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Our study objectives were to evaluate the effects of divergent rates of body weight (BW) gain during early gestation in beef heifers on F0 performance, metabolic and endocrine status, colostrum immunoglobulins, and subsequent F1 calf characteristics, growth performance, concentrations of hormones and metabolites, and response to vaccination. Angus-based heifers (n  = 100; BW = 369 ± 2.5 kg) were adapted to individual feeding for 14 d and bred using artificial insemination with female-sexed semen. Heifers were ranked by BW and assigned to either a basal diet targeting 0.28 kg/d gain (low [ LG ], n  = 50) or the basal diet plus an energy/protein supplement targeting 0.79 kg/d gain (moderate gain [ MG ], n  = 50) until day 84 of gestation. Dam BW and blood samples were collected at 6 time points during gestation; body composition was evaluated on days −10 and 84; and fetal measurements were taken on days 42, 63, and 84. At calving (LG, n  = 23; MG, n  = 23), dam and calf BW were recorded; and colostrum, calf body measurements, and blood samples were collected. Cow–calf pairs were managed on a common diet from calving to weaning, followed by a common postnatal development period for all F1 female offspring. Growth performance, hormone and metabolite profiles, feeding behavior, and reproductive performance were assessed from birth to prebreeding in F1 heifers. Offspring were vaccinated against respiratory disease and bovine viral diarrhea pathogens on days 62.3 ± 4.13 and 220.3 ± 4.13 postcalving. By design, MG dams were heavier (P  < 0.0001) than LG on day 84, and the BW advantage persisted until subsequent weaning of F1 calves. Concentrations of serum IGF-1 and glucose were increased throughout gestation (P  < 0.001) in MG dams, whereas concentrations of NEFA were decreased (P  < 0.001) in LG dams. Calves from MG dams were 2.14 kg heavier (P  = 0.03) and had larger chest circumference (P  = 0.04) at birth compared with LG cohorts. Heifers from MG dams continued to have greater (P  ≤ 0.03) BW gain and feed efficiency during the development period, but no differences were observed (P  ≥ 0.13) in body composition, concentrations of hormones and metabolites, feeding behavior, puberty attainment, and response to vaccination in F1 offspring. Hence, early gestation rate of gain impacted BW and concentrations of glucose and IGF-1 throughout gestation in the F0 dam, resulting in altered F1 calf BW and measurements at birth and increased gain and efficiency during the development period. [ABSTRACT FROM AUTHOR]

To examine the effects of feeding a vitamin and mineral supplement to beef heifers throughout gestation on mineral status and hormone/endocrine profiles in the dam and calf, and morphometric characteristics and organ mass of the calf at 30 h after birth, Angus-based heifers (n  = 72, 14 to 15 mo of age, initial body weight [ BW ] = 380.4 ± 50.56 kg) were estrus synchronized and artificially inseminated (AI) with female-sexed semen. Heifers were blocked by BW and randomly assigned to receive either a basal diet (CON; n  = 36) or a basal diet plus a vitamin and mineral supplement (VTM ; n  = 36) via an individual feeding system beginning at breeding, with both diets targeting BW gains of 0.45 kg heifer−1·d−1. Heifers not pregnant after the first AI (CON, n  = 19; VTM, n  = 18) were rebred via AI 60 d after treatment initiation, and heifers gestating female fetuses (CON, n  = 7; VTM, n  = 7) received treatments throughout gestation and were experimental units for this study. Calves were separated from their dams and fed colostrum replacer within 2 h of birth and euthanized 30 h after the first feeding. Calf morphometrics were recorded, and tissues were weighed and sampled. Serum from the dam at calving and serum, liver, and muscle from the calf at 30 h were analyzed for concentrations of minerals. Serum from the dam and calf were analyzed for concentrations of leptin, vitamins A, D, and E, cortisol, growth hormone, and insulin-like growth factor 1. All response variables were analyzed using the MIXED procedure of SAS. Calf body morphometrics and BW of the dam at calving (P  ≥ 0.32), calf organ weights (P  ≥ 0.21), and calf ovarian follicle counts (P  ≥ 0.13) were not affected by maternal treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P  ≤ 0.02) in VTM. Serum concentrations of Co and vitamin A in the dam were greater (P  ≤ 0.01) in supplemented compared with nonsupplemented dams, and serum concentrations of vitamin D were greater (P  ≤ 0.0003) in supplemented dams and calves compared with the nonsupplemented cohort. Maternal supplementation supported vitamin and mineral status in the neonate, yet had no discernable impact on BW, organ mass, or circulating hormones/metabolites in the calf. Evaluating offspring at later postnatal time points is warranted to determine if prenatal vitamin and mineral supplementation affects performance, health, metabolism, and efficiency of energy utilization in key metabolic tissues in the calf. [ABSTRACT FROM AUTHOR]

