Contribution of the seminal microbiome to paternal programming

The field of Developmental Origins of Health and Disease (DOHaD) has primarily focused on maternal programming of offspring health. However, emerging evidence suggests that paternal factors, including the seminal microbiome, could potentially play important roles in shaping the developmental trajectory and long-term offspring health outcomes. Historically, the microbes present in the semen were regarded as inherently pathogenic agents. However, this dogma has recently been challenged by the discovery of a diverse commensal microbial community within the semen of healthy males. In addition, recent studies suggest that the transmission of semen-associated microbes into the female reproductive tract during mating has potentials to not only influence female fertility and embryo development but could also contribute to paternal programming in the offspring. In this review, we summarize the current knowledge on the seminal microbiota in both humans and animals followed by discussing their potential involvement in paternal programming of offspring health. We also propose and discuss potential mechanisms through which paternal influences are transmitted to offspring via the seminal microbiome. Overall, this review provides insights into the seminal microbiome-based paternal programing, which will expand our understanding of the potential paternal programming mechanisms that currently are focused on the epigenetic modifications, oxidative stresses, and cytokines.

Influence of Maternal Nutrition and One-Carbon Metabolites Supplementation during Early Pregnancy on Bovine Fetal Small Intestine Vascularity and Cell Proliferation

To investigate the effects of nutrient restriction and one-carbon metabolite (OCM) supplementation (folate, vitamin B12, methionine, and choline) on fetal small intestine weight, vascularity, and cell proliferation, 29 (n = 7 ± 1 per treatment) crossbred Angus beef heifers (436 ± 42 kg) were estrous synchronized and conceived by artificial insemination with female sexed semen from a single sire. Then, they were allotted randomly to one of four treatments in a 2 × 2 factorial arrangement with the main factors of nutritional plane [control (CON) vs. restricted feed intake (RES)] and OCM supplementation [without OCM (-OCM) or with OCM (+OCM)]. Heifers receiving the CON level of intake were fed to target an average daily gain of 0.45 kg/day, which would allow them to reach 80% of mature BW by calving. Heifers receiving the RES level of intake were fed to lose 0.23 kg/heifer daily, which mimics observed production responses in heifers that experience a diet and environment change during early gestation. Targeted heifer gain and OCM treatments were administered from d 0 to 63 of gestation, and then all heifers were fed a common diet targeting 0.45 kg/d gain until d 161 of gestation, when heifers were slaughtered, and fetal jejunum was collected. Gain had no effect (p = 0.17) on the fetal small intestinal weight. However, OCM treatments (p = 0.02) displayed less weight compared to the -OCM groups. Capillary area density was increased in fetal jejunal villi of RES - OCM (p = 0.02). Vascular endothelial growth factor receptor 2 (VEGFR2) positivity ratio tended to be greater (p = 0.08) in villi and was less in the crypts (p = 0.02) of the RES + OCM group. Cell proliferation decreased (p = 0.02) in villi and crypts of fetal jejunal tissue from heifers fed the RES + OCM treatment compared with all groups and CON - OCM, respectively. Spatial cell density increased in RES - OCM compared with CON + OCM (p = 0.05). Combined, these data show OCM supplementation can increase expression of VEGFR2 in jejunal villi, which will promote maintenance of the microvascular beds, while at the same time decreasing small intestine weight and crypt cell proliferation.

Supplementing vitamins and minerals to beef heifers during gestation: impacts on mineral status in the dam and offspring, and growth and physiological responses of female offspring from birth to puberty

We evaluated the effects of feeding a vitamin and mineral supplement to nulliparous beef heifers throughout gestation on the mineral status of the dam, calf, placenta, and colostrum; offspring growth performance; and physiological responses of offspring raised as replacement heifers. Angus-based heifers (n = 31, initial body weight [BW] = 412.5 ± 53.68 kg) were adapted to an individual feeding system for 14 d, estrus synchronized and bred with female-sexed semen. Heifers were ranked by BW and randomly assigned to receive either a basal diet (CON; n = 14) or the basal diet plus 113 g heifer-1 d-1 of the vitamin and mineral supplement (VTM; n = 17). Targeted BW gains for both treatments was 0.45 kg heifer-1 d-1. Liver biopsies were obtained from dams at breeding, days 84 and 180 of gestation. At calving, liver biopsies were taken from dams and calves; colostrum, placenta, and blood samples were collected; and calf body measurements were recorded. After calving, all cow-calf pairs received a common diet through weaning, and F1 heifer calves were managed similarly after weaning. Offspring growth performance, feeding behavior, blood metabolites, and hormones were evaluated from birth through 15 mo of age. Data were analyzed using the MIXED procedure in SAS with repeated measures where appropriate. Hepatic concentrations of Se decreased in VTM dams (P ≤ 0.05) from day 84 to calving, while concentrations of Cu decreased in VTM and CON (P ≤ 0.05) from day 84 to calving. Calf liver concentrations of Se, Cu, Zn, and Co at birth were greater for VTM than CON (P ≤ 0.05), but calf birth BW and body measurements were not different (P = 0.45). Placental Se, colostrum quantity, total Se, Cu, Zn, and Mn in colostrum were greater (P ≤ 0.04) in VTM dams than CON. Finally, offspring from VTM dams were heavier than CON (P < 0.0001) from weaning through 15 mo of age. These results were coupled with greater (P ≤ 0.04) blood glucose at birth, decreased (P ≤ 0.05) blood urea nitrogen at pasture turn out and weaning, and altered feeding behaviors in VTM offspring compared with CON. Maternal gestational vitamin and mineral supplementation enhanced mineral status in dams and F1 progeny, augmented postnatal offspring growth and blood metabolites. Consequently, in utero vitamin and mineral supplementation may exert programming outcomes on the performance and productivity of females raised as herd replacements and should be considered when developing diets for gestating cows and heifers.

One-carbon metabolite supplementation to nutrient-restricted beef heifers affects placental vascularity during early pregnancy

We hypothesized that restricted maternal nutrition and supplementation of one-carbon metabolites (OCM; methionine, folate, choline, and vitamin B12) would affect placental vascular development during early pregnancy. A total of 43 cows were bred, and 32 heifers successfully became pregnant with female calves, leading to the formation of four treatment groups: CON - OCM (n = 8), CON + OCM (n = 7), RES - OCM (n = 9), and RES + OCM (n = 8). The experimental design was a 2 × 2 factorial, with main factors of dietary intake affecting average daily gain: control (CON; 0.6 kg/d ADG) and restricted (RES; -0.23 kg/d ADG); and OCM supplementation (+OCM) in which the heifers were supplemented with rumen-protected methionine (7.4 g/d) and choline (44.4 g/d) and received weekly injections of 320 mg of folate and 20 mg of vitamin B12, or received no supplementation (-OCM; corn carrier and saline injections). Heifers were individually fed and randomly assigned to treatment at breeding (day 0). Placentomes were collected on day 63 of gestation (0.225 of gestation). Fluorescent staining with CD31 and CD34 combined with image analysis was used to determine the vascularity of the placenta. Images were analyzed for capillary area density (CAD) and capillary number density (CND). Areas evaluated included fetal placental cotyledon (COT), maternal placental caruncle (CAR), whole placentome (CAR + COT), intercotyledonary fetal membranes (ICOT, or chorioallantois), intercaruncular endometrium (ICAR), and endometrial glands (EG). Data were analyzed with the GLM procedure of SAS, with heifer as the experimental unit and significance at P ≤ 0.05 and a tendency at P > 0.05 and P < 0.10. Though no gain × OCM interactions existed (P ≥ 0.10), OCM supplementation increased (P = 0.01) CAD of EG, whereas nutrient restriction tended (P < 0.10) to increase CAD of ICOT and CND of COT. Additionally, there was a gain × OCM interaction (P < 0.05) for CAD within the placentome and ICAR, such that RES reduced and supplementation of RES with OCM restored CAD. These results indicate that maternal rate of gain and OCM supplementation affected placental vascularization (capillary area and number density), which could affect placental function and thus the efficiency of nutrient transfer to the fetus during early gestation.

Sequencing and culture-based characterization of the vaginal and uterine microbiota in beef cattle that became pregnant or remained open following artificial insemination

IMPORTANCE

Emerging evidence suggests that microbiome-targeted approaches may provide a novel opportunity to reduce the incidence of reproductive failures in cattle. To develop such microbiome-based strategies, one of the first logical steps is to identify reproductive microbiome features related to fertility and to isolate the fertility-associated microbial species for developing a future bacterial consortium that could be administered before breeding to enhance pregnancy outcomes. Here, we characterized the vaginal and uterine microbiota in beef cattle that became pregnant or remained open via artificial insemination and identified microbiota features associated with fertility. We compared similarities between vaginal and uterine microbiota and between heifers and cows. Using culturing, we provided new insights into the culturable fraction of the vaginal and uterine microbiota and their antimicrobial resistance. Overall, our findings will serve as an important basis for future research aimed at harnessing the vaginal and uterine microbiome for improved cattle fertility.

Holistic View and Novel Perspective on Ruminal and Extra-Gastrointestinal Methanogens in Cattle

Despite the extensive research conducted on ruminal methanogens and anti-methanogenic intervention strategies over the last 50 years, most of the currently researched enteric methane (CH4) abatement approaches have shown limited efficacy. This is largely because of the complex nature of animal production and the ruminal environment, host genetic variability of CH4 production, and an incomplete understanding of the role of the ruminal microbiome in enteric CH4 emissions. Recent sequencing-based studies suggest the presence of methanogenic archaea in extra-gastrointestinal tract tissues, including respiratory and reproductive tracts of cattle. While these sequencing data require further verification via culture-dependent methods, the consistent identification of methanogens with relatively greater frequency in the airway and urogenital tract of cattle, as well as increasing appreciation of the microbiome-gut-organ axis together highlight the potential interactions between ruminal and extra-gastrointestinal methanogenic communities. Thus, a traditional singular focus on ruminal methanogens may not be sufficient, and a holistic approach which takes into consideration of the transfer of methanogens between ruminal, extra-gastrointestinal, and environmental microbial communities is of necessity to develop more efficient and long-term ruminal CH4 mitigation strategies. In the present review, we provide a holistic survey of the methanogenic archaea present in different anatomical sites of cattle and discuss potential seeding sources of the ruminal methanogens.

