk. There were no significant differences between treatment groups in protein milk composition throughout lactation. WSW data showed no significant differences between treatments in milk production. While no significant differences were observed in milk composition and production, future analysis will show the effects of Agolin-Pig on milk fat and immunoglobulin composition during lactation. [ABSTRACT FROM AUTHOR]

Gestating sows become more sensitive to high temperatures at the end of gestation. Cooling pads have been developed that reduce the impact of high environmental temperatures on sows. Some of the added heat stress response may be due to oxidative stress which might be reduced with dietary antioxidants. The objective of this study was to evaluate the daily patterns of common measures of heat stress on late gestation sows with or electronic cooling pads (ECP) with or without the addition of Moringa, a plant with antioxidant activity. Sows (n = 24), 2 days before farrowing, were assigned a 2 × 2 factorial arrangement of treatments: farrowing crates with or without cooling pads and corn-soybean based diets containing either 0 or 4% Moringa leaf powder. Sows were fed 1.36 kg of feed twice a day and had ad-libitum access to water. The farrowing room was targeted to have a 32℃ daytime from 1100 to 1700 h and 26℃ nighttime). The ECP flushed 2.0 L of cool water when one of the three temperature sensors reached 26℃. Skin temperature (TS) was measured hourly using an infrared gun 10 cm behind the ear, and hourly respiration rate (RR) recorded from 600 to 2200 h. Rectal temperatures were (TI) taken at 600, 1300, 1600 and 1900 h. Two statistical analyses were conducted. The first was a mixed model including the fixed effects of ECP, diet, hour of measurement and their interactions with sow included as a random effect. Also, mixed model periodic regressions were fitted to the RR and TS data. The RR was impacted by ECT, hour, and ECP × hour interactions (P < 0.001). The final model for RR included the random effect of sow, main effect of ECP, single phase sine/cosine and 2-phase cosine variables and the interaction with the single-phase variables with ECP treatment (P < 0.001). For TS, there was only a tendency for the ECP treatment (32.4 vs. 33.0℃, P = 0.064) and effect of hour of measurement (P < 0.001) The final model for TS using periodic regression included the random effect of sow, ECP treatment (P = 0.12), single-phase sine and cosine and two-phase sine variables (P < 0.001) and interaction of single-phase sine variable by ECP treatment (P = 0.024). Overall ECP reduced internal temperatures by 0.23℃ (P = 0.17) with trend for a ECP × time interaction (P = 0.074) with the greatest impact at 1300 h (38.04 vs. 37.53, P < 0.02). The ECP produced greater relative reductions in RR and smaller differences in TI. Daily mid- to late-afternoon increases in RR, TS, and TI were reduced for ECP sows. No significant diet or diet by hour interactions were found. [ABSTRACT FROM AUTHOR]

Essential oils are being introduced in swine diets as an alternative to antibiotic usage. The objectives of this preliminary study were to determine the effects of Agolin-Pig, a combination of micro-encapsulated essential oils, on sow feed intake, sow health and body condition, piglet growth performance, and future evaluation of microbiota structure. The experimental design consisted of 26 sows randomly allotted to either control (n = 13) or treatment groups (n = 13). Both groups consumed diets that met NRC standards (NRC, 2012), with the treatment group receiving 200 ppm of Agolin-Pig in a premix made in-house for 2 weeks pre-farrowing, and throughout farrowing and lactation. Sow average daily feed intake (ADFI) and piglet average daily gain (ADG) were recorded and calculated to monitor effects of Agolin-Pig. Sow body weights, body condition scores (BCS), and Knauer Sow Caliper measurements were collected at the start of the trial, 1-week post-farrowing, and at weaning to determine the change in sow body condition during lactation. All data were analyzed using PROC Mixed procedure in SAS 9.4 (Cary, North Carolina) with treatment, week, and parity (P1 vs P=2) as main effects, repeated measures of sows and piglets, and number nursed used as a covariate where appropriate. All sows significantly increased ADFI (P = 0.0001) between weeks 1, 2, and 3 as expected during