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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.

Selenium (Se) is an essential micronutrient with beneficial effects on performance and immune function. Selenium plays a key role in enzymatic and metabolic pathways, primarily through selenocysteine-containing proteins. Despite increasing knowledge on the role of Se on conceptus development, less is known about its effects on maternal immune responses during gestation. Thus, our goal was to investigate the effects of supranutritional Se-supplementation during different trimesters of pregnancy on gene expression of monocyte blood cells and the underlying biological pathways. To this end, crossbred Angus cows (n = 40) received, except for the control group (CTR), Se-yeast boluses (105 mg of Se/wk) during the first (TR1), second (TR2), or third (TR3) trimester of gestation. Before calving, blood samples were collected from a jugular vein, and the monocytes were isolated and used for total RNA extraction. After quality control of the RNA-Seq data, 13,810 genes were tested for differential expression analysis using a t-test method implemented in the CeTF R-package. We identified 3,904 unique differentially expressed genes (DEGs) across all group comparisons (FDR < 0.05). Differentially expressed selenoprotein-coding genes included SELENOI, SELENOM, SELENON, SELENOP, SELENOT, and SEPSECS. Most of these genes were downregulated in the Se-supplemented groups compared with CTR. However, SELONOP was upregulated in TR1 and TR2 groups, and SELENOM in TR3 compared with CTR. Biological processes over-represented by the DEGs, were retrieved using the WebGestalt software (FDR < 0.05). Immune-related biological processes included positive regulation of the immune system process, immune system development, leukocyte migration, and inflammatory response. Genes underlying these biological processes included ILDR1, IL21R, IL9R, and IL18BP, all of which were upregulated in TR2 compared with CTR. On the other hand, IL1R1, IL6R, and IL1RN genes were downregulated in the Se-supplemented groups. Our results provide evidence that genes underlying immune cell function and Se metabolism were affected by supranutritional Se supplementation.

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

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

The hypothesis of this experiment was that dietary fructose would influence visceral organ mass, carbohydrase activity, and mRNA expression of carbohydrases and nutrient transporters in the small intestine in neonatal calves. Therefore, our objective was to use the neonatal calf as a model to evaluate the effects of postruminal fructose supply on small intestinal carbohydrate assimilation. Ten calves (

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 < 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.

The objectives of this study were to investigate the impacts of varying levels of one-carbon metabolite [OCM: folate (FA), vitamin B12 (B12), methionine (Met), and choline (Chol)] supplementation on the gene expression of hepatic methionine-folate cycle enzymes at d 14 of the estrous cycle in beef heifers. In this study, 30 Angus beef heifers were fed a standard diet (SHD: 75% alfalfa/grass hay mix, 21% corn silage, and 4% mineral pellet without rumensin) and assigned to 1 of 5 different structures (0XNEG = SHD + 0.9% saline injection; 0XPOS = SHD + rumen protected Met fed at 0.08% inclusion on a DM basis + 60 g/d rumen protected Chol + 0.9% saline injection; 0.5X = SHD + same Met and Chol + 5 mg B12 + 80 mg FA; 1X = SHD + same Met and Chol + 10 mg B12 + 160 FA; and 2X = SHD + same Met and Chol + 20 mg B12 + 320 mg FA) with injections given at d 0 and 7 of the estrous cycle. Heifers were harvested on d 14 of the estrous cycle. Real-time PCR analysis followed by statistical contrasts revealed that combined B12 and FA treatments had greater (P < 0.05) methionine adenosyltransferase 2A (MAT2A), methionine adenosyltransferase 2B (MAT2B), and protein arginine methyltransferase 1 (PRMT1) expression compared with 0XPOS. The FA treatments yielded linear increases (P < 0.05) in MAT2A, MAT2B, PRMT1, glycine N-methyltransferase (GNMT), 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR), and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) and tended (P < 0.072) to linearly increase methylenetetrahydrofolate reductase (MTHFR) expression. DNA methyltransferase 1, DNA methyltransferase 3A, and methionine adenosyltransferase 1A, were unaltered by treatments. Data are interpreted to imply that strategic supplementation of OCM can increase expression of key genes in the one-carbon metabolic pathways found in the liver of beef heifers.

