Proper development of the small intestinal epithelium and establishment of a diverse microbiome is critical for transport and absorption of nutrients, and gut health, but may be negatively impacted by restricted nutrition during gestation. To determine if maternal nutrient restriction impairs morphological characteristics and microbial community of fetal small intestine, multiparous Dorset ewes pregnant with twins were fed 100% (n = 8) or 60% (n = 7) of requirements from d 30 – d 130 of gestation. Ewes were euthanized at d 130 of gestation, and fetal measurements and samples were collected. Fetuses are referred to as CON (n = 8 female; n = 8 male) or RES (n = 9 female; n = 5 male), corresponding to their dam’s diet. DNA was extracted from jejunal mucosal scrapings and v4 of 16S was amplified and sequenced to determine microbial diversity. Small intestine weight (g/kg BW) in RES-females was 11.5% lighter than CON-females (P=0.04). In the duodenum, villi height (VH; µm) were 20.2% and 21.6% shorter in RES-males relative to CON-males and RES-females (P≤0.04). In the jejunum, VH were 7.9% and 10.6% shorter in RES-males relative to CON-females and RES-females (P≤0.03). In the ileum, VH were 11.5% shorter in CON-males relative to CON-females (P=0.005). A Shannon Index for α-diversity revealed that RES-males have decreased diversity relative to CON-females (P=0.013) and a Bray-Curtis analysis for β-diversity had a main effect of treatment (P=0.04) indicating a difference in species composition. Maternal nutrient restriction during gestation influences fetal offspring small intestine development and microbial environment in a sex-specific manner. (Supported by USDA-NIFA 2023-67012-39740)

This study investigated the effects of astaxanthin (ASTX) supplementation on oxidative status during a deconditioning‐reconditioning cycle. Twelve polo ponies were assigned to no supplementation (CON) or an ASTX supplemented group, which received oral administration of a supplement containing 75 mg ASTX daily for 32 weeks. Polo ponies underwent a 16‐week deconditioning period (DECON) followed by a 16‐week reconditioning program (RECON). Submaximal exercise tests (SETs) were performed at the beginning of the study (Baseline), after DECON, and after RECON. Blood samples were collected at −30, 0, 15, 30, and 60 min relative to each SET for oxidative status analysis. Muscle samples were collected 2 weeks before (Pre‐Ex) and 2 h after (Post‐Ex) each SET for muscle oxidative status and gene expression analyses. Pre‐Ex muscles were analyzed for high‐resolution respirometry. Circulating glutathione peroxidase (GPX) activity was increased ( p ≤ 0.02) and protein carbonylation was decreased in ASTX ( p ≤ 0.05). Muscle oxidative status was affected by DECON and reconditioning ( p ≤ 0.05). ASTX increased gene expression of PPARGC1A after reconditioning ( p ≤ 0.05). Deconditioning reduced oxidative phosphorylation at complex I and II ( p = 0.01). Thus, a deconditioning‐reconditioning cycle had greater impacts on muscle oxidative capacity than ASTX supplementation.

