Disrupted one-carbon metabolism in heifers negatively affects their health and physiology.

The objective of this study was to determine the dose-dependent response of one-carbon metabolite (OCM: methionine, choline, folate, and vitamin B12) supplementation on heifer dry matter intake on fixed gain, organ mass, hematology, cytokine concentration, pancreatic and jejunal enzyme activity, and muscle hydrogen peroxide production. 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 d 0 and 7 of the estrous cycle, 0XPOS: TMR, rumen protected methionine (MET) fed at 0.08% of the diet dry matter, rumen protected choline (CHOL) fed at 60 g/d, and saline injections at d 0 and 7, 0.5X: TMR, MET, CHOL, 5-mg B12, and 80-mg folate injections at d 0 and 7, 1X: TMR, MET CHOL, 10-mg vitamin B12, and 160-mg folate at d 0 and 7, and 2X: TMR, MET, CHOL, 20-mg vitamin B12, and 320-mg folate at d 0 and 7. All heifers were estrus synchronized but not bred, and blood samples were collected on d 0, 7, and at slaughter (d 14) during which tissues were collected. By design, heifer ADG did not differ (P = 0.96). Spleen weight and uterine weight were affected cubically (P = 0.03) decreasing from 0XPOS to 0.5X. Ovarian weight decreased linearly (P < 0.01) with increasing folate and B12 injection. Hemoglobin and hematocrit percentage were decreased (P < 0.01) in the 0.5X treatment compared with all other treatments. Plasma glucose, histotroph protein, and pancreatic α-amylase were decreased (P ≤ 0.04) in the 0.5X treatment. Heifers on the 2X treatment had greater pancreatic α-amylase compared with 0XNEG and 0.5X treatment. Interleukin-6 in plasma tended (P = 0.08) to be greater in the 0XPOS heifers compared with all other treatments. Lastly, 0XPOS-treated heifers had reduced (P ≤ 0.07) hydrogen peroxide production in muscle compared with 0XNEG heifers. These data imply that while certain doses of OCM do not improve whole animal physiology, OCM supplementation doses that disrupt one-carbon metabolism, such as that of the 0.5X treatment, can induce a negative systemic response that result in negative effects in both the dam and the conceptus during early gestation. Therefore, it is necessary to simultaneously establish an optimal OCM dose that increases circulating concentrations for use by the dam and the conceptus, while avoiding potential negative side effects of a disruptive OCM, to evaluate the long-term impacts of OCM supplementation of offspring programming.

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.

When pregnant cattle have restricted access to feed or specific nutrients, calf development can be affected, and the degree of impairment depends, at least partially, on timing, duration, and severity of the limitations. A biochemical pathway present in cells that can be affected by limited nutrition is one-carbon metabolism. This pathway is related to epigenetics, which regulates gene expression or the turning on and off of genes. Two important vitamins in one-carbon metabolism are vitamins B12 and folate. By understanding the amounts of those vitamins available to the developing calf, we can gain better insight into the regulation and potential avenues of improvement of calf growth and development. In this study, we found a nutrient restricted maternal diet increased the amount of B12 and folate in calf allantoic and amniotic fluids. We also found that folate and B12 were correlated to the presence of other nutrients in serum, allantoic fluid, and amniotic fluid. In addition, we found that a protein methylating gene in one-carbon metabolism had increased expression in calves from heifers receiving limited nutrition. This study is an important step in understanding how the nutrients available to a pregnant heifer during gestation affects nutrients available to the conceptus.

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.

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).

Effects of hempseed cake on ruminal fermentation parameters, nutrient digestibility, nutrient flow, and nitrogen balance in finishing steers.

