Search

The residual intake and gain (RIG) aims to select animals that present low feed intake in relation to the expected. This study aimed to evaluate the associations of selection for RIG with performance and carcass traits in Nellore cattle. Initially, residual feed intake (RFI) and residual gain (RG) were determined. From this, the RIG was calculated, and the animals were classified as efficient and inefficient for RIG. The efficient animals for RIG showed higher daily weight gain (DWG), Longissimus muscle area (LMA), and mid-test metabolic body weight (MMBW) than the inefficient ones. No significant correlations were found between subcutaneous fat thickness (SFT), marbling (MAR), LMA, MMBW, and the RIG. Thus, it’s concluded that the RIG is a measure that can be used to identify and select animals with higher rates of DWG and LMA without changes in the dry matter intake (DMI), SFT, and MAR. However, this index should still be observed with caution, as it may be dependent on body size. Based on the findings, the selection of animals according to the RIG can be an important factor to generate phenotypic evolution in characteristics such as weight gain and rib eye area without adverse effects on the carcass fat deposition. [ABSTRACT FROM AUTHOR]

In this study, the effects of fully littered, slatted and their varying combinations on growth, performance, carcass and meat quality characteristics in broiler chickens were investigated. In the experiment, five treatment groups were formed as fully littered (FL), fully slatted (FS), 1/3 littered + 2/3 slatted (2/3 SF), 1/2 littered + 1/2 slatted (1/2SF), 2/3 littered + 1/3 slatted (1/3 SF). Each treatment group included 5 replicates (24 chicks in each) and a total of 600 male-female mixed fast growing broiler chicks (Ross-308) were used during 6 weeks. Weekly body weight (BW, g), feed intake (FI, g), feed conversion ratio (FCR, g.feed intake/g.weight gain), livability (%) and EPEF (European Production Efficiency Factor) were determined as performance characteristics. Carcass yield (CY, %), and the percentages of abdominal fat (AFP, %), edible internal organs (EIOP, %), gizzard (GP, %), breast (BRP, %) and thigh (TP, %) meat were the carcass characteristics. Meat quality measured by pH and color (L*: lightness, a*: redness, b*: yellowness) of breast and thigh meat, and occurrence of white striping and hemorrhaging in breast meat. The weekly BW differences among the floor treatments were significant (P < 0.01), and 1/3SF broilers were the heaviest at slaughter age (3311.6 g). The 6-week FCR in FS broilers was significantly worse than the others (1.471), but FI, livability and EPEF were similar among treatments. AFP tended to be higher in FL birds (P = 0.066), while CY, EIOP, GP, BRP and TP did not differ between groups. Breast pH was similar between treatments, with 1/2SF showing the highest (6.34) and FL the lowest (6.24) breast pH (P < 0.01). The partially slatted systems caused lighter, redder and yellower color values in breast meat (P < 0.01) than the fully littered or slatted systems, but did not change the color of the thigh meat. White striping and hemorrhaging in breast meat were not affected by the floor treatments. This study suggests that the use of partially slatted systems in broiler chickens improves meat color without compromising performance traits (body weight, feed efficiency, EPEF), litter moisture and slaughter traits and these systems could be an alternative to fully littered systems. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of varying stocking densities during the first 10 days on the performance, welfare, slaughter and meat quality characteristics of broiler chickens in the subsequent period (11–42 days). In the study, treatments representing 3 different stocking densities with the same group sizes were established and a total of 432 d-old chicks were used. In the first 10 days of the rearing period, treatments of 18 (SD18), 27 (SD27) and 36 (SD36) chicks per m2 were formed, and at 11 days of age, chicks in all treatments were reared at a density of 18 chicks/m2. Body weight differences in SD18, SD27 and SD36 treatments at 10 and 42 days of age were significant (P < 0.05), they were 252.6, 254.3 and 241.5 g in SD18, SD27 and SD36 groups at 10 days and 2961.1, 2874.8 and 2842.7 g at 42 days of age, respectively. In the first 10 days of growing period, SD36 showed a significant difference (P < 0.05) from the other groups in feed intake and feed conversion ratio, but this was not significant at slaughter age. The livability at 10 and 42 days was not different among treatments and was between 98.6 and 99.3% and 93.5–93.8%, respectively. The uniformity at 10 days was significant among the stocking density groups (P < 0.05) and the best uniformity level was obtained in the SD36 group, the differences in CV values at 42 days were not significant among the treatments. EPEF (European production efficiency factor) values were not different between the groups, the highest numerical value was determined in the SD36 group. Foot pad dermatitis, hock burn and breast burn levels were significantly higher in SD18 chickens (P < 0.05), however incidence of finger crookedness and valgus-varus deformity did not differ between the treatments. The litter moisture contents were similar between treatments, and ranged from 25.6 to 32.6%. Different stocking density treatments during the first 10 days of the experiment had no significant effect on slaughter, abdominal fat, carcass parts, color and pH values in the breast and thigh meat. In conclusion, rearing broiler chickens by dividing the poultry house area by half during the first 10 days (36 birds/m2) could help to improve the overall productivity (EPEF) by providing ease of maintenance, efficient heating and better control. [ABSTRACT FROM AUTHOR]

Chromium (Cr) is a mineral that helps animals subjected to stressful conditions. The suckling period is characterized by several stressful episodes, particularly during the first hours after birth and at weaning. There is little consumption of concentrate by calves in the first weeks of life; consequently, consuming any supplement added to feed would be negligible. Thus, the hypothesis was that the calves would take it in earlier if Cr were consumed in a milk replacer instead. Therefore, our study aimed to determine whether including organic Cr in calf feed (via milk replacer or concentrate) during the suckling phase would improve calf health and growth performance. Twenty-four male Holstein calves with an average age of 8 ± 4 days and 39.8 ± 6.9 kg average body weight were used. Calves were randomly divided into three groups: (a) Chromium-Milk (CR-M), receiving 4 mg Cr/animal/day via milk replacer during the 60 experimental days of suckling (n = 8); (b) Chromium-Concentrate (CR-C), receiving 4 mg Cr/animal/day via concentrate (n = 8); (c) Control (C), animals that did not receive Chromium (n = 8). The experiment lasted 75 days, divided into two well-defined stages: suckling (1–60 days) and weaning (61–75 days). Body weight weekly, daily feed intake, and blood samples taken every two weeks during the experiment were evaluated. At the end of the experiment, the apparent digestibility evaluation was carried out, with the results of weight and consumption carried out, and a feed efficiency analysis was carried out. It was observed that the inclusion of organic Cr (regardless of whether it was milk or concentrate) increased body weight gain (kg) for the CR-C group: 41.8 kg, CR-M: 40.4 kg compared to the C: 34.2 kg (p = 0.01). The protein digestibility was higher in the CR-M group (52%, p = 0.05). Cr consumption increased Cr concentrations in the serum of the calves and was higher in the first week in the animals in the CR-M group. This did not happen for the C group; however, with higher concentrate consumption, Cr concentrations increased and remained high until the end of the experiment. Glucose concentrations were higher in the groups that consumed Cr. Total protein concentrations were higher in the CR-M and CR-C groups than in group C. Immunoglobulin A concentrations were higher in groups CR-C and CR-M than in group C (days 40 and 60). In conclusion, the adding Cr to calf feed improves their health, indirectly favors growth performance, and increases protein digestibility. [ABSTRACT FROM AUTHOR]

The re-integration of former foodstuffs, such as bakery products (BP), into pig feed reduces the feed-food competition and increases the sustainability of pig production. Nevertheless, there are concerns about the altered fatty acid profile in BP compared to standard diets and their effects on meat quality and the intestinal microbiome. The present study investigated the effects of replacing 30% cereal grains with BP in the diet on performance, microbiome composition and metabolites in feces of fattening pigs, economic aspects and meat quality characteristics. A total of 132 pigs (Large White × Piétrain; 11 weeks of age) were fed two diets containing 0 or 30% BP until reaching slaughter weight in three replicate batches. Fecal samples were collected for 16S rRNA amplicon sequencing after 6 weeks, whereas body fat samples were collected after 9 weeks on the diet. The results showed that BP can replace cereals in pig diets by up to 30% without impairing animal performance, while improving feed efficiency and reducing feed costs by 9% compared to the control. Additionally, pigs fed the BP diet had a 50%-higher n-3 fatty acid content in the neck and abdominal fat compared to the control. The improved feed efficiency in BP-fed pigs may be related to positive effects on the fecal microbiome, such as a higher alpha diversity and a reduction of fungi and yeasts. Our study provides valuable insights into the benefits of including BP in diets of fattening pigs, which should be investigated in future studies on other BP types. [ABSTRACT FROM AUTHOR]

This study compared the effects of feeding a new strain of Saccharomyces cerevisiae HSA2020 with a commercial strain on in vitro rumen fermentation and production performance of dairy cows. Permeate was used as a substrate for the laboratory production of the new strain of S. cerevisiae after the hydrolysis by β-galactosidase (5000 µ/mL at 37°C). Two experiments were conducted: in Experiment 1, the effects of three levels (1, 2 and 3 g/kg dry matter) of S. cerevisiae on in vitro ruminal fermentation kinetics were evaluated. In Experiment 2, for 60 days, sixty multiparous Holstein cows (639±24.8 kg BW, 3±1 parity, 7±1 days in milk, with a previous milk production of 23±2.0 kg/d) during the previous lactation, were randomly assigned to 3 treatments in a completely randomized design. Cows were fed without any additives (control treatment) or supplemented with 2 g/kg feed daily of laboratory produced (PY) or commercial (CY) S. cerevisiae. In Experiment 1, inclusion of PY and CY increased (P<0.05) gas production, propionate, and nutrient disappearance, while decreased (P<0.05) methane production and protozoal count. Moreover, in Experiment 2, PY followed by CY increased (P<0.01) nutrient digestibility, and serum concentrations of total protein, albumin, and glucose (P<0.05). Higher daily milk yield, and milk energy output were observed with PY and CY without affecting concentrations of milk components or milk fatty acid profile. Compared to control, increased feed efficiency was observed with PY and CY. Compared to PY, CY increased serum concentrations of urea-N and decreased triglycerides, while PY decreased serum aspartate transaminase and increased concentration of conjugated linoleic acids in milk. In early lactating cow diets, both strains of S. cerevisiae improved production performance at 2 g/kg, and minimal differences between strains were found. [ABSTRACT FROM AUTHOR]