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.

Maternal nutritional status affects conceptus development and, therefore, embryonic survival, growth, and development. These effects are apparent very early in pregnancy, which is when most embryonic losses occur. Maternal nutritional status has been shown to affect conceptus growth and gene expression throughout the periconceptual period of pregnancy (the period immediately before and after conception). Thus, the periconceptual period may be an important “window” during which the structure and function of the fetus and the placenta are “programmed” by stressors such as maternal malnutrition, which can have long-term consequences for the health and well-being of the offspring, a concept often referred to as Developmental Origins of Health and Disease (DOHaD) or simply developmental programming. In this review, we focus on recent studies, using primarily animal models, to examine the effects of various maternal “stressors,” but especially maternal malnutrition and Assisted Reproductive Techniques (ART, including in vitro fertilization, cloning, and embryo transfer), during the periconceptual period of pregnancy on conceptus survival, growth, and development. We also examine the underlying mechanisms that have been uncovered in these recent studies, such as effects on the development of both the placenta and fetal organs. We conclude with our view of future research directions in this critical area of investigation.

Maternal nutritional status affects conceptus development and, therefore, embryonic survival, growth, and development. These effects are apparent very early in pregnancy, which is when most embryonic losses occur. Maternal nutritional status has been shown to affect conceptus growth and gene expression throughout the periconceptual period of pregnancy (the period immediately before and after conception). Thus, the periconceptual period may be an important "window" during which the structure and function of the fetus and the placenta are "programmed" by stressors such as maternal malnutrition, which can have long-term consequences for the health and well-being of the offspring, a concept often referred to as Developmental Origins of Health and Disease (DOHaD) or simply developmental programming. In this review, we focus on recent studies, using primarily animal models, to examine the effects of various maternal "stressors," but especially maternal malnutrition and Assisted Reproductive Techniques (ART, including in vitro fertilization, cloning, and embryo transfer), during the periconceptual period of pregnancy on conceptus survival, growth, and development. We also examine the underlying mechanisms that have been uncovered in these recent studies, such as effects on the development of both the placenta and fetal organs. We conclude with our view of future research directions in this critical area of investigation.

Selenium (Se) is an essential micronutrient for growth and immune function in beef cattle. We previously showed that supranutritional maternal organic Se supplementation during late pregnancy improves immune function in their newborn calves; however, the effects of maternal organic Se-supplementation on fetal programming during different pregnancy stages have yet to be elucidated. Herein, we investigated the effects of supranutritional maternal organic Se-supplementation in different pregnancy trimesters on their beef calf’s genome-wide transcriptome profiles. Within 12 to 48 h of birth, whole blood and Longissimus dorsi (LD) muscle biopsies were collected from calves born to 40 crossbred Angus cows that received, except for the control group (CTR), Se-yeast boluses (105 mg of Se/wk) during the first (TR1), second (TR2), or third (TR3) trimester of gestation. Whole-blood Se concentrations of newborn calves increased from CTR, TR1, TR2 to TR3, whereas muscle Se concentrations of newborn calves were only increased in TR3 group. We identified 3048 unique differentially expressed genes (DEGs) across all group comparisons (FDR ≤ 0.05 and |log2FC| ≥ 1.5). Furthermore, we predicted 237 unique transcription factors that putatively regulate the DEGs. Independent of supplementation trimester, supranutritional maternal organic Se supplementation downregulated genes involved in adaptive immunity in all trimesters. Dependent on supplementation trimester, genes involved in muscle development were upregulated by TR3 Se supplementation and downregulated by TR1 Se-supplementation, and genes involved in collagen formation were downregulated by TR2 Se-supplementation. Supranutritional maternal organic Se supplementation in the last trimester of pregnancy resulted in upregulation of myosin and actin filament associated genes, potentially allowing for optimal muscle function and contraction. Our findings suggest a beneficial effect of supranutritional maternal organic Se supplementation during late gestation on Se-status and muscle development and function of newborn calves.

