bluuebunny/crossref_metadata_2025_split huggingface dataset:
59 Effects of exogenous glucocorticoid administration on leptin concentrations in perinatal dairy bull calves
Authors: Morris Camille , McCarty Keelee J , Long Nathan 
Published: November 2020

Abstract
Previous studies suggest a relationship between leptin and cortisol immediately postpartum is linked to improved feedlot efficiency on cattle exposed to perinatal stressors. The objective of the current study was to determine the effects of exogenous cortisol administration on circulating leptin concentrations in perinatal dairy bull calves. Within four hours of parturition, Holstein bull calves were randomly assigned to treatments and intravenously infused with low cortisol (LC; n = 9, 3.5 ug/kg of cortisol), high cortisol (HC; n = 9, 7.0 ug/kg of cortisol), or a sham infusion control (CON; n = 9, similar volume of saline). Calves were housed similarly and fed milk replacer (28% CP, 20% fat) three times daily. Blood collections were performed via jugular venipuncture using Z/9mL serum collection tubes (Sarstedt, Newton, NC) from d 0 to 5 of age. Serum samples were incubated for 1 h at room temperature then overnight at 4°C, centrifuged at 1800 x g at 4°C for 20 minutes, serum decanted, and stored long term at -20°C until analysis. At 5 d of age, calves were euthanized utilizing an overdose of sodium pentobarbital (Schering-Plough Animal Health, Union, NJ) and cerebral-spinal fluid (CSF) from the third ventricle of the brain was collected and stored at -80°C until analysis. All samples were analyzed for leptin concentrations via a previously-validated radioimmunoassay. Serum leptin concentrations were analyzed via repeated measures of ANOVA and CSF leptin concentrations via the GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA). Serum leptin concentrations of HC and LC were decreased (P = 0.013) compared to CON, and d 0 was decreased (P &lt; 0.001) compared to all other days of age. Cerebral-spinal fluid leptin concentrations of HC and LC were decreased (P = 0.005) compared to CON. In summary, exogenous cortisol administered to perinatal dairy bull calves reduced leptin concentrations in serum and CSF.
129 Presynchronization with Prostaglandin F2αand prolonged exposure to exogenous progesterone impacts estrus expression and alters fertility in beef heifers
Authors: Oosthuizen Nicola , Fontes Pedro , Lamb Cliff 
Published: November 2020

Abstract
To determine the effects of 2 presynchronization strategies in conjunction with delayed fixed-time artificial insemination (TAI) on pregnancy rates to TAI (PR/AI), 1,700 Angus beef heifers at 3 locations were enrolled in a completely randomized design with a 2×2 factorial arrangement of treatments. Within location, all heifers were randomly assigned to 1 of 4 treatments: 1) PG54 (n = 434), heifers received a 25-mg injection of prostaglandin F2α (PGF) 7 d prior (d -14) to the initiation of the 7-d CO-Synch + CIDR protocol wherein they received a 100-µg injection of gonadotropin-releasing hormone (GnRH) and a CIDR insert on d -7, a 25-mg injection of PGF at CIDR removal on d 0, and a second injection of GnRH concurrently with TAI 54±2 h later; 2) PG72 (n = 426), heifers were exposed to the same treatment as PG54; however, TAI was performed 72 ± 2 h after CIDR removal; 3) PG-CIDR54 (n = 422), same as PG54 but heifers received a CIDR insert on d -14 in addition to PGF; 4) PG-CIDR72 (n = 418), same as PG-CIDR54; however, TAI was performed 72±2 h after CIDR removal. Estrus detection patches were applied to all heifers on d 0 and were evaluated for activation at TAI. Pregnancy was diagnosed between 30 and 47 d after TAI. The percentage of heifers exhibiting estrus between d 0 and TAI was greater (P &lt; 0.001) in the PG72, PG-CIDR54, and PG-CIDR72 treatments compared to the PG54 treatment (78.11, 86.59, and 91.09 vs. 31.05%, respectively). Furthermore, estrus response was greater (P &lt; 0.001) in PG-CIDR72 heifers when compared to PG72. Pregnancy rates to TAI differed among treatments and were greater (P &lt; 0.05) in the PG72 and PG-CIDR54 treatments when compared to PG-CIDR72 (48.8 and 50.4 vs. 38.4%, respectively), and were greater (P = 0.034) in PG-CIDR54 vs. PG54 (43.1%). Moreover, a tendency (P = 0.097) was determined on PR/AI between PG54 and PG72. In conclusion, presynchronization strategies and prolonged exposure to exogenous progesterone have the potential to alter estrus expression and improve fertility in replacement beef heifers.
181 Uterine and vaginal bacteria and cytokine profiles prior to artificial insemination between resulting pregnant and open postpartum beef cows
Authors: Poole Rebecca , Ault Taylor B , Myer Phillip R , Lear Andrea , Pohler Ky 
Published: November 2020