lactation, regardless of treatment. There was no significant impact of Agolin-Pig treatment on sow ADFI and piglet ADG. Piglets significantly increased ADG each week for 3 weeks (P ± 0.0001). During lactation, Agolin-Pig significantly reduced the loss of body condition as measured by the caliper (P = 0.028). Calipers are proven to detect changes in body condition more accurately than visual, subjective BCS, indicating that the caliper identifies a reduction in body condition that may have been missed by BCS or weight change altered by lactation. The gilts in the control group tended to show a reduction in BCS compared with sows in the control group (P = 0.074). In comparison, there was no significant difference in BCS between gilts and sows in the Agolin-Pig treated group suggesting that Agolin-Pig is effective at reducing the loss of BCS in gilts during lactation. Current analysis of fecal microbiota and milk composition may give greater insight on the effects of Agolin-Pig on sows. Overall, Agolin-Pig was effective at reducing the loss of body condition during lactation, as measured by the caliper. Additionally, Agolin-Pig tended to reduce the difference in loss of body condition of gilts compared with the control group. The findings of this pilot study warrant future studies with greater sample size to determine the efficacy of Agolin-Pig on reducing body condition loss and impacting other performance measures during lactation in sows. [ABSTRACT FROM AUTHOR]

Nutrient requirements increase dramatically in the late gestation beef female to allow for proper growth and function of the uteroplacenta, fetus, and mammary gland. In fall- and spring-calving systems, late gestation grazing beef cattle often have limited forage nutrient availability. Late gestational nutrient restriction research generally associates decreased prenatal nutrient delivery with programming fetal growth and development, resulting in poor postnatal outcomes. However, the effects gestational nutrient partitioning may have on programming the mammary gland to decrease postnatal nutrient delivery is far less understood. In a fall-calving experiment, primiparous females were individually fed either 100% or 70% of energy and protein requirements from d 160 of gestation until parturition. Nutrient restricted females lost body weight and condition and had less nutrients in maternal circulation during late pregnancy. Calf birth weight was not affected, but nutrient restricted dams had less vigorous calves and 40% less colostrum yield. Colostrum of nutrient restricted females was more concentrated with IgG, and calf 48-h serum IgG indicated that offspring of both treatments had successful passive transfer of immunity. Colostrum of nutrient restricted females had less total lactose, but similar total protein and triglycerides compared with control females. Even when females were fed to meet their energy and protein requirements during lactation, late gestational nutrient restriction reduced milk yield by 15% and decreased milk protein concentration during the first 150 d of lactation. Reduced milk production was partially explained by a 19% reduction in blood flow supplying the mammary gland during this time. Less total lactose, protein, and triglycerides provided by the milk resulted in calf body weight diverging by 42 d of age, and calves born to nutrient restricted dams were 13% smaller at weaning. Interestingly, calf metabolic status pre-weaning was not as severely altered as expected considering milk nutrient and calf growth differences. By d 21 of lactation, metabolic status of previously nutrient restricted dams had returned to concentrations similar to control dams. During lactation, previously nutrient restricted females gained maternal weight faster and increased body condition, but had still not fully recovered to that of control females by weaning. Females were managed together and followed through their second parity to examine effects during the subsequent parity. Previously nutrient restricted dams still weighed less, were in thinner body condition, and had less mammary blood flow during their second lactation. Lactational performance and second parity calf growth were similar between treatments. While late gestational nutrient restriction may not always reduce fetal growth, our results illustrate that impaired postnatal nutrient delivery mechanisms in the cow and calf deserve continued consideration. Additionally, persisting effects in the second parity on maternal size, fleshing ability, and mammary blood flow demonstrate the possibility of long-term programming effects on the dam. [ABSTRACT FROM AUTHOR]

