bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating Plasma Metabolomic Profiles at the Time of Weaning, Based on Pregnancy Outcome, in Bos Taurus heifers
Authors: Rutledge Lauren V , Marks Landon , Rodning Soren P , Elmore Josh , Stanford Kent , Dyce Paul W 
Published: May 2021

Abstract
The objective of this study was to identify differences in the metabolomic profiles of heifers at the time of weaning based on their subsequent pregnancy outcomes. Angus/Simmental-cross heifers (n = 36) were weighed at weaning and 10ml of blood was collected. The blood plasma and white blood cells (WBCs) were isolated. Heifers were then assessed 30 days prior to artificial insemination (AI) for weight, pelvic area (PA), body condition scores (BCS) and reproductive tract scores (RTS). Reproductively mature heifers underwent an AI program with estrus detection and were then exposed to a bull two weeks after AI. Heifers were categorized into three groups: pregnant by AI, pregnant by natural breeding or open after 3 consecutive estrous cycles. 9 heifers pregnant by AI and 11 open heifers were chosen for metabolomic profiling. Of the 20 heifers selected, there was no difference in weight at weaning (355.6±21.9 kg AI, 364.2±33.3 kg Open, p &gt;0.05), BCS (5.7±0.4 AI, 5.6±0.4 Open, P &gt;0.05), RTS (4.1±0.6 AI, 4.0±0.7 Open, P &gt; 0.05) or PA (173.7±10.8cm2 AI, 175.6±9.1cm2 Open, P &gt; 0.05). Ten metabolites were found to be significantly up or down regulated in the heifers who remained open after three consecutive cycles, when compared to those pregnant by AI. Alanine, cystine, lysine, methionine, tyrosine, tryptophan and valine were down regulated while glycerol, fructose-6-phosphate and ribulose-5-phosphate were found to be up regulated in open heifers (P &lt; 0.05). RNA isolated from WBCs was used to compare the expression of five inflammatory cytokines in the open and pregnant by AI groups (TNFα, IL6, CXCL5, POSTN and MCP1). Inflammatory cytokines were increased in all heifers that remained open after three consecutive cycles (p&lt; 0.05). In summary, the quantity of specific metabolites present within the blood plasma are different at weaning between heifers with differing reproductive potentials. This could potentially be used to develop an assay to aid in selecting replacement females.
Effects of Exogenous Glucocorticoid Administration on Appetitic Center Brain Development in Dairy Bull Calves
Authors: McCarty Keelee J , Long Nathan 
Published: May 2021

Abstract
The objective of study was to determine the effects of exogenous cortisol on leptin concentrations and appetitic center development of perinatal dairy bull calves. Holstein bull calves (n = 27) were weighed and randomly assigned to treatments within 4 h of parturition (d0). Each calf was intravenously infused with either a low cortisol (LC; n = 9, 3.5 ug/kg of BW), high cortisol (HC; n = 9, 7.0 ug/kg of BW), or a sham infusion control (CON; n = 9, similar volume of saline). Each calf was administered a second infusion (half dose) of its respective treatment 24 h postpartum. All calves were housed similarly and fed milk replacer (28% CP, 20% fat) three times daily. Blood was collected via jugular venipuncture before infusion and from d 0–5 of age. At 5 d of age, calves were euthanized via sodium pentobarbital overdose. Cerebral-spinal fluid (CSF) from the third ventricle of the brain, hypothalamus, and adipose tissue (AT; omental, perirenal, and mesenteric) were collected. Blood and CSF samples were analyzed for leptin concentrations via a validated RIA. Adipose tissue samples were analyzed via western blotting for leptin and glucocorticoid receptor (GR) expression and normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression. Hypothalamus samples were analyzed via qRT-PCR for genes associated with neuronal growth factors and normalized to the average of two housekeeping genes. All data were analyzed via ANOVA or repeated measures analysis using appropriate models (SAS Institute Inc., Cary, NC). Serum and CSF leptin concentrations were decreased (P &lt; 0.013) in HC and LC compared to CON. Leptin protein expression was decreased (P &lt; 0.044) in perirenal and omental AT of LC calves compared to CON. Hypothalamic expression of BDNF, FGF1, and FGF2 were decreased (P &lt; 0.006) in HC and LC compared to CON. In summary, exogenous cortisol administered to calves at birth reduced leptin concentrations and altered appetitic control center development of the brain.
The Effect of Melatonin Supplementation on Dam Milking Traits and Calf Performance in Beef Cattle
Authors: Reid Dana S , Geary Thomas W , Zezeski Abigail L , Reil M Susan , Waterman Richard C , Devost-Burnett Derris D , Lemley Caleb O 
Published: May 2021