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 the microbiota in bovine fetuses at early gestation. Amniotic and allantoic fluids, and intestinal and placental (cotyledon) tissue samples harvested 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 allantoic and amniotic fluids, and fetal intestine and placenta on day 83 of gestation in beef cattle. Microbial community structure was significantly different between allantoic and amniotic fluid, and intestinal and placental microbiota (0.047 ≥ R2 ≥ 0.019, P ≤ 0.031). Allantoic fluid had a greater (P < 0.05) microbial richness (number of OTUs) (122 ± 10) compared to amniotic fluid (84 ± 6), intestine (63 ± 7) and placenta (66 ± 6). Microbial diversity (Shannon index) was similar for the intestinal and placental samples, and both were less diverse compared to the fetal fluid microbiota (P < 0.05). At the phylum level, 39 different archaeal and bacterial phyla were detected across all fetal samples, with Proteobacteria (55%), Firmicutes (16.2%), Actinobacteria (13.6%) and Bacteroidetes (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. Overall, the results of this study indicate that colonization with pioneer microbiota may occur during early gestation in bovine fetuses.

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

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.

The cotyledon and caruncle tissues provide a functional bridge between the fetus and the dam. However, the relationship between these tissues and the transcriptomic profile that underlies the tissue functions remains elusive. Herein we investigate the expression profile of cotyledon and caruncle from nulliparous beef heifers carrying female fetuses at day 83 of pregnancy to identify changes occurring across tissues that contribute to placental function and their tissue-specific roles. We identified 2654 differentially expressed genes [padj ≤ 0.05, abs(log2FC) ≥ 1], including nutrient transporters and paternally imprinted genes. We found key regulators of tissue function and differentiation, including FOXO4, GATA2, GATA3, and HAND1, rewired between the tissues. Finally, we shed light on the over-represented pathways related to immune tolerance, tissue differentiation and remodeling. Our findings highlighted the intricate and coordinated cross-talk between fetal-maternal tissues. They provided evidence of a fine-tuned gene regulatory network underlying pregnancy and tissue-specific function in the bovine placenta.

Our research group demonstrated that vitamin A restriction affected meat quality of Angus cross and Simmental steers. Therefore, the aim of this study is to highlight the genotype variations in response to dietary vitamin A levels. Commercial Angus and Simmental steers (n = 32 per breed; initial BW = 337.2 ± 5.9 kg; ~8 months of age) were fed a low-vitamin A (LVA) (1017 IU/kg DM) backgrounding diet for 95 days to reduce hepatic vitamin A stores. During finishing, steers were randomly assigned to treatments in a 2 × 2 factorial arrangement of genotype × dietary vitamin A concentration. The LVA treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM); the control (CON) was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM. Blood samples were collected at three time points throughout the study to analyze serum retinol concentration. At the completion of finishing, steers were slaughtered at a commercial abattoir. Meat characteristics assessed were intramuscular fat concentration, color, Warner-Bratzler shear force, cook loss and pH. Camera image analysis was used for determination of marbling, 12th rib back fat and longissimus muscle area (LMA). The LVA steers had lower (P < 0.001) serum retinol concentration than CON steers. The LVA treatment resulted in greater (P = 0.03) average daily gain than the CON treatment, 1.52 and 1.44 ± 0.03 kg/day, respectively; however, there was no effect of treatment on final BW, DM intake or feed efficiency. Cooking loss and yield grade were greater and LMA was smaller in LVA steers (P < 0.05). There was an interaction between breed and treatment for marbling score (P = 0.01) and percentage of carcasses grading United States Department of Agriculture (USDA) Prime (P = 0.02). For Angus steers, LVA treatment resulted in a 16% greater marbling score than CON (683 and 570 ± 40, respectively) and 27% of LVA Angus steers graded USDA Prime compared with 0% for CON. Conversely, there was no difference in marbling score or USDA Quality Grades between LVA and CON for Simmental steers. In conclusion, feeding a LVA diet during finishing increased marbling in Angus but not in Simmental steers. Reducing the vitamin A level of finishing diets fed to cattle with a high propensity to marble, such as Angus, has the potential to increase economically important traits such as marbling and quality grade without negatively impacting gain : feed or yield grade.