Context: Animal feed production systems have been suffering from a shortage of feedstuffs because of competition for these resources with human food consumption. The use of by-products can increase efficiency and circularity in production chains, reducing this competition. Aims: This study investigated the impacts of Paullinia cupana peel meal (PCPM) on the growth performance, meat quality, and haematological and serum biochemical parameters of slow-growing broilers. Methods: Two hundred and forty slow-growing male Label Rouge broilers were distributed in a completely randomised experimental design. The treatments consisted of five inclusion levels of PCPM (0%, 2.5%, 5.0%, 7.5%, and 10%) in the diets, with four replicates of 12 birds each. Growth performance data, and haematological and serum biochemical parameters were monitored. Twelve broilers per treatment were slaughtered for meat-quality analysis. Key results: In the starter stage, there was a significant increase (P < 0.05) in feed intake and weight gain with and increasing inclusion level of PCPM in the diet. However, this effect diminished in the final stage. Even with a reduction (P < 0.05) in feed intake during the final stage, the broilers showed an increase (P < 0.05) in weight gain and improvement (P < 0.05) in feed efficiency in the cumulative performance. Broilers fed diet with a higher inclusion level of PCPM had lower (P < 0.05) concentrations of erythrocytes and blood triglycerides, as well as a decreased haematocrit percentage. However, these broilers exhibited higher (P < 0.05) results for mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Broilers fed diets with a higher inclusion level of PCPM were heavier (P < 0.05) at slaughter, with higher (P < 0.05) carcass yield, greater (P < 0.05) liver, gizzard, and heart weight, increased breast, drumstick, and thigh yields, and higher moisture and lipid contents in the breast. Conclusions: The high inclusion levels of PCPM in diets for slow-growing broilers positively affect growth performance, meat quality, and yields of valuable cuts, although they increase moisture and decrease protein in breast meat, affecting some blood parameters. Implications: This study showed the potential advantages of using PCPM as an alternative food in diets for slow-growing broilers to improve the productivity and health of a sustainable livestock. The challenge of feeding our planet sustainably is more pressing than ever, pushing us to find smarter ways to use available resources. This study looked at using Paullinia cupana peel meal (PCPM) as a new ingredient in the feed of slow-growing broilers. The research found that adding PCPM improved the growth and health of slow-growing broilers, suggesting that it could be a game-changer in sustainable livestock farming. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Milk production and overall dairy farm economics depend on rearing dairy heifers. This study investigated the presence of a genotype by environment interaction in Holstein (HOL), Nordic Red dairy cattle (RDC), and their F 1 crossbreeds (HOL × RDC) when provided different feed rations. The aim of our study was to assess how different energy concentrations in feed rations affect growth, BCS, feed intake, and feed efficiency in the 3 groups during the prepubertal period. The 3 breed groups were randomly allocated to receive either a standard or a low-energy feed ration. Holstein heifers exhibited reduced growth and a lower BCS when they were fed the low-energy feed ration. In contrast, the RDC heifers demonstrated similar growth rates with the different feed rations and maintained similar BCS irrespective of feed energy concentration. The HOL × RDC crossbred heifers performed as an intermediate between the HOL and RDC groups. Significant differences were observed in DMI and energy intake in the HOL and HOL × RDC groups depending on feed ration treatment. The RDC heifers had similar feed intake irrespective of treatment. There were no significant differences in the feed conversion ratio among breeds and feed treatments. These results indicate the presence of a genotype by environment interaction in prepubertal HOL and RDC heifers in response to differences in feed ration treatment. Due to the influence of prepubertal growth on future milk production, reproduction, and health status, it is important to be aware of breed-specific requirements during the prepubertal period, particularly in mixed breed and crossbred groups, to optimize growth rates and production potential. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The objectives of this study were to determine the effects of 2 dietary microbial additives on productive performance and feed efficiency when supplemented to diets of Holstein cows. One hundred seventeen Holstein cows were enrolled at 61 d (31–87 d) postpartum in a randomized complete block design experiment. Cows were blocked by parity group, as nulliparous or multiparous cows and, within parity, by pretreatment ECM yield. Within block, cows were randomly assigned to one of 3 treatments administered as top-dress for 140 d. Treatments consisted of either 100 g of corn meal containing no microbial additive (CON; 15 primiparous and 25 multiparous), 100 g of corn meal containing 5 g of a mixture of Clostridium beijerinckii and Pichia kudriavzevii (G1; 4 × 107 cfu of C. beijerinckii and 1 × 109 cfu of P. kudriavzevii ; 14 primiparous and 24 multiparous), or 100 g of corn meal containing 5 g of a mixture of C. beijerinckii , P. kudriavzevii , Butyrivibrio fibrisolvens , and Ruminococcus bovis (G2; 4 × 107 cfu of C. beijerinckii, 1 × 109 cfu of P. kudriavzevii, 1 × 108 cfu of B. fibrisolvens , and 1 × 108 cfu of R. bovis ; 15 primiparous and 24 multiparous). Intake of DM, milk yield, and BW were measured daily, whereas milk composition was analyzed at each milking 2 d a week, and body condition was scored twice weekly. Milk samples were collected on d 60 and 62 in the experiment and analyzed for individual fatty acids. The data were analyzed with mixed-effects models with orthogonal contrast to determine the effect of microbial additive (MA; CON vs. 1/2 G1 + 1/2 G2) and type of microbial additive (TMA; G1 vs. G2). Results are described in sequence as CON, G1, and G2. Intake of DM (22.2 vs. 22.4 vs. 22.4 kg/d), BW (685 vs. 685 vs. 685 kg) and the daily BW change (0.40 vs. 0.39 vs. 0.39 kg/d) did not differ among treatments; however, feeding MA tended to increase BCS (3.28 vs. 3.33 vs. 3.36). Supplementing MA increased yields of milk (39.9 vs. 41.3 vs. 41.5 kg/d), ECM (37.9 vs. 39.3 vs. 39.9 kg/d), fat (1.31 vs. 1.37 vs. 1.40 kg/d), TS (4.59 vs. 4.75 vs. 4.79 kg/d), and ECM per kg of DMI (1.72 vs. 1.76 vs. 1.80 kg/kg). Furthermore, cows fed MA increased yields of preformed fatty acids in milk fat (>16C; 435 vs. 463 vs. 488 g/d), particularly UFA (367 vs. 387 vs. 410 g/d), such as linoleic (C18:2 cis -9, cis -12; 30.9 vs. 33.5 vs. 35.4 g/d) and α-linolenic acids (C18:3 cis -9, cis -12, cis -15; 2.46 vs. 2.68 vs. 2.82 g/d) on d 60 and 62 in the experiment. Collectively, supplementing G1 and G2 improved productive performance of cows with no differences between the 2 MA. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 CP levels (16.8% and 15.5% of DM), with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles [DDGS]) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 DIM, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high-protein diet (16.8% CP, HP), HP diet with HB (HP+HB), low-protein diet (15.5% CP, LP), or LP diet with HB (LP+HB). An interaction between CP × HB on DMI was detected, with DMI being unaffected by HB inclusion in cows fed the high-protein diets, but was lower in cows fed HB when the low-protein diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and MUN content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N use efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low-protein diets. In conclusion, feeding a low-protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high-CP diet, but compromised cow performance with a low-CP diet. [ABSTRACT FROM AUTHOR]

Genetic selection for feed efficiency is possible in Holstein dairy cattle. However, measuring individual cow feed intake is expensive, which limits available phenotypes, resulting in lower prediction accuracy of breeding values than desired. New indicator trait phenotypes for feed efficiency could help improve breeding value accuracies if they can be measured widely across dairy herds. The objective of this study was to identify milk metabolites associated with feed intake and efficiency traits that may serve as new indicator traits. Metabolites were obtained from three sources and two distinct groups of cows. Gas chromatography mass spectrometry (GC-MS), and liquid chromatography mass spectrometry (LC-MS) assays were conducted on a subset of 39 cows identified based on their extreme residual feed intake (RFI; top and bottom 15%). Routinely collected on-farm milk testing data were evaluated on a second, larger subset of 357 cows. Statistical models were created to evaluate if metabolites: 1) provided novel feed efficiency information; 2) served as proxies for body weight traits not routinely collected on farms; and 3) were associated with breeding values for feed efficiency traits, including: predicted transmitting abilities (PTA) for feed saved (FS), RFI and body weight composite (BWC). Ontology enrichment analysis was used to identify enriched pathways from the contrast of extreme RFI cows by GC-MS and LC-MS. The false discovery rate (FDR, reported as q-values) and Hommel corrections were used as multiple testing corrections. Partial least squares discriminate analysis confirmed animals could be classified as high or low feed efficiency groups. A total of 33 GC-MS metabolites, 10 LC-MS ontology pathways (both q<0.20) and 42 fatty acid or milk quality assays from on-farm tests (Hommel adj-p<0.05) were identified for analyses 1, 2, and 3 respectively. Ontology enrichment analysis of LCMS data identified the sphingolipid metabolism (analysis 2), and beta-alanine metabolism (analysis 1) pathways (q<0.20). Heptanoic acid was identified as associated with PTA BWC (GC-MS, Model 3; q<0.15). These metabolites represent new candidate indicator traits for feed efficiency that could be included in existing on-farm milk testing systems upon validation. [ABSTRACT FROM AUTHOR]

Background: Feed costs account for a high proportion of the variable cost of beef production, ultimately impacting overall profitability. Thus, improving feed efficiency of beef cattle, by way of determining the underlying genomic control and selecting for feed efficient cattle provides a method through which feed input costs may be reduced whilst also contributing to the environmental sustainability of beef production. The rumen microbiome dictates the feed degradation capacity and consequent nutrient supply in ruminants, thus potentially impacted by feed efficiency phenotype. Equally, liver tissue has been shown to be responsive to feed efficiency phenotype as well as dietary intake. However, although both the rumen microbiome and liver transcriptome have been shown to be impacted by host feed efficiency phenotype, knowledge of the interaction between the rumen microbiome and other peripheral tissues within the body, including the liver is lacking. Thus, the objective of this study was to compare two contrasting breed types (Charolais and Holstein-Friesian) divergent for residual feed intake (RFI) over contrasting dietary phases (zero-grazed grass and high-concentrate), based on gene co-expression network analysis of liver transcriptome data and microbe co-abundance network of rumen microbiome data. Traits including RFI, dry matter intake (DMI) and growth rate (ADG), as well as rumen concentrations of volatile fatty acids were also included within the network analysis. Results: Overall, DMI had the greatest number of connections followed by RFI, with ADG displaying the fewest number of significant connections. Hepatic genes related to lipid metabolism were correlated to both RFI and DMI phenotypes, whilst genes related to immune response were correlated to DMI. Despite the known relationship between RFI and DMI, the same microbes were not directly connected to these phenotypes, the Succiniclasticum genus was however, negatively connected to both RFI and ADG. Additionally, a stepwise regression analysis revealed significant roles for both Succiniclasticum genus and Roseburia.faecis sp. in predicting RFI, DMI and ADG. Conclusions: Results from this study highlight the interactive relationships between rumen microbiome and hepatic transcriptome data of cattle divergent for RFI, whilst also increasing our understanding of the underlying biology of both DMI and ADG in beef cattle. [ABSTRACT FROM AUTHOR]