Fatty acids (FA) are a common supplement for lactating cows to increase energy supply, potentially improving feed efficiency and milk and milk fat yields. However, different FA can cause varying responses probably because of different FA digestibility and interactions with other nutrients (e.g., fibers). Lysophospholipids (LPL) are natural emulsifiers and LPL as a feed additive have shown increases in FA digestibility and nutrient absorption in non-ruminant animals. This study aimed to investigate the effects of FA sources with LPL supplementation on nutrient digestibility in lactating cows. Mid-lactation cows (n = 48) were allocated into 12 blocks, and cows in each block were randomly assigned to the following dietary treatments:1) a diet with a FA supplement [1.8% of dietary dry matter (DM)] mainly containing palmitic acid (PA); 2) the PA diet with LPL (0.003% of dietary DM); 3) a diet with a FA supplement (1.8% of dietary DM) mainly containing stearic acid (SA); and 4) the SA diet with LPL (0.003% of DM). The experiment was conducted for 6 weeks, and spot samples of feces and urine were collected over 3 days (every 3 hours within a 24-hour cycle) during the last week of the experiment to determine nutrient digestibility and utilization. Data were analyzed using the mixed model with FA source, LPL, and their interaction as fixed effects and block as a random effect. The digestibility of DM, organic matter, and crude protein were not affected by the FA source and no interaction between FA and LPL was observed. However, PA had greater neutral detergent fiber (NDF) digestibility (41.4 vs. 38.8%; P = 0.04) than SA with no interaction between the FA source and LPL. In addition, as expected, PA decreased (P < 0.01) the digestibility of 16-carbon FA compared with SA due to the greater C16:0 supply, and SA decreased (P < 0.01) that of 18-carbon FA compared with PA due to the greater C18:0 supply. Supplementation of LPL did not affect digestibility of DM, OM, CP, and NDF, but increased total FA digestibility (64.7 vs. 60.5%; P = 0.02) compared with no LPL. In addition, LPL increased 18-carbon FA digestibility (68.2 vs. 74.1%; P < 0.01) compared with no LPL. An interaction between LPL and FA was observed for 16-carbon digestibility because LPL increased 16-carbon digestibility with SA but not with PA. In conclusion, PA supplementation improved fiber digestibility compared with SA, which could be a factor for increased productivity (e.g., milk fat). Supplementation of LPL was effective in increasing FA digestibility and may have potential to increase dietary energy supply or provide a similar energy supply with less dietary fat content in practice. However, more studies are needed to understand different interactions of LPL with FA sources. [ABSTRACT FROM AUTHOR]

Larger litter sizes in swine production systems and potential milk limitations for piglets have given new opportunities to incorporating creep feeding as a management strategy. Sows (n = 51) and their litters were used to test the effects of creep feed and nursery diets on piglet lactation and nursery growth performance. Ten days before weaning, litters were assigned to one of three creep feeding treatments: 1) Control diet: 2) Control+Flavoring (50 ppm Allium XL, Pancosma): 3) No creep feed. Creep feed was delivered twice/day via one bowl creep feeder/litter. Sows and litters (17/treatment) were allotted to equalize parity (average = 2.8), genetics, number of piglets (average = 10.9), and weaning age (average = 19.1). Litter weights and creep feed intake were recorded on d 0, 4, and 10 (weaning). Post-weaning pigs were allotted to Control or Flavoring (50 ppm Allium XL) diets in a 3x2 factorial arrangement. During nursery there were 10 pens/treatment with 7 or 8 pigs/pen, blocked by initial BW within creep treatment. Nursery treatments were fed in phase 1 (1.13 kg/pig) and 2 (2.27 kg/pig) diets followed by common phase 3 (6.8 kg/pig) and 4 (ad lib to d 35) diets. Weekly pig BW and feed intake were used to calculate nursery pen ADG, ADFI, and G:F. Data were analyzed using GLM procedure of SAS 9.4. Creep feeding treatment during lactation did not affect