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Simple Summary: Understanding placental vascularity is vital for ensuring the proper nourishment of the fetus and, therefore, a healthy offspring. We aimed to investigate the impact of vitamin and mineral supplementation and/or different rates of body weight gain on placental vascularity in beef heifers. To this end, in the first experiment, heifers were divided into groups that received vitamin and mineral supplementation or did not at least 72 days before breeding. At breeding, they were further divided into low or moderate-weight gain groups, resulting in four different treatments maintained until day 83 of pregnancy when tissue collection was performed. In the second experiment, another group of heifers received a basal diet or a diet with vitamin and mineral supplementation from breeding until parturition. We evaluated placental blood vessel density in both experiments and the placental expression of genes related to blood vessel growth in the first experiment. Results showed that supplementation and the rate of body weight gain during early pregnancy did not significantly affect placental vascularity or the expression of angiogenic factors. On the other hand, placental vascularity measured at parturition was increased in the fetal placenta of the supplemented group. These findings suggest that supplementation with vitamins and minerals throughout all gestation may impact placental function at a later stage of pregnancy. The effect of vitamins and minerals supplementation (VTM) and/or two rates of body weight gain (GAIN) on bovine placental vascular development and angiogenic factors gene expression were evaluated in two experiments: In Exp. 1, crossbred Angus heifers (n = 34) were assigned to VTM/NoVTM treatments at least 71 days before breeding to allow changes in the mineral status. At breeding, through artificial insemination (AI), heifers were assigned to low-gain (LG) 0.28 kg/d or moderate-gain (MG) 0.79 kg/d treatments, resulting in NoVTM-LG (Control; n = 8), NoVTM-MG (n = 8), VTM-LG (n = 9), and VTM-MG (n = 9) until day 83 of gestation; In Exp. 2, crossbred angus heifers (n = 28), were assigned to control (CON; n = 12), receiving a basal total mixed ration (TMR) or TMR + VTM (VTM; n = 16) from breeding until parturition. Placentomes from Exp. 1 and cotyledons (COT) from Exp. 2 were evaluated by immunohistochemistry for COT vascular density area. COTs from Exp. 1 were evaluated for angiogenic factor (ANGPT-1, ANGPT-2, eNOS2, eNOS3, FLT1, KDR, TEK, VEGFA) gene expression. In Exp. 1, COT vascularity was not affected by the interaction of VTM and GAIN (p = 0.67) or the main effects of VTM (p = 0.50) and GAIN (p = 0.55). Likewise, angiogenic factors were not differentially expressed between treatments (p < 0.05). In Exp. 2, COT vascularity was greater in VTM vs. CON (p = 0.07). In conclusion, there is a suggested later-stage influence of vitamin and mineral supplementation on placental vascularity, emphasizing the importance of supplementation beyond early pregnancy. [ABSTRACT FROM AUTHOR]