The production of crossbred beef × dairy (B × D) calves is increasing; however, evaluation of pre-weaning feeding strategies for B × D calves is limited. We hypothesized that both male and female B × D calves fed added fat and protein through milk replacer would have increased muscle growth, muscle fiber cross-sectional area, average daily gain, BW, and morphometric measurements. We also hypothesized that calves fed the additional fat and protein milk replacer would have upregulation of regulatory genes involved in muscle hypertrophy. SimAngus × Holstein calves (n = 42) were assigned to one of two milk replacers: 30.0% crude protein (CP), 32% crude fat (CF) milk replacer (HPHF, n = 11 males, 11 females), or 22% CP, 20% CF milk replacer (CON, n = 10 males, 10 females) from 0 to 8 wk of age. B × D calves were weighed at birth and weekly thereafter. At week 2 and 8, longissimus muscle biopsies were collected for muscle fiber cross-sectional area (CSA) or gene expression analysis. Ultrasounds were performed at 4 and 8 wk of age to quantify ribeye area (REA), and backfat and rump fat thickness. Morphometric measurements, BW, CSA, and ultrasound data were analyzed with PROC MIXED with animal as the subject and fixed effects of milk replacer, age, sex, and their interactions. Gene expression data were analyzed in R Studio. Calves that consumed the HPHF milk replacer were heavier than calves consuming the CON milk replacer (HPHF: 70.7 ± 0.39 kg; CON: 68.5 ± 0.41 kg; P < 0.01). At 8 wk of age, HPHF calves tended to have 14% larger muscle fiber CSA than CON calves (P = 0.06). No differences due to diet were observed for REA or fat thickness (P ≥ 0.38). Expression of MyoD tended to be 34% greater in CON females than HPHF females at 2 wk (P = 0.06), but at 8 wk, HPHF females tended to express 39% more MyoD than CON females (P = 0.09). Myogenin expression was 3% greater in CON calves than HPHF calves at 2 wk (P = 0.02), and CON females tended to express 52% more IGF-1 than HPHF females (P = 0.07). Feeding a milk replacer with a protein and fat content similar to beef cow milk improves B × D calf growth compared with a conventional milk replacer with less protein and fat. Improvements in early growth may improve B × D carcass quality and quantity, with the potential to increase return to the producer.

Disturbances in maternal nutrient availability through increased or decreased abundance of specific or total nutrients during pre-natal development can have negative impacts on offspring growth. These changes are likely mediated, at least in part, by hormonal systems that control energy homeostasis and appetite. Regulation of insulin signaling is critical to ensuring appropriate glucose homeostasis. Poor maternal nutrition during gestation impacts circulating glucose and insulin concentration in both the dam and offspring, reducing circulating insulin and glucose in offspring of restricted-fed dams and increased circulating insulin and glucose in the offspring of over-fed dams. Leptin and ghrelin are key regulators of appetite and feed intake. Offspring of over-fed ewes often exhibit leptin resistance, which may lead to changes in adiposity. Leptin responses in offspring of restricted-fed ewes are not well defined, although restricted-fed ewes themselves exhibit decreased circulating leptin concentrations. Little is known about the effects of poor maternal nutrition on offspring ghrelin. Glucocorticoids and thyroid hormones are required for appropriate fetal development. Poor maternal nutrition during gestation alters the development of the hypothalamic-pituitary-adrenal and thyroid axes in the offspring, although the effects vary according to the type, duration, timing, and severity of the nutritional insult. The relationships between insulin, leptin, ghrelin, glucocorticoids, and thyroid hormones can result in synergistic effects, exacerbating negative outcomes for the offspring. The impacts of poor maternal nutrition are multi-faceted, and the resulting alterations in body composition can continue to impact hormone regulation beyond the initial insult caused by poor maternal nutrition during gestation.

Poor maternal nutrition (restricted- and over-feeding) during gestation can negatively impact the efficiency of livestock production by generating offspring with decreased muscle mass, increased adiposity, and impaired metabolism. The mechanisms behind these altered phenotypes are not well-characterized. The effects of poor maternal nutrition during gestation on offspring growth and development begin in utero and contribute to metabolic dysregulation of offspring into maturity and across subsequent generations, demonstrating long-term negative effects on the livestock. Fetal programming results in epigenetic modifications that can involve changes in offspring gene expression and downstream function, with no alteration on the DNA sequence. Using a sheep model of poor maternal nutrition, we have previously shown that F1 offspring from restricted- and over-fed dams are smaller at 10 mo of age relative to offspring from control-fed dams. Additionally, we observed that this phenotype persisted in the F2 offspring from restricted-fed granddams, while F2 offspring from over- and control-fed granddams were of similar body weight. We have recently demonstrated that F1 offspring from poorly nourished ewes have differential methylation patterns and altered gene expression in liver tissue demonstrating a potential mechanism that contributes to persistent altered growth. We have also begun evaluating the effects of maternal nutrient restriction on the development of fetal small intestine, a key facilitator of nutrient transport. Poor maternal nutrition during gestation alters development of offspring small intestine and further understanding of developmental programming in key metabolic tissues can aid in the development of nutritional strategies to improve efficiency of livestock production.