Abstract
Numerous factors impact reproductive success in beef cattle; however, the presence and activity of bacteria in the reproductive tract and its effects on fertility is relatively unknown. The objective of this study was to evaluate the relationship between reproductive tract bacterial communities and cytokine profiles prior to timed-AI (TAI) and compare between resulting pregnancy status at d30. Sixty-eight beef cows, 80 ± 2.6 d postpartum at TAI, were synchronized and subjected to TAI on d0. Pregnancy was diagnosed via transrectal ultrasonography on d30. Uterine and vaginal flushes were collected on d -21 and -2 for bacterial DNA extraction to sequence the V1-V3 hypervariable regions of the 16S rRNA gene and to measure pro-inflammatory [interlukin-6 (IL-6)] and anti-inflammatory [IL-10 and transforming growth factor-beta (TGFβ)] cytokine concentrations using validated commercial ELISAs. Concentration data were analyzed using repeated measures in PROC MIXED of SAS and correlations were performed in SAS using Pearson correlation. There were no differences in cytokine concentrations by day or status x day. There were no differences in uterine IL-6 or IL-10 concentrations (P &gt; 0.05). Uterine TGFβ concentrations were overall elevated in pregnant cows compared to open cows (72.6 vs. 13.7 ± 12.1 pg/mL, respectively; P &lt; 0.05). On d -2, a positive correlation exists between TGFβ and the relative abundance of Actinobacteria in the uterus of pregnant cows (r=0.93, P = 0.02). There were no differences in vaginal IL-6 or TGFβ concentrations (P &gt; 0.05). On d -2, vaginal IL-10 concentrations were elevated in open cows compared to pregnant cows (741.6 vs. 602.1 ± 47.0 pg/mL, respectively; P &lt; 0.05) and a positive correlation exists between IL-10 and the relative abundance of Lentisphaerae in the vagina of pregnant cows (r=0.89, P = 0.04). These data suggest a possible relationship between bacterial communities and cytokines concentrations within the reproductive tract of beef cattle which may affect fertility.
136 Quantitative and qualitative analysis of interferon stimulated genesMX2, OAS1, and ISG15 for detection of pregnancy in cattle
Authors: DeCarlo Andrea N , Parrish Joseph , Long Nathan , Pratt Scott 
Published: November 2020

Abstract
Pregnancy in cattle can be determined using transrectal ultrasonography or by detection of pregnancy associated glycoproteins present in maternal circulation begging at approximately d 28 of gestation; however, the majority of pregnancy loss occurs prior to this date. Interferon stimulated genes (ISG) have been observed to be upregulated in pregnant cattle and measurable at d 18 of gestation. The objective of this study was to assess ISG expression as an indicator of pregnancy at d 18 post-insemination. A 7-d Co Synch and CIDR estrous synchronization protocol was utilized on cows of varying age and parity (n = 80) and insemination to a single sire performed 60 to 66 h following removal of the CIDR. On d 0 and d 18 post-insemination, blood was collected via jugular venipuncture for isolation of total RNA by PAXgene Blood RNA kit (PreAnalytiX, Hombrechtikon, Switzerland). Pregnancy detection was performed on d 30 of gestation by transrectal ultrasonography. Differences in ISG expression between d 0 and d 18 samples in both pregnant (n = 10) and open (n = 10) cows, according to d 30 ultrasound, were assessed. Primers for ISGs (MX2, OAS1, and ISG15) and housekeeping, cyclophilin were generated for use in end-point PCR and qRT-PCR. Data for qRT-PCR were normalized to cyclophilin expression. Analysis of variance and pair-wise student’s t-test among LSMeans were performed with fixed effects for pregnancy status, day, and their interactions. End-point products in all ISGs, regardless of day or pregnancy status, were observed. Expression of MX2 and ISG15 were upregulated in open cows and in d 0 samples (P &lt; 0.05). Expression of OAS1 was increased in open cows (P = 0.001). These data disagree with previous findings in which ISGs were upregulated in pregnant animals, and indicate expression of these ISGs may not be good indicators for pregnancy.
47 Effect of Zelnate administered at initial processing in high-risk, newly received beef calves on performance and morbidity
Authors: Martin Brady E , Cauble Reagan N , Kegley Elizabeth , Powell Jermey G 
Published: November 2020