Role of the placenta in developmental programming: Observations from models using large animals

Developmental programming, which proposes that "insults" or "stressors" during intrauterine or postnatal development can have not only immediate but also long-term consequences for healthy and productivity, has emerged as a major biological principle, and based on studies in many animal species also seems to be a universal phenomenon. In eutherians, the placenta appears to be programmed during its development, which has consequences for fetal growth and development throughout pregnancy, and likewise has long-term consequences for postnatal development, leading to programming of organ function of the offspring even into adulthood. This review summarizes our current understanding of the placenta's role in developmental programming, the mechanisms involved, and the challenges remaining.

Genetic Distinctness and Diversity of American Aberdeen Cattle Compared to Common Beef Breeds in the United States

American Aberdeen (AD) cattle in the USA descend from an Aberdeen Angus herd originally brought to the Trangie Agricultural Research Centre, New South Wales, AUS. Although put under specific selection pressure for yearling growth rate, AD remain genomically uncharacterized. The objective was to characterize the genetic diversity and structure of purebred and crossbred AD cattle relative to seven common USA beef breeds using available whole-genome SNP data. A total of 1140 animals consisting of 404 purebred (n = 8 types) and 736 admixed individuals (n = 10 types) was used. Genetic diversity metrics, an analysis of molecular variance, and a discriminant analysis of principal components were employed. When linkage disequilibrium was not accounted for, markers influenced basic diversity parameter estimates, especially for AD cattle. Even so, intrapopulation and interpopulation estimates separate AD cattle from other purebred types (e.g., Latter's pairwise FST ranged from 0.1129 to 0.2209), where AD cattle were less heterozygous and had lower allelic richness than other purebred types. The admixed AD-influenced cattle were intermediate to other admixed types for similar parameters. The diversity metrics separation and differences support strong artificial selection pressures during and after AD breed development, shaping the evolution of the breed and making them genomically distinct from similar breeds.

Whole-body microbiota of newborn calves and their response to prenatal vitamin and mineral supplementation

Early life microbial colonization and factors affecting colonization patterns are gaining interest due to recent developments suggesting that early life microbiome may play a role in Developmental Origins of Health and Disease. In cattle, limited information exists on the early microbial colonization of anatomical sites involved in bovine health beyond the gastrointestinal tract. Here, we investigated 1) the initial microbial colonization of seven different anatomical locations in newborn calves and 2) whether these early life microbial communities and 3) serum cytokine profiles are influenced by prenatal vitamin and mineral (VTM) supplementation. Samples were collected from the hoof, liver, lung, nasal cavity, eye, rumen (tissue and fluid), and vagina of beef calves that were born from dams that either received or did not receive VTM supplementation throughout gestation (n = 7/group). Calves were separated from dams immediately after birth and fed commercial colostrum and milk replacer until euthanasia at 30 h post-initial colostrum feeding. The microbiota of all samples was assessed using 16S rRNA gene sequencing and qPCR. Calf serum was subjected to multiplex quantification of 15 bovine cytokines and chemokines. Our results indicated that the hoof, eye, liver, lung, nasal cavity, and vagina of newborn calves were colonized by site-specific microbiota, whose community structure differed from the ruminal-associated communities (0.64 ≥ R² ≥ 0.12, p ≤ 0.003). The ruminal fluid microbial community was the only one that differed by treatment (p < 0.01). However, differences (p < 0.05) by treatment were detected in microbial richness (vagina); diversity (ruminal tissue, fluid, and eye); composition at the phylum and genus level (ruminal tissue, fluid, and vagina); and in total bacterial abundance (eye and vagina). From serum cytokines evaluated, concentration of chemokine IP-10 was greater (p = 0.02) in VTM calves compared to control calves. Overall, our results suggest that upon birth, the whole-body of newborn calves are colonized by relatively rich, diverse, and site-specific bacterial communities. Noticeable differences were observed in ruminal, vaginal, and ocular microbiota of newborn calves in response to prenatal VTM supplementation. These findings can derive future hypotheses regarding the initial microbial colonization of different body sites, and on maternal micronutrient consumption as a factor that may influence early life microbial colonization.

Dataset of RNA-Seq transcriptome of the fetal liver at day 83 of gestation associated with periconceptual maternal nutrition in beef heifers

Herein, we present a dataset based on the RNA-Seq analysis of liver tissue from bovine female fetuses at day 83 of gestation. The findings were reported in the main article, "Periconceptual maternal nutrition affects fetal liver programming of energy- and lipid-related genes" [1]. These data were generated to investigate the effects of periconceptual maternal vitamin and mineral supplementation and rates of body weight gain on the transcript abundance of genes associated with fetal hepatic metabolism and function. To this end, crossbred Angus beef heifers (n = 35) were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial design. The main effects tested were vitamin and mineral supplementation (VTM or NoVTM - at least 71 days pre-breeding to day 83 of gestation) and rate of weight gain (low (LG - 0.28 kg/d) or moderate (MG - 0.79 kg/d) - from breeding to day 83). The fetal liver was collected on day 83 ± 0.27 of gestation. After total RNA isolation and quality control, strand-specific RNA libraries were prepared and sequenced on the Illumina® NovaSeq 6000 platform to generate paired-end 150-bp reads. After read mapping and counting, differential expression analysis was performed with edgeR. We identified 591 unique differentially expressed genes across all six vitamin-gain contrasts (FDR ≤ 0.1). To our knowledge, this is the first dataset investigating the fetal liver transcriptome in response to periconceptual maternal vitamin and mineral supplementation and/or the rate of weight gain. The data described in this article provides genes and molecular pathways differentially programming liver development and function.

Feeding hempseed cake alters the bovine gut, respiratory and reproductive microbiota

A growing number of studies have investigated the feasibility of utilizing hemp by-products as livestock feedstuffs; however, their impact on livestock microbiomes remains unexplored. Here, we evaluated the effects of feeding hempseed cake on the gastrointestinal, respiratory, and reproductive microbiota in beef heifers. Angus-crossbred heifers (19-months old, initial body weight = 494 ± 10 kg [SE]) were fed a corn-based finishing diet containing 20% hempseed cake as a substitute for 20% corn dried distillers' grains with solubles (DM basis; Control; n = 16/group) for 111 days until slaughter. Ruminal fluid and deep nasopharyngeal swabs (days 0, 7, 42, 70 and 98), and vaginal and uterine swabs (at slaughter) were collected, and the microbiota assessed using 16S rRNA gene sequencing. Diet affected the community structure of the ruminal (d 7-98; 0.06 ≤ R² ≤ 0.12; P < 0.05), nasopharyngeal (d 98; R² = 0.18; P < 0.001), and vaginal (R² = 0.06; P < 0.01) microbiota. Heifers fed hempseed cake had increased microbial diversity in the rumen, reduced microbial richness in the vagina, and greater microbial diversity and richness in the uterus. In addition to the distinct microbial communities in the rumen, nasopharynx, vagina and uterus, we identified 28 core taxa that were shared (≥ 60% of all samples) across these sampling locations. Feeding hempseed cake appeared to alter the bovine gut, respiratory and reproductive microbiota. Our results suggest that future research aiming to evaluate the use of hemp by-products in livestock diet should consider their impact on animal microbiome and microbiome mediated animal health and reproductive efficiency. Our findings also highlight the need for research evaluating the impact of hemp-associated food and personal care products on the human microbiome.

Maternal Mineral Nutrition Regulates Fetal Genomic Programming in Cattle: A Review

Maternal mineral nutrition during the critical phases of fetal development may leave lifetime impacts on the productivity of an individual. Most research within the developmental origins of the health and disease (DOHaD) field is focused on the role of macronutrients in the genome function and programming of the developing fetus. On the other hand, there is a paucity of knowledge about the role of micronutrients and, specifically, minerals in regulating the epigenome of livestock species, especially cattle. Therefore, this review will address the effects of the maternal dietary mineral supply on the fetal developmental programming from the embryonic to the postnatal phases in cattle. To this end, we will draw a parallel between findings from our cattle model research with data from model animals, cell lines, and other livestock species. The coordinated role and function of different mineral elements in feto-maternal genomic regulation underlies the establishment of pregnancy and organogenesis and, ultimately, affects the development and functioning of metabolically important tissues, such as the fetal liver, skeletal muscle, and, importantly, the placenta. Through this review, we will delineate the key regulatory pathways involved in fetal programming based on the dietary maternal mineral supply and its crosstalk with epigenomic regulation in cattle.

A Longitudinal Characterization of the Seminal Microbiota and Antibiotic Resistance in Yearling Beef Bulls Subjected to Different Rates of Gain

In this study, we evaluated the seminal and fecal microbiota in yearling beef bulls fed a common diet to achieve moderate (1.13 kg/day) or high (1.80 kg/day) rates of weight gain. Semen samples were collected on days 0 and 112 of dietary intervention (n = 19/group) as well as postbreeding (n = 6/group) using electroejaculation, and the microbiota was assessed using 16S rRNA gene sequencing, quantitative PCR (qPCR), and culturing. The fecal microbiota was also evaluated, and its similarity with seminal microbiota was assessed. A subset of seminal bacterial isolates (n = 33) was screened for resistance against 28 antibiotics. A complex and dynamic microbiota was detected in bovine semen, and the community structure was affected by sampling time (R2 = 0.16, P < 0.001). Microbial richness increased significantly from day 0 to day 112, and diversity increased after breeding (P > 0.05). Seminal microbiota remained unaffected by the differential rates of gain, and its overall composition was distinct from fecal microbiota, with only 6% of the taxa shared between them. A total of 364 isolates from 49 different genera were recovered under aerobic and anaerobic culturing. Among these seminal isolates were pathogenic species and those resistant to several antibiotics. Overall, our results suggest that bovine semen harbors a rich and complex microbiota which changes over time and during the breeding season but appears to be resilient to differential gains achieved via a common diet. Seminal microbiota is distinct from the fecal microbiota and harbors potentially pathogenic and antibiotic-resistant bacterial species. IMPORTANCE Increasing evidence from human and other animal species supports the existence of a commensal microbiota in semen and that this seminal microbiota may influence not only sperm quality and fertility but also female reproduction. Seminal microbiota in bulls and its evolution and factors shaping this community, however, remain largely underexplored. In this study, we characterized the seminal microbiota of yearling beef bulls and its response to the bull age, different weight gains, and mating activity. We compared bacterial composition between seminal and fecal microbiota and evaluated the diversity of culturable seminal bacteria and their antimicrobial resistance. Our results obtained from sequencing, culturing, and antibiotic susceptibility testing provide novel information on the taxonomic composition, evolution, and factors shaping the seminal microbiota of yearling beef bulls. This information will serve as an important basis for further understanding of the seminal microbiome and its involvement in reproductive health and fertility in cattle.