Abstract Maternal diet influences offspring growth, but the impact of granddam diet on subsequent generations is less explored. We hypothesized that granddam diet would influence second parity F2 offspring growth. The objective of this study was to determine the influence of granddam diet on second parity F2 offspring growth, morphometric measurements, and organ weights. To determine the impact of poor maternal nutrition of F0 dams on second parity offspring of F1 ewes, multiparous Dorset ewes (F0, n = 46) were fed 100% (control), 60% (restricted), or 140% (over) of NRC requirements from d 30 of gestation until parturition. The F1 ewes (n = 37) were bred at 16 to 19 mo of age to one of two related Dorset rams to generate the first parity F2 generation. The following breeding season, F1 ewes (n = 30) were bred to the same rams to generate the second parity F2 generation offspring (n = 58; F2-2), which were identified as CON F2-2 (n = 6 ewes, 12 rams), RES F2-2 (n = 6 ewes, 12 rams), or OVER F2-2 (n = 9 ewes, 13 rams) corresponding to the diets of the F0 granddams. F2-2 offspring body weights (BW) were recorded weekly from birth (d 0) to d 28, every 14 d until d 126, and every 28 d until d 266 of age. Hip height (HH), crown rump length (CRL), heart girth (HG), and body condition score (BCS) were measured at d 0 and d 120 of age. Rams were necropsied at d 284 ± 0.23. Data were analyzed with R Studio with P ≤ 0.05 considered significant and 0.05 < P ≤ 0.10 considered a tendency. Granddam diet and offspring sex were included in the model with animal ID as a random effect where appropriate. On d 210 and d 238, CON F2-2 tended to weigh 6.8% and 6.3% less, respectively, than OVER F2-2 (P = 0.07) but were not different than RES F2-2 at d 210 (P = 0.55) or d 238 (P = 0.15). We did not detect an effect of granddam diet on HH (P = 0.28), CRL (P = 0.31), or HG (P = 0.62) at birth. At d 120, ewes had 3.1% shorter CRL (P = 0.07) and weighed 9.4% less (P = 0.003) than rams. Immediately before necropsy, CON F2-2 rams tended to have 5.9% less BCS compared with RES F2-2 rams (P = 0.07) and 5.6% less BCS than OVER F2-2 rams (P = 0.10). At necropsy, granddam diet did not influence organ weight. Overfed and restricted granddam diet may increase BW and BCS of second parity, second generation offspring, which provides evidence that maternal diet has multigenerational effects on offspring.

Abstract Maternal nutrition during gestation and resulting impacts on ram reproduction and epigenetics are poorly understood. We previously reported altered mRNA and epigenetic markers in F1 ram sperm due to poor maternal diet (restricted- and over-feeding) during gestation, yet the multigenerational effects on ram reproduction are unexplored. We hypothesized that F2 offspring born from restricted- and over-fed granddams would exhibit altered reproductive characteristics, and F1 and F2 offspring would display altered circulating concentrations of reproductive hormones. The objectives of this study were to determine the effects of poor maternal diet on 1) the reproductive function of F2 ram offspring, and 2) key reproductive hormones in F1 and F2 offspring. To evaluate these objectives, multiparous Dorset ewes (F0, n = 46) were fed 100% (CON), 60% (RES), or 140% (OVER) of National Research Council requirements from d 30 of gestation through parturition and a control diet during lactation. Offspring are identified as CON-F1 (n = 10 ewes; 12 rams), RES-F1 (n = 13 ewes; 21 rams), and OVER-F1 (n = 16 ewes; 15 rams). The F1 ewes (n = 37) were maintained on a control diet throughout and were bred between 16 and 19 mo of age to establish the F2 generation. Resulting male offspring are referred to as CON-F2 (n = 6 rams), RES-F2 (n = 13 rams), and OVER-F2 (n = 9 rams) in correspondence to the diets of the granddam. Semen samples of F2 rams were collected via electroejaculation at