Five ruminally and duodenally cannulated red angus steers (n = 5; initial body weight [BW] = 542 kg, SD = 40 kg) were used in a three-period Youden square design consisting of three 21-d periods, three treatments, and five steers (one or two steers per treatment within each period) to evaluate the effect of feeding hempseed cake on ruminal fermentation parameters, organic matter (OM) intake, total tract nutrient digestion, and nitrogen (N) balance in steers fed finishing diets. The control (CON) diet contained 75% dry-rolled corn, 20% corn silage, and 5% supplement (DM basis). The dried corn distillers grains plus solubles (DDGS) and hempseed cake (HEMP) diets contained 55% dry-rolled corn, 20% corn silage, 20% dried corn distillers grains plus solubles or hempseed cake, and 5% supplement (DM basis). Total ruminal volatile fatty acid concentration was greater (P < 0.01) in steers fed the HEMP diet than in steers fed the DDGS or CON diets. Ruminal fluid pH was not influenced (P = 0.93) by treatment. Organic matter intake tended (P = 0.07) to be greater and OM total tract digestibility was less (P = 0.03) in steers fed the HEMP diet compared with steers fed the DDGS or CON diets. Ruminal true and total tract apparent N digestibility was greater (P < 0.01) in steers fed the HEMP diet than steers fed the DDGS or CON diets. Duodenal flow of essential, nonessential, and total amino acids was not influenced (P ≥ 0.37) by dietary treatment, but the lack of response was likely because ruminally degradable protein (RDP) supply exceeded the RDP requirement. Steers fed the HEMP diet had greater (P < 0.01) N retention (g/d) than steers fed the DDGS diet, which was greater (P < 0.01) than steers fed the CON diet, suggesting that feeding hempseed cake improved utilization of N. Although inclusion of hempseed cake decreased total tract OM digestibility compared with dried corn distillers grains or corn, improvements in N utilization suggest that hempseed cake could be a useful alternative feed ingredient for finishing cattle diets.

This experiment evaluated the effects of dietary inclusion of hempseed cake or dried corn distillers grains plus solubles on ruminal fermentation parameters, organic matter (OM) intake, total tract nutrient digestion, and nitrogen (N) balance in steers fed finishing diets. Steers were assigned to one of three dietary treatments (no byproduct [CON], 20% dried corn distillers grains plus solubles [DDGS], or 20% hempseed cake [HEMP]; dry matter basis). Hempseed cake had greater acid detergent fiber concentrations, which resulted in greater acid detergent fiber flow to the small intestine and reduced total tract organic matter digestibility in steers fed the HEMP diet than in steers fed the DDGS or CON diets. Steers fed the HEMP diet had greater ruminal and total tract N digestibility, and greater ruminal ammonia concentrations than steers fed DDGS or CON diets, suggesting that the crude protein in hempseed cake is degraded to a greater extent in the rumen and total tract. Although inclusion of hempseed cake decreased total tract OM digestibility compared with dried corn distillers grains or no byproduct, the observed greater ruminal and total tract N digestibility suggest that it could be a useful alternative feed ingredient for finishing cattle diets.

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 ±â€…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.

The strategic inclusion of one-carbon metabolites, which include vitamins and minerals that are found in human prenatal vitamins, to beef cattle feeding and management protocols during the periconceptual period (the time around breeding) is a novel concept. Therefore, this study aimed to identify the feeding and injection doses of one-carbon metabolites in beef heifers to maintain increased circulating concentrations of one-carbon metabolites for use as a model from which other studies could base their treatments on. We determined that daily feeding of methionine and choline at 0.08% of dry matter and 60 g/d, respectively, and administration of vitamin B12 and folate at 20 mg and 320 mg once per week, respectively resulted in sustained elevated concentrations of one-carbon metabolites.

Weaning transition, but not the administration of probiotic candidate Kazachstania slooffiae, shaped the gastrointestinal bacterial and fungal communities in nursery piglets.