Maternal stressors that affect fetal development result in "developmental programming," which is associated with increased risk of various chronic pathologic conditions in the offspring, including metabolic syndrome; growth abnormalities; and reproductive, immune, behavioral, or cognitive dysfunction that can persist throughout their lifetime and even across subsequent generations. Developmental programming thus can lead to poor health, reduced longevity, and reduced productivity. Current research aims to develop management and therapeutic strategies to optimize fetal growth and development and thereby overcome the negative consequences of developmental programming, leading to improved health, longevity, and productivity of offspring.

We hypothesized that a moderate maternal nutrient restriction during the first 50 d of gestation in beef heifers would affect transcript abundance of genes associated with tissue metabolism, accretion, and function in fetal liver, muscle, and cerebrum. Angus-cross heifers were estrus synchronized and assigned at breeding to one of two dietary treatments (CON- 100% of nutrient requirements to gain 0.45 kg/d; RES- 60% of CON). At day 50 of gestation, 14 heifers were ovariohysterectomized, and fetal liver, muscle, and cerebrum were collected. Transcriptome analysis via RNA-seq was conducted on the Illumina HiSeq 2500 platform using 50-bp paired-end reads at a depth of 2 × 10.4M reads/sample. Bioinformatic analysis was performed using the Tuxedo Suite and ontological analysis with DAVID 6.8. For fetal liver, muscle, and cerebrum, a total of 548, 317, and 151 genes, respectively (P < 0.01) were differentially expressed, of which 201, 144, and 28 genes, respectively were false discovery rate protected (FDR; q < 0.10). Differentially expressed genes were screened for fit into functional categories of pathways or ontologies associated with known impacts on tissue metabolism, accretion, and function. In fetal liver, five functional categories of interest (n = 125 genes) were affected by nutritional treatment: metabolic pathways, protein kinase, nucleosome core, mRNA splicing, and complement/coagulation cascades, of which 105 genes were upregulated in RES. In fetal muscle, three functional categories of interest (n = 106 genes) were affected by nutritional treatment: skeletal muscle, embryogenesis, and signaling cascades, of which 64 genes were upregulated in RES. In fetal cerebrum, three functional categories of interest (n = 60 genes) were affected by nutritional treatment: hippocampus and neurogenesis, metal-binding, and cytoskeleton, of which 58 genes were upregulated in RES. These results demonstrate that a moderate maternal nutrient restriction during the first 50 d of gestation in beef heifers alters transcript abundance of genes potentially impacting tissue metabolism, accretion, and function in fetal liver, muscle, and cerebrum. Furthermore, these results indicate that affected categories are tissue-specific and moderate maternal nutrient restriction generally increases expression of genes in fetuses from RES fed dams. Finally, these data lay the foundation upon which further research that identifies phenotypic responses to changes in these pathways may be elucidated.

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.