Abstract
Melatonin has been documented to alleviate compromised pregnancies and enhance livestock performance traits. The objective of this study was to determine the effect of melatonin supplementation on milking traits in beef cattle dams and subsequent influence on calf performance. Cows (n = 60) were blocked based on embryo transfer donor and sire, potential calf breed and embryo grade. At d190, 220 and 250 of gestation, dams were administered either 2 subdermal ear melatonin implants (preMEL) or no implants (preCON). After parturition, birth weights were recorded and calves randomly received either melatonin implants (posMEL) or none (posCON) on approximately d 0, 30, and 60. At approximately d 60 of lactation, a subset of dams (n = 32) were selected based on age, weight and calf sex for milk collection and analysis. At weaning, calf weight and morphometric data were collected and adjusted according to weaning age. Prenatal melatonin administration did not change calf birth weight (P = 0.956). Milk yield tended to decrease in the preMEL group (P = 0.054) at 2.368 kg ± 0.11 compared to preCON at 2.054 kg ± 0.11. Milk fat percent tended to decrease (P = 0.07) in preMEL at 3.25 ± 0.19 versus preCON at 3.92 ± 0.19. There were no differences in prenatal treatment in respect to milk protein, lactose, solid non-fats, somatic cell count, and urea nitrogen (P &gt; 0.16). At weaning, calf head circumference decreased (P &lt; 0.031) in the preMEL group at 77.92cm ± 0.42 versus preCON at 79.31cm ± 0.45. Otherwise, there were no prenatal or postnatal treatment differences in respect to weaning weight, crown-rump length, hip height and head length (P &gt; 0.12). Previous studies show crown-to-rump length and ponderal index differences. Our lack of differences might be attributed to geographical locations that impact day length or endogenous melatonin status.
Profitability of Supplementing Dried Distillers’ Grains Cubes to Improve Animal Performance and Replace N Fertilizer for Steers Grazing Introduced Pastures
Authors: Adams Jordan , Farris Rodney , Clawson Scott , Ward Earl , Beck Paul 
Published: May 2021

Abstract
During the summer grazing season, steers grazing introduced forages are oftentimes provided supplemental protein and energy to improve animal performance. However, it is important to determine if the additional supplementation is economically beneficial. Therefore, the objective was to evaluate the profitability of supplementing dried distillers’ grains cubes (DDGS) to improve animal performance or replace the use of N fertilizer (112 kg N/ha from urea) for steers (n = 149; BW = 238 ± 13.8 kg) grazing mixed tall fescue (Festuca arundinacea)/bermudagrass (Cynodon dactylon) pastures (n = 9 pastures, 7.2 ± 2.90 ha) from April 14 to September 17 (n = 155 d) using an enterprise budget analysis. Main plot supplemental treatments (n = 3 pastures/treatment) included 1) Fertilized Control (FC), no supplementation on fertilized pastures; 2) Fertilized Supplement (FS), 2.9 kg/steer DDGS supplemented 3-d/wk on fertilized pastures; and 3) Supplement (S), supplemental DDGS at 0.75% BW/d prorated for 5-d/wk feeding on unfertilized pastures. The assumptions used in this analysis were based on actual costs of inputs for pasture management and the DDGS offered, as well as the 5-year average Oklahoma auction market prices for 227 kg steers in April and 386 kg steers in October. Total cost per hectare was greater for S (P &lt; 0.01), was least (P &lt; 0.01) for FC, and FS was intermediate (P &lt; 0.01). Cost per kg gain for FS and S was greater (P &lt; 0.01) than for FC. Gross return per hectare tended to be greatest for S (P = 0.06), but net return per hectare was less for FS and S (P &lt; 0.01) than FC. Although FS and S allowed for improvement of animal performance, our results imply that FC was the most profitable due to the cost of supplementation and low supplemental efficiency of S and FS.
Effects of Maternal Nutrient Restriction During Gestation on LH Production in the Female Bovine Fetus
Authors: Fahey Sterling H , West Sarah , Long John M , Satterfield Carey , Cardoso Rodolfo C 
Published: May 2021