As in-feed antibiotics are phased out of swine production, producers are seeking alternatives to facilitate improvements in growth typically seen from this previously common feed additive. Kazachstania slooffiae is a prominent commensal fungus in the swine gut that peaks in relative abundance shortly after weaning and has beneficial interactions with other bacteriome members important for piglet health. In this study, piglets were supplemented with K. slooffiae to characterize responses in piglet health as well as fungal and bacterial components of the microbiome both spatially (along the entire gastrointestinal tract and feces) and temporally (before, during, and after weaning). Litters were assigned to one of four treatments: no K. slooffiae (CONT); one dose of K. slooffiae 7 days before weaning (day 14; PRE); one dose of K. slooffiae at weaning (day 21; POST); or one dose of K. slooffiae 7 days before weaning and one dose at weaning (PREPOST). The bacteriome and mycobiome were analyzed from fecal samples collected from all piglets at day 14, day 21, and day 49, and from organ samples along the gastrointestinal (GI) tract at day 21 and day 49. Blood samples were taken at day 14 and day 49 for cytokine analysis, and fecal samples were assayed for antimicrobial resistance. While some regional shifts were seen in response to K. slooffiae administration in the mycobiome of the GI tract, no remarkable changes in weight gain or health of the animals were observed, and changes were more likely due to sow and the environment. Ultimately, the combined microbiome changed most considerably following the transition from suckling to nursery diets. This work describes the mycobiome along the piglet GI tract through the weaning transition for the first time. Based on these findings, K. slooffiae administered at this concentration may not be an effective tool to hasten colonization of K. slooffiae in the piglet GI tract around the weaning transition nor support piglet growth, microbial gut health, or immunity. However, diet and environment greatly influence microbial community development.

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.

Interaction of replacing corn silage with soyhulls as a roughage source with or without 3% added wheat straw in the diet: impacts on intake, digestibility, and ruminal fermentation in steers fed high-concentrate diets.

Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the same three treatments repeated with 3% added wheat straw (DM basis) replacing corn in the diet (0S, 50S, and 100S, respectively). Absolute dry matter intake (DMI; kg/d basis) tended to decrease both linearly and quadratically (P ≤ 0.09) and proportional DMI (% of BW) decreased linearly (P = 0.04) with increasing soyhull inclusion but was not affected by the addition of straw in the diet (P = 0.68). Total tract digestibility of organic matter and crude protein were not affected by soyhull inclusion or added straw (P ≥ 0.32). Ruminal pH did not differ (P = 0.65) with increasing soyhull inclusion but increased with the addition of straw (P < 0.01; 5.9 vs. 6.1 for no straw and straw, respectively). Molar proportions of acetate and butyrate decreased while propionate increased with increased soyhull inclusion (P ≤ 0.03; linearly and quadratically, respectively). Ruminal fluid kinetics were unaffected by either rate of replacement of corn silage with soyhulls or wheat straw inclusion (P ≥ 0.13). Decreases in DMI observed in this study would likely decrease finishing cattle performance and underscores the need for additional research before recommending this practice to cattle feeders.

Impacts of added roughage on growth performance, digestibility, ruminal fermentation, and ruminal pH of feedlot steers fed wheat-based feedlot diets containing 30% modified distillers grains with solubles.

Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± 33.0 kg) in a 4 × 4 Latin Square with either 10%, 12%, 14%, or 16% roughage as in the feedlot experiment. However, dietary roughage source was different between these two experiments and included a combination of grass hay and wheat straw (Feedlot Experiment), and corn silage (Digestibility Experiment). All data were analyzed with the Mixed Procedures of SAS. Feed intake was recorded, with duodenal and fecal output calculated using chromic oxide. Ruminal pH and fermentation were assessed. Growth performance and most carcass characteristics were not affected by increasing roughage (P ≥ 0.11). Marbling tended to decrease linearly (P = 0.10) with increasing roughage inclusion. Increasing dietary roughage content had no effect on organic matter intake (P = 0.60) in the digestibility experiment. Intake, duodenal flow, and digestibility of neutral detergent fiber and acid detergent fiber were not affected by treatment (P ≥ 0.16). Ruminal pH increased linearly (P < 0.01) as rate of roughage inclusion increased. Ruminal concentrations of acetate and butyrate increased, and propionate decreased in a linear fashion (P < 0.01) thereby increasing (P < 0.01) acetate and butyrate to propionate ratio with increasing dietary roughage. Our data indicate that increasing roughage inclusion in wheat-based diets including 30% MDGS increased ruminal pH and shifted ruminal fermentation patterns. Additionally, increasing roughage inclusion did not affect feedlot performance in steers fed wheat at 36% to 42% of dietary dry matter in combination with 30% MDGS.