Excretion and residue depletion of cannabinoids in beef cattle fed hempseed cake for 111 days

Thirty-two crossbred heifers were fed either a control diet or 20% (dry matter basis) hempseed cake in a complete ration for 111 days; of the cattle fed hempseed cake, four each were harvested with 0, 1, 4, and 8-day withdrawal periods. Urine and plasma were collected during the feeding and withdrawal periods and liver, kidney, skeletal muscle, and adipose tissue were collected at harvest. Total cannabinoid (n = 10) concentration of hempseed cake averaged 11.3 ± 11.7 mg kg^-1 across the feeding period with total cannabidiol and tetrahydrocannabinol (CBD/THC) concentrations of 1.3 ± 0.8 mg kg^-1. Neutral cannabinoids (cannabinol [CBN], CBD/THC, and cannabidivarin [CBDV]) were not detected in plasma or urine, but CBD/THC was measured in adipose tissue at all withdrawal periods (6.3 ± 2.1 to 10.1 ± 2.5 ng g^-1). In contrast, cannabinoid acids (cannabinolic acid [CBNA], cannabidiolic acid [CBDA]/tetrahydrocannabinolic acid [THCA], cannabichromenic acid [CBCA], and cannabidivarinic acid [CBDVA]) were sporadically detected (<15 ng mL^-1) in plasma and urine of cattle fed hempseed cake. Cannabinoid acids were depleted from liver by withdrawal day 4, but could still be measured (<1 ng g^-1) in kidney of some animals harvested on withdrawal day 8. Assessment of human exposures to CBD/THC residues through the consumption of beef fat from animals fed hempseed cake suggests that the probability of consuming the equivalent of an acute reference dose (ARfD) is remote, even with the use of a conservative reference dose ARfD (1 μg kg^-1 body weight).

Periconceptual Maternal Nutrition Affects Fetal Liver Programming of Energy- and Lipid-Related Genes

During pregnancy, the fetus relies on the dam for its nutrient supply. Nutritional stimuli during fetal organ development can program hepatic metabolism and function. Herein, we investigated the role of vitamin and mineral supplementation (VTM or NoVTM-at least 71 days pre-breeding to day 83 of gestation) and rate of weight gain (low (LG) or moderate (MG)-from breeding to day 83) on the fetal liver transcriptome and the underlying biological pathways. Crossbred Angus beef heifers (n = 35) were randomly assigned to one of four treatments in a 2 × 2 factorial design (VTM_LG, VTM_MG, NoVTM_LG, and NoVTM_MG). Gene expression was measured with RNA-Seq in fetal livers collected on day 83 ± 0.27 of gestation. Our results show that vitamin and mineral supplementation and rate of weight gain led to the differential expression of hepatic genes in all treatments. We identified 591 unique differentially expressed genes across all six VTM-gain contrasts (FDR ≤ 0.1). Over-represented pathways were related to energy metabolism, including PPAR and PI3K-Akt signaling pathways, as well as lipid metabolism, mineral transport, and amino acid transport. Our findings suggest that periconceptual maternal nutrition affects fetal hepatic function through altered expression of energy- and lipid-related genes.

Fetal Hepatic Lipidome Is More Greatly Affected by Maternal Rate of Gain Compared with Vitamin and Mineral Supplementation at day 83 of Gestation

Herein, we evaluated the hepatic lipid metabolic profiles of bovine fetuses in response to maternal vitamin and mineral supplementation (VMSUP; supplemented (VTM) or not (NoVTM)) and two different rates of gain (GAIN; low gain (LG), 0.28 kg/d, or moderate gain (MG), 0.79 kg/d). Crossbred Angus heifers (n = 35; initial BW = 359.5 ± 7.1 kg) were randomly assigned to a 2 × 2 factorial arrangement, resulting in the following treatment combinations: NoVTM-LG (n = 9), NoVTM-MG (n = 9), VTM-LG (n = 9), and VTM-MG (n = 8). Heifers received their treatments until d 83 of gestation, when they were ovariohysterectomized. Fetuses were harvested and liver samples were analyzed via ultrahigh-performance liquid chromatography-tandem mass spectroscopy to characterize lipid profiles and abundances. We identified 374 biochemicals/metabolites belonging to 57 sub-pathways of the lipid metabolism super-pathway. The majority of the biochemicals/metabolites (n = 152) were significantly affected by the main effect of GAIN. Maternal moderate rates of gain resulted in greater abundances (p ≤ 0.0001) of ω-3 fatty acids (eicosapentaenoate, docosapentaenoate, and docosahexaenoate) and lower abundances (p ≤ 0.0001) of ω-6 fatty acids. Further, MG resulted in the accumulation of several diacylglycerols and depletion of the majority of the monoacylglycerols. Concentrations of nearly all acylcarnitines (p ≤ 0.03) were decreased in VTM-LG fetal livers compared to all other treatment combinations, indicating a greater rate of complete oxidation of fatty acids. Levels of secondary bile acids were impacted by VMSUP, being greater (p ≤ 0.0048) in NoVTM than in VTM fetal livers. Moreover, NoVTM combined with lower rate of gain resulted in greater concentrations of most secondary bile acid biochemicals/metabolites. These data indicate that maternal diet influenced and altered fetal hepatic lipid composition in the first trimester of gestation. Maternal body weight gain exerted a greater influence on fetal lipid profiles than vitamin and mineral supplementation. Specifically, lower rate of gain (0.28 kg/d) resulted in an increased abundance of the majority of the biochemicals/metabolites identified in this study.

Concentrations of vitamin B12 and folate in maternal serum and fetal fluids, metabolite interrelationships, and hepatic transcript abundance of key folate and methionine cycle genes: the impacts of maternal nutrition during the first 50 d of gestation

Adequate maternal nutrition is key for proper fetal development and epigenetic programming. One-carbon metabolites (OCM), including vitamin B12, folate, choline, and methionine, play a role in epigenetic mechanisms associated with developmental programming. This study investigated the presence of B12 and folate in maternal serum, allantoic fluid (ALF), and amniotic fluid (AMF), as well as how those concentrations in all three fluids correlate to the concentrations of methionine-folate cycle intermediates in heifers receiving either a control (CON) or restricted (RES) diet for the first 50 d of gestation and fetal hepatic gene expression for methionine-folate cycle enzymes. Angus cross heifers (n = 43) were estrus synchronized, bred via artificial insemination with semen from a single sire, and randomly assigned to one of two nutrition treatments (CON = 20, RES = 23). Heifers were ovariohysterectomized on either day 16 (n = 14), 34 (n = 15), or 50 of gestation (n = 14), where samples of maternal serum (n = 42), ALF (n = 29), and AMF (n = 11) were collected and analyzed for concentrations of folate and B12. Concentrations of B12 and folate in ALF were greater (P < 0.05) in RES compared to CON. For ALF, folate concentrations were also greater (P < 0.01) on day 34 compared to day 50. There was a significant (P = 0.04) nutrition × fluid interaction for B12 concentrations where concentrations were greatest in restricted ALF, intermediate in control ALF, and lowest in CON and RES serum and AMF. Folate concentrations were greatest (P < 0.01) in ALF, intermediate in serum, and lowest in AMF. Additionally, positive correlations (P < 0.05) were found between ALF and AMF folate concentrations and AMF concentrations of methionine, serine, and glycine. Negative correlations (P < 0.05) between AMF folate and serum homocysteine were also observed. Both positive and negative correlations (P < 0.05) depending on the fluid evaluated were found between B12 and methionine, serine, and glycine concentrations. There was a downregulation (P = 0.05) of dihydrofolate reductase and upregulation (P = 0.03) of arginine methyltransferase 7 gene expression in RES fetal liver samples compared with CON fetal liver on day 50. Combined, these data show restricted maternal nutrition results in increased B12 and folate concentrations present in fetal fluids, and increased expression of genes for enzymes within one-carbon metabolism.

Using precision tools to manage and evaluate the effects of mineral and protein/energy supplements fed to grazing beef heifers

Our objectives were to develop a Mobile Cow Command Center (MCCC) capable of precision monitoring of grazing heifers to 1) examine the relationship between supplement intake on concentrations of liver mineral and blood metabolites and 2) examine activity, reproductive, and health behavior. Yearling crossbred Angus heifers (N = 60; initial BW = 400.4 ± 6.2 kg) were fitted with radio frequency identification ear tags that allowed access to electronic feeders (SmartFeed system; C-Lock Inc., Rapid City, SD), and with activity monitoring tags (CowManager B.V., the Netherlands) that monitored reproductive, feeding, and health-associated behaviors. Heifers were assigned randomly to one of three treatments for a 57-day monitoring period: 1) no supplement (CON; N = 20), 2) free choice mineral (MIN; Purina Wind and Rain Storm [Land O'Lakes, Inc.], N = 20), or 3) free choice energy and mineral supplement (NRG; Purina Accuration Range Supplement 33 with added MIN [Land O'Lakes, Inc.], N = 20). Consecutive day body weights, blood, and liver biopsies were collected at pasture turnout and final day of monitoring. By design, mineral intake was greatest in MIN heifers (49 ± 37 g/d) and energy supplement intake was greatest in NRG heifers (1,257 ± 37 g/d). Final BW and ADG were similar among treatments (P > 0.42). Concentrations of glucose on day 57 were greater (P = 0.01) in NRG compared with CON and MIN heifers. Liver concentrations of Se and Fe on day 57 were greater (P < 0.05) in NRG heifers than CON, with MIN being intermediate. Activity tags reported NRG heifers spent less time eating (P < 0.0001) and more time (P < 0.0001) being "highly active" than MIN with CON heifers being intermediate. Data retrieved from activity tags identified 16 of 28 pregnant heifers exhibiting some type of estrus-associated behavior even after confirmation of established pregnancy. The activity monitoring system triggered a total of 146 health alerts from 34 of the 60 heifers monitored, but only 3 heifers of the heifers initiating an electronic health alert needed clinical treatment. However, animal care staff identified nine additional heifers that required treatment for which no electronic health alert was generated. The electronic feeders successfully controlled intake of individual heifers managed in groups pastures; however, the activity monitoring system misrepresented estrus and health events.