litter or piglet BW gain pre-weaning. Flavoring did not affect total creep feed intake (control = 114 g/pig vs. flavoring = 110 g/pig). Providing creep feed during lactation increased ADFI on days 2, 3, and 4 post-weaning (P < 0.013). Pigs fed either creep feed increased week 1 nursery ADFI (8.8%; P< 0.02), numerically increased ADG (5.2%), and greater d ay7 BW (P = 0.055). Week 3 ADG (P < 0.05) and ADFI (P < 0.05) were greater for the no creep pigs than pigs fed the control creep feed, flavored creep feed pigs were intermediate. For week 4, ADG, and week 4 and 5 ADFI, pigs previously fed control creep had greater growth performance than pigs previously fed flavored creep with pigs fed no creep being intermediate (P< 0.05). Overall (days 0-35), pigs fed control creep had greater ADG (P< 0.05) and ADFI (P < 0.05) than flavored creep fed pigs with no creep pigs being intermediate in ADG and greater ADFI than flavored creep fed pigs. Final BW (P < 0.05) was greater for control creep fed pigs than flavored creep fed pigs with no creep pigs being intermediate (23.5 kg, 23.0 kg, 23.3 kg, respectively). Nursery dietary flavoring treatment did not affect post-weaning ADG, ADFI, or G:F at any point during the study (P > 0.12). Lactation creep feeding significantly increases ADFI and ADG during the first week post-weaning, which could improve post-weaning performance and reduce the rate of pigs failing to thrive post-weaning. [ABSTRACT FROM AUTHOR]

In a context of maximizing the use of dietary phosphorus (P) in swine production, research should focus on understanding the mechanisms of bone P and calcium (Ca) utilization in sows. A better knowledge of P and Ca quantities that can be mobilized from bones during lactation, which would then be restored during gestation, would allow the development of new feeding strategies including this dynamic process. In turn, it can lead to a substantial decrease in dietary P supply. The role of dietary phytase supplementation also needs to be quantified in such potential strategies. In addition to the bone mineral status of sows, the consequences of these strategies on litter performance need to be documented. The objectives of the experiment were to measure the capacity of the sow to mobilize bone minerals reserves during lactation according to dietary digestible P (P dig) content and phytase addition, to restore them, during the following gestation, and to measure the effects on the growth performance of the offspring. Whole body bone mineral content (BMC) of primiparous Swiss Large White sows (n = 24) from the Agroscope sow herd was measured by dual-energy X-ray absorptiometry (DXA) on days 2, 14, 26, 66, and 106 after parturition. Four lactation diets were formulated to cover all nutritional requirements except for Ca and P dig: control without phytase (100%; 3.0 g P dig, 9.9 g Ca/kg), 75% of P dig without phytase (75%; 2.3 g P dig, 8.3 g Ca/kg), 50% of P dig without phytase (50; 1.5 g P dig, 6.0 g Ca/kg), and 50% of P dig with phytase (50+Phyt; 3.0 g P dig, 7.6 g Ca/kg). The gestation diet was formulated to cover nutritional requirements of Ca and P dig (2.6 g P dig, 8.2 g Ca/kg). Piglets were weighed at 1 and 14 days after parturition and at weaning (day 26), and the average daily gain (ADG) per piglet was calculated. During lactation, BMC of the sow (in g/kg of body weight, BW) tended to be less in treatment 50% than in treatment 100% (-12.8%, linear effect x time quadratic, P = 0.05). During gestation, BMC was similar between treatments. Therefore, sows in treatment 50% were able to recover their bonemineralization deficit during the next gestation. The BMC (in g and in g/kg BW) was similar between treatments 100% and treatment 50+Phyt throughout the experimental period. Piglet weight at days 1, 14, and 26 and ADG (days 1 to 14, 14 to 26 and 1 to 26) were similar between dietary treatments. These results show the possibility of drastically reducing dietary P during lactation without decreasing litter performance and highlight the ability of primiparous sows to mobilize bone mineral during lactation and restore it during gestation. [ABSTRACT FROM AUTHOR]