Simple Summary: Prolonged stress negatively affects pig health, welfare, and productivity. Herein, we used a porcine model of stress during the growing period, divided into stressed and control groups. Stressed pigs experienced reduced space and were mixed twice, leading to decreased body weight and feed efficiency. Differences in feeding behavior were also observed; stressed pigs visited feeders less frequently and spent more time per meal. The microbiota of stressed pigs showed an increase in opportunistic bacteria, while control pigs had a higher abundance of beneficial butyrate- and propionate-producing bacteria. This study highlights the potential of using specific fecal microorganisms as non-invasive biomarkers to assess stress and well-being in pigs, with implications for improving both animal welfare and research applied to the human gut-brain axis. Stress significantly affects the health, welfare, and productivity of farm animals. We performed a longitudinal study to evaluate stress's effects on pig performance, feeding behavior, and fecal microbiota composition. This study involved 64 Duroc pigs during the fattening period, divided into two experimental groups: a stress group (n = 32) and a control group (n = 32). Stressed groups had less space and were mixed twice during the experiment. We monitored body weight, feed efficiency, feeding behavior, and fecal microbiota composition. Compared to the control group, the stressed pigs exhibited reduced body weight, feed efficiency, fewer feeder visits, and longer meal durations. In the fecal microbiota, resilience was observed, with greater differences between groups when sampling was closer to the stressful stimulus. Stressed pigs showed an increase in opportunistic bacteria, such as Streptococcus, Treponema and members of the Erysipelotrichaceae family, while control pigs had more butyrate- and propionate-producing genera like Anaerobutyricum, Coprococcus and HUN007. Our findings confirm that prolonged stress negatively impacts porcine welfare, behavior, and performance, and alters their gut microbiota. Specific microorganisms identified could serve as non-invasive biomarkers for stress, potentially informing both animal welfare and similar gut-brain axis mechanisms relevant to human research. [ABSTRACT FROM AUTHOR]

Background: Feed efficiency is a crucial economic trait in poultry industry. Both host genetics and gut microbiota influence feed efficiency. However, the associations between gut microbiota and host genetics, as well as their combined contributions to feed efficiency in laying hens during the late laying period, remain largely unclear. Methods: In total, 686 laying hens were used for whole-genome resequencing and liver transcriptome sequencing. 16S rRNA gene sequencing was conducted on gut chyme (duodenum, jejunum, ileum, and cecum) and fecal samples from 705 individuals. Bioinformatic analysis was performed by integrating the genome, transcriptome, and microbiome to screen for key genetic variations, genes, and gut microbiota associated with feed efficiency. Results: The heritability of feed conversion ratio (FCR) and residual feed intake (RFI) was determined to be 0.28 and 0.48, respectively. The ileal and fecal microbiota accounted for 15% and 10% of the FCR variance, while the jejunal, cecal, and fecal microbiota accounted for 20%, 11%, and 10% of the RFI variance. Through SMR analysis based on summary data from liver eQTL mapping and GWAS, we further identified four protein-coding genes, SUCLA2, TNFSF13B, SERTM1, and MARVELD3, that influence feed efficiency in laying hens. The SUCLA2 and TNFSF13B genes were significantly associated with SNP 1:25664581 and SNP rs312433097, respectively. SERTM1 showed significant associations with rs730958360 and 1:33542680 and is a potential causal gene associated with the abundance of Corynebacteriaceae in feces. MARVELD3 was significantly associated with the 1:135348198 and was significantly correlated with the abundance of Enterococcus in ileum. Specifically, a lower abundance of Enterococcus in ileum and a higher abundance of Corynebacteriaceae in feces were associated with better feed efficiency. Conclusions: This study confirms that both host genetics and gut microbiota can drive variations in feed efficiency. A small portion of the gut microbiota often interacts with host genes, collectively enhancing feed efficiency. Therefore, targeting both the gut microbiota and host genetic variation by supporting more efficient taxa and selective breeding could improve feed efficiency in laying hens during the late laying period. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of dietary supplementation of a mixture of botanical compounds and essential oil (Phyto AquaMeric, PAM) on the growth, immune and antioxidant parameters and environmental benefits in Nile tilapia. Two diets including a control and a PAM-supplemented diet at 0.5 g kg−1 were prepared for the trial. The diets were isonitrogenous (30% crude protein) and isoenergetic (17 MJ kg−1) extruded diets. Nile tilapia weighing initially 74.22 ± 1.96 g fish−1 were stocked in 2 m3 hapas at a density of 20 fish per m3 (40 fish per hapa). Each group was tested in triplicates over 80 days. The antioxidant potential of PAM was compared to vitamin C through KRL test, showing a higher value from 35 to 100 mg. The in vivo trial did not exhibit any significant growth performance improvement. However, the PAM group had a significantly improved feed conversion ratio (FCR) and protein efficiency ratio (PER). Moreover, the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), Malondialdehyde (MDA), immune parameters (ACH50, lysozyme, phagocytic and phenoloxidase activities), digestive enzymes and hepatic enzymes were significantly improved in the PAM-fed group. An evaluation of eutrophication potential of PAM supplementation revealed a low input in the system. In conclusion, this mixture of botanicals and essential oil exhibited in vitro and in vivo antioxidant potential, improved health and digestive parameters and contributed to a reduced eutrophication risk in the tilapia production system. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the repeatability of feed efficiency and its association with carcass traits in Hanwoo steers during the entire growing and fattening periods. Methods: The growth and intake of thirty-six Hanwoo steers (259±19.7 kg; nine months) were monitored throughout five periods, including two growing periods (GP) and three fattening periods (FP). The steers were fed two types of concentrate mixes with varying nutrient compositions until they reached a target weight of 800 kg for slaughter. For each period, steers were categorized into three classes based on their feed efficiency rankings using residual feed intake (RFI) and feed conversion ratio (FCR). Feed efficiency repeatability was assessed using the Spearman correlation coefficient, decomposition of random errors, and the Theil segregation index (TSI). The Pearson correlation coefficient was used to examine the relationship between feed efficiency and carcass traits. Results: The results demonstrated a significant and high correlation with RFI, but not FCR, during the growing or fattening stages (r>0.5; p<0.01). When steers were classified according to their feed efficiency rankings, 58% of the animals in the high RFI class (low efficient) initially (GP 1) remained in the same class by the last period (FP 3), whereas steers were randomly distributed based on FCR. The repeatability, assessed by the decomposition of random errors, was higher for RFI (0.61) than for FCR (0.15). The TSI also indicated that RFI rankings, rather than FCR rankings, are more likely to be maintained. Moreover, a weak association was observed between feed efficiency and carcass traits. Conclusion: In conclusion, RFI repeatability throughout the GP and FP surpassed that of the FCR, with steers classified as high RFI during the GP more likely to remain in the same class during the FP. Feed efficiency was weakly correlated with carcass traits. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of supplementing sodium bicarbonate or a commercial blend of buffering agents (BBA) comprising calcareous calcitic, magnesium oxide, calcareous algae, and sodium bicarbonate on the productive, behavioral and metabolic parameters of Holstein cows fed starchy diets. Over a 60-day trial period, thirty-six multiparous cows with an average milk yield of 38.84 ± 9.24 kg/day and 63.74 ± 18.63 days in milk (DIM), were randomly divided into two groups. The control group (n = 18) received a supplementation of 1.1% dry matter (DM) of sodium bicarbonate (Raudi®, Totalmix, Brazil), while the BBA group (n = 18) was administered with 0.5% DM of a blend of buffering agents (Equalizer®, Nutron/Cargill, Brazil). The mean values of ruminal pH (control 6.80 ± 0.06 and BBA 6.77 ± 0.06; P > 0.05) and volatile fatty acid (VFA) production (control: acetate 62.63 ± 1.29%, propionate 22.99 ± 1.07%, butyrate 14.30 ± 0.52%; BBA: acetate 63.07 ± 1.32%, propionate 23.47 ± 1.10%, butyrate 13.70 ± 0.57%), were similar (P > 0,05) between the two groups. The value of faecal pH was higher (P < 0.05) in the BBA group (6.25 ± 0.02) than the control group (6.12 ± 0.02). Animals treated with BBA exhibited lower (P < 0,05) dry matter intake (DMI) (24.75 ± 0.64 kg/day), higher feed efficiency (FE) (1.64 ± 0.03), and reduced feeding frequency (52.89 ± 3.73 n°/day) than the control group (DMI, 26.75 ± 0.62 kg/day; FE, 1.50 ± 0.03; feeding frequency, 66.07 ± 3.64 n°/day). Milk production remained similar across both groups (control, 39.11 ± 0.92 kg/day and BBA, 39.87 ± 0.92 kg/day; P > 0.05). Notably, the control group displayed a higher (P < 0,05) concentration of milk protein (1.21 ± 0.05 kg/day) than the BBA (1.18 ± 0.05 kg/day) group. The study concluded that both treatments effectively buffered the rumen and mitigated the risk of ruminal acidosis. Moreover, the higher faecal pH in the BBA-treated group suggests potential intestinal action attributable to the synergistic effects of diverse additives with buffering properties. Despite a reduced DMI, BBA-treated animals exhibited improved FE. [ABSTRACT FROM AUTHOR]

ABSTRACT: The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 CP levels (16.8% and 15.5% of DM), with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles [DDGS]) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 DIM, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high-protein diet (16.8% CP, HP), HP diet with HB (HP+HB), low-protein diet (15.5% CP, LP), or LP diet with HB (LP+HB). An interaction between CP × HB on DMI was detected, with DMI being unaffected by HB inclusion in cows fed the high-protein diets, but was lower in cows fed HB when the low-protein diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and MUN content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N use efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low-protein diets. In conclusion, feeding a low-protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high-CP diet, but compromised cow performance with a low-CP diet.