Effects of feeding a vitamin and mineral supplement to cow-calf pairs grazing native range

Our objectives were to evaluate the impacts of providing vitamin and mineral (VTM) supplements to cow-calf pairs during the summer grazing period on cow and calf performance and liver concentrations of minerals. During a two-year period, 727 crossbred cows and their calves (initial cow BW = 601.7 ± 48.1 kg; calf BW = 87.8 ± 5.0 kg; n = 381 in year 1, n = 346 in year 2) from the Central Grasslands Research Extension Center (Streeter, N.D.) were blocked by parity (young [parity 1 to 3], and old [parity 4+]) and randomly assigned to pastures at the beginning of the grazing season (16 in year 1 and 14 in year 2). Pastures were assigned to receive a free-choice VTM supplement (SUPP) or no VTM supplement (CON) from pasture turnout to pasture removal (158 and 156 days in year 1 and 2, respectively). Consecutive day weights were taken from cows and calves at pasture turnout and removal and liver biopsies were collected from a subset of cows at both timepoints and from calves at weaning. Cows were bred via AI 37 to 41 d after pasture turnout and by natural service cleanup bulls for a 70 to 80 d breeding season. Calving and weaning data were collected from the calf conceived and gestated during treatments. Data were analyzed for the effect of VTM treatment (SUPP vs. CON), block of parity, and their interaction using the GLM procedure of SAS with pasture as the experimental unit. Year was considered a random effect in the final analysis. Cow pregnancy success was evaluated using the GLIMMIX procedure in SAS with model terms of VTM treatment, parity, and their interaction with year as a random effect. In year 2, cows in differing days postpartum (DPP) groups at pasture turnout (66.1, 48.8, and 34.5 ± 1.04 DPP for EARLY, MID, and LATE groups, respectively) were selected for liver biopsies with cow as the experimental unit. Cow and calf BW and BW change were not impacted (P ≥ 0.20) by VTM access. Pregnancy rate to AI, overall pregnancy rate, gestating calf birth BW and calving distribution were not affected (P ≥ 0.11) by treatment. Liver concentrations of Se, Cu, and Co were greater (P ≤ 0.002) at pasture removal and weaning for cows and suckling calves that had access to VTM. Cows considered EARLY calving had greater (P = 0.05) concentrations of liver Se compared with LATE calving cows. Although VTM supplementation enhanced concentrations of key minerals in the liver of cow-calf pairs, reproductive and growth performance was not affected.

One-carbon metabolite supplementation to heifers for the first 14 d of the estrous cycle alters the plasma and hepatic one-carbon metabolite pool and methionine-folate cycle enzyme transcript abundance in a dose-dependent manner

The objective of this study was to determine the dose of folate and vitamin B12 in beef heifers fed rumen protected methionine and choline required to maintain increased B12 levels and intermediates of the methionine-folate cycle in circulation. Angus heifers (n = 30; BW = 392.6 ± 12.6 kg) were individually fed and assigned to one of five treatments: 0XNEG: Total mixed ration (TMR) and saline injections at day 0 and 7 of the estrous cycle, 0XPOS: TMR, rumen protected methionine (MET) fed at 0.08% of the diet DM, rumen protected choline (CHOL) fed at 60 g/d, and saline injections at day 0 and 7, 0.5X: TMR, MET, CHOL, 5 mg B12, and 80 mg folate at day 0 and 7, 1X: TMR, MET CHOL, 10 mg vitamin B12, and 160 mg folate at day 0 and 7, and 2X: TMR, MET, CHOL, 20 mg B12, and 320 mg folate at day 0 and 7. All heifers were estrus synchronized but not bred, and blood was collected on day 0, 2, 5, 7, 9, 12, and 14 of a synchronized estrous cycle. Heifers were slaughtered on day 14 of the estrous cycle for liver collection. Serum B12 concentrations were greater in the 0.5X, 1X, and 2X, compared with 0XNEG and 0XPOS on all days after treatment initiation (P < 0.0001). Serum folate concentrations were greater for the 2X treatment at day 5, 7, and 9 of the cycle compared with all other treatments (P ≤ 0.05). There were no differences (P ≥ 0.19) in hepatic methionine-cycle or choline analyte concentrations by treatment. Concentrations of hepatic folate cycle intermediates were always greater (P ≤ 0.04) in the 2X treatment compared with the 0XNEG and 0XPOS heifers. Serum methionine was greater (P = 0.04) in the 0.5X and 2X heifers compared with 0XNEG, and S-adenosylhomocysteine (SAH) tended (P = 0.06) to be greater in the 0.5X heifers and the S-adenosylmethionine (SAM):SAH ratio was decreased (P = 0.05) in the 0.5X treatment compared with the 0XNEG, 0XPOS, and 2X heifers. The hepatic transcript abundance of MAT2A and MAT2B were decreased (P ≤ 0.02) in the 0.5X heifers compared with the 0XNEG, 0XPOS, and 2X heifers. These data support that beef heifers fed rumen protected methionine and choline require 20 mg B12 and 320 mg folate once weekly to maintain increased concentrations of B12 and folate in serum. Furthermore, these data demonstrate that not all supplementation levels are equal in providing positive responses, and that some levels, such as the 0.5X, may result in a stoichiometric imbalance in the one-carbon metabolism pathway that results in a decreased SAM:SAH ratio.

Maternal nutrition and developmental programming of offspring

Developmental programming is the concept that 'stressors' during development (i.e. pregnancy, the perinatal period and infancy) can cause long-term changes in gene expression, leading to altered organ structure and function. Such long-term changes are associated with an increased risk of a host of chronic pathologies, or non-communicable diseases including abnormal growth and body composition, behavioural or cognitive dysfunction, metabolic abnormalities, and cardiovascular, gastro-intestinal, immune, musculoskeletal and reproductive dysfunction. Maternal nutrition during the periconceptual period, pregnancy and postnatally can have profound influences on the developmental program. Animal models, including domestic livestock species, have been important for defining the mechanisms and consequences of developmental programming. One of the important observations is that maternal nutritional status and other maternal stressors (e.g. environmental temperature, high altitude, maternal age and breed, multiple fetuses, etc.) early in pregnancy and even periconceptually can affect not only embryonic/fetal development but also placental development. Indeed, altered placental function may underlie the effects of many maternal stressors on fetal growth and development. We suggest that future directions should focus on the consequences of developmental programming during the offspring's life course and for subsequent generations. Other important future directions include evaluating interventions, such as strategic dietary supplementation, and also determining how we can take advantage of the positive, adaptive aspects of developmental programming.

Seminal and vagino-uterine microbiome and their individual and interactive effects on cattle fertility

Reproductive failure is a major economical drain on cow-calf operations across the globe. It can occur in both males and females and stem from prenatal and postnatal influences. Therefore, the cattle industry has been making efforts to improve fertility and the pregnancy rate in cattle herds as an attempt to maintain sustainability and profitability of cattle production. Despite the advancements made in genetic selection, nutrition, and the implementation of various reproductive technologies, fertility rates have not significantly improved in the past 50 years. This signifies a missing factor or factors in current reproductive management practices that influence successful fertilization and pregnancy. Emerging lines of evidence derived from human and other animals including cattle suggest that the microbial continuum along the male and female reproductive tracts are associated with male and female fertility-that is, fertilization, implantation, and pregnancy success-highlighting the potential for harnessing the male and female reproductive microbiome to improve fertility in cattle. The objective of this narrative review is to provide an overview of the recent studies on the bovine seminal and vagino-uterine microbiome and discuss individual and interactive roles of these microbial communities in defining cattle fertility.

Selenium supplementation and pregnancy outcomes

In vertebrates and invertebrates, selenium (Se) is an essential micronutrient, and Se deficiency or excess is associated with gonadal insufficiency and gamete dysfunction in both males and females, leading to implantation failure, altered embryonic development and, ultimately, infertility. During pregnancy, Se excess or deficiency is associated with miscarriage, pre-eclampsia (hypertension of pregnancy), gestational diabetes, fetal growth restriction and preterm birth. None of this is surprising, as Se is present in high concentrations in the ovary and testes, and work in animal models has shown that addition of Se to culture media improves embryo development and survival in vitro in association with reduced reactive oxygen species and less DNA damage. Selenium also affects uterine function and conceptus growth and gene expression, again in association with its antioxidant properties. Similarly, Se improves testicular function including sperm count, morphology and motility, and fertility. In animal models, supplementation of Se in the maternal diet during early pregnancy improves fetal substrate supply and alters fetal somatic and organ growth. Supplementation of Se throughout pregnancy in cows and sheep that are receiving an inadequate or excess dietary intake affected maternal whole-body and organ growth and vascular development, and also affected expression of angiogenic factors in maternal and fetal organs. Supplemental Se throughout pregnancy also affected placental growth, which may partly explain its effects on fetal growth and development, and also affected mammary gland development, colostrum yield and composition as well as postnatal development of the offspring. In conclusion, Se supplementation in nutritionally compromised pregnancies can potentially improve fertility and pregnancy outcomes, and thereby improve postnatal growth and development. Future research efforts should examine in more detail and more species the potential benefits of Se supplementation to reproductive processes in mammals.

PS-6 Nutrition During Early Pregnancy Impacts Offspring Ovarian Characteristics

During early pregnancy offspring are directly exposed to nutrients consumed by their mother, and the development of their own reproductive tract is underway. The objective of this research was to determine how characteristics of offspring ovaries were affected by different maternal rates of gain during the first trimester of gestation in beef heifers. Before breeding antral follicle counts were determined via ultrasound. Beginning at breeding Angus heifers were managed to achieve one of two rates of gain: low (0.20 kg/d, n = 8; LG) or moderate (0.75 kg/d, n = 8; MG) for the first trimester of pregnancy, after which they were managed as a single group through F1 calving. Calves remained with their dams until weaning and were managed as a single group through breeding. These F1 heifer calves were then synchronized and bred to a single sire using female sexed semen. On the 84th day of gestation (approximate heifer age 17 months) ovaries were removed from the reproductive tract, weighed, and visible antral follicles were counted. Cross-sections from each ovary were post-fixed and embedded in paraffin, then each of 3 sections (5 µm, with 10 sections between to avoid counting follicles more than once) were stained with Hematoxylin and Eosin for histological evaluation. Number of primordial, primary, secondary, and antral follicles were determined for each section. Data were analyzed using the GLM procedure of SAS with significance declared at P ≤ 0.05. The CORR procedure of SAS was used to calculate correlations between pre-breeding antral follicle counts, surface follicle counts, and histological follicle counts. Though no differences were observed in number of visible follicles (P = 0.45), the corpus luteum (CL) was heavier (P = 0.03) and average ovarian length was greater (P = 0.04) in offspring from LG dams compared with those from MG dams. No differences were observed in the number of primordial, primary, secondary, or antral follicles between treatments (P ≤ 0.18). There was a correlation between the number of histological follicles and surface follicles (r = 0.73; P = 0.002) and pre-breeding antral follicles and surface follicles (r = 0.60; P = 0.014), but there was no correlation between pre-breeding antral follicles and histological follicles (P = 0.10). Heavier CLs have a positive correlation with amount of progesterone released, which is essential for pregnancy maintenance. Longer lengths of ovaries suggest more area for follicles to develop, which is indicative of future reproductive success. Data corroborates previous reports regarding positive correlations between antral follicle count determined via ultrasound and counts of surface follicles on extracted ovaries. These findings demonstrate that nutrition during the first trimester of gestation impacts offspring reproductive tract development.