The objective of this study was to evaluate different combinations of one-carbon metabolites [OCM: rumen-protected methionine (RPM), rumen-protected choline (RPC), folate (FA), vitamin B12 (B12)] on pancreatic and jejunal carbohydrase activity at d 14 of the estrous cycle in beef heifers. Thirty Angus heifers were fed a high-roughage diet and assigned to treatments: 0% RPM + 0 g/d RPC + saline injection (0XNEG), 0.08% RPM + 60 g/d RPC + saline injection (0XPOS), 0.08% RPM + 60 g/d RPC + 80 mg FA + 5 mg B12 (0.5X), 0.08% RPM + 60 g/d RPC + 160 mg FA + 10 mg B12 (1X), or 0.08% RPM + 60 g/d RPC + 320 mg FA + 20 mg B12 (2X). Dietary treatments were fed for 14 d and FA and B12 injections were given on d 0 and 7 of the estrous cycle with tissues collected on d 14. The effect of RPM+RPC supplementation was evaluated using a contrast statement comparing 0XNEG vs. others. Polynomial contrasts were used to determine effects of FA+B12 dose. Protein concentration and carbohydrase activities of the pancreas and jejunum were not influenced (P≥0.21) by RPM+RPC supplementation. Pancreatic protein concentration responded cubically (P< 0.01) to FA+B12 dose where pancreatic protein concentration was lesser for 0.5X compared with other treatments. Likewise, pancreatic α-amylase activity responded cubically (P< 0.01) to increasing FA+B12 dose because pancreatic α-amylase activity was lesser for 0.5X (182 U/g) compared with 0XPOS (350 U/g), 1X (347 U/g), and 2X (412 U/g). Jejunal protein concentration and maltase and glucoamylase activities were not influenced (P≥0.29) by FA+B12 dose. Jejunal isomaltase activity tended to decrease linearly (P=0.07) with increasing FA+B12 dose. These findings suggest that the balance of different OCM could be important for regulation of pancreatic protein turnover and α-amylase activity. USDA is an equal opportunity provider and employer.

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.

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.

Maternal nutrients are essential for proper fetal and placental development and function. However, the effects of vitamin and mineral supplementation under two rates of maternal weight gain on placental genome-wide gene expression have not been investigated so far. Furthermore, biological processes and pathways in the placenta that act in response to early maternal nutrition are yet to be elucidated. Herein, we examined the impact of maternal vitamin and mineral supplementation (from pre-breeding to day 83 post-breeding) and two rates of gain during the first 83 days of pregnancy on the gene expression of placental caruncles (CAR, maternal placenta) and cotyledons (COT, fetal placenta) of crossbred Angus beef heifers. We identified 267 unique differentially expressed genes (DEG). Among the DEGs from CAR, we identified ACAT2, SREBF2, and HMGCCS1 that underlie the cholesterol biosynthesis pathway. Furthermore, the transcription factors PAX2 and PAX8 were over-represented in biological processes related to kidney organogenesis. The DEGs from COT included SLC2A1, SLC2A3, SLC27A4, and INSIG1. Our over-representation analysis retrieved biological processes related to nutrient transport and ion homeostasis, whereas the pathways included insulin secretion, PPAR signaling, and biosynthesis of amino acids. Vitamin and mineral supplementation and rate of gain were associated with changes in gene expression, biological processes, and KEGG pathways in beef cattle placental tissues.

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 < 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.

Objectives were to evaluate effects of feeding vitamin and mineral (VTM) and (or) energy (NRG) supplements on concentrations of amino acids (AA) in heifer serum and allantoic (ALF) and amniotic (AMF) fluids at d 83 of gestation. Thirty-five crossbred Angus heifers (body weight = 359.5 ± 7.1 kg) were randomly assigned to one of four treatments (n = 8 or 9/group) in a 2 × 2 factorial arrangement with main effects of vitamin and mineral (NoVTM or VTM) and energy (NoNRG or NRG) supplements. Heifers were fed a basal total mixed ration once daily with VTM and NRG treatments top-dressed. The VTM treatment (113 g•heifer-1•d-1) was initiated 71 to 148 d before artificial insemination (AI). The NRG treatment was initiated at AI targeting gains of 0.28 kg/d for NoNRG and 0.79 kg/d for NRG. Serum, ALF, and AMF were collected at d 83 ± 0.27 of gestation and analyzed for concentrations of AA. In serum, a VTM × NRG interaction (P = 0.02) was observed for Glu, with greater concentrations for VTM-NoNRG than VTM-NRG. Concentrations of serum Cys, Met, and Trp were greater (P ≤ 0.03) for NRG than No-NRG. In ALF, concentrations of Glu were affected by a VTM × NRG interaction, where VTM-NRG was greater (P < 0.01) than all others. In ALF, VTM increased (P ≤ 0.05) concentrations of His, Asp, and 12 of the 14 neutral AA, whereas NRG increased (P ≤ 0.05) Arg, Cys, and Asp. In AMF, AA concentrations were not affected (P ≥ 0.10) by VTM, NRG, or their interaction. In conclusion, an increase in neutral AA concentration in ALF from beef heifers was observed at d 83 of gestation with VTM supplementation, suggesting effects on the mechanisms of AA uptake and balance between the maternal circulation and fetal fluid compartments.