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 United States, there is an increasing interest in feeding byproducts of industrial hemp production to livestock. A completely randomized design experiment using crossbred finishing heifers (initial body weight [BW] ±â€…SE = 494 ±â€…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 the 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 d, and every 14 d BW were measured and blood samples were collected. Blood plasma was analyzed for glucose, urea nitrogen, and individual amino acids, and results were 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 for 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 with 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, nonessential 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 net energy for maintenance and gain relative to DDGS when adequate metabolizable protein is supplied, while still providing adequate nutrition to support the acceptable performance of finishing cattle.

This experiment evaluated the effects of dietary inclusion of hempseed cake in comparison with dried corn distillers grains plus solubles (DDGS) on growth performance, feeding behavior, carcass characteristics, and blood parameters in finishing heifers. Angus-crossbred heifers were assigned randomly to one of two treatments (20% hempseed cake [HEMP] or 20% DDGS; dry matter basis) and were fed for 111 d until slaughter. Heifers receiving the DDGS treatment had greater final body weights, average daily gain, gain efficiency, dietary concentration of net energy for maintenance and gain, and carcass weight than heifers fed the HEMP treatment. All other carcass characteristics, as well as feeding behavior, were not influenced by treatment. Plasma urea nitrogen was greater in heifers fed the HEMP diet compared with the DDGS diet, while glucose was not influenced by treatment. Several plasma amino acid concentrations were influenced by treatment. Although the inclusion of hempseed cake decreased growth performance, it could be a viable alternative feed source for cattle.

Impacts of bunk management on steer performance and ruminal hydrogen sulfide concentrations in steers fed modified distillers grains with solubles.

Two experiments were conducted to evaluate the impacts of bunk management on dry matter intake (DMI), growth performance, carcass characteristic, and hydrogen sulfide (H2S) concentrations in beef steers fed modified distillers grains with solubles (MDGS; DM basis). In Experiment 1, 139 steers (440.4 ± 31.0 kg) were randomly assigned to one of 16 pens with pen randomly assigned to one of two treatments: 1) Control (CON, bunks managed to be devoid of feed prior to feeding), or 2) Over-fed (OVF, bunks managed to have minimum of 2.54 cm of feed remaining each morning) during adaptation. Following adaptation all steers in Experiment 1 were transitioned to CON bunks and followed to finishing. In Experiment 2, 126 steers (445.4 ± 40.63 kg) were randomly assigned to one of 16 pens. Treatments in Experiment 2 were arranged in a 2 × 2 factorial and include the two bunk management strategies utilized in Experiment 1 (OVF or CON) and either 25% MDGS or 50% MDGS (DM basis). Ruminal H2S was measured via rumenocentesis during dietary adaptation. There were no differences (P ≥ 0.13) observed in either experiment for growth performance due to bunk management. In Experiment 1, OVF steers had greater (P = 0.001) DMI during adaptation; however, overall DMI was not different (P = 0.14) between treatments. In Experiment 2, DMI (d 0 to 104) tended to decrease (P = 0.09) with greater MDGS inclusion. Hot carcass weight, ribeye area, marbling score, and quality grade were not affected (P ≥ 0.48) by either bunk management or MDGS inclusion. In Experiment 2, back fat (1.30 vs. 1.17 ± 0.042 cm) and yield grade (3.2 vs. 3.0 ± 0.11) were greater (P = 0.03) for CON steers compared with OVF but were not affected (P = 0.59) by MDGS inclusion. In Experiment 1, H2S tended (P = 0.07) to be greater in steers on OVF compared with CON. In Experiment 2, bunk management strategy did not impact (P = 0.82) H2S concentrations. There was a MDGS inclusion × day interaction for H2S with steers fed 50% MDGS having greater (P < 0.01) H2S concentrations compared with steers fed 25% MDGS on d 28 and 35. Bunk management strategy during adaptation did not impact growth performance but did reduce intake in Experiment 1. Yield grade decreased when OVF bunk management was applied throughout Experiment 2. Response of H2S concentrations in the rumen were variable and likely influenced by inconsistencies in bunk management and resulting DMI during the early portions of the feedlot study.