3 Impacts of Vitamin and Mineral Supplementation to Beef Heifers During Gestation on Performance Measures of the Neonatal Calf, Trace Mineral Status, and Organ Weights at 30 Hours After Birth

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.

213 from Conception to Birth: The Role of Minerals on Beef Cattle Fetal Programming

Fetal adaptations to nutrition in utero lead to long-term effects on fetal growth and postnatal performance. Although required in minute amounts, minerals play an essential role in fetal programming, likely through epigenetic mechanisms. Thus, changes in the embryonic and fetal epigenome modulate gene transcription and, consequently, the differentiation, growth, and development of cells and tissues. Despite the growing knowledge in nutritional epigenetics and gene expression, literature on the implications of minerals on the (epi)genome and fetal development is still scarce. Our research investigates fetal and postnatal offspring outcomes in response to maternal nutrition throughout the periconceptual period of pregnancy using a beef cattle model. We have reported placental adaptations through changes in gene expression in beef heifers supplemented with vitamins and minerals (113 g•heifer-1•d-1) during the first 83 days of pregnancy. We found coordinated crosstalk between fetal-maternal tissues and a fine-tuned regulation of placental genes involved with nutrient transport, tissue function and differentiation. Interestingly, the concentrations of minerals and amino acids in the allantoic and amniotic fluids and maternal serum were also affected. Furthermore, genes were differentially expressed in the fetal brain, liver, and muscle in response to the maternal diet. The nutrient-sensing PI3K-Akt signaling pathway was over-represented in muscle and cerebrum, whereas mineral and lipid metabolism were identified in the liver. A second study showed that providing supranutritional maternal selenium supplementation (105 mg of Se/wk as Se yeast) during different trimesters of gestation increased Se concentration in the whole blood and muscle of newborn calves. Likewise, calves born to dams supplemented in the last trimester had increased expression of myogenic genes. Altogether, these findings reinforce the implications of maternal nutrition during pregnancy on fetal programming. However, further studies are still required to understand the regulatory mechanisms and postnatal effects.

303 Overview of Paternal Programming in Livestock Species

The concept of developmental programming from a maternal standpoint is well established. Perhaps even more impactful, however, is developmental programming that may arise from paternal contributions when single sires are responsible for breeding multiple females. Research in rodent models has shown that paternal obesity, high fat or low protein diets, exercise, stress, and drug and alcohol exposure can lead to epigenetic modifications in sperm and seminal plasma. Some of these changes withstand the extensive remodeling associated with fertilization and early embryo development, culminating in discernable offspring phenotypes that remain present for multiple generations. Certainly, the observations in rodent models related to alterations in offspring body weight, adiposity, metabolic responses, bone density, and reproductive outcomes and function have implications for the livestock industries if similar paternal programming phenomena exist. Livestock production systems are robust and dynamic and many paradigms exist with potential to alter male germ line epigenome, with specific changes likely related to timing of aberrant conditions relative to spermatogenesis and sperm residence in the epididymis. Within the context of routine management systems, our livestock patriarchs can experience major diet and weight changes, transportation and handling stress, environmental extremes, and/or changes in exercise duration, frequency, and intensity. In addition, livestock managers may embrace the concept of delivering specific quantities and types of feedstuffs, and apply other interventions if proven beneficial. Several research groups using livestock models have revealed that epigenetic machinery delivered in sperm and seminal plasma can be altered. A sheep model demonstrated the feeding rumen-protected methionine to rams from weaning to puberty resulted in epigenetic and phenotypic alterations still present in the F2 generation. This presentation will review the status of literature regarding paternal programming, identify knowledge gaps, and suggest areas for future research efforts with potential to enhance production efficiencies of livestock operations.

PSV-B-17 Effect of Dietary Supplementation with Vitamins/Minerals and/or Energy on Fetoplacental Vascularity in Crossbred Angus Heifers

The objective of these studies was to evaluate if vascularity of the fetal part of the placenta, termed cotyledon (COT), of crossbreed Angus heifers is affected by vitamin and mineral (VTM) and/or energy (NRG) supplementation during pregnancy. We hypothesized that dietary supplementation with VTM and/or NRG would improve fetoplacental vascular development, which is an important index of placental function. Two experiments were conducted: In Exp. 1, 34 heifers were randomly assigned to VTM/NoVTM supplementation 71 days before artificial insemination (AI). At breeding, the diet was maintained and heifers were randomly assigned to receive NRG, resulting in the following treatments combinations: NoVTM-NoNRG (n=8), NoVTM-NRG (n=8), VTM-NoNRG (n=9), and VTM-NRG (n=9). Dietary supplementation was maintained until d 83 when heifers were ovariohysterectomized and COT was collected. On Exp. 2, 72 heifers were randomly assigned to VTM supplementation (n=36) or control (CON) (n=36) treatments at breeding and continuing until parturition when COT from a subset of 28 heifers was collected. The COT from both experiments was evaluated by immunohistochemistry using rabbit anti-CD34 and anti-CD31 antibodies as markers for vascularity along with DAPI for background nuclear staining. In the d 83 group, BS1 lectin was used as a marker of fetal placental tissue. Three images per animal were captured and the percentage/number of blood vessels within the tissue area was analyzed. The data were analyzed using the GLM procedure of SAS. Results indicated that on d 83 COT vascularity was not affected by VTM (P-value = 0.5030), NRG (P-value = 0.5450), or their interaction (P-value = 0.6664), whereas on parturition there was a tendency for COT vascularity to be greater in VTM than CON (P- value=0.0723). These results suggest that dietary VTM supplementation from breeding until parturition potentially has a beneficial effect on placental vascular development in crossbred Angus heifers.

346 Feeding Hempseed Cake Alters the Bovine gut, Respiratory and Reproductive Microbiota

A growing number of studies have investigated the viability of feeding hemp by-products as livestock feedstuffs; however, their impact on livestock microbiomes remains unexplored. Here, we evaluated the effects of feeding hempseed cake (HSC) on the gastrointestinal, respiratory, and reproductive microbiota in beef heifers. Angus-crossbred heifers [19-months old; initial body weight (BW) = 494 ± 10 kg] were fed a corn-based finishing diet (10% forage) containing either 20% HSC (n = 15) or 20% corn distillers grains (Control, n = 16) for 111 days until slaughter. Individual feed intake, feeding behavior and BW were measured throughout the study. Rumen fluid and deep nasopharyngeal swabs (days 0 7, 42, 70 and 98), and vaginal and uterine swabs (at slaughter) were collected, and the microbiota assessed using 16S rRNA gene sequencing. HSC feeding resulted in reduced average daily gain (P = 0.05) without influencing feed intake and feeding behavior (P &gt; 0.05) (reported elsewhere). Sampling time had a significant effect on both ruminal (PERMANOVA: R2 = 0.39; P &lt; 0.001) and nasopharyngeal (R2 = 0.18; P &lt; 0.001) microbial community structure. There was also a significant effect of diet on the ruminal (d7– 98; 0.06 ≤ R2 ≤ 0.12; P &lt; 0.05), nasopharyngeal (d 42; R2= 0.18; P &lt; 0.001), and vaginal (R2 = 0.06; P &lt; 0.01) microbiota. Although microbial richness in the rumen, nasopharynx, vagina, and uterus was not affected (P &gt; 0.05) by HSC feeding, microbial diversity (Shannon diversity) was increased in the rumen (d42-98) but reduced in the uterus of HSC heifers (P &lt; 0.05). The relative abundance of five ruminal genera was enriched, while five vaginal genera were reduced in HSC heifers (P &lt; 0.05). Overall, the results of our longitudinal study suggest that feeding hemp by-products can alter the bovine gut, respiratory and reproductive microbiota.

367 Characterization of the Seminal Microbiota in Beef Bulls Subjected to Different Rate of Gains Using 16S Rrna Gene Sequencing and Culturomics

Increasing evidence supports the existence of a microbial community in bovine semen, and that this seminal microbiota may influence not only the male reproductive health, but also female and offspring health through microbial transfer. In this study, we evaluated seminal microbiota in beef bulls (BW= 503±7.2 kg) fed a common diet to achieve moderate (1.13 kg/d) or high (1.80 kg/d) rates of weight gain. Semen samples were collected at day 0 and day 112 of dietary intervention (n = 19 per group), and post-breeding (n = 6) using electroejaculation and the microbiota assessed using 16S rRNA gene sequencing, quantification of total bacteria by qPCR, and viable bacteria culturing. A complex and dynamic microbiota was detected in the semen, and the community structure changed significantly over the course of the study (R 2 = 0.126, P &lt; 0.001) but remained unaffected by the dietary treatment (P &gt; 0.05). Microbial richness (number of ASVs) increased from d0 (253 ± 12) to d112 (293 ± 14) while diversity (Shannon index) was reduced (P &lt; 0.05). Twenty-seven bacterial phyla were identified across all samples, with Fusobacteriota (36.3%), Bacteroidetes (30.4%), Firmicutes (17.1%) and Actinobacteriota (14.9%) being the most predominant phyla. Total bacterial load declined over time (P &lt; 0.05). Diet had no effect on alpha diversity metrics, microbial composition, or total bacterial concentration (P &gt; 0.05). A total of 364 bacterial isolates were recovered under aerobic (n = 220) and anaerobic (n = 144) culturing conditions. These isolates represented 48 different genera within the Firmicutes (60%), Proteobacteria (25%), Actinobacteria (9%), Bacteroidetes (4%) and Fusobacteriota (2%) phyla. Bacillus, Staphylococcus, Escherichia, Enterococcus and Arthrobacter were the predominant genera. Overall, our results suggest that bovine semen harbors a rich and complex microbiota which changes over time but appears to be resilient to differential gains achieved via common diet.