Abstract
The objective of this study was to investigate the effects of Zelnate, a DNA immunostimulant, administered to calves (n = 261; BW 253 ± 4.0 kg) upon arrival, on morbidity and mortality, growth performance, and producer costs. Crossbred male beef calves (steers and bulls) were acquired from multiple auction markets and transported to the University of Arkansas stocker unit for a 42-d backgrounding period. Calves were randomly allocated to chute side into treatment groups: 1) Control (CON) in which no immunostimulant was administered or 2) Zelnate (ZEL), DNA immunostimulant administered. Animals were checked daily for signs of morbidity and treated with preplanned antibiotics. Records for morbidity and mortality were kept in addition to body temperature, clinical score, and body weight at the time of treatment. Data were analyzed using the GLIMMIX procedures of SAS. Significance was declared at P &lt; 0.05 and tendencies were observed between 0.05 ≤ P &lt; 0.10. No animals died during the duration of this study; however, Zelnate treated calves tended (P = 0.09) to have a lower relapse rate compared to control calves. Average daily gain was similar (P = 0.60) between the two treatment groups. This study also indicated that the treatment cost (Zelnate plus antibiotics) for the Zelnate group was more expensive than the cost to treat the control group (P &lt; 0.01). Overall, our findings indicate that Zelnate administered upon arrival to high risk calves did not improve morbidity rates and respiratory treatment or affect performance; however, it did increase costs by $9.24 per calf. Based upon these results, Zelnate does not appear to be an effective therapy for BRD when given upon arrival.
169 The effects of once or twice daily feed delivery on the finishing performance and carcass characteristics of feedlot steers
Authors: Wilson Blake K , Ryan Will , Richards Chris 
Published: November 2020

Abstract
Yearling Angus steers (n = 64; arrival BW = 322 ± 44 kg) from a single ranch were used to determine the effects of delivering feed once (1X) or twice (2X) per day on finishing performance and carcass characteristics. Steers were blocked by BW and randomly assigned to pens (4.57 × 15.24 m; 4 steers per pen). Pens were randomly assigned to 1 of the 2 experimental treatments (1X or 2X). All steers were fed a common dry-rolled corn finishing ration for 141 d. Feed was delivered to steers in fence-line concrete bunks (4.57 m in length; 1.14 m per steer) with the only difference between experimental treatments being the frequency of feed delivery. The 1X steers received 100% of the daily feed call at 0930 h, while the 2X steers received 50% of the daily feed call at both 0930 and 1400 h. Pen served as the experimental unit, and all steers were harvested on d 142. There were no differences in final BW (P = 0.95) or overall ADG (P = 0.94) between experimental treatments; however, overall DMI was greater for the 1X steers (P &lt; 0.01). The difference in DMI combined with no difference in ADG resulted in a 4% improvement in overall G:F for the 2X steers (P = 0.03). There were no differences between the experimental treatments for any carcass characteristics (P ≥ 0.28). While this experiment was conducted in a small pen research setting, the results suggest that the frequency of feed delivery impacts the intake and feed efficiency of feedlot steers. Consideration should be given to the impacts of feed delivery on feedlot logistics and batching in commercial settings.
32 Determining the feeding value of corn gluten feed relative to corn when supplemented to beef calves grazed on stockpiled tall fescue pastures
Authors: Zumbaugh Charles A , Murray Adam R , Langford Taylor A , Claire Olivia M , Wilson Thomas B 
Published: November 2020