d 248.4 ± 0.36 (collection 1) and d 255.4 ± 0.36 (collection 2). Semen quality (volume, pH, sperm motility, and sperm concentration) was evaluated at both collections using mCASA; iSperm, Aidmics Biotechnology Co., LTD. Scrotal circumference was measured at collection 2. Sperm morphology was determined by contrast microscopy. Testosterone (T) and follicle stimulating hormone (FSH) were measured in F1 and F2 serum samples collected at d 256 ± 0.13 using commercially available kits. Data were analyzed using R Studio with P ≤ 0.05 considered significant and 0.05 < P ≤ 0.10 considered a tendency. An effect of granddam diet was not observed for F2 ram semen volume, pH, sperm motility, sperm concentration, scrotal circumference, nor histological sperm morphology (P ≥ 0.25). An effect of F0 diet was not observed for F1 or F2 offspring serum concentrations of T and FSH (P ≥ 0.28). In our model, F0 diet during gestation did not affect F2 male offspring sperm quality or circulating T and FSH in F1 and F2 generations. However, based on our previous reports that F0 diet altered F1 sperm epigenome, there may be an impact of maternal diet on epigenetic inheritance which warrants further exploration.

Abstract Poor maternal nutrition (under- or over-feeding) during gestation negatively impacts antioxidant activity and oxidative stress markers in first generation (F1) offspring. To determine if these alterations persist into subsequent generations, multiparous Dorset ewes (F0; n = 46) pregnant with twins were fed 100% (CON), 60% (RES), or 140% (OVER) of total nutrient requirements (NRC) from d 30 of gestation until parturition. At 16 to 19 mo of age, F1 ewes (n = 37) were maintained on a control diet and bred to generate second generation offspring (F2; CON-F2, RES-F2, OVER-F2 corresponding to F0 diet). At 112 and 224 d of age, plasma samples were collected from F2 offspring, and at d 284 semitendinosus (STN) samples were collected from rams at necropsy and muscle biopsies in ewes. Data were analyzed in SAS using PROC MIXED where significance was determined at P ≤ 0.05. Circulating superoxide dismutase (SOD) activity was decreased by 21% and 25% in RES-F2 and OVER-F2 offspring, respectively, compared with CON-F2 (P < 0.0001). Plasma SOD activity was 17% less at d 224 than d 112 (P < 0.0001). Ewes had 9% greater circulating SOD activity compared with rams (P = 0.03). Muscle SOD activity was 31% and 35% greater in CON-F2 compared with RES-F2 and OVER-F2 offspring, respectively (P ≤ 0.003). Rams had 26% greater STN SOD activity than ewes (P = 0.006). Plasma glutathione peroxidase (GPx) activity was 14% greater in CON-F2 than RES-F2 and OVER-F2 offspring (P ≤ 0.003). Circulating GPx activity was 14% less at d 224 than d 112 (P < 0.0001). Muscle GPx activity was 39% and 35% greater in CON-F2 offspring compared with RES-F2 and OVER-F2, respectively (P < 0.0001). Ewes had 11% and 16% greater GPx activity in circulation and STN, respectively, than rams (P ≤ 0.005). Plasma concentrations of malondialdehyde (MDA) were 18% and 10% greater in RES-F2 and OVER-F2 offspring, respectively, than CON-F2 (P = 0.004). Circulating MDA concentrations were 20% greater at d 224 compared with d 112 (P < 0.0001). Concentrations of MDA in STN were increased in RES-F2 and OVER-F2 offspring by 36% and 50%, respectively, compared with CON-F2 (P ≤ 0.006). Ewes had 87% greater concentrations of MDA in STN compared with rams (P < 0.0001). Circulating protein carbonyl (PC) concentrations were 16% greater in RES-F2 offspring than CON-F2 and OVER-F2 (P ≤ 0.04). Plasma PC concentrations were 9% greater at d 224 compared with d 112 (P = 0.04). The concentrations of PC in STN were 81% and 69% greater in RES-F2 and OVER-F2 rams, respectively, compared with CON-F2 rams (P ≤ 0.0001). Alterations in oxidative status persist into the F2 generation and may impact muscle growth and metabolism.