Rapid quantification of cannabinoids in beef tissues and bodily fluids using direct-delivery electrospray ionization mass spectrometry

Hempseed cake is a byproduct of hempseed oil extraction and is potentially a useful source of protein and fiber for use in ruminant diets. However, data are lacking on the appearance and/or clearance of cannabinoids in tissues of animals fed hempseed cake. To this end, a rapid method for quantifying cannabinol (CBN), cannabidiol (CBD), cannabinolic acid (CBNA), cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), cannabichromenic acid (CBCA), cannabidivarin (CBDV), cannabidivarinic acid (CBDVA), tetrahydrocannabinol (THC) and tetrahydrocannabinolic acid (THCA) in cattle tissues, plasma, and urine was developed using rapid screen electrospray ionization mass spectrometry (RS-ESI-MS). Regression coefficients of matrix-matched standard curves ranged from 0.9946 to >0.9999 and analyte recoveries averaged from 90.2 ± 15.5 to 108.7 ± 18.7% across all compounds. Limits of detection and quantification ranged from 0.05 to 2.79 ng · mL^-1 and 0.17 to 9.30 ng · mL^-1, respectively, while the inter-day relative standard deviation ranged from 5.1 to 15.1%. Rapid screening electrospray ionization mass spectrometry (RS-ESI-MS) returned no false positives for any cannabinoid in plasma, urine, and tissue (liver, skeletal muscle) samples from 6 non-dosed control animals (n = 90 samples; of which 72 samples were plasma or urine and 18 samples were tissues). Across-animal cannabinoid concentrations measured in 32 plasma samples of cattle dosed with ground hemp were quantified by RS-ESI-MS; analytical results correlated well (r² = 0.963) with independent LC-MS/MS analysis of the same samples.

Yearling bulls have reduced sperm concentration and increased seminal plasma interleukin-8 after a 28-day breeding season

We hypothesized that yearling bulls selected for a 28-d breeding season would have reduced sperm concentrations, morphology, and have increased seminal plasma concentrations of pro-inflammatory cytokine interleukin-8 (IL-8). Yearling bulls were selected based on a breeding soundness examination at approximately 415-d of age and contained at least 750 million sperm in the ejaculate, with 12 bulls randomly selected for breeding (BREEDERS) and 12 bulls not selected for breeding (NON-BREEDERS). After a 28-d breeding period, all bulls underwent a breeding soundness exam. Plasma and seminal plasma were collected at each time point for analysis. Data were analyzed utilizing either the MIXED or GLIMMIX procedures with repeated measures in SAS with breeding group, age, and the interaction as fixed effects. Sperm concentration per ml of ejaculate was reduced (P<0.05) in yearling bulls used for breeding compared with those not used for breeding at the end of the breeding season. Seminal plasma IL-8 concentrations in yearling bulls used for breeding were increased (P<0.05) after the breeding season compared to bulls not used for breeding. Taken together, yearling bulls selected for a 28-d breeding season have reduced sperm production per ml of an ejaculate and increased inflammatory response in the seminal plasma that can lead to impaired breeding response if they are to be used for more than 30-d of breeding.

Vitamin and Mineral Supplementation and Rate of Weight Gain during the First Trimester of Gestation in Beef Heifers Alters the Fetal Liver Amino Acid, Carbohydrate, and Energy Profile at Day 83 of Gestation

The objective of this study was to evaluate the effects of feeding heifers a vitamin and mineral supplement and targeting divergent rates of weight gain during early gestation on the fetal liver amino acid, carbohydrate, and energy profile at d 83 of gestation. Seventy-two crossbred Angus heifers were randomly assigned in a 2 × 2 factorial arrangement to one of four treatments comprising the main effects of vitamin and mineral supplementation (VTM or NOVTM) and feeding to achieve different rates of weight gain (low gain [LG] 0.28 kg/day vs. moderate gain [MG] 0.79 kg/day). Thirty-five gestating heifers with female fetuses were ovariohysterectomized on d 83 of gestation and fetal liver was collected and analyzed by reverse phase UPLC-tandem mass spectrometry with positive and negative ion mode electrospray ionization, as well as by hydrophilic interaction liquid chromatography UPLC-MS/MS with negative ion mode ESI for compounds of known identity. The Glycine, Serine, and Threonine metabolism pathway and the Leucine, Isoleucine, and Valine metabolism pathway had a greater total metabolite abundance in the liver of the NOVTM-LG group and least in the VTM-LG group (p < 0.01). Finally, both the TCA Cycle and Oxidative Phosphorylation pathways within the Energy Metabolism superpathway were differentially affected by the main effect of VTM, where the TCA cycle metabolites were greater (p = 0.04) in the NOVTM fetal livers and the Oxidative Phosphorylation biochemicals were greater (p = 0.02) in the fetal livers of the VTM supplemented heifers. These data demonstrate that the majority of metabolites that are affected by rate of weight gain or vitamin/mineral supplementation are decreased in heifers on a greater rate of weight gain or vitamin/mineral supplementation.

Vitamin and Mineral Supplementation and Rate of Gain in Beef Heifers I: Effects on Dam Hormonal and Metabolic Status, Fetal Tissue and Organ Mass, and Concentration of Glucose and Fructose in Fetal Fluids at d 83 of Gestation

Thirty-five crossbred Angus heifers (initial BW = 359.5 ± 7.1 kg) were randomly assigned to a 2 × 2 factorial design to evaluate effects of vitamin and mineral supplementation [VMSUP; supplemented (VTM) vs. unsupplemented (NoVTM)] and different rates 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 dam hormone and metabolic status, fetal tissue and organ mass, and concentration of glucose and fructose in fetal fluids. The VMSUP was initiated 71 to 148 d before artificial insemination (AI), allowing time for mineral status of heifers to be altered in advance of breeding. At AI heifers were assigned their GAIN treatment. Heifers received treatments until the time of ovariohysterectomy (d 83 ± 0.27 after AI). Throughout the experiment, serum samples were collected and analyzed for non-esterified fatty acids (NEFA), progesterone (P4), insulin, and insulin-like growth factor 1 (IGF-1). At ovariohysterectomy, gravid reproductive tracts were collected, measurements were taken, samples of allantoic (ALF) and amniotic (AMF) fluids were collected, and fetuses were dissected. By design, MG had greater ADG compared to LG (0.85 vs. 0.34 ± 0.04 kg/d, respectively; p < 0.01). Concentrations of NEFA were greater for LG than MG (p = 0.04) and were affected by a VMSUP × day interaction (p < 0.01), with greater concentrations for NoVTM on d 83. Insulin was greater for NoVTM than VTM (p = 0.01). A GAIN × day interaction (p < 0.01) was observed for IGF-1, with greater concentrations for MG on d 83. At d 83, P4 concentrations were greater for MG than LG (GAIN × day, p < 0.01), and MG had greater (p < 0.01) corpus luteum weights versus LG. Even though fetal BW was not affected (p ≥ 0.27), MG fetuses had heavier (p = 0.01) femurs than LG, and VTM fetuses had heavier (p = 0.05) livers than those from NoVTM. Additionally, fetal liver as a percentage of BW was greater in fetuses from VTM (P = 0.05; 3.96 ± 0.06% BW) than NoVTM (3.79 ± 0.06% BW), and from LG (p = 0.04; 3.96 ± 0.06% BW) than MG (3.78 ± 0.06% BW). A VMSUP × GAIN interaction was observed for fetal small intestinal weight (p = 0.03), with VTM-MG being heavier than VTM-LG. Therefore, replacement heifer nutrition during early gestation can alter the development of organs that are relevant for future offspring performance. These data imply that compensatory mechanisms are in place in the developing conceptus that can alter the growth rate of key metabolic organs possibly in an attempt to increase or decrease energy utilization.

Influence of hempseed cake inclusion on growth performance, carcass characteristics, feeding behavior and blood parameters in finishing heifers

As the hemp industry continues to develop in the US, there is interest in feeding byproducts of industrial hemp production to livestock. A completely randomized design experiment using crossbred finishing heifers [initial body weight (BW) ± SE = 494 ± 10 kg] was conducted to determine the effects of feeding hempseed cake in a corn-based finishing diet (10% forage) formulated to meet or exceed ruminally degradable and metabolizable protein requirements on growth performance, carcass characteristics, feeding behavior, and plasma parameters. Dietary treatments were inclusion of 20% [dry matter (DM) basis] of: dried corn distillers grains plus solubles (DDGS, n = 16), or hempseed cake (HEMP, n = 15). Cattle were housed in two pens, had ad-libitum access to feed and water, and individual intakes and feeding behavior were monitored using the Insentec feeding system. Cattle were fed treatment diets for 111 days, and every 14 days BW were measured, and blood samples collected. Blood plasma was analyzed for glucose, urea nitrogen, and individual amino acids and results analyzed using repeated measures analysis in SAS. Final BW, average daily gain, gain:feed, and hot carcass weight decreased (P ≤ 0.05) by 2.3%, 7.7%, 7.7%, and 2.6% respectively in heifers fed the HEMP diet than in heifers fed the DDGS diet. Net energy for maintenance and gain (Mcal/kg of feed, DM basis), estimated based on heifer intake and performance, were greater (P = 0.02) for the DDGS diet than the HEMP diet. All other performance and carcass characteristics were not different (P ≥ 0.20) between treatments. Heifers fed the HEMP diet had greater (P < 0.05) plasma urea nitrogen concentration in samples from each collection day compared to heifers fed the DDGS diet, although there was a treatment by day interaction (P < 0.01) because of variability in the magnitude of treatment differences over time. Plasma glucose concentration was not influenced (P = 0.17) by dietary treatment. Plasma concentrations of total amino acids, non-essential amino acids, and essential amino acids were not different between treatments (P ≥ 0.09), although there were several interactions between treatment and day (P ≤ 0.04) for individual amino acids. These data suggest that hempseed cake has a lower NEm and NEg relative to dried corn distillers grains plus solubles when adequate metabolizable protein is supplied, while still providing adequate nutrition to support acceptable performance of finishing cattle.

PSIII-7 The Effect of One-Carbon Metabolite Supplementation in Combination with Adequate or Restricted Feed Intake During Early Gestation on Maternal Hematology

During gestation maternal blood volume increases to meet the needs of the growing fetus. Folate and vitamin B12 are hematopoietic vitamins required for DNA synthesis in developing red blood cells. Our objective was to evaluate the effect of one-carbon metabolites (OCM; folate, vitamin B12, choline, and methionine) supplementation in combination with adequate or restricted intake in early gestation on maternal hematology. Thirty-two cross-bred Angus heifers were estrous synchronized and artificially inseminated with female-sexed semen. At breeding (day 0), heifers were assigned to treatments in a 2 × 2 factorial design. The first factor was control intake (CON; 0.60 kg/day average daily gain) versus restricted (RES; -0.23 kg/day gain). The second factor was OCM supplementation (+OCM; rumen protected choline [0.60 g/day] and methionine [10 g/day] in a fine ground corn carrier and weekly injections of 320 mg folate and 10mg vitamin B12) or no supplementation (-OCM; corn carrier and saline injections). Blood samples were collected on d -2 and d 62 relative to breeding. Samples were analyzed for hematocrit and complete blood cell count with differential. Data were analyzed using the MIXED procedure of SAS with d -2 as a covariate and significance at P &lt; 0.05. Red blood cell count was greater (P = 0.0019) in RES than CON (9.29 vs 8.30 ± 0.186 × 106 cells/mm3). Hematocrit (P = 0.08) and packed cell volume tended (P = 0.09) to be greater in RES than CON. The percentage of monocytes was less (P = 0.04) in +OCM than -OCM (1.5 vs 3.0 ± 0.50 %). The percentage of segmented neutrophils was greater (P = 0.01) in CON than RES (24.6 vs 16.8 ± 1.93 %). These results indicate that supplementation with OCM did not increase hematopoiesis in early gestation in heifers receiving an adequate or restricted plane of nutrition.