ABSTRACT: The objectives of this study were to determine the effects of 2 dietary microbial additives on productive performance and feed efficiency when supplemented to diets of Holstein cows. One hundred seventeen Holstein cows were enrolled at 61 d (31–87 d) postpartum in a randomized complete block design experiment. Cows were blocked by parity group, as nulliparous or multiparous cows and, within parity, by pretreatment ECM yield. Within block, cows were randomly assigned to one of 3 treatments administered as top-dress for 140 d. Treatments consisted of either 100 g of corn meal containing no microbial additive (CON; 15 primiparous and 25 multiparous), 100 g of corn meal containing 5 g of a mixture of Clostridium beijerinckii and Pichia kudriavzevii (G1; 4 × 107 cfu of C. beijerinckii and 1 × 109 cfu of P. kudriavzevii; 14 primiparous and 24 multiparous), or 100 g of corn meal containing 5 g of a mixture of C. beijerinckii, P. kudriavzevii, Butyrivibrio fibrisolvens, and Ruminococcus bovis (G2; 4 × 107 cfu of C. beijerinckii, 1 × 109 cfu of P. kudriavzevii, 1 × 108 cfu of B. fibrisolvens, and 1 × 108 cfu of R. bovis; 15 primiparous and 24 multiparous). Intake of DM, milk yield, and BW were measured daily, whereas milk composition was analyzed at each milking 2 d a week, and body condition was scored twice weekly. Milk samples were collected on d 60 and 62 in the experiment and analyzed for individual fatty acids. The data were analyzed with mixed-effects models with orthogonal contrast to determine the effect of microbial additive (MA; CON vs. 1/2 G1 + 1/2 G2) and type of microbial additive (TMA; G1 vs. G2). Results are described in sequence as CON, G1, and G2. Intake of DM (22.2 vs. 22.4 vs. 22.4 kg/d), BW (685 vs. 685 vs. 685 kg) and the daily BW change (0.40 vs. 0.39 vs. 0.39 kg/d) did not differ among treatments; however, feeding MA tended to increase BCS (3.28 vs. 3.33 vs. 3.36). Supplementing MA increased yields of milk (39.9 vs. 41.3 vs. 41.5 kg/d), ECM (37.9 vs. 39.3 vs. 39.9 kg/d), fat (1.31 vs. 1.37 vs. 1.40 kg/d), TS (4.59 vs. 4.75 vs. 4.79 kg/d), and ECM per kg of DMI (1.72 vs. 1.76 vs. 1.80 kg/kg). Furthermore, cows fed MA increased yields of preformed fatty acids in milk fat (>16C; 435 vs. 463 vs. 488 g/d), particularly UFA (367 vs. 387 vs. 410 g/d), such as linoleic (C18:2 cis-9,cis-12; 30.9 vs. 33.5 vs. 35.4 g/d) and α-linolenic acids (C18:3 cis-9,cis-12,cis-15; 2.46 vs. 2.68 vs. 2.82 g/d) on d 60 and 62 in the experiment. Collectively, supplementing G1 and G2 improved productive performance of cows with no differences between the 2 MA.

ABSTRACT: Milk production and overall dairy farm economics depend on rearing dairy heifers. This study investigated the presence of a genotype by environment interaction in Holstein (HOL), Nordic Red dairy cattle (RDC), and their F1 crossbreeds (HOL × RDC) when provided different feed rations. The aim of our study was to assess how different energy concentrations in feed rations affect growth, BCS, feed intake, and feed efficiency in the 3 groups during the prepubertal period. The 3 breed groups were randomly allocated to receive either a standard or a low-energy feed ration. Holstein heifers exhibited reduced growth and a lower BCS when they were fed the low-energy feed ration. In contrast, the RDC heifers demonstrated similar growth rates with the different feed rations and maintained similar BCS irrespective of feed energy concentration. The HOL × RDC crossbred heifers performed as an intermediate between the HOL and RDC groups. Significant differences were observed in DMI and energy intake in the HOL and HOL × RDC groups depending on feed ration treatment. The RDC heifers had similar feed intake irrespective of treatment. There were no significant differences in the feed conversion ratio among breeds and feed treatments. These results indicate the presence of a genotype by environment interaction in prepubertal HOL and RDC heifers in response to differences in feed ration treatment. Due to the influence of prepubertal growth on future milk production, reproduction, and health status, it is important to be aware of breed-specific requirements during the prepubertal period, particularly in mixed breed and crossbred groups, to optimize growth rates and production potential.

Abstract Background Feed costs account for a high proportion of the variable cost of beef production, ultimately impacting overall profitability. Thus, improving feed efficiency of beef cattle, by way of determining the underlying genomic control and selecting for feed efficient cattle provides a method through which feed input costs may be reduced whilst also contributing to the environmental sustainability of beef production. The rumen microbiome dictates the feed degradation capacity and consequent nutrient supply in ruminants, thus potentially impacted by feed efficiency phenotype. Equally, liver tissue has been shown to be responsive to feed efficiency phenotype as well as dietary intake. However, although both the rumen microbiome and liver transcriptome have been shown to be impacted by host feed efficiency phenotype, knowledge of the interaction between the rumen microbiome and other peripheral tissues within the body, including the liver is lacking. Thus, the objective of this study was to compare two contrasting breed types (Charolais and Holstein-Friesian) divergent for residual feed intake (RFI) over contrasting dietary phases (zero-grazed grass and high-concentrate), based on gene co-expression network analysis of liver transcriptome data and microbe co-abundance network of rumen microbiome data. Traits including RFI, dry matter intake (DMI) and growth rate (ADG), as well as rumen concentrations of volatile fatty acids were also included within the network analysis. Results Overall, DMI had the greatest number of connections followed by RFI, with ADG displaying the fewest number of significant connections. Hepatic genes related to lipid metabolism were correlated to both RFI and DMI phenotypes, whilst genes related to immune response were correlated to DMI. Despite the known relationship between RFI and DMI, the same microbes were not directly connected to these phenotypes, the Succiniclasticum genus was however, negatively connected to both RFI and ADG. Additionally, a stepwise regression analysis revealed significant roles for both Succiniclasticum genus and Roseburia.faecis sp. in predicting RFI, DMI and ADG. Conclusions Results from this study highlight the interactive relationships between rumen microbiome and hepatic transcriptome data of cattle divergent for RFI, whilst also increasing our understanding of the underlying biology of both DMI and ADG in beef cattle.

Abstract Background Feed efficiency is a crucial economic trait in poultry industry. Both host genetics and gut microbiota influence feed efficiency. However, the associations between gut microbiota and host genetics, as well as their combined contributions to feed efficiency in laying hens during the late laying period, remain largely unclear. Methods In total, 686 laying hens were used for whole-genome resequencing and liver transcriptome sequencing. 16S rRNA gene sequencing was conducted on gut chyme (duodenum, jejunum, ileum, and cecum) and fecal samples from 705 individuals. Bioinformatic analysis was performed by integrating the genome, transcriptome, and microbiome to screen for key genetic variations, genes, and gut microbiota associated with feed efficiency. Results The heritability of feed conversion ratio (FCR) and residual feed intake (RFI) was determined to be 0.28 and 0.48, respectively. The ileal and fecal microbiota accounted for 15% and 10% of the FCR variance, while the jejunal, cecal, and fecal microbiota accounted for 20%, 11%, and 10% of the RFI variance. Through SMR analysis based on summary data from liver eQTL mapping and GWAS, we further identified four protein-coding genes, SUCLA2, TNFSF13B, SERTM1, and MARVELD3, that influence feed efficiency in laying hens. The SUCLA2 and TNFSF13B genes were significantly associated with SNP 1:25664581 and SNP rs312433097, respectively. SERTM1 showed significant associations with rs730958360 and 1:33542680 and is a potential causal gene associated with the abundance of Corynebacteriaceae in feces. MARVELD3 was significantly associated with the 1:135348198 and was significantly correlated with the abundance of Enterococcus in ileum. Specifically, a lower abundance of Enterococcus in ileum and a higher abundance of Corynebacteriaceae in feces were associated with better feed efficiency. Conclusions This study confirms that both host genetics and gut microbiota can drive variations in feed efficiency. A small portion of the gut microbiota often interacts with host genes, collectively enhancing feed efficiency. Therefore, targeting both the gut microbiota and host genetic variation by supporting more efficient taxa and selective breeding could improve feed efficiency in laying hens during the late laying period.

Residual feed intake (RFI) is a metric that provides a more accurate measure of feed efficiency. The lower the RFI, the higher the feed efficiency. The changes in the host microbiome and metabolome contribute to the greater feed efficiency of low RFI (LRFI) animals. The aim of this study was to explore the differences in rumen microorganisms, rumen metabolites and plasma metabolites of Hu sheep with differing RFI through the microbiome and metabolome. A total of 80 Hu sheep were used. The experiment consisted of a 15-d pretrial period and a 128-d experimental period. The RFI in the experimental period was calculated for all sheep, and the sheep were screened into high RFI (HRFI, n = 8) and LRFI (n = 8) groups. The HRFI and LRFI sheep did not differ in their initial and final body weights, average daily gain and body measurements, but the dry matter intake of LRFI sheep was significantly decreased (28.4%, P

The objective of this study is to investigate the effects of increasing levels of soybean hulls in broiler chicken diets on growth performance, carcase composition, organ weights, nutrient digestibility, amino acid digestibility, and intestinal histomorphology to determine the optimal inclusion level for maximising poultry health and performance. A total of 680, 1-day-old male broiler chicks (Hubbard) were randomly assigned to five treatments with eight replicates, each consisting of seventeen birds, and housed in an environmentally controlled room with nipple drinkers and trough feeders. The experimental diets, containing 0%, 2%, 4%, 6%, and 8% dietary soybean hulls (SH), were fed to the broilers for 35 days. During the starter phase, the growth performance of chickens fed 2% SH was not significantly different from the control group, but differences emerged during the later stages. Chickens fed 2% SH showed significantly higher body weight and weight gain compared to higher SH levels. Carcase yield decreased with increasing SH content in the diet, while wing meat yield was highest in birds fed 0% and 2% SH. The relative weights of gizzard, jejunum, and ileum varied significantly among groups. Higher SH levels led to decreased nutrient digestibility but increased excreta nitrogen and ether extract content. Ileal amino acid digestibility varied among SH levels. Intestinal histomorphology revealed significant differences in villi height and crypt depth among groups. Overall, diets with 2% and 4% SH demonstrated superior nutrient utilisation and intestinal health compared to higher SH levels. These findings suggest an optimal inclusion level of SH in broiler diets to optimise performance and intestinal morphology.