Maternal nutrition during gestation and resulting impacts on ram reproduction and epigenetics are poorly understood. We previously reported altered mRNA and epigenetic markers in F1 ram sperm due to poor maternal diet (restricted- and over-feeding) during gestation, yet the multigenerational effects on ram reproduction are unexplored. We hypothesized that F2 offspring born from restricted- and over-fed granddams would exhibit altered reproductive characteristics, and F1 and F2 offspring would display altered circulating concentrations of reproductive hormones. The objectives of this study were to determine the effects of poor maternal diet on 1) the reproductive function of F2 ram offspring, and 2) key reproductive hormones in F1 and F2 offspring. To evaluate these objectives, multiparous Dorset ewes (F0, n = 46) were fed 100% (CON), 60% (RES), or 140% (OVER) of National Research Council requirements from d 30 of gestation through parturition and a control diet during lactation. Offspring are identified as CON-F1 (n = 10 ewes; 12 rams), RES-F1 (n = 13 ewes; 21 rams), and OVER-F1 (n = 16 ewes; 15 rams). The F1 ewes (n = 37) were maintained on a control diet throughout and were bred between 16 and 19 mo of age to establish the F2 generation. Resulting male offspring are referred to as CON-F2 (n = 6 rams), RES-F2 (n = 13 rams), and OVER-F2 (n = 9 rams) in correspondence to the diets of the granddam. Semen samples of F2 rams were collected via electroejaculation at d 248.4 ± 0.36 (collection 1) and d 255.4 ± 0.36 (collection 2). Semen quality (volume, pH, sperm motility, and sperm concentration) was evaluated at both collections using mCASA; iSperm, Aidmics Biotechnology Co., LTD. Scrotal circumference was measured at collection 2. Sperm morphology was determined by contrast microscopy. Testosterone (T) and follicle stimulating hormone (FSH) were measured in F1 and F2 serum samples collected at d 256 ± 0.13 using commercially available kits. Data were analyzed using R Studio with P ≤ 0.05 considered significant and 0.05 < P ≤ 0.10 considered a tendency. An effect of granddam diet was not observed for F2 ram semen volume, pH, sperm motility, sperm concentration, scrotal circumference, nor histological sperm morphology (P ≥ 0.25). An effect of F0 diet was not observed for F1 or F2 offspring serum concentrations of T and FSH (P ≥ 0.28). In our model, F0 diet during gestation did not affect F2 male offspring sperm quality or circulating T and FSH in F1 and F2 generations. However, based on our previous reports that F0 diet altered F1 sperm epigenome, there may be an impact of maternal diet on epigenetic inheritance which warrants further exploration.