186 Vitamin and Mineral Supplementation During Gestation does not Influence Milk Yield or Composition During Early Lactation in Grazing or Parlor-Milked Beef Heifers

Two experiments were conducted to evaluate effects of vitamin and mineral supplementation during gestation on milk yield and composition at a single point in time, or via daily milk production during early lactation in beef heifers. Forty-one Angus-based heifers received either a basal ration (CON) or the basal diet plus vitamin mineral supplementation (VTM, 113 g•heifer-1•d-1) from breeding until parturition. For experiment 1, 29 heifers (12 CON and 17 VTM) were managed as one pasture group after parturition. Using a portable milking machine, heifers were milked at d 56 postpartum between 7 and 10.5 hours after calf removal. For experiment 2, 12 heifers (6 CON and 6 VTM) were acclimated to a free stall barn and milked twice daily for 78 d following parturition. Milk yield was recorded at each milking and samples were collected at d 32, 58, and 78 for component analysis. Data were analyzed using the GLM procedure of SAS. For grazing heifers, milk yield and components (P ≤ 0.91) did not differ between treatments, with mean yield of 9.95 ± 0.34 kg/d, 4.09 ± 0.11% fat and 2.82 ± 0.04% protein. Twice daily milking data (8.19 ± 0.08 kg/d mean yield with 3.43 ± 0.14 % fat and 3.17 ± 0.03 % protein) revealed that after d 7 milk yield remained similar for the rest of the evaluation period (P ≥ 0.12); however, protein was greater (P = 0.02) at d 58 (3.26 ± 0.05%) compared with d 32 (3.10 ± 0.05%) and urea was reduced (P &lt; 0.0001) at d 78 compared with either d 32 or 58 (11.24 ± 0.55 vs. 18.84 ± 0.55 and 19.10 ± 0.55 mg/dL, respectively). Overall, the successful management of these beef heifers in a dairy facility lays the platform for future work that will establish energy requirements during early lactation for primiparous beef cows.

42 Genome-wide Association Study of Ovary Characteristics in Admixed Beef Heifers Through Comparative Bayesian Approaches

Reproductive performance of heifers is a key indicator of herd productivity. The objective was to evaluate markers and genes associated with reproductive tract characteristics through a comparative approach. For this study, 295 admixed beef heifers were examined via transrectal ultrasonography at approximately 13 months of age. Exploratory factor analysis of antral follicular count (count per size, side, and total), length, height and diameter for left and right sides of ovaries, and uterine horn diameter revealed a latent variable that included total antral follicle count and ovary diameters per side (n = 3 traits), termed OVARY. Confirmatory factor analysis produced OVARY values per heifer. Quality controls left 116,133 SNP per heifer for association analyses. A marker window-based univariate approach with OVARY was conducted using an empirical Bayesian approach adjusting for nested population structure using marker frequency differences (Method 1) as well as an MCMC Bayesian approach identifying the fraction of SNP to be included with population structure as a fixed effect (Method 2). SNP with high genetic variance in important windows (PPAW &gt; 0.75) were mapped to their closest gene for enrichment analysis. Using Method 1, 2 genes were found to be associated and enrichment analysis identified SMYD2 contributing generally to epigenetic and transcriptional regulatory pathways and GO terms (adjusted P &lt; 0.05). Using Method 2, 11 genes were discovered to be associated with OVARY (adjusted P &lt; 0.05). Three of 11 genes were involved in neural transduction, cornification, epithelial integrity, and adipogenic pathways and GO terms. Eight of 11 genes were involved in reproductive hormonal signaling, post-natal growth, sex determination and reproductive organs development, embryo implantation, and signaling transduction GO terms. Given this, Method 2 provides better insights towards the association of markers and genes for future selection of admixed beef heifers with overall better reproductive characteristics than Method 1.

180 Supplementation of One-Carbon Metabolites to Beef Heifers During Early Gestation Increases Fetal Organ Weight at Day 63 of Gestation

We hypothesized a low maternal plane of nutrition will impair fetal growth in early gestation and that supplementation of one-carbon metabolites (OCM) will rescue the growth restriction. The experimental design was a 2 × 2 factorial with 2 levels of gain, each with or without supplementation of OCM. Angus-cross heifers were bred with female-sexed semen from a single sire. At breeding (d 0), beef heifers were individually fed using a Calan gate system and assigned to treatment (n = 8 per treatment): Control intake (targeted: 0.45 kg/d, actual: 0.60 kg/d ADG) without OCM (CON-OCM), CON with OCM (CON+OCM), Restricted intake (targeted/actual: -0.23 kg/d ADG) without OCM (RES-OCM), or RES with OCM (RES+OCM). The OCM supplement consisted of ruminal-protected choline (60 g/d) and methionine (10 g/d) in a fine-ground corn carrier fed daily, and weekly injections of folate (320 mg) and vitamin B12 (10 mg). The -OCM heifers received the corn carrier and saline injections. Heifers were slaughtered and fetal tissues collected on d 63. Data were analyzed using the MIXED procedures of SAS. Fetal body weight tended (P = 0.07) to be lighter and stomach complex weight was lighter (P = 0.03) in RES than CON. When organ weights were normalized to total brain weight to assess allometric growth, OCM × gain interactions were observed in heart (P = 0.04), left longissimus dorsi (P = 0.04), and right hemisphere (P = 0.01) with CON+OCM greater than CON–OCM. The normalized left hemisphere trend to be greater in RES+OCM than RES-OCM (P = 0.08). These data suggest that OCM supplementation during early gestation increases allometric growth of fetal cardiac and skeletal muscle tissue. Day 63 is within the period of peak primary myogenesis in cattle, therefore differences in muscle growth during this time could have lasting implications in post-natal calf growth and performance.

56 Vitamin and Mineral Supplementation Throughout Gestation Affects Liver Trace Mineral Status of Dam and Neonatal Calves but not Calf Morphometric Characteristics

Objectives were to evaluate the effects of feeding a vitamin and mineral supplementation (VMSUP) to heifers throughout gestation on trace mineral status of the dam and calf, calving parameters, and calf characteristics. We hypothesized that VMSUP throughout gestation would enhance mineral status in the dam and offspring at birth and positively impact calf morphometric characteristics. Thirty-one Angus-based heifers (body weight [BW]=273.7 ± 1.10 kg) were estrous synchronized, bred with female sexed semen, then were randomly assigned to either a basal diet targeting gain of 0.45 kg/d (CON; n=14) or the basal diet plus a vitamin and mineral supplement (VTM; n=17; 113 g•heifer-1•d-1). Liver biopsies were obtained from dams at breeding, d 84 and 180 of gestation, and at calving from dams and calves. Trace mineral concentrations were determined via inductively coupled plasma mass spectrometry. Calving ease, calf vigor and body weight were recorded at birth, and body measurements were recorded at 24 h after birth. Data were analyzed using the GLM Procedure of SAS using repeated measures analysis when appropriate. In maternal liver, concentrations of selenium and copper were affected by a treatment × day interaction (P &lt; 0.0001), being greater (P &lt; 0.001) for VTM than CON at all post-breeding timepoints and decreasing (P ≤ 0.05) from d 84 to calving; while zinc, molybdenum, manganese, and cobalt were not (P ≥ 0.20) affected by treatment. In calves, concentrations of liver selenium, copper, zinc, and cobalt were greater for VTM than CON (P &lt; 0.05). Gestation length, calving distribution, ease and vigor scores, calf BW and body measurements were not affected by treatment (P = 0.278). Therefore, VTM supplementation throughout gestation affected liver trace mineral reserves of dam and calf; but did not affect calf size or any of the calving parameters evaluated. These results suggest that as gestation progresses, maternal liver mineral stores decrease to provide for the gestating calf.

59 Divergent Planes of Nutrition Altered Concentrations of Hormones and Metabolites but not Semen Characteristics in Mature Rams

Objectives were to evaluate impacts of divergent planes of nutrition on body weight (BW), hormone and metabolite concentrations, and semen characteristics in rams. Mature Rambouillet rams (n = 24, BW = 83.1 ± 2.64 kg) were individually housed and randomly assigned to positive (POS; n = 8), maintenance (MAINT; n = 8), or negative (NEG; n = 8) planes of nutrition for 84 d. Rams were fed a common diet with feed allocations adjusted weekly based on BW to achieve targeted weight gain or loss (approximately 12% initial BW). On d 0, 28, 56, and 84, body condition scores (BCS) and scrotal circumference (SC) were recorded, and blood and semen were collected. Blood was analyzed for triiodothyronine (T3), thyroxine (T4), testosterone, insulin-like growth factor-1 (IGF-1), glucose, and non-esterified fatty acids (NEFA). Semen was collected via electroejaculation and analyzed by Computer Assisted Semen Analysis. Data were analyzed with the GLM or MIXED procedure of SAS, with ram as experimental unit and significance determined at P &lt; 0.05. By design, BW was influenced by a treatment × day interaction (P &lt; 0.0001), and daily weight change was greater (P &lt; 0.0001) for POS (0.11 ± 0.011 kg) than MAINT (0.01 ± 0.011 kg), which was greater (P &lt; 0.0001) than NEG (-0.12 ± 0.011 kg). Consequently, BCS, and SC were greater for POS than NEG as evidenced by a treatment × day interaction (P &lt; 0.0001). Concentrations of T3, IGF-1, and NEFA were increased in POS compared with NEG and MAINT by day 84 (P ≤ 0.03), whereas T4, testosterone, and glucose remained unaffected (P ≤ 0.39). No differences were observed among treatments for semen volume/concentration, motility, or morphology (P ≤ 0.49). Collectively, BW, hormone, and metabolites differed among treatments, indicating a potential for epigenetic alterations which could influence offspring outcomes.