Abstract
Gestational nutrient restriction causes epigenetic and phenotypic changes that affect multiple physiological processes in the offspring. Gonadotropes, the cells in the anterior pituitary that secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are particularly sensitive to nutritional changes during fetal development. Our objective herein was to investigate the effects of gestational nutrient restriction on LH protein content and number of gonadotropes in the fetal bovine pituitary. We hypothesized that moderate nutrient restriction during mid to late gestation decreases pituitary LH production, which is associated with a reduced number of gonadotropes. Embryos were produced in vitro with X-bearing semen from a single sire then split to generate monozygotic twins. Each identical twin was transferred to a virgin dam yielding four sets of female twins. At gestational d 158, the dams were randomly assigned into two groups, one fed 100% NRC requirements (control) and the other fed 70% of NRC requirements (restricted) during the last trimester of gestation, ensuring each pair of twins had one twin in each group. At gestational d 265, the fetuses (n = 4/group) were euthanized by barbiturate overdose, and the pituitaries were collected. Western blots were performed using an ovine LH-specific antibody (Dr. A.F. Parlow, NIDDK). The total LH protein content in the pituitary tended to be decreased in the restricted fetuses compared to controls (P &lt; 0.10). However, immunohistochemistry analysis of the pituitary did not reveal any significant changes in the total number of LH-positive cells (control = 460±23 cells/0.5 mm2; restricted = 496±45 cells/0.5 mm2, P = 0.58). In conclusion, while maternal nutrient restriction during gestation resulted in a trend of reduced LH content in the fetal pituitary, immunohistological findings suggest that these changes are likely related to the individual potential of each gonadotrope to produce LH, rather than alterations in cell differentiation during fetal development.
Melatonin-induced Changes in the Bovine Vaginal Microbiota During Maternal Nutrient Restriction in Brangus Heifers
Authors: Messman Riley D , Lemley Caleb O , Contreras-Correa Zully E , Paz Henry A 
Published: May 2021

Abstract
Altering the composition of the bovine vaginal microbiota has proved challenging; with recent studies deeming the microbiota dynamic due to few overall changes being found. Therefore, the objectives of this study were to determine if gestational age, endogenous progesterone, maternal nutrient restriction, or dietary melatonin altered the composition of the bovine vaginal microbiota. Brangus heifers (n = 29) from timed artificial insemination to d 240 of gestation were used; at d 160 of gestation, heifers were assigned to either an adequate (ADQ; n = 14; 100% NRC requirements) or restricted (RES; n = 15; 60% NRC requirements) nutritional plane and were either supplemented with dietary melatonin (MEL; n = 15) or not supplemented (CON; n = 14). Samples for vaginal microbiota analysis were taken on d 0 (prior to artificial insemination), d 150 (prior to dietary treatments), and d 220 of gestation (60 days post-treatment initiation) using a double guarded culture swab. The vaginal bacterial community composition was determined through sequencing the V4 region of the 16S rRNA gene using the Illumina Miseq platform. Alpha diversity was compared via two-way ANOVA; beta diversity was compared via PERMANOVA. The linear discriminant analysis for effect size (LEfSe) pipeline was utilized for analysis of taxonomic rank differences between bacterial communities. Gestational age, progesterone concentration, and maternal nutritional plane did not alter alpha or beta diversity of the vaginal microbiota. However, gestational age resulted in compositional changes at the order, family, and genus level. Moreover, dietary melatonin supplementation did not alter alpha diversity of the vaginal microbiota but did alter beta diversity (P = 0.02). Specifically, melatonin altered the composition at the genus level and increased the prevalence of aerobic bacteria in the vaginal tract. To date, melatonin is the first hormone associated with altering the composition of the vaginal microbiota.
Effects of Winter vs. Year-round Supplementation of Multiparous Bos Indicus-influenced Beef Cows on Offspring Postnatal Growth, Immunity, and Carcass Characteristics
Authors: Palmer Elizabeth A , Vedovatto Marcelo , Oliveira Rhaiza A , Ranches Juliana , Vendramini Joao , Poore Matt H , Moriel Philipe 
Published: May 2021