A total of 576 rabbits were housed in 18 open-top elevated pens (32 rabbits per pen) during the fattening period (54–71 d of age) and fed a standard diet or a diet enriched in purified wood lignocellulose and fat formulated to guarantee rabbit optimal digestive health and convenient feed conversion ratio. The impacts on gut microbiota (both hard faeces and caecal content) and caecal fermentation, diet digestibility and rabbit performance were examined. The microbial diversity and the bacterial community structure of hard faeces barely differed from that of caecal content (p > .05). No differences in alpha and beta diversity of microbiota were detected between rabbits fed the different diets. Twelve genera, mostly belonging to the family of Lachnospiraceae, increased (p

Abstract The recent chromosome-based genome assembly and the newly developed 70K single nucleotide polymorphism (SNP) array for American mink (Neogale vison) facilitate the identification of genetic variants underlying complex traits in this species. The objective of this study was to evaluate the association between consensus runs of homozygosity (ROH) with growth and feed efficiency traits in American mink. A subsample of two mink populations (n = 2,986) were genotyped using the Affymetrix Mink 70K SNP array. The identified ROH segments were included simultaneously, concatenated into consensus regions, and the ROH-based association studies were carried out with linear mixed models considering a genomic relationship matrix for 11 growth and feed efficiency traits implemented in ASReml-R version 4. In total, 298,313 ROH were identified across all individuals, with an average length and coverage of 4.16 Mb and 414.8 Mb, respectively. After merging ROH segments, 196 consensus ROH regions were detected and used for genome-wide ROH-based association analysis. Thirteen consensus ROH regions were significantly (P

ABSTRACT: The large-scale recording of traits such as feed efficiency (FE) and methane emissions (ME) for use in genetic improvement programs is complex, costly, and time-consuming. Therefore, heritable traits that can be continuously recorded in dairy herds and are correlated with FE and ME traits could provide useful information for genetic evaluation. Rumination time has been suggested to be associated with FE, methane production (MeP; ME in g/d), and production traits at the phenotypic level. Therefore, the objective of this study was to investigate the genetic relationships among rumination time (RT), FE, methane and production traits using 7,358 records from 656 first-lactation Holstein cows. The estimated heritabilities were moderate for RT (0.45 ± 0.14), MeP (0.36 ± 0.12), milk yield (0.40 ± 0.08), fat yield (0.29 ± 0.06), protein yield (0.32 ± 0.07), and energy-corrected milk (0.28 ± 0.07), but were low and nonsignificant for FE (0.15 ± 0.07), which was defined as the residual of the multiple linear regression of DMI on energy-corrected milk and metabolic body weight. A favorable negative genetic correlation was estimated between RT and MeP (−0.53 ± 0.24), whereas a positive favorable correlation was estimated between RT and energy-corrected milk (0.49 ± 0.11). The estimated genetic correlation of RT with FE (−0.01 ± 0.17) was not significantly different from zero but showed a trend of a low correlation with dry matter intake (0.21 ± 0.13). These results indicate that RT is genetically associated with MeP and milk production traits, but high standard errors indicate that further analyses should be conducted to verify these findings when more data for RT, MeP, and FE become available.

ABSTRACT: The objective of this study was to evaluate the effects of supplementing monensin (19.8 g/Mg DM TMR; MON) and Saccharomyces cerevisiae CNCM I-1077 live-cell yeasts (Saccharomyces cerevisiae CNCM I-1077; 1 × 1010 cfu/head per day; LCY) on lactation performance, feeding behavior, and total-tract nutrient digestibility of high-producing dairy cows. Sixty-four multiparous Holstein cows (3.2 ± 1.5 lactations; 97 ± 16 DIM, and 724 ± 68 kg of BW at covariate period initiation) and 32 gate feeders were enrolled in a study with a completely randomized design and a 2 × 2 factorial arrangement. Cows and gate feeders were randomly assigned to treatments (16 cows and 8 gate feeders per treatment). Cows were allowed 2 wk to acclimate to feeding gates followed by a 2-wk covariate period. During the acclimation and covariate periods, all cows were fed a diet containing MON and LCY. Following the covariate period, cows were enrolled in a 10-wk treatment period during which cows were randomly assigned to 1 of 4 treatments: (1) a combination of MON and LCY (MON-LCY), (2) MON-CON, (3) CON-LCY, or (4) neither MON nor LCY (CON-CON). Data were analyzed using a mixed model with week as a repeated measure and fixed effects of MON, LCY, week, and all their interactions. Cow (treatment) was included as a random effect. The average covariate period value of each variable was used as a covariate. Three-way interactions were observed for DMI and feed efficiency. Dry matter intake decreased from wk 4 to 5 and wk 8 to 10 in MON-LCY cows compared with CON-CON. No treatment differences were observed for actual or component-corrected milk yield or milk components, except for a tendency for LCY to decrease milk fat yield. Feed efficiency was greater for MON-LCY relative to CON-CON in 4 of 10 wk. Interactions between MON and LCY were observed for dry matter and organic matter digestibility, where both were lower for CON-CON than other treatments. Under the conditions of the present study, feeding dairy cows in a high feed bunk density a combination of MON and LCY can decrease intake and improve feed efficiency without affecting milk production or components. Additionally, monensin and live-cell yeasts may each improve total-tract digestibility based on improvements in DM and OM digestibility.

ABSTRACT: Lysine is one of the limiting AA in the diets of dairy cows and is typically fed as rumen-protected Lys (RPL). We hypothesized that supplementation of RPL during the postpartum period would improve the productive performance in dairy cows. Objectives were to use meta-analytic methods to explore the effects of feeding RPL on performance and blood AA profile in lactating dairy cows. An additional objective was to identify an optimal concentration (%) of Lys in MP (LYSMP) and determine if responses to LYSMP were associated with the concentration (%) of Met in MP (METMP). The literature was systematically reviewed, and 13 experiments, comprising 40 treatment means and 594 lactating cows, were included in the meta-analysis. All experiments had a nonsupplemental control (CON; n = 17 treatment means), or a group supplemented with RPL (n = 23 treatment means). Cows supplemented with RPL were supplied additionally with a mean (±standard deviation) 19.3 ± 10.3 g/d metabolizable Lys (5.1–40.6 g/d). Meta-analytical statistics were used to estimate the weighted mean difference in STATA. Mixed models were fitted to the data to investigate the linear and quadratic effects of LYSMP, METMP, and interactions between LYSMP and METMP. All models included the random effect of experiment and weighting by the inverse of the SE of the means squared. Cows that began receiving RPL in early lactation (≤90 DIM) or for an extended duration (≥70 DIM) produced 1.51 kg/d more milk compared with CON cows. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased yields of milk, FCM, ECM, and milk fat by 1.8, 2.5, 2.4, and 0.10 kg/d, respectively, and tended to increase milk protein yield and body weight gain by 0.07 and 0.09 kg/d, respectively, without a concurrent increase in DMI. Interactions between the linear effects of LYSMP and METMP were observed for FCM/DMI or ECM/DMI. In a diet with low METMP (e.g., 1.82% of MP), a digestible supply of 7.40% LYSMP would result in 1.46 and 1.47 kg/kg FCM/DMI or ECM/DMI, respectively; however, with high digestible METMP (e.g., 2.91% of MP), supplying 7.40% of digestible LYSMP would result in 1.68 and 1.62 kg/kg FCM/DMI or ECM/DMI, respectively. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased blood concentrations of Lys by 16.6 µM, whereas blood concentrations of Met and Ala decreased by 4.6 and 6.0 µM, respectively. Nevertheless, an interaction was also observed between LYSMP and METMP for blood concentrations of total EAA because as METMP increased, the positive response to LYSMP on total EAA was also increased, suggesting a competitive mobilization of AA and their utilization in various body tissues. Only 4 out of the 13 experiments in this meta-analysis involved primiparous cows; thus, insufficient data were available to understand the role of supplemental RPL in primiparous cows. Collectively, feeding RPL improved productive performance, and the increments were maximized up to 9.25% of LYSMP in multiparous dairy cows.

Abstract Feed efficiency (FE) is essential for pig production, has been reported to be partially explained by gut microbiota. Despite an extensive body of research literature to this topic, studies regarding the regulation of feed efficiency by gut microbiota remain fragmented and mostly confined to disorganized or semi-structured unrestricted texts. Meanwhile, structured databases for microbiota analysis are available, yet they often lack a comprehensive understanding of the associated biological processes. Therefore, we have devised an approach to construct a comprehensive knowledge graph by combining unstructured textual intelligence with structured database information and applied it to investigate the relationship between pig gut microbes and FE. Firstly, we created the pgmReading knowledge base and the domain ontology of pig gut microbiota by annotating, extracting, and integrating semantic information from 157 scientific publications. Secondly, we created the pgmPubtator by utilizing PubTator to expand the semantic information related to microbiota. Thirdly, we created the pgmDatabase by mapping and combining the ADDAGMA, gutMGene, and KEGG databases based on the ontology. These three knowledge bases were integrated to form the Pig Gut Microbial Knowledge Graph (PGMKG). Additionally, we created five biological query cases to validate the performance of PGMKG. These cases not only allow us to identify microbes with the most significant impact on FE but also provide insights into the metabolites produced by these microbes and the associated metabolic pathways. This study introduces PGMKG, mapping key microbes in pig feed efficiency and guiding microbiota-targeted optimization.

In markets for beef and sheep meat, an appropriate level of intramuscular fat (IMF) is highly desirable for meat-eating quality, but strategies to improve it usually lead to an undesirable excess in carcase fat, presenting a major challenge to livestock producers. To solve this problem, we need to understand the partitioning of fat among the major fat depots: IMF, subcutaneous fat (SCF) and visceral fat (VF). In most genotypes of cattle and sheep, the rate of accretion is lower for IMF than for SCF and VF, so genetic selection for a high level of IMF, or the use of an increased dietary energy supply to promote IMF deposition, will increase overall fatness and feed costs. On the other hand, feeding postnatal calves with excessive concentrates promotes IMF deposition, so a nutritional strategy is feasible. With genetic strategies, several problems arise: 1) positive genetic correlations between IMF, SCF and VF differ among genotypes in both cattle and sheep; 2) genotypes appear to have specific, characteristic rates of accretion of IMF during periods of growth and fattening; 3) most breeds of cattle and sheep naturally produce meat with relatively low levels of IMF, but IMF does vary substantially among individuals and breeds so progress is possible through accurate measurement of IMF. Therefore, an essential prerequisite for selection will be knowledge of the genetic correlations and fat accretion rates for each genotype. Currently, selection for IMF is based on existing technology that directly measures IMF in the progeny or siblings, or estimates IMF in live animals. New technology is needed to permit the simultaneous measurement of SCF and IMF in the field, thus opening up the possibility of accurate selection, particularly for fat partitioning in live animals. Specifically, there would be great value in detecting individuals with an IMF advantage at an early age so the generation interval could be shortened and genetic gain accelerated. Genetic gain would also be greatly aided if we could select for genes that control adipogenesis and lipogenesis and are also differentially expressed in the various depots.