Effects of feeding bulls dried corn distiller's grains plus solubles or CaSO4 on mineral and metabolite concentrations in serum and seminal plasma.

Yearling Angus bulls (n = 36) were assigned one of three diets: 1) 60 % concentrate as corn (CON, 0.2 % S, 13.4 % CP; n = 12); 2) 60 % dried corn distiller's grains plus solubles (60DDGS 0.5 % S, 22.0 % CP; n = 12); 3) CON diet + equivalent sulfur of 60DDGS as CaSO4 (SULF, 0.5 % S, 13.9 % CP; n = 12) to evaluate effects of feeding 60 % DDGS or sulfur as CaSO4 on mineral and metabolite concentrations in serum and seminal plasma. Treatment × day interactions (P < 0.03) were observed for serum Cu, Se, and Mo. For Cu at d 112, lesser (P < 0.01) concentrations were observed in bulls fed the 60DDGS compared to SULF and CON diets. There were greater (P < 0.01) concentrations of Se at d 112 in bulls fed 60DDGS than CON and SULF diets. Concentrations of Mo were greater at d 56 and 112 (P < 0.01) in bulls fed CON compared to SULF and 60DDGS diets. In seminal plasma, there were treatment × day interactions (P < 0.02) for Cu and Mo. For Cu, at d 112, there was a lesser (P < 0.01) concentration in the bulls fed SULF compared to CON and 60DDGS diets. For Mo, there was a greater (P < 0.01) concentration in bulls fed the CON than 60DDGS and SULF diets at d 56 and 112. Changes in mineral and metabolite concentrations may have effects on bull reproductive performance when there is a relatively greater dietary sulfur content.

Effects of feeding 60% dried corn distillers grains plus solubles or the equivalent sulfur as CaSO4 on performance and reproductive traits of yearling Angus bulls.

The objectives of this study were to investigate the effects of feeding 60% dried corn distillers grains plus solubles (DDGS) or the equivalent sulfur as calcium sulfate (CaSO4) on semen quality and performance characteristics in yearling bulls. Thirty-six half-sibling Angus bulls [291 ± 8.5 d; initial body weight (BW) = 320 ± 2.7 kg] were assigned to one of three diets: 1) 60% concentrate as corn (CON; S = 0.18%; n = 12); 2) 60% DDGS replacing corn (60DDGS; S = 0.55% DM; n = 12); 3) CON + equivalent sulfur of 60DDGS added as CaSO4 (SULF; S = 0.54%; n = 12). Bulls were fed for 112 d to target an average daily gain (ADG) of 1.6 kg/d. Blood samples were collected on d 0, 56, and 112, and evaluated for testosterone, thyroxine, triiodothyronine (T3) and glutathione peroxidase (GPx) activity. Ruminal H2S was measured on d 0, 14, and 42. Scrotal circumference and semen were collected on d 0, 28, 56, 84, and 112 to evaluate sperm characteristics and GPx activity in seminal plasma. A computer assisted semen analysis was used to evaluate kinematic profiles in motile and progressive sperm throughout the study. Data were analyzed as repeated measures using MIXED procedures of SAS. No differences (P ≥ 0.14) were observed for final BW, ADG, or scrotal circumference; however, SULF tended (P = 0.07) to have reduced gain:feed compared with CON, with 60DDGS being intermediate. Concentrations of ruminal H2S on d 42 were greatest (P < 0.01) for SULF. Increased ejaculate volume was observed for 60DDGS and CON (P < 0.01) compared with SULF. For motile populations of sperm, velocity on an average path (VAP) and curvilinear velocity (VCL) were reduced (P ≤ 0.02) for SULF compared with CON, with 60DDGS being intermediate. In progressively motile sperm throughout the study, VAP and VSL were reduced (P ≤ 0.05) in 60DDGS and SULF compared to CON. For VCL, SULF was reduced (P ≤ 0.02) compared with CON, with 60DDGS being intermediate. In serum, concentrations of T3 were reduced (P = 0.009) in 60DDGS compared with CON or SULF. A treatment by day interaction (P = 0.03) was observed for seminal plasma GPx. At d 56, GPx activity was greater (P = 0.03) for 60DDGS compared with CON, with SULF intermediate; and at d 112, 60DDGS had the greatest (P ≤ 0.02) GPx activity. Therefore, feeding 60% DDGS to developing bulls altered semen kinematics, T3 concentrations, and GPx activity leading to the conclusion that these differences may not be solely dependent on concentrations of dietary sulfur.