Abstract
This 2-yr study evaluated the effects of winter vs. year-round supplementation of Bos indicus-influenced beef cows on offspring feedlot performance. Brangus cows (82–84 cows/yr) were stratified by BW and BCS (475 ± 67 kg; 4.85 ± 0.73) and randomly assigned to bahiagrass pastures (13–14 cows/pasture). Treatments were randomly assigned to pastures (2 pastures/treatment/yr) and consisted of winter supplementation with molasses (MOL-W), or year-round supplementation with molasses (MOL-Y) or cubes (CUB-Y). Supplements were isocaloric and isonitrogenous (75% TDN, 20% CP; DM basis). Total yearly supplement DM amount was 272 kg/cow for all treatments. At weaning (d 421), 33–35 steers/yr were vaccinated against bovine respiratory disease, transported for 720 miles to the feedlot, penned according to prepartum pasture distribution, and fed the same corn silage-based diet until harvest. Data were analyzed using SAS GLIMMIX procedure. Cow BCS at calving was greater (P &lt; 0.01) for MOL-Y and CUB-Y vs. CON cows. Calving rate, calving date, calf birth weight, and calf preweaning BW did not differ (P ≥ 0.22) among treatments. Steer feedlot BW did not differ (P ≥ 0.36) at time of feedlot entry but was greater (P ≤ 0.05) for MOL-Y and MOL-W steers vs. CUB-Y steers at feedlot exit. Plasma haptoglobin concentrations at feedlot entry were greater (P = 0.05) for CUB-Y vs. CON steers, with MOL-Y steers being intermediate, whereas plasma cortisol concentrations at feedlot entry were greater (P ≤ 0.05) for CUB-Y vs. MOL-Y and MOL-W steers. Marbling score, yield grade, and carcass weight did not differ (P ≥ 0.14), but CON steers had greater fat thickness at the 12th rib than MOL-Y and CUB-Y steers. Hence, year-round supplementation (molasses or cubes) of beef cows increased cow BCS at calving but had minor effects on offspring post-weaning growth and immunity compared to winter supplementation of molasses.
The Influence of Diet Type on Ranking for Feed Intake in Angus Cows
Authors: Holder Amanda , Rogers James , Walker Ryon , Beck Paul 
Published: May 2021

Abstract
The objective of this study was to determine the effect of diet type on feed intake in mature Angus cows. Forty-eight gestating Angus cows (708 ± 52 kg; 7 ± 0.75 years old) were assigned to one of four drylot pens based on their genomic score for residual feed intake (“High” RFI, 7.3 ± 0.5, “Low” RFI, 5.5 ± 0.7). Each pen contained an automatic waterer as well as four GrowSafe individual feed intake units. During the first period, two of the four pens were assigned to a processed hay diet (10.0% CP, 1.98 Mcal ME/kg DM) while the other two pens consumed a mixed ration consisting of 43.0% hay, 33.0% corn, 13.0% soybean hulls, and 11.0% liquid supplement, DM basis (11.7% CP, DM basis and 2.43 Mcal ME/kg DM). Following a 14-day adaptation period, feed intake was recorded for 45 days. Subsequently, diet type was switched and followed by 14 days of adaptation to the new diet and 45 days of feed intake measurement. Data were analyzed as a crossover study using the GLIMMIX procedure in SAS v9.4. Pearson correlation coefficients were determined between phenotypic traits and genomic score. Feed intake was highly correlated (r = 0.75) among the two diet types. In comparison, average daily gain (ADG) was negatively correlated (r = -0.37) among the two diet types. No differences were observed in DMI or performance for cows ranked “high” or “low” based on genomic score. More research is required to determine if selection for increased weight gain when consuming a high-quality mixed ration could be detrimental to cattle performance consuming moderate to low-quality forage.
Tamegrass Forage Options for Growing Heifers During the Summer
Authors: Farney Jaymelynn K , Reeb Macie E , Buessing Zachary T , Malone Katie 
Published: May 2021