Abstract
This experiment compared the performance response of supplementing corn gluten feed (CGF) or corn to calves grazing stockpiled tall fescue pastures over a 70-d period. Forty-four Angus x Simmental calves (238 ± 4 kg) were stratified across 6 treatments by BW and sex in a 2 x 3 factorial arrangement. Calves were supplemented cracked corn (n = 16) or CGF (n = 18). Calves were housed in 2 pastures and supplemented individually using the SmartFeed Pro feeding system, with all treatments represented in each pasture. Supplement DMI was programmed at 0.59, 0.87, or 1.13% BW. Calves which failed to train to the feeding system (n = 10) were treated as an un-supplemented control. Weight and flesh condition score (FCS) were recorded every 14-d, and ultrasound 12th rib fat thickness (FT) was measured on d 0 and 70. Data were analyzed with PROC GLM in SAS with supplement type as a main effect, sex as a fixed effect, and group as a random effect. Individual supplement DMI was included in the model as a covariate rather than a main effect due to high variation. Significance was defined at P ≤ 0.05 and means were separated using LSD. Initial BW, FCS, and FT were similar (P ≥ 0.12) among treatments. No differences (P ≥ 0.25) were observed in supplement DMI throughout the experiment. No differences (P ≥ 0.64) were observed in ADG and supplement G:F through 14 d. Through d 28 to 70, CGF-fed calves had greater (P ≤ 0.03) ADG and supplement G:F relative to corn-fed calves. Final FCS was greater (P &lt; 0.01) for CGF-supplemented calves relative to those supplemented corn, though FT was not different (P = 0.87). These data indicate that supplementing CGF rather than corn yields a greater performance response in beef calves grazing stockpiled tall fescue.
9 Backgrounding system diet effects on performance of beef calves during transportation and feedyard adaptation
Authors: Tigue Daniel A , Rehm John G , Kerklin Alisha , Rodning Soren P , Mullenix Mary K , Bratcher Christy L 
Published: November 2020

Abstract
Nutritional management during the backgrounding phase may influence beef calf performance and ease-of-transition into the feedyard. The objective of this study was to evaluate effects of various diets on performance of calves during backgrounding, transportation, and arrival at a feedyard. In June 2019, 119 fall-born steers (n = 79, 266 ± 34 kg BW) and heifers (n = 40, 236 ± 26 kg BW) at E.V. Smith Research Center (Shorter, AL) were weaned and randomly assigned to one of four diets (3 pens per dietary treatment, 10 calves per pen): cool-season baleage (oats, annual ryegrass, and crimson clover; B), cool-season baleage and 1% BW of a commercial, high-energy grower supplement (BC), cool-season baleage and 1% BW dried distiller’s grains with solubles (DDGS; BD), or ‘Tifton 85’ bermudagrass hay and 1% BW DDGS (HD). After a 10-d acclimation period, calves began a 60-d backgrounding trial and were weighed at d 0, d 30, and d 60. There was a diet × period interaction (P = 0.0017) such that ADG decreased from 0.38 to 0.19 kg/d for calves on B, while in treatments with supplementation, calves maintained gains of 0.67 kg/d or greater into the second, 30-d period. After the end of the backgrounding trial, calves were transported to Hy-Plains Feedyard in Montezuma, KS. Calves were weighed prior to transport, immediately after transport, after 24 h rest, and 7 d on feed. Immediately after tranport, B calves had the greatest shrink (12.8%, P &lt; 0.001) compared to calves that had received supplemental feed (10.1%). After 7 d, B calves regained the lowest percentage of pre-shipping BW (93.5% weight, P &lt; 0.01) compared to calves that had received supplemental feed (96.3% weight). These data suggest that supplementing forage-based diets may provide a performance advantage during the preconditioning phase and better prepare calves for transportation and the transition into the feedyard.
82 Evaluation of feeding immunoglobulin-Y to Holstein feeder cattle for the control of liver abscesses & reduction of macrolide-resistant bacteria dissemination
Authors: Stotz Miranda K 
Published: November 2020

Abstract
Despite the regular use of macrolide-antibiotics in the diets of feedlot cattle, liver abscesses persist representing a financial burden to both pre- and post-mortem sectors of the beef industry. Alternative strategies, which simultaneously address liver infections and reduce the dissemination of antibiotic-resistant bacteria, are needed. An immunoglobulin-Y (IGY) product, developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses and its effect on macrolide-resistant Enterococcus growth from feces. Sixty-four Holstein steers (Initial BW= 384±13.5kg) consuming a finishing diet (90% concentrate) for 188 days (Final BW= 660±42 kg) were used in a completely randomized design where treatments included: TYL (Tylosin phosphate fed at 90 mg/hd/day; n = 32) or IGY (fed at 2.5g/hd/day; n = 32).Feed intake was recorded daily and BW was recorded every 28 days until slaughter. After 150 d on treatment fecal samples were randomly obtained from each treatment group four times (n = 40) and cultured on bile-esculine agar enriched with 8 μg/mL of erythromycin. Continuous variables of feedlot growth performance, carcass data and bacterial growth were analyzed using the MIXED procedure of SAS with the fixed effect of treatment and random effects of steer or sampling day, respectively. Ordinal carcass data was analyzed using the FREQ procedure of SAS observing the Cochran-Mantel-Haenszel value. Treatment did not affect DMI (P = 0.21), ADG (P = 0.50) or G:F (P = 0.36). Treatment neither affected hot carcass weight (P = 0.37) nor longissimus muscle area (P = 0.25). However, TYL resulted in greater back fat thickness than IGY (0.32 vs. 0.23 in.; P &lt; 0.02) and consequently greater numerical yield grade (P &lt; 0.02). Quality grade was not affected by treatment (P = 0.65). No treatment difference was observed for liver abscesses prevalence (TYL= 63% vs. IGY= 52%; P = 0.40) or severity (P = 0.23). There was a greater proportion of erythromycin-resistant Enterococcus growth for TYL than IGY (42.6 vs. 21.9%; P &lt; 0.04). Specifically formulated IGY feed additives may be viable alternatives to antibiotics in the diets of feedlot cattle.
152 The Effect of Nerve Growth Factor Beta on Embryonic Cleavage Rates
Authors: Jones Kayla 
Published: November 2020