The effects of maternal nutrition during the first 50 d of gestation on the location and abundance of hexose and cationic amino acid transporters in beef heifer uteroplacental tissues.

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

Maternal periconceptual nutrition, early pregnancy, and developmental outcomes in beef cattle.

The focus of this review is maternal nutrition during the periconceptual period and offspring developmental outcomes in beef cattle, with an emphasis on the first 50 d of gestation, which represents the embryonic period. Animal agriculture in general, and specifically the beef cattle industry, currently faces immense challenges. The world needs to significantly increase its output of animal food products by 2050 and beyond to meet the food security and agricultural sustainability needs of the rapidly growing human population. Consequently, efficient and sustainable approaches to livestock production are essential. Maternal nutritional status is a major factor that leads to developmental programming of offspring outcomes. Developmental programming refers to the influence of pre-and postnatal factors, such as inappropriate maternal nutrition, that affect growth and development and result in long-term consequences for health and productivity of the offspring. In this review, we discuss recent studies in which we and others have addressed the questions, "Is development programmed periconceptually?" and, if so, "Does it matter practically to the offspring in production settings?" The reviewed studies have demonstrated that the periconceptual period is important not only for pregnancy establishment but also may be a critical period during which fetal, placental, and potentially postnatal development and function are programmed. The evidence for fetal and placental programming during the periconceptual period is strong and implies that research efforts to mitigate the negative and foster the positive benefits of developmental programming need to include robust investigative efforts during the periconceptual period to better understand the implications for life-long health and productivity.

Influence of stocking rate and advancing season on forage intake, digestibility, and ruminal fermentation in steers supplemented with dried distillers grains with solubles while grazing northern Great Plains rangelands.

The objectives of this study were to evaluate the effects of stocking rate and advancing season on diet chemical composition, intake, digestibility, and ruminal fermentation in steers supplemented with distillers grains with solubles [0.3% of body weight (BW)] while grazing northern Great Plains rangelands. Angus cross beef steers (n = 188; 320 ± 30.3 kg initial BW) were used to establish targeted stocking rates, and 12 ruminal cannulated steers (272 ± 20.0 kg initial BW) were used for diet sampling while cograzing with the noncannulated animals on 12 pastures (n = 3 per treatment). Stocking rates were set to target 65%, 50%, 35%, and 20% of an average annual above-ground biomass remaining at the end of the grazing season (May-September). Five 10-d collection periods were conducted for May 13-22, June 10-19, July 8-17, August 5-14, and September 2-11. There was no difference in steer BWs or average daily gain during any of the collection periods or between stocking rate (P ≥ 0.10). Organic matter (OM), neutral detergent fiber, and acid detergent fiber of forage masticate samples were not affected (P ≥ 0.25) by stocking rate. Crude protein, and all N fractions of forage masticates also did not differ between stocking rate treatments (P ≥ 0.18). Forage OM intake (grams per kilogram of BW) increased cubically across the entire grazing season (P = 0.05). Organic matter digestibility decreased quadratically (P < 0.01) from May to September. Neutral detergent fiber digestibility showed a cubic effect (P < 0.01) across the grazing season, increasing from May to June, then decreasing till September. Crude protein digestibility decreased linearly (P < 0.01) as the season advanced. Ruminal ammonia and volatile fatty acid (VFA) concentrations were affected by stocking rate × period interactions (P ≤ 0.02). Ruminal pH, ammonia, and VFA concentrations were not affected by the stocking rate (P > 0.13) but were impacted by the advancing season (P < 0.01). Ruminal pH increased quadratically (P ≤ 0.01) with advancing season (6.3 to 6.6 ± 0.05 from May to September, respectively). The results of this study demonstrate that intake, fermentation, and digestibility of northern Great Plains forages were influenced more by seasonal factors associated with forage maturity than stocking rate under the conditions of this study.