Abstract
Developing methods to provide high quality forage through a majority of the year is important for cattle operations. The purpose of this study was to determine forage management options to off-set the summer “slump” with fescue. Four grass pasture treatments (10 pastures total; 1.67 ha each) were used in a completely randomized design and stocked with growing heifers (initial wt 190 ± 9.1 kg). Pasture treatments consisted of fescue (FES; n = 2 pastures with 4 head/pasture), crabgrass (CRAB; n = 3 pastures with 4 head/pasture), bermudagrass (BERM; n = 3 pastures with 5 head/pasture), and sorghum-sudan interseeded into fescue (SS-FES; n = 2 pastures with 6 head/pasture from April to July, then 4 head/pasture from July to November). Heifers were weighed in April, May, July, September, and November. Heifers assigned to FES/SS-FES pastures grazed from April to November (213 d) and for CRAB and BERM treatments, May through September (131 d). Heifers on FES grazed continuously, while other grass treatments were rotationally grazed. Heifers remained in treatment pasture through the entire grazing period. Data were analyzed using mixed procedures of SAS with pasture as experimental unit. Average daily gain for the entire grazing period was greater for heifers on SS-FES as compared to all other grass treatments (P = 0.001). Between April and May, FES heifers had greater ADG than SS-FES (P = 0.001); yet, heavier stocking rate in SS-FES resulted in similar BW gain/ha (P = 0.16). May to July ADG and BW gain/ha was greatest for BERM, then CRAB, with FES and SS-FES having the lowest gains (P &lt; 0.001). From July through September, ADG was greater for SS-FES and CRAB as compared to FES, with BERM intermediate (P = 0.03); and BW gain/ha tended to be lower for FES compared to other treatments (P = 0.10). Average daily gain and BW gain/ha were greater for SS-FES than FES (P = 0.001) from late September to November. As a summer grazing option, warm season grass alternatives, either as the sole source of pasture or interseeded into fescue, are better options for gain as compared to fescue alone.
Economics and Feasibility of Legume Inclusion in Southeastern Perennial Grass-Based Systems
Authors: Mullenix Kim K , Tucker Jennifer J 
Published: May 2021

Abstract
Perennial grass pastures provide the basis for beef production systems across the Southeast United States. One common management practice that is widely recommended among agronomists is interseeding cool-season legumes. Legumes can serve as a complementary resource for filling in production gaps, reducing supplemental feedstuffs, reducing the need for nitrogen fertilization, increasing the nutritional quality of forage available, increase biomass production, improve animal performance, and can reduce the toxic effects of endophyte-infected tall fescue through dilution. A simulated economic analysis was developed to further the economic understanding of the cost of implementation, the subsequent animal and forage performance benefits, and net returns from the inclusion of legumes over many research trials and years. Data from 15 peer-reviewed papers was used to simulate the economic benefits of implementing this production practice. Cost of production and revenue for each paper were calculated using the 10-year average from 2010 to 2019. This analysis provides users with a further understanding of the net returns, critical breakeven areas, and return on investment that is necessary in order to successfully implement the inclusion of cool-season legumes in perennial grass-based systems.
Incorporating Alfalfa into Warm-season Grass Systems in the Southeast
Authors: Tucker Jennifer J 
Published: May 2021

Abstract
Bermudagrass is the primary warm season perennial forage crop grown in the Southeast (~20 million acres) for livestock and forage operations. While prominent in the region, bermudagrass requires large amounts of fertility and forage quality is moderate relative to other options. There has been great success and a growing interest in interseeding alfalfa into existing bermudagrass stands in the region. This combination eliminates the need for nitrogen fertilization, increases relative forage quality (RFQ) better meeting the nutritional needs of livestock, and decreases the need for supplemental feed. In recent years, research evaluations have been conducted across the Southeast to evaluate the use of alfalfa when incorporated into warm-season grass forage systems under various management strategies. Three projects conducted from 2016–2020 at the University of Georgia Tifton campus evaluated ‘Bulldog 805’ alfalfa interseeded into Tifton-85 bermudagrass (1) when harvested as baleage, (2) under grazing management and(3) in a clipping study to better define defoliation management recommendations. Overall findings from this work observed that alfalfa-bermudagrass mixtures provide greater seasonal herbage accumulation, extend the growing season by three to four months annually, and increase forage DM digestibility and CP compared to bermudagrass alone. Steers on ABG managed under rotational stocking had greater total gain/ha (~%33 increase) due to a higher stocking density throughout the growing season than a bermudagrass monoculture. Results indicate that interseeding alfalfa into bermudagrass is a viable option for southeastern forage systems and can be an effective way to improve forage quality, extend the grazing season, and reduce the need for additional supplementation when fed to livestock.