Rambouillet rams were managed on either a positive (POS ; gain 12% body weight [ BW ]; n  = 8), maintenance (MAINT ; maintain BW; n  = 8), or negative (NEG ; lose 12% BW; n  = 8) plane of nutrition before breeding. Rams were bred to ewes (n  = 10 per ram) that were managed similarly throughout gestation, and lambs were fed a common diet postnatally. Two ewe lambs (7.6 ± 0.02 mo of age, BW = 47.1 ± 1.17 kg) from each sire were selected and within-pair, randomly assigned to be managed for a moderate (MOD , 0.11 kg/d; n  = 23) or accelerated (ACC , 0.20 kg/d; n = 22) rate of gain for 56 d. Ewe lamb BW was recorded on a weekly basis and blood was collected on days 0, 28, and 56 for analysis of insulin-like growth factor 1 (IGF-1), triiodothyronine (T 3 ), thyroxine (T 4 ), glucose, blood urea nitrogen (BUN), and non-esterified fatty acids (NEFA). Intravenous glucose tolerance tests (IVGTT) were conducted from days −7 to −4 and days 57 to 64. A unilateral ovariectomy was performed and ovarian follicles were staged and counted macro and microscopically. Sire treatment × day and ewe treatment × day interactions were present for BW (P  ≤ 0.05), where POS had slower growth than MAINT and NEG, and tended (P  = 0.10) to have reduced average daily gain (ADG) when managed at an accelerated rate of gain. By design, ACC had greater BW and ADG than MOD (P  < 0.05). Concentrations of IGF-1 and T4 were greater in ACC than MOD (P  ≤ 0.05), and NEG tended to have greater concentrations of IGF-1 than POS and MAINT (P  = 0.08). At the first IVGTT, the concentration of insulin was influenced by a sire treatment × time interaction (P  ≤ 0.05), suggesting impaired secretion in NEG-sires ewes, but no differences in area under the curve (AUC) for glucose, insulin, or their ratio (P  ≥ 0.11). No interactive effects of sire and ewe treatment (P  ≥ 0.52) were observed at the second IVGTT, but insulin and insulin:glucose ratio were influenced by sire treatment × time (P  ≤ 0.02), as NEG had greater insulin concentration at 60 min than MAINT (P  = 0.03) and greater AUC than POS and MAINT (P  ≤ 0.04). No differences in ovary size, weight, or total counts of macro and microscopic follicles were observed (P  ≥ 0.23). Ewes-fed ACC had a greater number of small surface follicles (P  = 0.02), whereas MOD tended to have a greater number of large surface follicles and tertiary follicles (P  < 0.06). These findings suggest that the paternal plane of nutrition influences female offspring physiology, particularly at varying growth rates. [ABSTRACT FROM AUTHOR]

Our aim was to investigate the effects of maternal (F0) body weight (BW) gain during the first 84 d of gestation on body composition, ovarian reserve, and hormonal and metabolic parameters of breeding-age F1 heifers, as well as the BW and morphometry of F2 fetuses. The study also evaluated the effect of maternal BW gain (F0) on the mRNA relative abundance of the small intestine of both F1 heifers and F2 fetuses. Crossbred Angus heifers (F0; n  = 100) were managed to gain 0.20 kg/d (low gain [ LG ], n  = 50) or 0.75 kg/d (moderate gain [ MG ], n  = 50) for the first 84 d of gestation. Subsequently, F0 dams were managed on a common forage-based diet for the rest of gestation until the weaning of the F1 offspring. At 15 mo of age, a subset of F1 heifers was randomly selected for the current experiment (n  = 8 LG and n  = 8 MG). Heifers were bred via artificial insemination (AI ; day 0), then harvested on day 84 of gestation. On days −10, 42, and 84, BW was recorded, and blood was collected and analyzed for concentrations of glucose, non-esterified fatty acids, progesterone, insulin, and insulin-like growth factor-1. The weight of F1 carcasses, organs, gravid uteri, and F2 fetuses and organs were recorded at harvest. Visible follicles were counted on F1 ovaries at harvest, and histology was used to count microscopic follicles. Liver and jejunal samples from F1 heifers were collected to measure tissue oxygen consumption and jejunal samples from F1 heifers and F2 fetuses were collected for mRNA relative abundance analysis. BW of F1 heifers from MG dams tended to be 12 kg greater (P  = 0.06) than for F1 heifers from LG dams. Concentrations of glucose were greater (P  = 0.03) in F1 heifers from the MG group, with no differences in other blood metabolites or follicular populations (P  ≥ 0.16). Interestingly, mammary glands were heavier (P  = 0.05), and placentas and body depth tended to be heavier and greater, respectively (P  ≤ 0.10), for F2 fetuses from F0 LG heifers. Oxygen consumption in the liver and jejunum, as well as mRNA relative abundance in the jejunum of F1 heifers, were not affected by F0 rate of gain (P  ≥ 0.16). However, the NDUFC1 , SDHA , UQCR1 , and PPARG genes were upregulated (P  ≤ 0.05) in the jejunum of F2 fetuses from the LG group. In conclusion, BW gain of F0 heifers during early gestation exerts subtle effects on pre-breeding BW and blood metabolites in F1 offspring, with impacts present in F2 placenta, mammary gland, and intestine. [ABSTRACT FROM AUTHOR]