Abstract Restricted nutrition during gestation can reduce offspring productivity. Supplementation of betaine, a methyl donor, promotes fetal growth and liver function. We hypothesized that nutrient restriction during gestation impairs growth, including organ weights and muscle mass, while betaine supplementation would alleviate these negative effects. To determine if maternal betaine supplementation during gestation would improve growth of offspring of restricted-fed dams, multiparous Dorset ewes (n = 47) were estrus synchronized and bred to one of three rams. Ewes confirmed pregnant with twins (n = 32) and singletons (n = 15) were randomly assigned to one of four diets [100% NRC requirements (CON), 60% NRC (RES), CON+betaine (CON+BET; 2 g/d), and RES+BET] from d 30 to 130 of gestation. Among the twins, there were 27 males (CON-8, RES-5, CON+BET-5, and RES+BET-9) and 37 females (CON-8, RES-9, CON+BET-11, and RES+BET-9). Within singletons, there were 7 males (CON-2, RES-2, CON+BET-2, and RES+BET-1) and 8 females (CON-3, RES-1, CON+BET-1, and RES+BET-3). Dam body weight (BW) was measured weekly from d 30 to d 130 of gestation, and diet adjusted accordingly. Dams were euthanized at d 130 of gestation and fetal BW and tissue weights were collected. Data were analyzed using RStudio with P ≤ 0.05 considered significant and 0.05 < P ≤ 0.10 as tendency. At d 130, dams carrying twin fetuses in the CON group were 11.3% and 19.1% heavier than RES and RES+BET dams, respectively (P ≤ 0.05), and CON+BET dams were 18.4% and 10.5% heavier than RES and BET+RES dams, respectively (P ≤ 0.07). However, dams with singletons showed no significant difference in BW (P ≥ 0.37). Regarding fetal BW for singletons, RES fetuses (3.80 ± 0.28kg) were lighter than CON (4.60 ± 0.21kg), CON+BET (4.72 ± 0.27kg), and RES+BET (4.59 ± 0.24kg; P ≤ 0.03). Whereas in twins, RES+BET fetuses (3.19 ± 0.11kg) were lighter than CON (3.68 ± 0.12kg), RES (3.73 ± 0.14kg), and CON+BET (3.60 ± 0.13kg; P ≤ 0.02). In all fetuses, the livers of male RES (28.0 ± 1.49g) and male RES+BET (27.7 ± 1.44g) tended to be heavier than those of female RES+BET (24.5 ± 1.19g; P ≤ 0.07). In terms of muscle mass, female CON+BET (9.33 ± 0.43g) fetuses tended to have greater longissimus muscle (LM) mass compared with female CON (8.30 ± 0.35; P = 0.06), whereas male RES (9.06 ± 0.44g) tended to have heavier LM than male CON+BET (8.02 ± 0.43g; P = 0.09). There were no observed effects of diet, fetal sex, or fetal number on the weights of heart, kidney, perirenal fat, pancreas, semitendinosus muscle, and triceps brachii muscle (P ≥ 0.11). These findings suggest that betaine supplementation may have a significant role in improving fetal BW in singleton pregnancies, with variable effects in twins. Additionally, betaine supplementation may have sex-specific effects on muscle development.

Abstract Poor maternal nutrition (restricted- and over-nutrition) during gestation negatively impacts offspring pre- and post-natal growth. Previous work has identified decreased muscle mass and increased adiposity, leading to poor quantity and quality of animal protein products. Alterations in oxidative status, such as the imbalance of antioxidant activity and the production of free radicals, can result in oxidative stress damaging lipid membranes, proteins, and DNA. Changes in oxidative status may contribute to the poor growth outcomes observed in offspring from poorly nourished dams. Therefore, the objective of this research was to determine the effects of poor maternal nutrition during gestation on the oxidative status in offspring skeletal muscle in sheep. We hypothesized that offspring of restricted- and over-fed ewes would have decreased antioxidant activity and increased products of oxidative stress in skeletal muscle. To test this hypothesis, multiparous Dorset ewes (n = 46) pregnant with twins were fed 100% (CON), 60% (RES), or 140% (OVER) of total nutrient requirements (NRC) from d 30 of gestation until parturition. Following parturition, ewes were fed a control diet throughout lactation. At d 282 of age semitendinosus (STN) samples were collected from rams at necropsy, and at d 284 of age muscle biopsies from STN were collected from ewes. Data were analyzed in SAS using PROC MIXED with fixed effects of maternal diet and offspring sex. Data were considered significant at P ≤ 0.05. The activity of the endogenous antioxidant superoxide dismutase (SOD) was decreased by 45% and 33% in RES and OVER offspring, respectively, compared with CON (P ≤ 0.01). Offspring sex did not alter STN SOD activity (P = 0.35). Muscle glutathione peroxidase (GPx) activity was decreased in RES offspring by 20% compared with CON (P ≤ 0.04), but neither differed from OVER offspring (P ≥ 0.24). Ewes had 34% greater GPx activity compared with rams (P < 0.0001). Offspring from RES and OVER ewes had 77% and 87% greater concentrations of malondialdehyde (MDA), a marker of lipid peroxidation, when compared with CON (P < 0.0001). Ewes had 29% greater MDA concentrations compared with rams (P = 0.05). Protein carbonyl (PC), a marker of protein oxidation, concentrations were 36% and 38% greater in RES and OVER offspring, respectively, compared with CON (P ≤ 0.01). The decrease in antioxidant activities and increase in products of protein and lipid oxidation in offspring from poorly nourished dams suggests dysregulation in skeletal muscle oxidative status that may contribute to the negative consequences observed in offspring. Future work should focus on determining the mechanistic role of skeletal muscle oxidative stress in the decreased quantity and quality of animal protein products and identifying potential strategies to mitigate alterations in oxidative status as a result of poor maternal nutrition during gestation.