Aquaculture production is continuously increasing, consequently increasing the demand for feed. Unfortunately, the reliance on fish meal and fish oil also raises sustainability issues due to overfishing and resource depletion. Nanoparticle-enhanced feed presents a promising solution to these challenges. Nanoparticles, with their large surface area-to-volume ratio and encapsulation capabilities, significantly improve nutrient delivery, absorption, and utilization, enhancing growth and health. Their immune-modulatory and antimicrobial properties reduce antibiotic use and support sustainability. This review explores different nanoparticles in fish feed, including metal-based, non-metal-based, and composite types, each offering benefits for fish growth and health. It highlights the advantages of nanoparticle-enhanced feed, such as improved nutrient delivery, immune enhancement, antimicrobial action, stress reduction, and environmental sustainability. Concerns like potential toxicity, safety, bioaccumulation, and environmental impacts of nanoparticles, together with measures of addressing these concerns, are also highlighted. The review concludes with insights into future research directions. [ABSTRACT FROM AUTHOR]

Abstract: Optimizing feed efficiency through the feed conversion ratio (FCR) is paramount for economic viability and sustainability. In this study, we integrated RNA-seq, ATAC-seq, and genome-wide association study (GWAS) data to investigate key functional variants associated with feed efficiency in pigs. Identification of differentially expressed genes in the duodenal and muscle tissues of low- and high-FCR pigs revealed that pathways related to digestion of dietary carbohydrate are responsible for differences in feed efficiency between individuals. Differential open chromatin regions identified by ATAC-seq were linked to genes involved in glycolytic and fatty acid processes. GWAS identified 211 significant single-nucleotide polymorphisms associated with feed efficiency traits, with candidate genes PPP1R14C, TH, and CTSD. Integration of duodenal ATAC-seq data and GWAS data identified six key functional variants, particularly in the 1500985–1509676 region on chromosome 2. In those regions, CTSD was found to be highly expressed in the duodenal tissues of pigs with a high feed conversion ratio, suggesting its role as a potential target gene. Overall, the integration of multi-omics data provided insights into the genetic basis of feed efficiency, offering valuable information for breeding more efficient pig breeds. [ABSTRACT FROM AUTHOR]

We utilized plasma proteomics profiling to explore metabolic pathways and key proteins associated with divergent residual body weight gain (RADG) phenotype in crossbred (Angus × Hereford) beef steers. A group of 108 crossbred growing beef steers (average BW = 282.87 ± 30 kg; age = 253 ± 28 days) were fed a highforage total mixed ration for 49 days in five dry lot pens (20-22 beef steers per pen), each equipped with two GrowSafe8000 intake nodes to determine their RADG phenotype. After RADG identification, blood samples were collected from the beef steers with the highest RADG (most efficient; n = 15; 0.76 kg/d) and lowest RADG (least efficient; n = 15; -0.65 kg/d). Plasma proteomics analysis was conducted on all plasma samples using a nano LC-MS/MS platform. Proteins with FC = 1.2 and false-discovery rate-adjusted p-values (FDR) = 0.05 were considered significantly differentially abundant. The analysis identified 435 proteins, with 59 differentially abundant proteins (DAPs) between positive and negative-RADG beef steers. Plasma abundance of 38 proteins, such as macrophage stimulating 1 and peptidase D was upregulated (FC = 1.2, FDR = 0.05) in positive-RADG beef steers, while 21 proteins, including fibronectin and ALB protein were greater (FC < 1.2, FDR = 0.05) in negative-RADG beef steers. The results of the Gene Ontology (GO) analysis of all the DAPs showed enrichment of pathways such as metabolic processes, biological regulation, and catalytic activity in positive-RADG beef steers. Results of the EuKaryotic Orthologous Groups (KOG) analysis revealed increased abundance of DAPs involved in energy production and conversion, amino acid transport and metabolism, and lipid transport and metabolism in positive-RADG beef steers. The results of this study revealed key metabolic pathways and proteins associated with divergent RADG phenotype in beef cattle which give more insight into the biological basis of feed efficiency in crossbred beef cattle. [ABSTRACT FROM AUTHOR]

The recent chromosome-based genome assembly and the newly developed 70K single nucleotide polymorphism (SNP) array for American mink (Neogale vison) facilitate the identification of genetic variants underlying complex traits in this species. The objective of this study was to evaluate the association between consensus runs of homozygosity (ROH) with growth and feed efficiency traits in American mink. A subsample of two mink populations (n = 2,986) were genotyped using the Affymetrix Mink 70K SNP array. The identified ROH segments were included simultaneously, concatenated into consensus regions, and the ROH-based association studies were carried out with linear mixed models considering a genomic relationship matrix for 11 growth and feed efficiency traits implemented in ASReml-R version 4. In total, 298,313 ROH were identified across all individuals, with an average length and coverage of 4.16 Mb and 414.8 Mb, respectively. After merging ROH segments, 196 consensus ROH regions were detected and used for genome-wide ROH-based association analysis. Thirteen consensus ROH regions were significantly (P < 0.01) associated with growth and feed efficiency traits. Several candidate genes within the significant regions are known for their involvement in growth and body size development, including MEF2A, ADAMTS17, POU3F2, and TYRO3. In addition, we found ten consensus ROH regions, defined as ROH islands, with frequencies over 80% of the population. These islands harbored 12 annotated genes, some of which were related to immune system processes such as DTX3L, PARP9, PARP14, CD86, and HCLS1. This is the first study to explore the associations between homozygous regions with growth and feed efficiency traits in American mink. Our findings shed the light on the effects of homozygosity in the mink genome on growth and feed efficiency traits, that can be utilized in developing a sustainable breeding program for mink. [ABSTRACT FROM AUTHOR]

Lysine is one of the limiting AA in the diets of dairy cows and is typically fed as rumen-protected Lys (RPL). We hypothesized that supplementation of RPL during the postpartum period would improve the productive performance in dairy cows. Objectives were to use meta-analytic methods to explore the effects of feeding RPL on performance and blood AA profile in lactating dairy cows. An additional objective was to identify an optimal concentration (%) of Lys in MP (LYSMP) and determine if responses to LYSMP were associated with the concentration (%) of Met in MP (METMP). The literature was systematically reviewed, and 13 experiments, comprising 40 treatment means and 594 lactating cows, were included in the meta-analysis. All experiments had a nonsupplemental control (CON; n = 17 treatment means), or a group supplemented with RPL (n = 23 treatment means). Cows supplemented with RPL were supplied additionally with a mean (±standard deviation) 19.3 ± 10.3 g/d metabolizable Lys (5.1–40.6 g/d). Meta-analytical statistics were used to estimate the weighted mean difference in STATA. Mixed models were fitted to the data to investigate the linear and quadratic effects of LYSMP, METMP, and interactions between LYSMP and METMP. All models included the random effect of experiment and weighting by the inverse of the SE of the means squared. Cows that began receiving RPL in early lactation (≤90 DIM) or for an extended duration (≥70 DIM) produced 1.51 kg/d more milk compared with CON cows. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased yields of milk, FCM, ECM, and milk fat by 1.8, 2.5, 2.4, and 0.10 kg/d, respectively, and tended to increase milk protein yield and body weight gain by 0.07 and 0.09 kg/d, respectively, without a concurrent increase in DMI. Interactions between the linear effects of LYSMP and METMP were observed for FCM/DMI or ECM/DMI. In a diet with low METMP (e.g., 1.82% of MP), a digestible supply of 7.40% LYSMP would result in 1.46 and 1.47 kg/kg FCM/DMI or ECM/DMI, respectively; however, with high digestible METMP (e.g., 2.91% of MP), supplying 7.40% of digestible LYSMP would result in 1.68 and 1.62 kg/kg FCM/DMI or ECM/DMI, respectively. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased blood concentrations of Lys by 16.6 µ M , whereas blood concentrations of Met and Ala decreased by 4.6 and 6.0 µ M , respectively. Nevertheless, an interaction was also observed between LYSMP and METMP for blood concentrations of total EAA because as METMP increased, the positive response to LYSMP on total EAA was also increased, suggesting a competitive mobilization of AA and their utilization in various body tissues. Only 4 out of the 13 experiments in this meta-analysis involved primiparous cows; thus, insufficient data were available to understand the role of supplemental RPL in primiparous cows. Collectively, feeding RPL improved productive performance, and the increments were maximized up to 9.25% of LYSMP in multiparous dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of supplementing monensin (19.8 g/Mg DM TMR; MON) and Saccharomyces cerevisiae CNCM I-1077 live-cell yeasts (Saccharomyces cerevisiae CNCM I-1077; 1 × 1010 cfu/head per day; LCY) on lactation performance, feeding behavior, and total-tract nutrient digestibility of high-producing dairy cows. Sixty-four multiparous Holstein cows (3.2 ± 1.5 lactations; 97 ± 16 DIM, and 724 ± 68 kg of BW at covariate period initiation) and 32 gate feeders were enrolled in a study with a completely randomized design and a 2 × 2 factorial arrangement. Cows and gate feeders were randomly assigned to treatments (16 cows and 8 gate feeders per treatment). Cows were allowed 2 wk to acclimate to feeding gates followed by a 2-wk covariate period. During the acclimation and covariate periods, all cows were fed a diet containing MON and LCY. Following the covariate period, cows were enrolled in a 10-wk treatment period during which cows were randomly assigned to 1 of 4 treatments: (1) a combination of MON and LCY (MON-LCY), (2) MON-CON, (3) CON-LCY, or (4) neither MON nor LCY (CON-CON). Data were analyzed using a mixed model with week as a repeated measure and fixed effects of MON, LCY, week, and all their interactions. Cow (treatment) was included as a random effect. The average covariate period value of each variable was used as a covariate. Three-way interactions were observed for DMI and feed efficiency. Dry matter intake decreased from wk 4 to 5 and wk 8 to 10 in MON-LCY cows compared with CON-CON. No treatment differences were observed for actual or component-corrected milk yield or milk components, except for a tendency for LCY to decrease milk fat yield. Feed efficiency was greater for MON-LCY relative to CON-CON in 4 of 10 wk. Interactions between MON and LCY were observed for dry matter and organic matter digestibility, where both were lower for CON-CON than other treatments. Under the conditions of the present study, feeding dairy cows in a high feed bunk density a combination of MON and LCY can decrease intake and improve feed efficiency without affecting milk production or components. Additionally, monensin and live-cell yeasts may each improve total-tract digestibility based on improvements in DM and OM digestibility. [ABSTRACT FROM AUTHOR]