Objectives of this experiment were to characterize the effects of ram plane of nutrition on body composition, concentrations of hormones and metabolites, sperm characteristics, and offspring outcomes. Mature Rambouillet rams (n  = 24, BW = 82.9 ± 2.63 kg) were individually housed and randomly assigned to either a positive (POS ; n  = 8), maintenance (MAINT ; n  = 8), or negative (NEG ; n  = 8) plane of nutrition for an 84-day feeding period. Rams were fed a common diet, with daily feed allocations adjusted weekly based on body weight (BW) to achieve the targeted weight gain or loss (approximately 12% of initial BW). On 0, 28, 56, and 84-d, body condition score (BCS) and scrotal circumference (SC) were recorded, and blood and semen were collected. Following the feeding period, rams were placed in pens with 10 ewes each for a 28-d breeding period. Ewes were managed similarly throughout gestation and body weight and measurements were recorded at birth and weaning. Data were analyzed as repeated measures in time where appropriate with the mixed procedure of SAS, and individual ram was the experimental unit for all analysis. Ram BW was influenced by a treatment × day interaction (P  < 0.001), with POS (0.12 ± 0.01 kg) having greater daily weight change than MAINT (0.1 ± 0.01 kg), which was greater than NEG (-0.12 ± 0.01 kg). Ram BCS and SC were influenced by treatment × day interactions (P  ≤ 0.01), being similar on day 0 but POS being greater than NEG by day 56. Concentrations of triiodothyronine (T3) and T3:T4 ratio exhibited treatment × day interactions (P  ≤ 0.02), as POS had greater values than NEG by day 84 (P  ≤ 0.02). Concentration of insulin-like growth factor-1 was greater in POS than MAINT and NEG (P  ≤ 0.02), and non-esterified fatty acids and thyroxine (T4) were influenced by a day effect (P  ≤ 0.01), but testosterone was unaffected (P  ≥ 0.09). Minimal differences in semen volume, sperm concentration, motility, or morphology were observed among treatments (P  ≥ 0.31). A similar proportion of ewes bred by rams in the respective treatments lambed and weaned lambs (P  ≥ 0.54). Birth weight, chest circumference, and shoulder-hip length were greater (P  ≤ 0.05) in NEG lambs compared with POS and MAINT; however, no differences were detected in weaning weight and weaning body measurements (P ≥ 0.40). Findings suggest paternal nutrition during the period of sperm development may influence offspring outcomes, potentially as a result of in-utero programming of paternal origin. [ABSTRACT FROM AUTHOR]

Vitamins and minerals have key roles in hormone production and action, enzyme activity, tissue synthesis, oxygen transport, and energy production. These micronutrients are efficiently transferred from the dam to the fetus during gestation to be partitioned for metabolic use and stored as postnatal mineral reserves. Maternal nutrient intake is one of the main factors that influence the availability of vitamins and minerals to the fetus. Thus, an inadequate supply of these critical nutrients can have a long-lasting impact on offspring growth and health. Evidence suggests that biological processes regulating normal growth, development, and nutrient utilization are programmed in utero, even during the earliest developmental stages. Therefore, there is a critical need to evaluate the effects of micronutrient supplementation during gestation on fetal physiology and metabolic programming. Our research group has developed research models examining the impact of maternal vitamin and mineral supplementation (VTM, supplemented vs. NoVTM, not supplemented) during the periconceptual period or throughout gestation in beef heifers. A metabolomic analysis revealed that metabolites in the oxidative phosphorylation pathway were more abundant in the liver of fetuses from VTM than NoVTM dams, suggesting that a greater supply of micronutrients during the periconceptual period and first trimester of pregnancy may positively modulate mitochondrial energy metabolism in offspring. These changes in the abundance of metabolites suggested physiological adaptations to meet fetal metabolic needs. Further, high-resolution respirometry analysis revealed greater efficiency of energy utilization in small intestinal samples of neonatal calves from VTM dams. In fact, VTM offspring were heavier from weaning to breeding phase than NoVTM offspring, suggesting that maternal nutrition affects physiological mechanisms in utero that modulate offspring energetics and efficiency of nutrient utilization in the postnatal period. Furthermore, we reported increased concentrations of histidine, aspartate, and 