The effects of maternal nutrient restriction and day of early pregnancy on the location and abundance of neutral amino acid transporters in beef heifer utero-placental tissues.

We hypothesized that maternal nutrition and day of gestation would influence the abundance of the neutral amino acid transporters SLC1A1, SLC1A5, SLC7A5, SLC38A2, and SLC38A7 in heifer utero-placental tissues. Angus-cross heifers (n = 43) were estrus synchronized and bred via AI. At breeding, heifers were assigned to one of two dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d gain or restricted heifers (RES) = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d). Thus, the experimental design was a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross sections were taken from the horn ipsilateral to the CL, fixed in 10% NBF, sectioned at 5 µm, and stained for transporters. For each image, the areas of fetal membrane (FM; chorioallantois), endometrium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted on days 34 and 50. In ENDO, SLC7A5 was greater (P < 0.01) in CON compared with RES heifers. In SG, SLC1A1 was greater (P = 0.02) in day 16 RES compared with day 16 CON and days 34 and 50 RES. In DG, SLC1A1 was greater (P = 0.02) on day 16 compared with 50 of gestation. In MYO, SLC1A1 was greater (P = 0.02) in day 50 CON compared with day 16 CON and day 50 RES. Additionally, in MYO SLC38A2 was greater (P = 0.02) in day 16 RES compared with day 16 CON and day 34 RES. In FM, SLC7A5 tended (P = 0.08) to be greater in CON vs RES. Analysis of all uterine tissues on day 16 determined that expression of SLC1A1, SLC1A5, SL38A2, and SL38A7 differed across uterine tissue type (P < 0.01); however, only SLC7A5 tended (P = 0.10) to differ and be greater in CON compared with RES heifers. Analysis of all utero-placental tissues on days 34 and 50 determined that SLC1A1, SLC7A5, SLC38A2, and SLC38A7 were greater (P ≤ 0.03) in CON compared with RES heifers. Furthermore, abundance of all transporters investigated on days 34 and 50 differed across utero-placental tissue types (P < 0.01). These data support our hypothesis that maternal nutrition and day of gestation influence the abundance of neutral amino acid transporters in utero-placental tissues from days 16 to 50 of gestation. Additionally, these data combined with previously published works help further elucidate nutrient supply and demands of the maternal and fetal system during early gestation in beef heifers.

Maternal nutrition and stage of early pregnancy in beef heifers: impacts on hexose and AA concentrations in maternal and fetal fluids1.