A total of 105 sows (Line 241, DNA, Columbus, NE) were used across four batch farrowing groups to evaluate the effects of including a feed flavor (Krave AP, Adisseo, Alpharetta, GA) in lactation diets on sow and litter performance. Sow groups 1 and 2 farrowed in an old farrowing facility during the summer months with fans and drip coolers used to regulate the ambient temperature. Groups 3 and 4 farrowed in a new farrowing facility during the winter months and utilized fans and cool cells for environmental temperature control. Sows were blocked by BW within parity on d 110 of gestation and allotted to 1 of 2 dietary treatments, 55 sows on the control diet and 50 sows on the flavor diet. Dietary treatments were a standard cornsoybean-based lactation diet (control) or control diet with the addition of a feed flavor at 0.05% of the diet. Farrowing facility environment greatly impacted feed intake, with ADFI being greater (P < 0.001) in the new farrowing facility during the winter months compared with the old farrowing facility in the summer months (Table 1). Sows fed the flavor treatment had a tendency (P = 0.093) for greater ADFI overall compared with control fed sows across the entire experiment. Piglet BW from sows fed the flavor diet tended to be greater (P = 0.087) on d 10 and was greater (P = 0.039) at weaning compared with pigs from sows fed control diets. An interaction between flavor and farrowing facility was observed for pig ADG (P = 0.001), with pigs from sows fed the flavor diet in the old farrowing facility having a greater ADG compared with piglets from sows fed the control diet. The opposite was observed in the new farrowing facility. Litter ADG tended (P = 0.093) to be greater for pigs from sows fed the flavor diet. Preweaning mortality of piglets from sows fed a diet containing a feed flavor was greater from birth to d 2 (P = 0.038) and d 2 to weaning (P = 0.005) compared with piglets from sows fed the control diet. In conclusion, sows fed the flavor-containing diet tended to have greater overall ADFI and had greater piglet weaning weights. The differences in feed flavor response between season and environment suggests that adding a feed flavor to the lactation diet in situations where sow lactation ADFI is less than optimal could lead to improvements in sow and litter performance. [ABSTRACT FROM AUTHOR]

Gilts [n = 50; initial body weight (BW) 190.7 ± 4.2 kg] were used to determine the optional inclusion level of postbiotic Saccharomyces cerevisiae in late gestation and lactation diets to improve immunoglobulin transfer and piglet growth performance during the suckling period. Gilts were assigned to one of five (n = 10) diets: standard gestation and lactation diets (Y0) or diets with postbiotic yeast included at either 0.25% (Y0.25), 0.5% (Y0.5), 1.0% (Y1), or 1.2% (Y1.2). Diets were fed from d 85 of gestation until weaning (d 21 after farrowing). During gestation gilts were fed 2.6kg/d and feed was offered ad libitum during lactation. Gilt BW was recorded on d 85 and 110 of gestation, and gilt and piglet BW were recorded on d 1 and 21 of lactation. Twenty-four hours after farrowing, plasma was collected from each gilt and two median BW piglets per litter via orbital sinus. Additionally, 50 mL of colostrum was collected in equal parts from all functional teats on the right side. On d 21, plasma samples were collected from each gilt and two median BW piglets per litter. Concentrations of immunoglobulin (Ig) A, G, and M were quantified in plasma and colostrum. Data were analyzed in SAS with treatment as the main effect. Linear, quadratic, and yeast vs. no yeast contrast statements were used to assess responses to dietary inclusion of yeast. Time (minutes) between farrowing (defined as birth of the first piglet, confirmed by video recording) and sampling was used as a covariate for d 1 Ig concentrations. There were no differences in number of piglets born alive (12.5 ± 0.9), birth weight (1.40 ± 0.45kg), or gilt BW change during lactation (-7.98 ± 6.68kg). Lactation average daily feed intake tended to be 14.6% greater for gilts provided yeast versus no yeast (5.11 vs. 4.46 ± 0.31kg, respectively; P = 0.069). At weaning, offspring from Y0.25 fed gilts had greater BW than piglets from Y0- or Y1.2-fed gilts (6.48 vs. 5.66 and 5.82 kg ± 0.16, respectively; P < 0.001), with all other treatments intermediate. On d 1, colostrum and gilt plasma Ig concentrations were unaffected by diets. However, yeast increased piglet plasma concentrations of IgM (linear; P = 0.034) and tended to increase IgA (linear; P=0.093), and total Ig (linear; P = 0.074). On d 21, gilts fed yeast-containing diets tended to have greater plasma IgA (yeast vs. no yeast and quadratic; P = 0.063 and P = 0.076, respectively), but IgM was greater for gilts fed Y0 (yeast vs. no yeast; P < 0.05). On d 21, piglet plasma IgA tended to be greater when gilts were provided yeast-containing diets (yeast vs. no yeast; P = 0.069). Therefore, postbiotic Saccharomyces cerevisiae was effective in improving maternal transfer, with piglet IgA and IgM concentrations increasing linearly with increasing yeast inclusion, while Y0.25 also improved piglet growth performance during the suckling phase. [ABSTRACT FROM AUTHOR]