12 out of 14 neutral amino acids in the allantoic fluid of VTM-supplemented dams. Finally, genes involved with amino acid transport in fetal liver were upregulated in response to VTM supplementation, highlighting the intricate relationship between maternal and fetal nutrition. Vitamin and mineral supplementation were also associated with changes in gene expression, biological processes and pathways in placental tissue at d 83 of gestation. We observed an upregulation of genes in the calcium signaling and cyclic guanosine monophosphate (CGMP)-PKG signaling pathways in response to micronutrient supplementation. Calciummediated systems may modulate cell proliferation and steroidogenic activity in bovine placentomes, while CGMP-PKG plays a key role in vascular homeostasis. Placental blood vessel vascularity at term was indeed increased in heifers supplemented throughout gestation, emphasizing the importance of micronutrient supplementation beyond early pregnancy. Altogether, our findings suggest that vitamin and mineral supplementation in the periconceptual period and during gestation play a pivotal role in fetal metabolic programming with consequences extending to the postnatal period. [ABSTRACT FROM AUTHOR]

Objectives were to evaluate the effects of winter-feeding forage (2.02 Mcal/kg dietary ME) vs. concentrate (2.84 Mcal/kg of dietary ME) diets preand post- calving on enteric methane emissions, dry matter intake (DMI), and performance of beef cows. Forty-six pregnant (210 ± 10 d of gestation) Angus and Simmental-Angus cows [n = 46; body weight (BW) = 630 ± 12.0 kg) were blocked by breed, age, and BW and assigned to one of two treatments: 1) Ad-libitum feeding of forage-based diet (HFOR; n = 23); or 2) a concentrate corn-based diet with a restricted intake of 1.2% BW (HCON; n = 23). Cows were housed in a group-pen at the South Dakota State University CowCalf Education and Research Facility (Brookings, SD). Feed consumption was tracked using an electronic feeder (Insentec, The Hague, Netherlands) and enteric methane emissions were monitored using the GreenFeed trailer system (C-Lock Inc., Rapid City, SD). Body weight measurements were taken bi-weekly. Treatments started being applied on d 50 (± 10) precalving and will continue to be applied up to d 84 post-calving. Preliminary data reported herein was collected from d 42 pre-calving up to d 42 post-calving. Performance and dry matter intake data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, period, and their interaction as fixed effects and animal as a random effect. Enteric emissions were analyzed using a linear mixed effects model with animal as a random effect in R, with a posthoc contrast among treatments. Pre-calving, HFOR had greater (P < 0.01) CH4 emissions than HCON (264 ± 9.19 g/d and 246 ± 9 g/d for HFOR and HCON, respectively). Both groups presented dynamic changes in CH4 emissions over time (P < 0.01). Post-calving, no differences were observed between treatments (P = 0.55); however, temporal changes (P < 0.01) and treatment × d interaction (P < 0.01) persisted, indicating ongoing diet-temporal interplay. No treatment × period interactions (P ≥ 0.16) were observed for DMI and performance. As designed, dry matter intake was less (P < 0.01) for HCON (8.66 ± 0.45 kg) than HFOR (17.3 ± 0.45 kg) cows. Further, dry matter intake was less (P < 0.01) pre-calving (11.11 ± 0.28 kg) than postcalving (14.85 ± 0.48 kg). Cows in the HFOR group were heavier (P = 0.01) than HCON (646.22 ± 14 kg vs. 593.43 ± 14 kg, respectively) likely due to ruminal fill; and as expected cows were heavier (P < 0.01) prethan post-calving, with the greatest BW observed on d 14 pre-calving (639.52 ± 9.92 kg). These data indicate that high concentrate corn-based diets may be used in dry-lot settings to optimize nutritional management and reduce methane emissions when compared with conventional high forage winter-feeding strategies. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the effects of a flaxseed oil-based supplement (FlaxLic, New Generations, SD) on reproductive parameters, feeding behavior, and lipid profile in beef heifers. Crossbred Angus heifers [n = 60 body weight (BW) = 397kg ± 5.2 kg) were blocked by BW and antral follicle count and randomly assigned to two supplementation treatments: free-choice commercial lose mineral supplement (CON; n = 30) or free-choice flaxseed oilbased supplement (FLAX; n = 30) for 7 wk. Heifers were individually fed via the Insentec feeding system (Insentec RIC, Hokofarm, Marknesse, Netherlands), where basal diet (TMR) and supplements were provided in separate feeders to measure supplement intake and feeding behavior. Further, water intake and behavior were measured via Insentec water system. Individual intake was compiled over 24 h for each animal. Body weight, transrectal ultrasonography, and blood samples were collected weekly. On wk 5, heifers were enrolled in a