The large-scale recording of traits such as feed efficiency (FE) and methane emissions (ME) for use in genetic improvement programs is complex, costly, and time-consuming. Therefore, heritable traits that can be continuously recorded in dairy herds and are correlated with FE and ME traits could provide useful information for genetic evaluation. Rumination time has been suggested to be associated with FE, methane production (MeP; ME in g/d), and production traits at the phenotypic level. Therefore, the objective of this study was to investigate the genetic relationships among rumination time (RT), FE, methane and production traits using 7,358 records from 656 first-lactation Holstein cows. The estimated heritabilities were moderate for RT (0.45 ± 0.14), MeP (0.36 ± 0.12), milk yield (0.40 ± 0.08), fat yield (0.29 ± 0.06), protein yield (0.32 ± 0.07), and energy-corrected milk (0.28 ± 0.07), but were low and nonsignificant for FE (0.15 ± 0.07), which was defined as the residual of the multiple linear regression of DMI on energy-corrected milk and metabolic body weight. A favorable negative genetic correlation was estimated between RT and MeP (−0.53 ± 0.24), whereas a positive favorable correlation was estimated between RT and energy-corrected milk (0.49 ± 0.11). The estimated genetic correlation of RT with FE (−0.01 ± 0.17) was not significantly different from zero but showed a trend of a low correlation with dry matter intake (0.21 ± 0.13). These results indicate that RT is genetically associated with MeP and milk production traits, but high standard errors indicate that further analyses should be conducted to verify these findings when more data for RT, MeP, and FE become available. [ABSTRACT FROM AUTHOR]

A feeding trial was carried out to investigate the effects of a dietary fermented poultry by-product (FPBP) on the growth performance, feed efficiency, body chemical composition, blood biochemical tests and economic efficiency of the Nile tilapia, Oreochromis niloticus fingerlings. Poultry by-product was subjected to solid-state fermentation then incorporated into four experimental (Isonitrogenous 30% and iso-caloric 4400Kcal/ Kg) diets containing 0, 25, 50 and 75% FPBP instead of soybean meal. Results revealed that the replacement of soybean meal with FBPP had significantly high (P≤ 0.05) growth performance and feed utilization. Moreover, body ash content decreased insignificantly (P≤ 0.05) compared to the control. At a low substitution level of 25% FPBP, a significant increase in body fat content (P≤ 0.05) was recorded compared to the control. Furthermore, body ash and energy contents demonstrated a significant increase (P≤ 0.05) compared with the control. Additionally, biochemical blood tests revealed that FPBP does not have any harmful effects on either liver or kidney function parameters. It could be concluded that the replacement of soybean meal with FPBP at a level of 25% was the best in terms of growth performance and feed utilization under these experimental conditions. [ABSTRACT FROM AUTHOR]

This study's objective was to compare two options of pasture supplementation: corn silage (CS) alone or corn silage mixed with protein concentrate. The experiment was conducted with 18 lactating Holstein cows in mid‐lactation in a crossover design that included three treatments and three data collection periods. All cows had access to pasture for 17 h/day with an average herbage allowance of 16 kg dry matter (DM)/cow/day and were offered in‐barn corn silage, corn silage mixed with protein concentrate, or no supplementation. Cows were equipped with pH sensors residing in the reticulum and, during the 7‐day data collection periods, with a jaw movement recorder. Nonsupplemented cows produced 21.3 kg energy‐corrected milk (ECM) and ate 13.3 kg DM herbage at pasture. Cows supplemented with corn silage and corn silage plus protein produced 2.5 and 4.5 kg/day more ECM, respectively, consumed 3.4 and 3.3 kg/day more DM in total, respectively, ate for a shorter period of time, and ruminated longer than their nonsupplemented peers. Supplemented cows were almost able to cover their energy requirements and mobilised less body mass in contrast to the nonsupplemented cows. Cows offered corn silage plus protein showed increased ECM production, increased milk urea content and lower nitrogen use efficiency (NUE) compared to cows supplemented with corn silage only. Nonsupplemented dairy cows had the highest milk urea content and performed worst in terms of NUE. The best feed conversion efficiency resulted from the nonsupplemented dairy cows and those supplemented with corn silage plus protein. In nonsupplemented cows, the high feed conversion efficiency seemed to be due to the increased mobilisation of body mass. As a result of the starch‐rich supplementations, the ruminal acetic:propionic acid ratio became smaller, and the proportions of n‐butyric acid increased. The mean reticular pH values did not substantially vary across the three feeding treatments. For the choice of a supplementation option, herbage allowance and cost of supplement will have to be considered, but aspects of feed–food competition as well as animal welfare should not be ignored. [ABSTRACT FROM AUTHOR]

This meta-analysis aims to investigate the effects of residual feed intake (RFI) phenotype on performance, nutrient utilization and meat quality traits in Zebu (Bos indicus) cattle. Twenty-three peer-reviewed publications with 37 treatment means were included in the dataset. Weighted mean difference analysis compared animals categorized into low RFI (more efficient) versus medium or high RFI (less efficient) groups. Data heterogeneity via meta-regression and subgroup analysis, considering variables such as animal age, sex class, experimental duration, RFI group, dietary concentrate, and estimated metabolizable energy intake were also explored. The predominant genetic group of cattle in the dataset was Nellore (89.18%), followed by Brahman (10.81%). More efficient animals (low RFI phenotype) exhibited less dry matter intake (DMI; P < 0.010) than medium or high RFI animals (-0.95 kg vs. -0.42 kg/d). Cattle dietary crude protein and fiber digestibility were consistent across RFI groups (P > 0.05), while dietary ether extract digestibility tended to decrease (P = 0.050) in low RFI animals (-13.20 g/kg DM). Low RFI animals tended to increased (P = 0.065) ribeye area (REA) compared to the high/medium RFI groups, while carcass backfat thickness (BFT) decreased (P = 0.042) compared to high/medium RFI groups. Moreover, there was an increase (P < 0.001) of 0.22 kg in Warner-Bratzler shear force (WBSF) and a reduction (P < 0.001) in the myofibrillar fragmentation index (MFI) in low RFI animals. Meat color parameters (lightness [L*] and yellowness [b*]) and visual marbling scores were consistent (P > 0.05) across RFI groups. In conclusion, Zebu cattle classified as efficient (low RFI) exhibited reduced DMI, which improves their feed efficiency. However, BFT and meat quality parameters such as tenderness (WBSF and MFI) and redness [a*] were compromised by low RFI phenotype, highlighting the challenge of enhancing feed efficiency and meat quality traits in Zebu cattle. [ABSTRACT FROM AUTHOR]

Introduction The beginning of lactation is one of the important performance signs related to health, fertility and production in lactating cows. Meeting the energy needs is considered as the main challenge of lactating cows at this period. Increasing the mobilization of body fat is one of the ways to meet the lack of energy, which can lead to an increase in the supply of non-esterified fatty acids (NEFA). Therefore, management strategies based on nutrition can play an important role in increasing energy intake and minimizing negative energy balance (NEB). The use of fat supplements can be considered as an effective solution to increase the amount of energy in the diets of fresh cows. The objective of this study was to evaluate the effect of feeding different fat supplements containing saturated and unsaturated fatty acids on production performance, blood and rumen parameters in fresh Holstein cows. Materials and Methods In this study, 32 Holstein cows with average live body weight 649.2 ± 29.11 kg and body condition score of 3.78 ± 0.30 were used after calving for 21 days in a completely randomized design in four experimental groups. Experimental treatments included: 1) control: no fat supplement, 2) unsaturated: containing calcium salt of unsaturated fatty acids, three percent based on DM, 3) saturated: containing calcium salt of saturated fatty acids, three percentage based on DM and 4) mixed: contained an equal mixture of both types of fat supplements. Dry matter intake (DMI) was measured daily. Cows were milked three times a day at 05:00, 13:00 and 21:00 in a parlor and milk yield was recorded. Milk was sampled at each milking on days 7, 14 and 21 until analyzed for fat. Body weight was measured on days 7, 14 and 21 after parturition. Blood samples were collected from subcaudal vein with vacuum tubes containing anticoagulant heparin on days 0, 7 and 21 after parturition. After separating the serum using a centrifuge, for the measurement of glucose, triglyceride, cholesterol, NEFA and beta-hydroxybutyrate (BHBA), samples were sent to the laboratory. Ruminal fluid is collected on the d 21 after parturition, two to three hours after morning feeding by the esophageal tube and using a suction pump, and after passing through the filter and measuring the pH by a portable pH meter, was sent to the laboratory to measure volatile fatty acids (VFA). Results and Discussion The results of the study showed that the calcium salt of unsaturated fatty acids caused a decrease, and the calcium salt of saturated and mixed fatty acids caused an increase in DMI compared to the control treatment. Milk production, milk fat percentage, 4% fat corrected milk production, energy corrected milk production, feed efficiency, blood concentrations of glucose, cholesterol, triglyceride and BHBA values, as well as rumen fermentation parameters were not affected by the treatments. The concentration of NEFA in the plasma, in the control treatment and the treatment containing calcium salts of unsaturated fatty acids, were measured above the safety margin provided for sub clinical ketosis. Conclusion According to the lactation performance of cows, the absence of problems regarding the amounts of NEFA and BHBA as indicators of metabolic disorders and the ineffectiveness of supplements on rumen fermentation parameters, it seems that it is possible to use an equal mixture (50:50) of fat supplements of calcium salts containing saturated and unsaturated fatty acids in the diet of fresh dairy cows in the amount of three percent. [ABSTRACT FROM AUTHOR]