The hypothesis that exogenous xylanase added to diets for gestating and lactating sows will increase the apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF), and digestible energy (DE) and metabolizable energy (ME) was tested. Two diets for gestating and two diets for lactating sows containing corn, soybean meal, distillers dried grains with solubles, wheat middlings, and soybean hulls were formulated without or with 16,000 BXU per kg of exogenous xylanase (Econase XT; AB Vista, Marlborough, UK). Lactation diets contained an indigestible marker. Diets were fed to gestating and lactating sows in two reproductive cycles. A total of 106 gilts and sows were randomly allotted to the two gestation diets 7 d after breeding in a randomized complete block design with 4 blocks. On d 30 post-breeding, 8 non-pregnant animals were removed. From the remaining 98 animals, 48 sows (24 replicates per treatment, 12 sows per block) were placed in metabolism crates on d 35 (midgestation) for 10 d with feces and urine collected for 5 d. The same 48 sows were placed in metabolism crates again on d 95 (late-gestation). All sows were moved to the lactation unit on d 106 and lactation diet feeding was initiated. Fecal samples were collected (grab-sampling) for 5 d starting on d 10 post-farrowing. Sows were weaned on d 20 and 63 sows were rebred. Of these sows, 46 sows were placed in metabolism crates on d 35 and 95 as in the first cycle, and treatments in the farrowing unit were also as in the first cycle. Data were analyzed using the MIXED procedure of SAS with sow as the experimental unit, diet as fixed effect, and block and replicate as random effects. Results indicated that in the first cycle, the ME in mid-gestation, and the ATTD of TDF, and DE and ME in late-gestation were greater (P < 0.05) in sows fed the xylanase-diet compared with the control diet (Table 1). During the first lactation period, sows fed the xylanase-diet had greater (P < 0.05) ATTD of TDF and GE and greater (P < 0.05) DE than sows fed the control diet. During the second gestation period, sows fed the xylanase-diet had greater (P < 0.05) DE and ME in mid- and late-gestation, but no differences were observed in ATTD of TDF (Table 2). During the second lactation period, sows fed the xylanase-diet had greater (P < 0.05) ATTD of TDF and GE and greater (P < 0.05) DE than sows fed the control diet. In conclusion, DE was greater in the xylanase-diet than the control diets during two reproductive cycles, and sows fed lactation diets with xylanase had greater digestibility of fiber. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the impact of variation in piglet weaning weight (WW) resulting from interventions during lactation on postweaning performance. A split-split plot design was used with a 2 x 2 x 2 factorial arrangement of treatments: 1) Liquid milk replacer [MR; main plot; No Supplement (NS) vs. Supplement (SU)]; 2) Litter size [LS; subplot; LOW (4 pigs less than functional teat number) vs. HIGH (2 pigs greater than functional teat number)]; 3) WW [sub-sub-plot; LIGHT (2 lightest barrows and 2 lightest gilts within each litter) vs. HEAVY (2 heaviest barrows and 2 heaviest gilts within each litter)]. Each MR feeder was available to 2 litters, one on the LOW and one on the HIGH LS treatment. Cross-fostering was carried out at 24 h after birth to create LS treatment litters; MR treatment was applied from 24 h after birth until weaning (20 days of age). The study involved 256 pigs housed in mixed-sex pens of 4 pigs (2 barrows; 2 gilts) and was carried out from weaning to a fixed pen weight (130.0 ± 2.27 kg). Pigs were weighed at start and end of the study when ultrasound scans were collected (at the 10th rib) to measure backfat depth (BF) and Longissimus muscle area (LMA). Data were analyzed using PROC