Objectives were to evaluate effects of vitamin and mineral (VTM) and (or) energy (NRG) supplements on the abundance of the neutral amino acid (AA) transporter SLC7A5 in heifer placentomes at d 83 of gestation. Thirty-five crossbred Angus heifers (Body weight = 359.5 ± 7.1 kg) were randomly assigned to one of four treatments (n = 8 or 9/group) in a 2 × 2 factorial arrangement with main effects of vitamin and mineral (NoVTM or VTM) and energy (NoNRG or NRG) supplements. The VTM treatment was initiated 71 to 148 d before artificial insemination (AI). The NRG treatment was initiated at AI. Heifers were ovariohysterectomized at d 83 of gestation. Placentome cross sections (5 μm) were mounted onto glass slides, deparaffinized, and stained for SLC7A5. Fluorescent images of tissue areas including fetal membranes, caruncles (CAR), endometrial epithelium (EP), superficial glands (SG), deep glands (DG), and myometrium were obtained and analyzed for relative intensity of fluorescence within the areas of interest as an indicator of transporter abundance. The abundance of SLC7A5 was influenced by a VTM × NRG interaction (P = 0.05) in DG, with NoVTM-NRG being greater than heifers receiving VTM. Abundance of SLC7A5 was not influenced by NRG (P > 0.12) in any structures evaluated. In EP and SG abundance of SLC7A5 was less (P ≤ 0.05) in VTM than NoVTM heifers and tended to be less in CAR (P = 0.07). Our previous work revealed no differences in maternal serum AA concentrations, but VTM heifers had greater AA concentrations in allantoic fluid than NoVTM. We hypothesize that transporter efficiency may be reduced in NoVTM heifers, with greater transporter abundance being a mechanism of compensation to supply AA to the fetus. Together, these data help to further elucidate mechanisms of AA uptake and balance between the maternal and fetal compartments.

Fifteen mature beef bulls (BW = 800.4 ± 17.4 kg) were used in a 112-d experiment to evaluate effects of divergent planes of nutrition on body composition and concentrations of hormones and metabolites. Bulls were ranked by BW and randomly assigned to one of two treatments; 1) managed on a positive plane of nutrition (POS, n = 8), or 2) managed on a negative plane of nutrition (NEG, n = 7). Bulls were fed a common diet with deliveries into Insentec feeders adjusted biweekly to achieve targeted weight loss or gain (~12.5% of original BW). Blood samples were collected on d 0, 56, and 112. By design, bull BW was influenced by a treatment × day interaction (P < 0.0001), and POS bulls gained 1.27 ± 0.08 kg/d while NEG lost 0.93 ± 0.08 kg/d. Body condition score and scrotal circumference were similarly impacted by treatment × day interactions (P < 0.0001), both starting similar among treatments, then greater for POS than NEG thereafter. To achieve targeted weight divergence POS bulls (13.8 ± 0.45 kg/d) ate more (P < 0.0001) than NEG (5.1 ± 0.45 kg/d). Body composition was impacted (P ≤ 0.02), with rump fat, rib fat, loin muscle area, and intramuscular fat each increasing in POS and decreasing in NEG. Concentrations of NEFA in serum were greater in NEG bulls at d 56 and 112 compared with POS (treatment × day; P < 0.0001), concentrations of glucose (treatment × day; P = 0.02) were greater for POS bulls, and concentrations of urea were not impacted (P = 0.60). Additionally, concentrations of T3 and T4 on d 112 were greater (P ≤ 0.004) for POS. Our model resulted in altered body composition and profiles of hormones and metabolites which could influence semen on functional, morphological, and molecular levels.