Abstract The objective of this study was to determine the effects of poor maternal nutrition (restricted- and over-feeding) during gestation on the reproductive efficiency of female offspring. We hypothesized that ewes born to restricted- and over-fed dams would have reduced fertility and decreased concentrations of follicle stimulating hormone (FSH) and progesterone (P4). Multiparous Dorset ewes (F0; n = 46) were fed one of three diets from d 30 of gestation until parturition according to NRC requirements for total digestible nutrients: control- (100%), restricted- (60%), or over- (140%) fed. Resulting female offspring (F1; n = 38) were raised on a control diet and are identified as CON (n = 10), RES (n = 12), or OVER (n = 16) corresponding to diets of their dam. Between 16 and 19 mo of age, the F1 ewes were estrous synchronized by vaginal insertion of a controlled intravaginal drug release device (CIDR) for a 12-d period, followed by a 2 mL (5 mg/mL) intramuscular injection of prostaglandin F2α, and then bred to one of two related rams. Day 0 of gestation was considered when a raddle mark was observed on the rump of the ewe. Time to pregnancy was calculated as the number of days from when the ewes were initially housed with the ram until d 0 of gestation. Based on ultrasounds on d 37 ± 0.77 of gestation, all F1 ewes were identified as pregnant on first service and number of fetuses was recorded and lambs born were counted at parturition. Data were analyzed using RStudio with a significance of P ≤ 0.05 and a tendency of 0.05 < P ≤ 0.10. Maternal diet did not significantly affect time to pregnancy, number of fetuses, or number of lambs born (P ≥ 0.13). Blood samples (10 mL) were collected via jugular venipuncture at four timepoints (d -14, -7, 0, 7) corresponding to d 0 of gestation and were analyzed for concentrations of FSH and P4 by enzyme-linked immunoassays in 29 ewes (CON: n = 8, RES: n = 8, OVER: n = 13). The CON ewes had 15.2% less FSH than OVER ewes (P = 0.05) and RES ewes tended to have 14.2% less FSH than OVER ewes (P = 0.08). Concentrations of P4 were not different in F1 ewes (P ≥ 0.14). However, concentrations of P4 in F1 ewes tended to increase (P = 0.08) by 12% from d -14 to d 0, which corresponds with a normal estrous cycle. The increased concentration of FSH in OVER ewes could be due to a dysregulation of FSH. However, those effects may be mitigated at some point in time later in gestation since there were no differences in time to pregnancy nor number of lambs born.

AbstractTo determine the effects of astaxanthin (ASTX) supplementation on the equine gut microbiota during a deconditioning–reconditioning cycle, 12 polo ponies were assigned to a control (CON; n = 6) or supplemented (ASTX; 75 mg ASTX daily orally; n = 6) group. All horses underwent a 16‐week deconditioning period, with no forced exercise, followed by a 16‐week reconditioning program where physical activity gradually increased. Fecal samples were obtained at the beginning of the study (Baseline), after deconditioning (PostDecon), after reconditioning (PostRecon), and 16 weeks after the cessation of ASTX supplementation (Washout). Following DNA extraction from fecal samples, v4 of 16S was amplified and sequenced to determine operational taxonomic unit tables and α‐diversity and β‐diversity indices. The total number of observed species was greater at Baseline than PostDecon, PostRecon, and Washout (p ≤ 0.02). A main effect of ASTX (p = 0.01) and timepoint (p = 0.01) was observed on β‐diversity, yet the variability of timepoint was greater (13%) than ASTX (6%), indicating a greater effect of timepoint than ASTX. Deconditioning and reconditioning periods affected the abundance of the Bacteroidetes and Fibrobacteres phyla. Physical activity and ASTX supplementation affect the equine gut microbiome, yet conditioning status may have a greater impact.