We examined the hypothesis that maternal nutrition and day of gestation would affect the concentrations of AAs and hexoses in bovine utero-placental fluids and maternal serum from days 16 to 50 of gestation. Forty-nine cross-bred Angus heifers were bred via artificial insemination and fed a control diet (CON = 100% of requirements for growth) or a restricted diet (RES = 60% of CON) and ovariohysterectomized on days 16, 34, or 50 of gestation; nonpregnant controls were not bred and ovariohysterectomized on day 16 of the synchronized estrous cycle. The resulting design was a completely randomized design with a 2 × 3 factorial + 1 arrangement of treatments. Maternal serum, histotroph, allantoic fluid, and amniotic fluid were collected at time of ovariohysterectomy. Samples were then analyzed for concentrations of AAs and intermediary metabolites: alanine (Ala), arginine, asparagine (Asn), aspartate (Asp), citrulline, cysteine, glutamine, glutamate (Glu), glycine (Gly), histidine, isoleucine, leucine (Leu), lysine, methionine (Met), ornithine, phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), tryptophan, tyrosine (Tyr), and valine (Val). The concentrations of Gly, Ser, and Thr in maternal serum were greater (P ≤ 0.05) in CON compared with RES. Furthermore, day of gestation affected (P ≤ 0.05) concentrations of Asn, Glu, Phe, Thr, and Tyr in maternal serum. Status of maternal nutrition affected the Asp concentration of histotroph where RES was greater (P = 0.02) than CON. In histotroph, Ala, Leu, Met, and Val concentrations were greater (P ≤ 0.05) on day 50 compared with day 16. Additionally, Glu and Pro concentrations in histotroph were greater (P < 0.01) on days 34 and 50 compared with day 16. A day × treatment interaction was observed for the concentration of Val in allantoic fluid where day 34 CON was greater (P = 0.05) than all other days and nutritional treatments. In addition, the concentration of Gln in amniotic fluid experienced a day × treatment interaction where day 34 RES was greater (P ≤ 0.05) than day 34 CON, which was greater (P ≤ 0.05) than day 50 CON and RES. These data support our hypothesis that day of gestation and maternal nutrition affect the concentrations of various neutral and acidic AA in beef heifer utero-placental fluids and maternal serum from days 16 to 50 of gestation.

Effects of distillers dried grains with solubles supplementation on yearling heifers grazing Northern Great Plains rangeland: impacts on subsequent feedlot performance and meat quality.

Eighty-two yearling crossbred heifers (318.8 ± 1.03 kg) were utilized in a completely randomized design to evaluate the effects of distillers dried grains with solubles (DDGS) supplementation on animal performance, while grazing on rangeland of the Northern Great Plains, and subsequent feedlot performance, carcass characteristics, and meat quality traits. Treatments were: 1) 0% DDGS supplementation (CONT) and 2) 0.6% of body weight (BW) DDGS supplementation (SUP). Heifers received treatments for 70 d (6 June to 16 August) while grazing, and then were acclimated to and fed a common corn-based finishing diet for 109 d. Average daily gain (ADG) of SUP heifers was greater (P ≤ 0.01), resulting in heavier BW (P ≤ 0.03) following grazing compared with CONT heifers. Heifer performance, including ADG (1.91 ± 0.05 kg/d), gain to feed (G:F) (0.15 ± 0.003 kg), dry matter intake (DMI) (12.6 ± 0.20 kg), and final BW (572.4 ± 7.43 kg) were not different (P ≥ 0.13) during finishing. Hot carcass weight (335.7 ± 4.39 kg), Longissimus muscle area (81.30 ± 1.24 cm2), 12th rib fat thickness (1.24 ± 0.06 cm), and kidney, pelvic, heart fat (KPH) (1.85 ± 0.08%) were not different (P ≥ 0.47) between treatments. There were no differences (P ≥ 0.24) between treatments in yield grade (2.9 ± 0.10) or marbling (492 ± 22.3; Small00 = 400). Results from Warner-Bratzler shear force indicated that strip loin steaks from SUP heifers tended (P = 0.07) to have increased tenderness compared with strip loin steaks from CONT heifers (3.3 vs. 3.7 ± 0.12 kg, respectively). Inclusion of 0.6% BW supplementation during grazing increased (P = 0.01) strip loin steak muscle lightness (L*) compared with CONT steaks (46.5 vs. 45.5 ± 0.27, respectively). Strip loin steaks from heifers supplemented DDGS during grazing were perceived to be more tender by taste panelists (P = 0.02) than strip loin steaks from CONT heifers (5.9 vs. 5.5 ± 0.11; eight-point scale). Supplementation of DDGS during grazing improved ADG of yearling heifers with no effect on feedlot performance or carcass characteristics but did improve tenderness and steak sensory attributes.