Abstract
Nerve growth factor, (NGF) beta is a seminal plasma protein that has been associated with sire conception rates in cattle. Previous research showed that the administration of NGFβ, via culture media, to cows resulted in improved conceptus development. Though this finding was thought to be an indirect effect of improved corpus luteum (CL) function, questions raised if NGFβ could act directly on the embryo to promote development. This work seeks to determine the effect of NGFβ supplementation during in-vitro fertilization (IVF) on cleavage and blastocyst rates. How does the administration of NGFβ in culture media affect cleavage and blastocyst rates during in-vitro fertilization? Abattoir-derived bovine ovaries were used for recovery of cumulus-oocyte complexes (COC). Selected COC were placed in the maturation medium. Expanded COC were inseminated with frozen-thawed spermatozoa, and IVF media was supplemented with either 0 ng/mL or 100 ng/mL NGF. Presumptive zygotes were transferred to development medium in a tri-gas chamber with 5% CO2, 5% O2, and 90% N2 in a humidified atmosphere at 39°C, mimicking the bovine uterine climate, until 8 days. Treatment with NGFβ increased the percentage of cleaved embryos at 48 hours and the percentage of hatched embryos at 8 days per oocyte. Treatment of NGFβ did not alter the percentage of blastocysts per cleaved embryo or the percentage of hatched blastocysts. These results show that the NGFβ can act directly on the embryo during fertilization to alter embryonic development, specifically embryonic cleavage rates. Future in vivo studies should assess the downstream effects of NGF treatment on conception rates in cattle.
144 Rumen Fluid Metabolites as Potential Biomarkers of Feed Efficiency in Angus Steers
Authors: Clemmons Brooke A , Powers Joshua B , Campagna Shawn R , Ault Taylor B , Embree Mallory M , Myer Phillip R 
Published: November 2020

Abstract
Beef cattle is the most consumed red meat in the United States, and the United States is the largest producer and consumer of beef cattle globally. Feed is one of the largest input costs for the beef cattle industry, accounting for 40–60% of the total input costs. Identifying methods for improving feed efficiency in beef cattle herds could result in decreased cost to both producers and consumers, as well as increased animal protein available for global consumption. Identification of feed efficiency biomarkers could aid in the selection of more feed-efficient animals. To identify potential biomarkers of feed efficiency, rumen fluid was collected from low- (n = 14) and high-RFI (n = 15) Angus steers based on RFI ± 0.5 SD around the mean following a 70d feed efficiency trial to determine rumen metabolites associated with variations in feed efficiency. Steers were 7 months of age, weighing 264±2.7 kg. Rumen fluid was collected via gastric tubing, filtered through a 0.22 µM syringe filter, extracted for metabolomic analysis using 0.1% formic acid in acetonitrile:water:methanol (2:2:1), and injected into the Dionex UltiMate 3000 UHPLC system with an Exactive Plus Orbitrap MS. Peaks for known metabolites were identified using MAVEN and analyzed using MetaboAnalyst 4.0 and SAS. Significance was determined using an α ≤ 0.05. Based on fold change (high/low RFI), eight metabolites were greater in low-RFI steers compared to high-RFI steers, including 3,4-dihydroxyphenylacetate, 4-pyridoxate, citraconate, hypoxanthine, succinate/methylmalonate, thymine, uracil, and xylose (P ≤ 0.05), while 12 metabolites differed by ≥ 2-fold. These metabolites were predominantly involved in amino acid and lipid metabolism. Rumen fluid metabolomes differed in steers of varying feed efficiencies. These metabolites may be used as biomarkers of feed efficiency and may provide insight as to factors contributing to differences in feed efficiency that may be exploited to improve feed efficiency in beef cattle herds.