Simple Summary: Trace minerals play a critical role in several biological functions, being essential for fetal growth and development. Maternal nutrition influences the supply of trace minerals to the fetus, which can lead to long-term consequences on offspring performance and health. Our study shows that a maternal vitamin and mineral supplementation (VTM) pre-breeding and during the first trimester of gestation resulted in greater concentrations of Se, Cu, and Co in the liver of beef heifers and their fetuses. These minerals are an essential component of the antioxidant system, which may have positive impacts on the immune system of the future offspring. In addition, we reported that low rates of gain (LG, 0.28 kg/d) from breeding to d 83 of gestation resulted in greater concentrations of Mo and Co in fetal liver compared with moderate rates of gain (MG, 0.79 kg/d). Having a greater fetal trace mineral reserve may be beneficial for neonates, as the immune system of newborn calves is underdeveloped and minerals play a role in that development. Therefore, our study shows that liver weight and concentrations of hepatic trace minerals are affected by maternal dietary treatments, which may impact the performance and health of the future offspring. We evaluated the effects of vitamin and mineral supplementation (from pre-breeding to day 83 of gestation) and two rates of gain (from breeding to day 83 of gestation) on trace mineral concentrations in maternal and fetal liver, fetal muscle, and allantoic (ALF) and amniotic (AMF) fluids. Crossbred Angus heifers (n = 35; BW = 359.5 ± 7.1 kg) were randomly assigned to one of two vitamin and mineral supplementation treatments (VMSUP; supplemented (VTM) vs. unsupplemented (NoVTM)). The VMSUP factor was initiated 71 to 148 d before artificial insemination (AI), allowing time for the mineral status of heifers to be altered in advance of breeding. The VTM supplement (113 g·heifer−1·d−1) provided macro and trace minerals and vitamins A, D, and E to meet 110% of the requirements specified by the NASEM, and the NoVTM supplement was a pelleted product fed at a 0.45 kg·heifer−1·day−1 with no added vitamin and mineral supplement. At AI, heifers were assigned to one of two rates of gain treatments (GAIN; low gain (LG) 0.28 kg/d or moderate gain (MG) 0.79 kg/d) within their respective VMSUP groups. On d 83 of gestation fetal liver, fetal muscle, ALF, and AMF were collected. Liver biopsies were performed prior to VMSUP factor initiation, at the time of AI, and at the time of ovariohysterectomy. Samples were analyzed for concentrations of Se, Cu, Zn, Mo, Mn, and Co. A VMSUP × GAIN × day interaction was present for Se and Cu (p < 0.01 and p = 0.02, respectively), with concentrations for heifers receiving VTM being greater at AI and tissue collection compared with heifers not receiving VTM (p < 0.01). A VMSUP × day interaction (p = 0.01) was present for Co, with greater (p < 0.01) concentrations for VTM than NoVTM at the time of breeding. VTM-MG heifers had greater concentrations of Mn than all other treatments (VMSUP × GAIN, p < 0.01). Mo was greater (p = 0.04) for MG than LG, while Zn concentrations decreased throughout the experiment (p < 0.01). Concentrations of Se (p < 0.01), Cu (p = 0.01), Mn (p = 0.04), and Co (p = 0.01) were greater in fetal liver from VTM than NoVTM. Mo (p ≤ 0.04) and Co (p < 0.01) were affected by GAIN, with greater concentrations in fetal liver from LG than MG. In fetal muscle, Se (p = 0.02) and Zn (p < 0.01) were greater for VTM than NoVTM. Additionally, Zn in fetal muscle was affected by GAIN (p < 0.01), with greater concentrations in LG than MG. The ALF in VTM heifers (p < 0.01) had greater Se and Co than NoVTM. In AMF, trace mineral concentrations were not affected (p ≥ 0.13) by VMSUP, GAIN, or their interaction. Collectively, these data suggest that maternal nutrition pre-breeding and in the first trimester of gestation affects fetal reserves of some trace minerals, which may have long-lasting impacts on offspring performance and health. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Simple Summary: Cow-calf operations rely mostly in forage-based systems. Different supplementation strategies are used by beef producers in order to overcome nutrient deficiencies and achieve targeted growth or reproductive performances. This study provides information on the impacts of feeding pregnant replacement heifers with vitamin/mineral and protein/energy supplements on heifer performance and fetal outcomes. Our study shows that moderate rates of gain (achieved via protein/energy supplementation) resulted in fetuses with heavier femurs and reduced liver mass relative to fetal body weight. Moreover, vitamin and mineral supplementation increased fetal liver mass, and vitamin and mineral supplementation combined with moderate gain treatments resulted in greater fetal intestinal weights. These findings indicate that replacement heifer nutrition during early gestation can alter the development of organs in the fetus that are relevant for future offspring performance. Liver and intestines are key organs related to energy metabolism; therefore, this study shows 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. 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. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the impacts of feeding a vitamin/mineral supplement to beef heifers throughout gestation on concentrations of immunoglobulin (Ig) in colostrum and in calf serum 24 h after consumption of maternal colostrum (Exp. 1) or a colostrum replacement product (Exp. 2). Angusbased beef heifers [n = 72, initial body weight (BW) = 380.4 ± 50.56 kg] were managed in an individual feeding system and randomly assigned to a basal diet targeting gain of 0.45 kg·heifer-1·d-1 (CON; n = 36) or the basal diet plus 113 g·heifer-1·d-1 of a vitamin/mineral supplement (VTM; n = 36). For Exp. 1 treatments began at the time of artificial insemination (AI) to sexed semen, and heifers becoming pregnant after first service AI (CON, n = 14; VTM, n = 17) continued treatments throughout gestation. At calving, heifer calves were allowed to nurse their dams and remained alongside their dams until weaning. For Exp 2. non-pregnant heifers were rebred 60 d after initial dietary treatments began and continued treatments throughout gestation, with resultant heifer calves (CON, n = 7; VTM, n = 7) being removed from their dams at birth and receiving 1.5 L of colostrum replacer containing 150 g globulin protein via an esophageal feeder, followed every 12 h by 1.9 L of milk replacer. In both experiments samples of colostrum were collected after completely milking the rear-right quarter of the udder. Blood samples were collected from calves before (within 2 h of birth) and 24 h after colostrum consumption. Concentrations of IgG, IgM, and IgA were quantified in colostrum and serum via bovine radial immunodiffusion plates. Data for both experiments were analyzed for the effect of treatment using the MIXED procedure in SAS, with additional analysis of data from Exp. 1 using the CORR procedure to determine correlations among dam colostrum and calf serum Ig concentrations at 24 h. In both experiments, maternal treatment did not affect (P = 0.21) concentrations of IgG, IgM, or IgA in colostrum at calving or in calf serum at 24 h. All calves from both experiments had undetectable concentrations of these respective immunoglobulins at birth. Concentrations of IgG at 24 h in calves that received maternal colostrum were 2,595.8 ± 535.38 mg/dL (Exp. 1), whereas those that received colostrum replacer were 1,610.6 ± 335.09 mg/dL (Exp. 2). Concentrations of IgG, IgM, and IgA were positively correlated (r = 0.34; P = 0.05) with concentrations of calf serum IgG, IgM, and IgA at 24 h after suckling. Our results suggest that maternal vitamin/mineral supplementation throughout gestation did not impact Ig concentrations in colostrum or the resultant serum Ig concentrations in calves either 24 h after suckling or after delivery of a commercial colostrum replacer. [ABSTRACT FROM AUTHOR]