fixed-time artificial insemination (FTAI) commercial protocol. Largest follicle diameter (LF) and corpus luteum (CL) presence were recorded weekly and on d of the FTAI protocol (d 0, d 7, and d 0). Pregnancy diagnosis was performed 30 d and 60 d following AI. Blood samples were analyzed for progesterone (P4) by radioimmunoassay (RIA) to determine puberty attainment before wk 5, and fatty acid profile was determined via gas chromatography-flame ionization detection. Heifers with a CL or P4 ≤ 1.0 ng/mL were considered pubertal. Data were analyzed using SAS 9.4. ADG was similar between groups (P = 0.90) but was affected by week (P < 0.01). TMR intake was similar in duration and quantity (P > 0.18) between groups. Supplement intake was greater (P < 0.01) for FLAX (0.73 ± 0.03 kg/d) compared with CON (0.18 ± 0.02 kg/d) and from wk 2 to wk 8 (P = 0.01). Time spent consuming the supplements was greater for FLAX compared with CON heifers (62.65 ± 2.11 vs 0.10 ± 0.11 min/d, respectively) over the entire trial (P < 0.01). Further, FLAX heifers consumed less water than CON heifers (32.2 ± 0.39 vs 33.93 ± 0.35 kg/d, respectively; P = 0.03) and from wk 2 to wk 7 (P = 0.03). LF was not different between groups on any of the days of the protocol (d 0, d 7, d 0; P > 0.20). Additionally, P4 (P ≤ 0.20), puberty attainment by wk 5 (P = 0.24), and pregnancy rates (P > 0.48) were similar between groups. Concentrations of arachidonic acid (3.00 ± 0.24 vs 2.32 ± 0.19 mg/mL; P = 0.04), linoleic (60.11 ± 4.34 vs 40.35 ± 4.04 mg/mL; P = 0.002), αLinolenic (16.73 ± 0.26 vs 15.86 ± 0.23 mg/mL; P = 0.02), and total polyunsaturated fatty acids (PUFA; 130.52 ± 5.97 vs 111.19 ± 5.56 mg/mL; P = 0.02) were greater on wk 8 for FLAX compared with CON heifers. Collectively, these findings did not show evidence that the flaxseed oil-based supplement affects variables that impact reproductive performance. However, it altered the plasma lipid profile, increasing omega-3, arachidonic, and linoleic fatty acids, as well as total PUFA. [ABSTRACT FROM AUTHOR]

Despite the increased appreciation of the involvement of maternal nutrition in fetal development, its effects on jejunum programming remain largely unexplored. Here, we investigated the impact of maternal vitamin and mineral supplementation throughout gestation on the differential gene expression and underlying biological pathways in the jejunum of neonatal calves. For this, beginning 60 d before breeding and continuing throughout gestation, crossbred Angus heifers (n = 14) were fed either a basal diet (CON; n = 7) or the basal diet plus 113 g•heifer-1•d-1 of VTM supplement (VTM; n = 7). All heifers were gestating female calves, which were euthanized 30 h after birth. Samples of jejunum mucosa were collected, stored at -80°C, then subjected to total RNA isolation and RNA sequencing. After quality control, the reads were mapped using STAR aligner and differentially expressed genes (DEGs) were identified using DESeq2. Maternal VTM supplementation did not affect calf organ mass, including jejunum weight. However, high-resolution respirometry analysis revealed greater mitochondrial efficiency in jejunum of calves from VTM supplemented dams. Additionally, we identified 528 DEGs between the VTM and CON calves (P-value ≤ 0.05 and |log2FC| > 0.5). Among them, the genes IGFBP2 and IGFBP6, which are key genes in insulin pathway and involved in regulation of insulinlike growth factors (IGF), IGF transport, and uptake, were upregulated in the VTM group. Additional pathways were identified using ShinyGO, which included the pancreatic secretion pathway, over-represented by genes such as PLCB1, CCK, and SLC26A3. The gene PLCB1 has been associated with feed efficiency, growth, and carcass traits in multiple species. Likewise, the SLC26A3 gene encodes a key intestinal chloride anion exchanger associated with enhanced feed efficiency in cattle. Genes encoding signaling molecules involved with immune response, T cell activation, and defense response were also among the DEGs upregulated in the VTM calves, including the TNFSF18 and TNFRSF4 genes. Our findings suggest that maternal prenatal vitamin and mineral supplementation throughout gestation affects the expression of genes involved in the jejunum function of offspring at a neonatal time point. The long-term consequences of these changes, however, warrant further investigation. [ABSTRACT FROM AUTHOR]