Simple Summary: Intensively managing the use of concentrate supplementation to complement nutrition can increase production costs and reduce producers' income. Considering the frequently large price fluctuations for soybean meal, an alternative is the replacement of local protein sources in ruminant feeding. In this study, we compared the effects of different sources of protein (soybean meal, cottonseed meal, peanut meal, rapeseed meal, and distillers' dried grains with solubles) on the growth, digestibility, and rumen fermentation of growing lambs. Our results showed that when soybean meal was totally replaced with either cottonseed meal, peanut meal, rapeseed meal, or distillers' dried grains with solubles, there was no impact on the average daily gain of growing lambs, but digestibility was reduced. Our study provides a theoretical basis for the rational selection and utilization of proteins from different sources, which helps us to optimize the feeding management of growing lambs. Considering the frequently large price fluctuations for soybean meal, an alternative is the increased use of locally produced high-protein ingredients. The objective of this study was to evaluate the effects of the total replacement of soybean meal with different sources of protein on the growth performance, nutrient digestibility, serum parameters, rumen fermentation parameters, and bacterial communities in growing lambs. Sixty sheep with similar body weights (38.46 ± 0.71 kg) were distributed to one of five treatments: soybean meal (SBM); cottonseed meal (COM); peanut meal (PEM); rapeseed meal (RAM); and distillers' dried grains with solubles (DDGS). The experiment lasted 62 days with a 10-day adaptation period and a 52-day growing period. The results indicated that the body weight and average daily gain were not affected by different protein sources (p > 0.05), but the dry matter intake of the SBM group was lower than that of the other groups (p < 0.05); otherwise, the feed efficiency was higher (p < 0.05). The digestion of dry matter was higher in the SBM, COM, and RAM groups than in the DDGS and PEM groups (p < 0.05). Meanwhile, compared to the other groups, the SBM group had the highest digestion of gross energy and crude protein (p < 0.05). In addition, the concentration of glutathione peroxidase was highest in the SBM group (p < 0.05). Regarding the rumen fermentation, the SBM group had the highest concentration of NH3-N (p < 0.05). The rumen bacterial community was not affected by treatments (p > 0.05). In conclusion, the total replacement of soybean meal with cottonseed, peanut, rapeseed, or DDGS reduced digestibility but did not impact the body weight or average daily gain of growing lambs and had no effect on the immune function and rumen bacterial community; thus, they can be used to substitute the soybean meal. [ABSTRACT FROM AUTHOR]

1. This study investigated the effects of incorporating yellow mealworm (Tenebrio molitor) larval meal as a partial and/or complete substitute for soybean meal on carcass and meat quality in slow-growing chickens.2. A total of 256 one-day-old male broilers were randomly allocated to 1 of 32 experimental units distributed among four treatments (n = 8): the control treatment (C), where soybean (SB) meal was the protein source, and three experimental treatments, in which SB meal was replaced by Tenebrio molitor (TM) larval meal at levels of 50% (T1), 75% (T2) and 100% (T3), respectively. Three different feed phases (1–29; 29–57 and 57–92 d of age) were used for each treatment. All chickens were slaughtered at 92 d of age, with eight animals per treatment randomly selected to assess carcass and meat quality. Near-infrared reflectance spectroscopy (NIR) was used to classify meat quality.3. Carcass traits were not significantly different between treatments, except for head and thigh weight, which were higher in the control group (p < 0.01). In terms of physicochemical characteristics, treatment T2 showed less yellowness (p < 0.05), while water and cooking losses were lower in treatments T1 and T2 (p < 0.01). Meat from both T1 and T2 groups had lower shear forces (p < 0.01), higher moisture content (p < 0.01) and less protein (p < 0.05) compared to treatments C andT3. Birds fed T3 had the highest meat ash content (p < 0.01). Chickens consuming TM had higher monounsaturated fatty acid (MUFA) levels and lower polyunsaturated fatty acid (PUFA) and n-6 acidsPUFA (p < 0.01).4. Substitution of SB with TM is a protein alternative for slow-growing chickens that supports carcass and meat quality comparable to those fed a conventional diet. [ABSTRACT FROM AUTHOR]

Feed efficiency (FE) is essential for pig production, has been reported to be partially explained by gut microbiota. Despite an extensive body of research literature to this topic, studies regarding the regulation of feed efficiency by gut microbiota remain fragmented and mostly confined to disorganized or semi-structured unrestricted texts. Meanwhile, structured databases for microbiota analysis are available, yet they often lack a comprehensive understanding of the associated biological processes. Therefore, we have devised an approach to construct a comprehensive knowledge graph by combining unstructured textual intelligence with structured database information and applied it to investigate the relationship between pig gut microbes and FE. Firstly, we created the pgmReading knowledge base and the domain ontology of pig gut microbiota by annotating, extracting, and integrating semantic information from 157 scientific publications. Secondly, we created the pgmPubtator by utilizing PubTator to expand the semantic information related to microbiota. Thirdly, we created the pgmDatabase by mapping and combining the ADDAGMA, gutMGene, and KEGG databases based on the ontology. These three knowledge bases were integrated to form the Pig Gut Microbial Knowledge Graph (PGMKG). Additionally, we created five biological query cases to validate the performance of PGMKG. These cases not only allow us to identify microbes with the most significant impact on FE but also provide insights into the metabolites produced by these microbes and the associated metabolic pathways. This study introduces PGMKG, mapping key microbes in pig feed efficiency and guiding microbiota-targeted optimization. [ABSTRACT FROM AUTHOR]

The genetic trait of residual feed intake (RFI) holds considerable importance in the swine industry. Recent research indicates that the gut microbiota of pigs plays a pivotal role in the manifestation of the RFI trait. Nevertheless, the metabolic pathways involved in the functioning of these microorganisms remain elusive. Thus, based on the ranking of the RFI trait in Duroc pigs, the present study selected the top 10 and bottom 10 pigs as the experimental subjects. The distribution and metabolite differences of cecal microbiota were analyzed using 16S rRNA gene sequencing and liquid chromatography--tandem mass spectrometry (LC--MS/MS) techniques. The low RFI cecal group was named LRC, and the high RFI cecal group was named HRC. The results indicate that the LRC group had lower RFI, feed conversion ratio (FCR), average daily feed intake (ADFI) (p < 0.001), and thinner backfat (p < 0.05) compared with the HRC group. We simultaneously recorded the foraging behavior as well, the LRC group had a significant increase in total time spent at the feeder per day (TPD) (p < 0.05) and a significant increase in average feed intake per mins (AFI) and the number of visits to the feeder per day (NVD) compared to the HRC group (p < 0.001). Clostridium_XVIII, Bulleidia, and Intestinimonas were significantly enriched in the LRC group (p < 0.01), while Sutterella, Fusobacterium, and Bacteroides were significantly increased in the HRC group (p < 0.01). In the metabolome, we detected 390 (248 metabolites up and 142 down in the LRC compared with HRC), and 200 (97 metabolites up and 103 down in the LRC compared with HRC) differential metabolites in positive and negative ionization modes. The comprehensive analysis found that in the LRC group, Escherichia and Eubacterium in the gut may increase serotonin content, respectively. Bacteroides may deplete serotonin. We suggest that the RFI may be partly achieved through tryptophan metabolism in gut microbes. In individuals with low RFI, gut microbes may enhance feed efficiency by enhancing host synthesis and metabolism of tryptophan-related metabolites. [ABSTRACT FROM AUTHOR]

This study in dairy cow feeding explored the effects of growth stage and chop length for grass‐clover silage, and of concentrate protein level, including the interactions of these three factors. The experiment was conducted with 48 Norwegian Red cows according to a cyclic change‐over design with four 4‐week experimental periods and eight dietary treatments in a 2 × 2 × 2 factorial arrangement. Round bale silage from a mixed sward of timothy, meadow fescue, and red clover was harvested at two growth stages (H1, H2) and offered to dairy cows either unchopped with median particle length of 152 mm or chopped to 19 mm median particle length before feeding. A low protein (LP) concentrate containing 7% lignosulphonate treated soybean meal (SBM) and a high protein (HP) concentrate containing 12% solvent extracted SBM were compared. Silage was offered ad libitum and supplemented with 8 kg concentrate per day. Silage dry matter intake was 2.0 kg higher for H1 than H2 silage, which supported a higher yield of milk, energy‐corrected milk and the milk constituents, fat, protein, and lactose. All these measures of milk production, as well as feed energy efficiency and N use efficiency, increased when silage was fed chopped rather than unchopped. Lignosulphonate treated SBM spared N in the diet without milk yield reductions. For efficient milk production with high energy and N utilisation, we recommend chopping to 20 mm for timothy, meadow fescue, and clover silages harvested in late stem elongation or in reproductive growth stages. [ABSTRACT FROM AUTHOR]

"Nano", which derives from the Latin word nanus and means dwarf, refers to a very small unit of measurement equal to one billionth of a meter. Nanotechnology, which deals with the manipulation of matter at the atomic and molecular level, has an application area in animal husbandry as well as in many fields. Nano-sized feed additives, which have come to the forefront in the livestock sector in recent years, have become an innovative application used to increase the nutritional value of feeds and optimize animal health and performance. Since these additives are nano-sized particles with increased specific surface area, they can have a positive effect on a number of factors such as digestibility, nutrient absorption, immune system, growth and development. Minerals in the form of nanoparticles used as feed additives can increase bioavailability by passing through the intestinal wall to body cells faster compared to larger particles. The nano level of the substance not only increases the productivity of animals, but also brings the potential to improve the functionality of feed molecules. Nano feed additives increase the digestion and absorption of feed, allowing animals to benefit from feed more effectively. However, there are several challenges associated with this approach. These include the potential for endotoxin production, reduced nutrient absorption due to interaction with natural nutrients, the possibility of nanoparticle accumulation in the animal body, health risks, ethical considerations, environmental concerns and some negative effects such as interference with natural nutrients that can be avoided by encapsulation. This article discusses recent studies on nano-sized feed additives that offer potential benefits in animal nutrition. [ABSTRACT FROM AUTHOR]

This study focused on exploring the metabolomic profiles of crossbred beef cattle with varying levels of residual feed intake (RFI), a measure of feed efficiency in beef cattle. Sixty-seven crossbred growing beef steers (BW = 277 ± 29.7 kg) were subjected to a high-forage total mixed ration for 64 days to determine their RFI phenotypes. At the end of the 64d feeding trial, beef steers were divided into two groups based on their RFI values: low (or negative)-RFI beef steers (n = 28; RFI = −1.08 ± 0.88 kg/d) and high (or positive)-RFI beef steers (n = 39; RFI = 1.21 ± 0.92 kg/d). Blood samples were collected, and plasma samples were analyzed using Nuclear Magnetic Resonance spectroscopy, resulting in the identification of 50 metabolites. The study found a distinct metabolomic signature associated with RFI status. Eight metabolites, including amino acids (tyrosine, glycine, valine, leucine, and methionine) and other compounds (dimethyl sulfone, 3-hydroxy isovaleric acid, citric acid, creatine, and L-carnitine), showed differential abundance between low- and high-RFI groups. Specifically, tyrosine, glycine, and dimethyl sulfone exhibited significant specificity and sensitivity, which produced a discriminatory model with an area under the receiver operating characteristic (ROC) curve of 0.7, making them potential markers for RFI. A logistic regression model incorporating these biomarkers effectively distinguished between high- and low-RFI steers, with a threshold cutoff point of 0.48, highlighting a distinctive metabolite profile associated with efficient nutrient utilization in low-RFI cattle. The logistic regression model, incorporating these biomarkers, holds promise for accurately categorizing RFI values, providing insights into the metabolic basis of feed efficiency in beef cattle. [ABSTRACT FROM AUTHOR]