Poor maternal nutrition during gestation negatively affects offspring growth and metabolism. To evaluate the impact of maternal nutrient restriction and realimentation on metabolism in the fetal liver, skeletal muscle, and circulation, on day 50 of gestation, ewes (n = 48) pregnant with singletons were fed 100% (CON) or 60% (RES) of requirements until day 90 of gestation, when a subset of ewes (n = 7/treatment) were euthanized, and fetal samples were collected. The remaining ewes were maintained on a current diet (CON-CON, n = 6; RES-RES, n = 7) or switched to an alternative diet (CON-RES, RES-CON; n = 7/treatment). On day 130 of gestation, the remaining ewes were euthanized, and fetal samples were collected. Fetal liver, longissimus dorsi (LD), and blood metabolites were analyzed using LC-MS/MS, and pathway enrichment analysis was conducted using MetaboAnalyst. Then, 600, 518, and 524 metabolites were identified in the liver, LD, and blood, respectively, including 345 metabolites that were present in all three. Nutrient restriction was associated with changes in amino acid, carbohydrate, lipid, and transulfuration/methionine metabolic pathways, some of which were alleviated by realimentation. Fetal age also affected metabolite abundance. The differential abundance of metabolites involved in amino acid, methionine, betaine, and bile acid metabolism could impact fetal epigenetic regulation, protein synthesis, lipid metabolism, and signaling associated with glucose and lipid metabolism.

Poor maternal nutrition during gestation is common in livestock production and includes both nutrient restriction and over-nutrition. Poor maternal nutrition affects offspring pre- and post-natal growth including decreases in muscularity and increases in adiposity which results in poor quantity and quality of animal products. Oxidative stress, when free radicals exceed the capacity of antioxidants, damages lipid membranes, proteins, and DNA. Oxidative stress may contribute to the poor growth outcomes observed in offspring from poorly nourished dams. Therefore, the objective of this research was to determine the effects of poor maternal nutrition during gestation on offspring circulating oxidative status in sheep. We hypothesized that offspring of restricted- and over-fed ewes would have an altered oxidative status in circulation. To test this hypothesis, multiparous Dorset ewes (n = 45) pregnant with twins were fed 100% (CON), 60% (RES), or 140% (OVER) of National Research Council requirements from d 30 of gestation until parturition. At parturition, ewes were fed a control diet such that the nutritional insult only occurred during gestation. Blood samples were collected from offspring by jugular venipuncture at d 112 and d 224 of age to evaluate oxidative status in circulation. Data were analyzed in SAS 9.4 using PROC MIXED with fixed effects of offspring sex and maternal diet with sampling timepoint as repeated measure. Data were considered significant at P < 0.05. In offspring plasma, superoxide dismutase, an endogenous antioxidant, activity was 17% greater in CON offspring compared with RES and OVER (P ≤ 0.04). Malondialdehyde (MDA), a marker of lipid peroxidation, concentration was not different at d 112 but RES animals had 10% lesser concentration of MDA than CON at d 224 (P ≤ 0.02). Protein carbonyl (PC), a marker of protein oxidation, concentration was 9% greater in CON animals than RES and OVER (P = 0.01). Additionally, PC concentrations were 19% greater at d 224 compared with d 112 (P ≤ 0.001). These results indicate that at the chosen timepoints, RES and OVER offspring had less antioxidant activity but also less indication of oxidative damage. Overall, the alterations in antioxidant activity and oxidative damage suggest dysregulation in circulating oxidative status that may contribute to the negative consequences of poor maternal nutrition during gestation. Future work should focus on the impacts of poor maternal nutrition on oxidative stress in muscle.