MIXED of SAS; the model accounted for fixed effects of MR, LS, WW, and all interactions, and random effects of replicate, replicate by MR interaction and replicate by MR by LS interaction. There were no treatment interactions (P > 0.05) for any measurements (Table 1). The MR treatment had no effect (P > 0.05) on WW; the SU treatment had greater (P = 0.05) ADFI but had no effect (P > 0.05) on other measurements compared with the NS treatment (Table 1). Compared with the LOW LS treatment, the HIGH LS treatment had lighter WW (1.7 kg; P = 0.05), and greater days on test (4 days; P = 0.05); however, there were no differences (P > 0.05) for other measurements. Compared with the LIGHT WW treatment, HEAVY pigs had greater WW (1.7 kg; P = 0.05), fewer days on test (7.9 days; P = 0.05), greater (P = 0.05) overall ADG (38 g) and ADFI (78 g), less BF (0.17 cm; P = 0.05) and greater LMA (1.37 cm2; P = 0.05). In conclusion, providing MR during lactation had little effect on postweaning performance. However, increasing LS above sow functional teat number reduced WW and increased the time to reach harvest weight with no effect on postweaning growth performance. In addition, HEAVY WW piglets had improved post-weaning growth performance and carcass lean measurements compared with LIGHT WW piglets. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of dietary fiber (DF) sources on sow and litter performance, and apparent total tract digestibility (ATTD) of gross energy (GE) and nutrients. A total of 48 sows were stratified for body weight at mating and randomly assigned to one of four DF sources (mixed fiber [MF], palm kernel expellers [PKE], sugar beet pulp [SBP], or soy hulls [SH]) and fed the diet from mating until farrowing. Within DF treatments, sows were supplemented with one of two extra energy sources (glycerol or sugar dissolved in water), whereas a third group (control) received water from day 108 of gestation until farrowing. The number of total born, live-born, and stillborn pigs; birth time and birth weight of the pigs; farrowing duration; and farrowing assistance (FA) were recorded. Live-born pigs were weighed again at 12 and 24 h after birth to record weight gain, which was used to estimate intake and yield of colostrum. Blood samples were collected once daily from day −3 relative to farrowing until day 1 after farrowing in sows and once from selected pigs right after birth. Fecal samples were collected on day 114 of gestation and colostrum at 0, 12, 24, and 36 h after onset of farrowing. Intake of soluble and insoluble nonstarch polysaccharides (NSP) was greater for SBP (P < 0.001) and PKE (P < 0.001) supplemented sows, respectively, when compared with other groups. Farrowing duration and stillbirth rate were not affected by DF sources, but PKE and SH supplemented sows had greater FA than SBP and MF supplemented sows (P < 0.001). Extra energy supplement did not improve the farrowing performance. Concentration (P = 0.02) and output (P = 0.04) of dry matter in colostrum, and ATTD of GE (P < 0.001) and crude protein (CP; P < 0.001) were lower for PKE supplemented sows than in sows from the remaining groups. Intake of insoluble NSP correlated negatively with ATTD of GE (P < 0.001) and CP (P < 0.001). Concentrations of glucose (P < 0.001), lactate (P < 0.001), CO2 (P < 0.001), and HCO3 (P < 0.001) in sows blood were increased with time progress relative to farrowing. Newborn pigs from PKE supplemented sows had greater concentration of lactate (P = 0.02) and lower blood pH (P = 0.02) than the remaining treatments. In conclusion, PKE supplement reduced ATTD of GE and CP, and concentration and output of dry matter in colostrum but increased FA. Results of this experiment indicated that the use of PKE as a fiber source for late gestating sows should be avoided. [ABSTRACT FROM AUTHOR]