Objectives of this study were to identify if pain management strategies at the time of castration impact feed and water intake, performance, or blood cortisol concentrations in weaned beef steers. Black Angus and Simmental Angus cross bulls [n = 30; average age = 8 ± 1 mo, average body weight (BW) = 272 ± 45.5 kg] were randomly assigned to 1 of 3 treatment groups: 1) Control (CON; n = 10 bulls), castrated via banding; 2) Analgesic (M; n = 10 bulls), received an analgesic (meloxicam; 1 mg/kg BW) immediately after banding; or 3) Anesthetic + analgesic (ML; n = 10 bulls), received an intra-scrotal and intra-cord anesthetic (total lidocaine 15 to 20 mL + 10% sodium bicarbonate) injection immediately prior to banding and an analgesic (meloxicam; 1 mg/kg BW) immediately after banding. Blood collections to measure blood cortisol concentrations were taken on d -7, -0, +0 (day of castration pre- and post-procedure, respectively), 1, and 8. Data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, day, and their interaction as fixed effects and animal as a random effect. While administering analgesics or anesthetics may reduce discomfort, the results of this study showed that these pain management practices do not significantly impact (P ≥ 0.07) on feed (CON = 7.41 ± 0.27 kg; M = 7.72 ± 0.27 kg; ML = 8.06 ± 0.27 kg) and water intake (CON = 20.90 ± 0.69 kg; M = 23.04 ± 0.69 kg; ML = 22.58 ± 0.69 kg), performance (CON = 345.40 ± 12.09 kg; M = 356.97 ± 12.09 kg; ML = 331.93 ± 12.09 kg), or blood cortisol concentrations (CON = 1.01 ± 0.19 ug/Dl; M = 1.19 ± 0.19 ug/Dl; ML = 1.38 ± 0.19 ug/DL). These data indicate that pericastration pain management strategies can be adopted at the producers’ managerial discretion. [ABSTRACT FROM AUTHOR]

Maternal nutrition in the periconceptional period influences gene regulation in the fetal liver across generations, affecting long-term metabolism. This study aimed to examine the effects of the rate of body weight (BW) gain of the dam (F0) during early gestation on the differential gene expression of the liver of first (F1) and second-generation (F2) offspring. Crossbred Angus heifers (F0) were assigned into two groups based on their targeted rate of BW gain during the first 84 d of gestation: low gain (LG; 0.28 kg/d; n = 8) or moderate gain (MG; 0.79 kg/d; n = 8). Following this period, all heifers (F0) were kept on a forage-based diet until the F1 offspring were weaned at 8 mo. The F1 heifers underwent estrus synchronization and were artificially inseminated at 15 mo of age. Liver samples were obtained from the F1 heifers at birth and later when harvested at 84 d of gestation, along with liver samples from their F2 fetuses, for a comprehensive multigenerational RNA-Seq analysis. Differentially expressed genes (DEGs) were identified using the DESeq2 R-package, focusing on significant genes determined by a P-value ≤ 0.05 and a log2 fold change |0.5|. Metabolic pathways and biological processes were analyzed using the WebGestalt tool to understand the implications of the observed gene expression changes. At birth, F1 heifers from MG dams exhibited 281 DEGs, comprising 152 downregulated and 129 upregulated genes compared with the offspring of LG dams. These genes were over-represented in lipid metabolism, cellular homeostasis, and signaling pathways, such as MAPK and chemokine signaling. At harvest, 159 DEGs were identified in F1 heifers, with 67 genes downregulated and 92 genes upregulated in the MG group. These genes were related to cellular morphogenesis and biogenesis processes, with a notable downregulation of metabolic pathways. For the F2 fetuses, 192 DEGs were identified, where 71 genes were downregulated, and 121 genes were upregulated. These genes were involved in biological functions such as peptide secretion to cell proliferation and signaling pathways, including PI3KAkt and Hippo signaling. The analysis of DEGs shared between F1 heifers and F2 fetuses highlighted the influence of the moderate BW weight gain of the F0 dams. At birth and harvest, F1 heifers shared three genes (NAV2, FAM131C, SH3D21). F1 heifers at birth and F2 fetuses shared five genes (CD3E, H1-12, SLC7A11, PIP4P2, ENSBTAG00000051730). From the harvest at d 84 in F1 heifers and F2 fetuses, five genes were shared (DCDC2, RIN1, ENSBTAG00000008911, ENSBTAG00000040518, ENSBTAG00000048049). No DEGs were shared across all comparisons. These findings emphasize the multigenerational impact of early gestational BW gain of the dam on liver gene expression, influencing metabolic pathways and signaling across generations. [ABSTRACT FROM AUTHOR]

We hypothesized that maternal nutrition during the first 50 d of gestation would influence the abundance of hexose transporters, SLC2A1, SLC2A3, and SLC2A5, and cationic amino acid transporters, SLC7A1 and SLC7A2, in heifer uteroplacental tissues. Angus-cross heifers (n = 43) were estrus synchronized, bred via artificial insemination, and assigned at breeding to 1 of 2 dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d of BW gain or RES = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d) in a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross-sections were collected from the horn ipsilateral to the corpus luteum, fixed in 10% neutral buffered formalin, sectioned at 5 µm, and stained via immunofluorescence for transporters. For each image, areas of fetal membrane (FM ; chorioallantois), luminal