Changes in maternal nutrition that represent inadequacies or excesses in nutrient supply have been implicated in altered fetal development as well as offspring outcomes and have been termed fetal or developmental programming. Research in the area of developmental programming of livestock has greatly increased during the last two decades. For ruminants, most research efforts in developmental programming have focused on nutritional perturbations during the last two-thirds of gestation. Unfortunately, research investigating changes to maternal nutrient supply during early gestation or even periconceptually has been limited. The objectives of this invited review are to provide a summary of our current understanding of the impacts of inappropriate maternal nutrition during early gestation on embryo-fetal and offspring developmental outcomes. Nutrient supply to the conceptus varies during the time of early placental and conceptus development, and uterine glandular secretions, often called uterine milk or uterine histotroph, are major suppliers of nutrients during this time. Nutrients in histotroph are essential to conceptus development, and histotroph nutrient concentrations may be responsive to maternal nutrient supply. As the placenta develops and becomes fully functional, fetal nutrient supply becomes dependent on placental function. Research investigating changes in total maternal nutrient supply, even during early gestation, has clearly demonstrated impacts on offspring outcomes. Investigations into supply of specific nutrients and development outcomes have increased rapidly in recent years with results demonstrating that in some cases, even small changes in supply can have consequences on offspring development. Underlying mechanisms of developmental programming are associated with epigenetic events partially driven by methyl donors and cofactors. Emerging knowledge associated with the influence of periconceptual, fetal, and neonatal nutrition on offspring development, postnatal health, function, and productivity is creating opportunities for enhanced livestock production through strategic nutrient supplementation.

During pregnancy, the placenta plays a pivotal role in fetal-maternal communication. Despite the known involvement of trophoblast mononuclear (MNC) and binuclear (BNC) cells in placentation and fetal development, the regulatory mechanisms underlying the gene expression in these cells and their role in pregnancy have not been fully elucidated. Thus, a genome-wide expression profile analysis of MNC and BNC from ovine placentomes on day 90 and 130 of pregnancy was performed to identify differentially expressed genes (DEG) and regulatory pathways. After tissue separation, enzymatic digestion, and elutriation, MNC and BNC were obtained, and the total RNA was isolated and sequenced (n = 2 ewes/day). Differential expression analysis was carried out with DESeq2 after library quality control and read mapping using FastQC and STAR, respectively. Among six pairwise contrasts possible, herein, we focused on the one between MNC and BNC on day 130. Accordingly, we identified 514 genes upregulated and 161 downregulated in BNC (adj.Pval < 0.05). Interestingly, we found nine DE long intergenic noncoding RNAs (lincRNA). Although the function of lincRNAs remains under investigation, its transcription has been associated with gene expression regulation in utero. The DEGs functional over-representation analysis included Rap1 and PI3k-Akt signaling pathways as up-regulated in BNC (adj.Pval. < 0.05). These pathways are activated by extracellular signals and are involved in cell proliferation and differentiation, morphogenesis, and energy metabolism. Furthermore, we identified PLA2G10 gene that codes a phospholipase protein involved in the production of prostaglandins, which have been associated with placental blood flow. These findings suggest an intricate and complex network underlying gene expression between cells and time points that are essential for the fetal-maternal placenta relationship. This project was supported by Agriculture and Food Research Initiative Competitive Grant n. 2016-67016-24884 from the USDA National Institute of Food and Agriculture.