Milk is an easily digestible source of nutrients and bioactive factors, its composition reflects the neonate’s needs, and changes from colostrum to transitional and mature milk. Our objective was to measure milk fat, lactose, total carbohydrate, and protein content in parallel with global proteome of homogenate milk samples to characterize changes across the three phases of swine lactation. Milk samples were collected from multiparous sows (n = 9) on postnatal day 0 (D0; colostrum), 3 (D3; early transitional), 7 (D7; late transitional), and 14 (D14; mature). On D3, percent fat (16 ± 2.1) and lactose (3.8 ± 0.3) were higher (P < 0.05) than on D0 (10 ± 3.9 and 1.5 ± 0.3, respectively). Levels of fat and lactose were not different between D3 and D14. Percent total protein decreased (P < 0.05) between D0 (11 ± 2.1) and D3 (5 ± 0.7), but there was no significant change in percent protein between D3 and D14. Total carbohydrates increased (P < 0.05) between D3 (944 ± 353 µg/mL) and D14 (1,150 ± 462 µg/mL). Quantitative proteomic analysis using liquid chromatography tandem mass spectrometry (LC-MS/ MS) of homogenate D0, D3, and D14 milk samples (n = 6) identified 772 protein groups which corresponded to 501 individual protein-coding genes. A total of 207 high confidence proteins were detected in n = 3 sows/day. Of the high confidence proteins, 81 proteins were common among all 3 days of lactation. Among the proteins that decreased between the days (false discovery rate; FDR < 0.05) were multiple apolipoproteins and XDH which decreased between D0 to D3. Proteins that increased across the days (FDR < 0.05) were complement factors and 14-3-3 proteins (YWHAQ, YWHAE). Our data provide a good characterization of milk proteome changes that likely reflect mammary function as well as the neonate’s phasespecific developmental needs. This data may be useful in developing approaches to enhance the health and welfare of swine. [ABSTRACT FROM AUTHOR]

The main objective of this study was to evaluate the effect of peripartal administration of a commercially available nonspecific immune stimulant (mycobacterium cell wall fraction; MCWF [Amplimune, NovaVive Inc. Napanee, ON, Canada]) on the incidence of disease during early lactation and subsequent fertility of dairy cows. A second objective was to characterize the dynamics of circulating white blood cells (WBC) and metabolic markers following treatment administration. Cows in an United States Department of Agriculture (USDA) organic-certified dairy herd were blocked by parity and, based on sequential calving dates, randomly assigned to receive two injections (5 mL s.c.) of either a placebo (saline solution) as a control (CON ; n = 71) or MCWF (n = 65) at enrollment (7 d before expected calving) and within 24 h after calving. Blood samples were collected from a subsample of the study population (MCWF = 16; CON = 18) for WBC count at enrollment, at day 2 post enrollment, and at days 1, 3, 7, and 14 after calving. Serum fatty acids, beta-hydroxybutyrate, and Ca concentrations were determined at days 1 and 7 postpartum (MCWF = 21; CON = 21). Main outcome variables included incidence risk of peripartal and early lactation health disorders and pregnancy at first artificial insemination (AI), at 100, and at 150 days in milk (DIM). In addition, the average daily milk yield up to 90 DIM and death and live culling before 305 DIM were compared. Treatment effects were assessed using multivariable logistic regression, time-to-event analyses, and repeated measures analysis of variance (ANOVA). A treatment effect on the incidence risk of some of the health disorders in the study was established. Incidence risk of metritis and clinical mastitis <28 DIM was smaller in MCWF than in CON cows (36.9% vs. 50.7% and 6.3% vs. 19.7%, respectively). On the contrary, the incidence risk of respiratory disease <28 DIM was smaller in CON (0%) than in MCWF (7.7%). Reproductive performance of multiparous cows was affected by MCWF administration: pregnancy at first AI and pregnancy at 100 and 150 DIM were greater in MCWF than in CON (35.6% vs. 19.2%; 51.1% vs. 25.0%; and 64.4% vs. 40.4%, respectively). Overall, median intervals from calving to pregnancy were 90 vs. 121 d in MCWF and CON cows, respectively. No treatment effects on the dynamics of circulating WBC or in postpartum metabolic status were established. No differences for milk yield or for the proportion of cows that survived up to 305 DIM were determined, although cows in MCWF left the herd earlier than cows in CON. In conclusion, incidence risks of metritis and mastitis in early lactation were smaller in cows receiving MCWF, whereas the incidence risk of respiratory disease was smaller in CON. Fertility significantly improved in MCWF compared with CON cows. As this study was performed in an organic-certified dairy, specific health and reproductive management practices may affect the external validity of the current findings. [ABSTRACT FROM AUTHOR]