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), VTMNoNRG (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 [ABSTRACT FROM AUTHOR]

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

Vitamins and minerals are essential for proper fetal and placental development and function. However, the impact of micronutrient supplementation on placental function and gene expression remains unclear. Herein, we performed a transcriptomic analysis to determine the impact of pre-breeding maternal micronutrient supplementation on the gene expression of placental caruncles (CAR; maternal placenta). Crossbred Angus beef heifers were supplemented (VTM, n = 7) or not (CON, n = 7) with 113 g•heifer-1•d-1 of mineral premix (Purina® Wind & Rain® Storm® All-Season 7.5 Complete) from d 71 to 148 before breeding and until d 83 of gestation. After breeding, heifers were fed a diet to gain 0.79 kg/d. Uteroplacental tissues were collected at d 83. The largest placentome closest to the fetus was collected, and CAR was manually dissected from the cotyledon. Total RNA was isolated from CAR, and gene expression was measured with RNA-Seq. After data quality control and read mapping, differential expression was performed using DESeq2. We identified 46 upregulated and 19 downregulated genes in the VTM group (adj.Pval < 0.1). ShinyGO pathway analysis software was used to identify genes in the Ca and CGMP-PKG signaling pathways, including CALM2 and CAMK2G, which were down and upregulated, respectively. Calcium-mediated systems may activate steroidogenic activity in bovine placentomes, while the cGMP-PKG pathway plays a key role in vascular homeostasis mediated by nitric oxide and decreased Ca concentrations. Furthermore, biological processes underlying blood circulation were among those over-represented. Previous studies report that maternal nutrition may impact placental vascularity and uterine blood flow. ATP2B, that is upregulated in the VTM group, is a calcium/calmodulin-regulated, magnesiumdependent protein involved in intracellular Ca homeostasis. In summary, pre-breeding and early gestation maternal micronutrient supplementation leads to differential expression of genes involved in Ca homeostasis and has a putative effect on placenta vascular function. [ABSTRACT FROM AUTHOR]