epithelium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted for days 34 and 50. No transporters in target areas were influenced by a day × treatment interaction (P ≥ 0.06). In ENDO, all transporters were differentially abundant from days 16 to 50 of gestation (P ≤ 0.04), and SLC7A2 was greater (P = 0.05) for RES vs. CON. In SG, SLC7A1 and SLC7A2 were greater (P ≤ 0.04) at day 34 vs. day 16. In DG, SLC2A3 and SLC7A1 were greater (P ≤ 0.05) for CON vs. RES heifers; furthermore, SLC7A1 was greater (P < 0.01) at day 50 vs. days 16 and 34 of gestation. In MYO, SLC7A1 was greater (P < 0.01) for CON vs. RES and was greater (P = 0.02) at days 34 and 50 vs. day 16. There were no differences in FM (P ≥ 0.06). Analysis of all uterine tissues at day 16 determined that SLC2A1, SLC2A3, and SLC7A2 were all differentially abundant across uterine tissue type (P < 0.01), and SLC7A1 was greater (P = 0.02) for CON vs. RES. Analysis of all uteroplacental tissues at days 34 and 50 demonstrated that all transporters differed (P < 0.01) across uteroplacental tissues, and SLC7A1 was greater (P < 0.01) for CON vs. RES. These data are interpreted to imply that transporters are differentially affected by day of gestation, and that hexose and cationic amino acid transporters are differentially abundant across utero-placental tissue types, and that SLC7A1 is responsive to maternal nutritional treatment. [ABSTRACT FROM AUTHOR]

During gestation, alterations in maternal nutrition during fetal development may alter growth trajectory and metabolic function in the developing fetus. Additionally, there is increasing evidence that the fetal microbiome also influences developmental outcomes. Research in this area is limited, and gastrointestinal microbiota has been the primary focus in cattle. Our objective was to assess the whole-body biogeography of the newborn calf microbiota and the response of these microbial communities and the calf immune system to prenatal vitamin and mineral (VTM) supplementation. Samples were collected from the hoof, liver, lung, nasal cavity, eye, rumen (tissue and fluid), and vagina of female beef calves that were born from dams that received either prenatal VTM or no VTM (Control; n = 7/group) throughout gestation. Calves were separated from their dams immediately after birth and fed colostrum replacement until euthanasia at 30 h post-initial colostrum feeding. The microbiota from swab and tissue samples were assessed using 16S rRNA gene sequencing (V4) and qPCR. Serum samples were processed for multiplex quantification of 15 cytokines and chemokines. Sequencing revealed the presence of a relatively diverse and complex microbiota in each of the 7 anatomical locations. The community structure of the hoof, liver, ocular, and vaginal microbiota were significantly different from the ruminal microbiota (0.64 = R2 = 0.12, P = 0.003). The respiratory. (nasal and lung) had similar community structures to that of ocular, vaginal, and ruminal fluid microbiota (P > 0.11). The ocular, hoof, and vagina had the greatest microbial richness (observed ASVs; P < 0.05) but similar diversity (Shannon; P > 0.05) compared with other samples. The liver and ruminal fluid had the least microbially rich communities, the latter also being the least diverse (P < 0.05). Firmicutes, Actinobacteriota, and Proteobacteria were the dominant phyla across all sample types, but their abundance varied by location. The ruminal fluid and hoof had the greatest bacterial concentration, while the liver, lung and ruminal tissue had reduced bacterial abundance as estimated by qPCR. An influence of VTM supplementation on microbial community structure was only detected in the ruminal fluid microbiota (P < 0.01). While prenatal VTM supplementation did not affect the nasal, lung, liver, and hoof microbiota, differences (P < 0.05) were detected in microbial richness (vagina), diversity (ruminal tissue and fluid, ocular), composition at the phylum level (ruminal tissue, ocular, and vagina), and total bacterial abundance (ocular and vagina). Among the 15 cytokines evaluated, the concentration of IP-10 was increased (P = 0.02) while IL-4 and IL-17A were reduced (P < 0.05). [ABSTRACT FROM AUTHOR]