Bovine Animal Model for Studying the Maternal Microbiome, in utero Microbial Colonization and Their Role in Offspring Development and Fetal Programming

Recent developments call for further research on the timing and mechanisms involved in the initial colonization of the fetal/infant gut by the maternal microbiome and its role in Developmental Origins of Health and Disease (DOHaD). Although progress has been made using primarily preterm infants, ethical and legal constraints hinder research progress in embryo/fetal-related research and understanding the developmental and mechanistic roles of the maternal microbiome in fetal microbial imprinting and its long-term role in early-life microbiome development. Rodent models have proven very good for studying the role of the maternal microbiome in fetal programming. However, some inherent limitations in these animal models make it challenging to study perinatal microbial colonization from a biomedical standpoint. In this review, we discuss the potential use of bovine animals as a biomedical model to study the maternal microbiome, in utero microbial colonization of the fetal gut, and their impact on offspring development and DOHaD.

Epigenetic Modifier Supplementation Improves Mitochondrial Respiration and Growth Rates and Alters DNA Methylation of Bovine Embryonic Fibroblast Cells Cultured in Divergent Energy Supply

Epigenetic modifiers (EM; methionine, choline, folate, and vitamin B12) are important for early embryonic development due to their roles as methyl donors or cofactors in methylation reactions. Additionally, they are essential for the synthesis of nucleotides, polyamines, redox equivalents, and energy metabolites. Despite their importance, investigation into the supplementation of EM in ruminants has been limited to one or two epigenetic modifiers. Like all biochemical pathways, one-carbon metabolism needs to be stoichiometrically balanced. Thus, we investigated the effects of supplementing four EM encompassing the methionine–folate cycle on bovine embryonic fibroblast growth, mitochondrial function, and DNA methylation. We hypothesized that EM supplemented to embryonic fibroblasts cultured in divergent glucose media would increase mitochondrial respiration and cell growth rate and alter DNA methylation as reflected by changes in the gene expression of enzymes involved in methylation reactions, thereby improving the growth parameters beyond Control treated cells. Bovine embryonic fibroblast cells were cultured in Eagle’s minimum essential medium with 1 g/L glucose (Low) or 4.5 g/L glucose (High). The control medium contained no additional OCM, whereas the treated media contained supplemented EM at 2.5, 5, and 10 times (×2.5, ×5, and ×10, respectively) the control media, except for methionine (limited to ×2). Therefore, the experimental design was a 2 (levels of glucose) × 4 (levels of EM) factorial arrangement of treatments. Cells were passaged three times in their respective treatment media before analysis for growth rate, cell proliferation, mitochondrial respiration, transcript abundance of methionine–folate cycle enzymes, and DNA methylation by reduced-representation bisulfite sequencing. Total cell growth was greatest in High ×10 and mitochondrial maximal respiration, and reserve capacity was greatest (p &lt; 0.01) for High ×2.5 and ×10 compared with all other treatments. In Low cells, the total growth rate, mitochondrial maximal respiration, and reserve capacity increased quadratically to 2.5 and ×5 and decreased to control levels at ×10. The biological processes identified due to differential methylation included the positive regulation of GTPase activity, molecular function, protein modification processes, phosphorylation, and metabolic processes. These data are interpreted to imply that EM increased the growth rate and mitochondrial function beyond Control treated cells in both Low and High cells, which may be due to changes in the methylation of genes involved with growth and energy metabolism.

Characterization of the Microbiota Associated With 12-Week-Old Bovine Fetuses Exposed to Divergent in utero Nutrition

A recent study reported the existence of a diverse microbiota in 5-to-7-month-old calf fetuses, suggesting that colonization of the bovine gut with so-called “pioneer” microbiota may begin during mid-gestation. In the present study, we investigated 1) the presence of microbiota in bovine fetuses at early gestation (12 weeks), and 2) whether the fetal microbiota is influenced by the maternal rate of gain or dietary supplementation with vitamins and minerals (VTM) during early gestation. Amniotic and allantoic fluids, and intestinal and placental (cotyledon) tissue samples obtained from fetuses (n = 33) on day 83 of gestation were processed for the assessment of fetal microbiota using 16S rRNA gene sequencing. The sequencing results revealed that a diverse and complex microbial community was present in each of these fetal compartments evaluated. Allantoic and amniotic fluids, and fetal intestinal and placenta microbiota each had distinctly different (0.047 ≥ R² ≥ 0.019, P ≤ 0.031) microbial community structures. Allantoic fluid had a greater (P < 0.05) microbial richness (number of OTUs) (Mean 122) compared to amniotic fluid (84), intestine (63), and placenta (66). Microbial diversity (Shannon index) was similar for the intestinal and placental samples, and both were less diverse compared with fetal fluid microbiota (P < 0.05). Thirty-nine different archaeal and bacterial phyla were detected across all fetal samples, with Proteobacteria (55%), Firmicutes (16.2%), Acidobacteriota (13.6%), and Bacteroidota (5%) predominating. Among the 20 most relatively abundant bacterial genera, Acidovorax, Acinetobacter, Brucella, Corynebacterium, Enterococcus, Exiguobacterium, and Stenotrophomonas differed by fetal sample type (P < 0.05). A total of 55 taxa were shared among the four different microbial communities. qPCR of bacteria in the intestine and placenta samples as well as scanning electron microscopy imaging of fetal fluids provided additional evidence for the presence of a microbiota in these samples. Minor effects of maternal rate of gain and VTM supplementation, and their interactions on microbial richness and composition were detected. Overall, the results of this study indicate that colonization with pioneer microbiota may occur during early gestation in bovine fetuses, and that the maternal nutritional regime during gestation may influence the early fetal microbiota.

Programming of Embryonic Development

Assisted reproductive techniques (ART) and parental nutritional status have profound effects on embryonic/fetal and placental development, which are probably mediated via "programming" of gene expression, as reflected by changes in their epigenetic landscape. Such epigenetic changes may underlie programming of growth, development, and function of fetal organs later in pregnancy and the offspring postnatally, and potentially lead to long-term changes in organ structure and function in the offspring as adults. This latter concept has been termed developmental origins of health and disease (DOHaD), or simply developmental programming, which has emerged as a major health issue in animals and humans because it is associated with an increased risk of non-communicable diseases in the offspring, including metabolic, behavioral, and reproductive dysfunction. In this review, we will briefly introduce the concept of developmental programming and its relationship to epigenetics. We will then discuss evidence that ART and periconceptual maternal and paternal nutrition may lead to epigenetic alterations very early in pregnancy, and how each pregnancy experiences developmental programming based on signals received by and from the dam. Lastly, we will discuss current research on strategies designed to overcome or minimize the negative consequences or, conversely, to maximize the positive aspects of developmental programming.

PSVIII-22 Maternal vitamin and mineral supplementation affect fetal hepatic expression of genes underlying mineral homeostasis and lipid metabolism in early pregnancy

Vitamins and minerals play critical roles in functions such as hormone production, DNA synthesis, regulation of gene expression, and lipid metabolism. However, the impact of vitamin and mineral supplementation on fetal programming and the interplay with gene expression of fetal organs remains unclear. We used a differential gene expression analysis to determine effects of maternal vitamin and mineral supplementation (from pre-breeding to d 83 post-breeding) on fetal hepatic gene expression and the pathways underlying liver function and metabolism at 83 d of gestation. Crossbred Angus beef heifers were supplemented (VTM, n = 7) or not (CON, n = 8) with 113 g•heifer-1•d-1 of mineral premix (Purina® Wind & Rain Storm All-Season 7.5 Complete) from a minimum d 71 before breeding through d 83 of gestation. After breeding, heifers were fed to gain 0.79 kg/d. All heifers were surgically ovariohysterectomized on d 83 and fetal liver collected. Total RNA was isolated from the fetal liver (n = 15) and gene expression measured with RNA-Seq. After library quality control and read mapping, differential expression was performed using edgeR. We identified 53 genes upregulated and 37 downregulated in the VTM group (adj.Pval &lt; 0.1). Genes involved with mineral homeostasis, such as MT1A, MT1E, and MT2A, were among those differentially expressed underlying the mineral absorption pathway. ABCA1 and ABCA6, which are involved in cholesterol and metal ion transport across the plasma membrane, and PPARG and SDR16C5, that act on lipoprotein transport and metabolism, were upregulated in the VTM group. Also upregulated in the VTM group, the CUBN gene plays a role in vitamin and iron metabolism. In summary, maternal vitamin and mineral supplementation from pre-breeding to d 83 of gestation leads to upregulation of fetal hepatic genes acting on mineral homeostasis, lipid transport, and metabolism.

254 Effects of Nutrition on Bull Fertility

The greatest effects of nutrition on bull fertility occur by providing a relatively high plane of nutrition during calfhood when the seminiferous epithelium of the testes is developing. A high plane of nutrition from 5 to 25 weeks of age results in greater circulating gonadotropin concentrations, greater testicular volume, and greater sperm production at maturity. At this age, diet can be manipulated by creep feeding bull calves with both protein and energy supplements which could accelerate puberty and increase sperm production. Increased rate of gain in bull calves post-weaning can accelerate puberty a few weeks, but excess post-weaning gain and fat buildup in the neck of the scrotum can have detrimental effects on fertility. Considerable emphasis has been placed on specific micronutrient (especially minerals) effects on peripubertal bull fertility. Trace mineral supplementation is believed to be critical for optimal fertility and both copper (Cu) and zinc (Zn) supplementation have influenced male fertility in other species. However, there are no guidelines for recommended levels of these minerals to ensure fertility. Providing organic or complexed compared to inorganic mineral to peripubertal bulls have increased liver concentrations of mineral and in some cases, have accelerated puberty, but enhanced fertility-associated measures have not been realized. Because both Cu and Zn are present in the ejaculate, mineral needs during the breeding season may differ from the off-season. During the breeding season, bulls can lose 10 to 20% of their weight and need to re-gain this weight before the next breeding season. Divergent planes of nutrition provided to mature bulls during the off-season revealed enhanced sperm energy and stress-fighting potential with decreasing plane of nutrition. Specific mineral supplementation during the off-season in mature bulls provides no beneficial effect on fertility-associated measures. In summary, significant effects of nutrition post-weaning on bull fertility-associated measures have not been realized.

302 Vitamin and Mineral Supplementation and Rate of Gain in Beef Heifers: Effects on Fetal Trace Mineral Reserves at Day 83 of Gestation

Thirty-five crossbred Angus heifers (body weight = 359.5 &gt;± 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 &lt; 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 &lt; 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.