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

In the present study, we evaluated whether the nasopharyngeal, ruminal, and vaginal microbiota would diverge (1) in virgin yearling beef heifers (9 months old) due to the maternal restricted gain during the first trimester of gestation; and (2) in pregnant beef heifers in response to the vitamin and mineral (VTM) supplementation during the first 6 months of pregnancy. As a secondary objective, using the microbiota data obtained from these two cohorts of beef heifers managed at the same location and sampled at the same time, we performed a holistic assessment of the microbial ecology residing within the respiratory, gastrointestinal, and reproductive tract of cattle. Our 16S rRNA gene sequencing results revealed that both α and β-diversity of the nasopharyngeal, ruminal and vaginal microbiota did not differ between virgin heifers raised from dams exposed to either a low gain (targeted average daily gain of 0.28 kg/d, n = 22) or a moderate gain treatment (0.79 kg/d, n = 23) during the first 84 days of gestation. Only in the vaginal microbiota were there relatively abundant genera that were affected by maternal rate of gain during early gestation. Whilst there was no significant difference in community structure and diversity in any of the three microbiota between pregnant heifers received no VTM (n = 15) and VTM supplemented (n = 17) diets, the VTM supplementation resulted in subtle compositional alterations in the nasopharyngeal and ruminal microbiota. Although the nasopharyngeal, ruminal, and vaginal microbiota were clearly distinct, a total of 41 OTUs, including methanogenic archaea, were identified as core taxa shared across the respiratory, gastrointestinal, and reproductive tracts of both virgin and pregnant heifers. [ABSTRACT FROM AUTHOR]

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

Objectives were to determine the influence of a vitamin and mineral supplement (VTM), an energy supplement (NRG), and day post-artificial insemination (DPAI) on concentrations of glucose and non-esterified fatty acids (NEFA) in beef heifers. Cross-bred heifers (n = 72; initial weight = 351.2 kg) were assigned to 4 treatments arranged as a 2 × 2 factorial with main factors of VTM and NRG supplement. Treatments were: 1) control (no VTM or NRG), 2) VTM (initiated 71 to 106 before breeding) only, 3) NRG (initiated at breeding) only, and 4) VTM and NRG. Heifers were synchronized then bred via artificial insemination on d 0. Blood was drawn on d -9, 14, 28, and 42 from all heifers and on d 56, 70, and 84 from pregnant heifers (n = 31). Plasma samples were analyzed for concentrations of glucose and NEFA. Data were analyzed using the MIXED procedure in SAS. There were no interactions between VTM, NRG, or DPAI (P > 0.05). In addition, pregnancy status did not influence concentrations of glucose or NEFA (P > 0.05). There were no effects (P > 0.35) of VTM on glucose or NEFA concentrations. Energy supplementation increased (P = 0.012) glucose and decreased (P = 0.013) NEFA concentrations. Glucose concentrations were greatest at d -9, decreased through d 42, and then, on d 70 and 84 increased to levels similar to d -9 (81.9, 76.1, 73.6, 73.7, 74.3, 76.2, and 78.4 ± 2.97 for d -9, 14, 28, 42, 56, 70, and 84, respectively). Concentrations of NEFA were greater (P < 0.01) at d -9 compared with 14, 28, 42, 56, and 70, and concentrations on d 84 were greater (P < 0.01) than all other days. In conclusion, glucose and NEFA were affected by NRG and DPAI, but not VTM. [ABSTRACT FROM AUTHOR]

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. • Genes involved with nutrient transport and tissue differentiation and remodeling were differentially expressed between the fetal and maternal tissues. • The Wnt pathway is likely repressed in cotyledon at day 83 of pregnancy. • Downregulated differentially expressed genes are involved with immune tolerance in the fetal placental tissue. • Key transcription factors play a key role in modulating gene expression between cotyledon and caruncle. • Paternally imprinted genes were upregulated in the cotyledon tissue. [ABSTRACT FROM AUTHOR]