Objectives were to evaluate the effects of feeding a vitamin and mineral (VTM) supplement to beef heifers during gestation on calf performance, body measurements, trace mineral status, and organ weights at 30 h after birth. We hypothesized that VTM supplementation during gestation would improve mineral status in the neonatal calf but not impact calf performance parameters and body and organ weights at 30 hours after birth. Fourteen Angus-based heifers [initial body weight (BW)] = 273.7 ± 1.10 kg) were randomly assigned to receive either a basal diet (CON; n = 7) or a basal diet plus a VTM supplement (VTM; n = 7; 113 g•heifer-1•d-1, targeting gain of 0.45 kg/day) from 60 d pre-breeding through gestation. Immediately after parturition, blood samples were collected from dams and calves, then calves were separated from their dams. Calves were fed one feeding of colostrum replacer, followed by milk replacer every 12 h, then euthanized at 30 h. Body weight and measurements were recorded, then organs and viscera were removed, weighed, and sampled. Dam serum and neonatal serum, liver, and blood were analyzed for concentrations of minerals. Data were analyzed using the GLM Procedure of SAS with individual animal as the experimental unit. Dietary treatments did not impact calf weight (0 h or 30 h), calf body measurements, or body weight of the dam at calving (P ≥ 0.32). Further, neonatal organ weights were not influenced (P ≥ 0.21) by maternal VTM treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P ≤ 0.02) by VTM treatment; however, concentrations of Cu, Mn, Mo, and Zn in calf muscle, liver, and serum were not impacted (P ≥ 0.07) by VTM treatment. Concentrations of Co in serum of the dam was the only mineral affected by dietary treatments, being greater (P = 0.001) in VTM than CON dams. In the current experiment providing trace mineral supplementation throughout gestation did not impact calf weight or body measurements at birth. However, the implications of altered mineral status of the neonatal calves at birth, and presumably throughout gestation, may have additional postnatal effects that warrant further investigation. [ABSTRACT FROM AUTHOR]

Thirty-five crossbred Angus heifers (body weight = 359.5 >± 7.1 kg) were randomly assigned to a 2 × 2 factorial design to evaluate the effects of vitamin and mineral supplementation [VMSUP; supplemented (VTM) vs. unsupplemented (NoVTM)] and rate of gain [GAIN; low gain (LG), 0.28 kg/d vs. moderate gain (MG), 0.79 kg/d] during the first 83 d of gestation on trace mineral concentrations in fetal liver, muscle, and allantoic (ALF) and amniotic (AMF) fluids. The VTM treatment (113 g supplement•heifer-1•d-1) was initiated a minimum 71 d before breeding. At breeding, heifers were either maintained on the basal diet (LG) or received the MG diet by adding a protein/energy supplement to the basal diet. On d 83 of gestation, samples of fetal liver, muscle, ALF, and AMF were collected and analyzed for trace mineral concentrations. In fetal liver, Se, Cu, Mn, and Co concentrations were greater (P ≤ 0.04) for VTM than NoVTM, while Mo and Co greater (P ≤ 0.04) for LG than MG. In fetal muscle, VTM increased (P ≤ 0.02) concentrations of Se and Zn, whereas LG increased (P < 0.01) Zn. In ALF, Mo concentrations were affected (P = 0.03) by a VMSUP × GAIN interaction, with VTM-MG greater than NoVTM-MG; while VTM increased (P < 0.01) concentrations of Se and Co. Trace mineral concentrations were not affected (P ≥ 0.13) in AMF. In conclusion, VTM increased fetal liver Se, Cu, Mn, and Co concentrations; fetal muscle Se and Zn; and ALF Se and Co; while LG increased fetal liver Mo and Co concentrations and fetal muscle Zn. Our results confirm that managerial decisions associated with vitamin and mineral supplementation and rate of gain can alter fetal reserves of trace elements during early pregnancy. [ABSTRACT FROM AUTHOR]

We evaluated effects of rate of gain during the first 84 d of gestation on composition of colostrum and milk. At breeding, forty-five Angus-based heifers received either a basal total mixed ration allowing 0.28 kg/d gain [low gain (LG), n = 23] or basal diet plus starchbased supplement allowing 0.79 kg/d gain [moderate gain (MG), n = 22] for 84 days. Heifers were then managed on a common diet until parturition. Colostrum samples (50 mL) were collected before first suckling. Milk samples (50 mL) were collected 6 hours after calf removal on d 62 ± 10 and 103 ± 10 postpartum. Samples were collected by stripping each teat 15 to 20 times after discarding the first 5 strips. At d 103 sampling techniques were compared by collecting a second sample after 1 mL oxytocin administration and 90 sec lag. Data were analyzed using the GLM procedure of SAS. Fat, protein, somatic cell count (SCC), milk urea nitrogen, and other solids were analyzed in colostrum for effect of treatment, whereas milk was evaluated for effects of treatment, day and their interaction. Heifer was experimental unit and significance was set at P ≤ 0.05. Colostrum SCC was greater (P = 0.05) in LG (6,949 ± 739 cells/mL) than MG (4,776 ± 796 cells/mL). In milk, protein and other solids were greater (P ≤ 0.03) in MG (3.02 ± 0.03 and 6.20 ± 0.02 %, respectively) than LG (2.87 ± 0.03 and 6.14 ± 0.02 %, respectively). On d 103, oxytocin administration and extended lag time after teat stimulation (0.96 ± 0.05 %) increased fat content in milk (P < 0.01) compared with immediate milk sample collection (0.34 ± 0.05 %). Nutrition during early gestation had a sustained impact on milk composition and techniques of oxytocin administration results in greater milk fat content. [ABSTRACT FROM AUTHOR]