bluuebunny/crossref_metadata_2025 huggingface dataset:
12 Growth Performance, Physiology, and Carcass Merit of Supplementing Brahman Steers with Zilpaterol Hydrochloride Under Heat Stress Conditions
Authors: Rios Andrea , Grijalva Pablo , Garcia Samuel , Webster Chelsea , Beard Joslyn , Petersen Jessica L , Yates Dustin T , Schmidt Ty B , Diaz Duarte E
Published: October 2022

Supplementation with a β- adrenergic agonist (β-AA) for 21 days in Brahman steers under heat stress conditions (HS) was evaluated with respect to feedlot performance and carcass merit. Twenty-four Brahman steers (kg = 338 ± 39) were housed in two controlled environment chambers with one of two environmental (ENV) conditions 1) heat stress (HS; THI = 73 to 85) and 2) thermoneutral (TN; THI = 68) with either Zilpaterol hydrochloride (ZL) or soymeal supplementation (CN) using a randomly assigned in a 2 x 2 factorial design (n=6/group). Daily data were collected for dry matter intake, water intake, respiratory rate (RR), and rectal temperature (RT). At the end of 21 d period, total weight gain was used to calculate average daily gain (ADG) and gain to feed. Blood samples were collected from the jugular vein on days -7, 3, 10, and 21 for cortisol analysis, and biological impedance analysis (BIA) was determined on days 3, 10, and 21 on each animal. Steers were harvested at 544 kg on average post supplementation/environment conditions, and carcass merit was determined. There were no differences (P > 0.05) in feedlot performance. Brahmans exposed to heat stress had greater RR during the heat stress periods of the experiment, regardless of supplementation. Environment and day interactions (P < 0.04) were observed for RT, HS steers had a greater RT on d 8 but similar RT on d 15 and 19. Stressed steers with ZL had higher RT (P < 0.05) than TN/CN steers on d 11. There was no interaction (P > 0.05) between environmental conditions and CN and ZH supplementation for cortisol concentrations. Regardless of environmental treatment or supplementation, no difference (P > 0.05) was associated with BIA characteristics. There were no differences (P > 0.05) for hot carcass weight, cold carcass weight, USDA yield grade, 12th rib loin eye area, marbling score, KPH percentage, and 12th rib fat thickness between groups. Twelfth-rib loin eye area lean color from HS/CN had higher lightness (L*) (P < 0.05) than TN/CN steers. HS/CN steers present a similar (L*) to ZL in TN and HS conditions. Redness-greenness (a*) was greater (P = 0.01) in carcasses from HS steers with or without ZL than TN/ZL but similar to TN/CN. Steers exposed to HS and CN had a higher (P = 0.02) change of 12th rib lean color from yellow to blue (b*) than TN steers with CN and ZL. Supplementation with β-AA did not negatively impact growth, carcass performance, or carcass merit in heat-stressed steers.
14 Effect of Pulmonary Arterial Pressure and Precipitation Interaction on Reproductive Performance in Angus Heifers in South Central Wyoming
Authors: Duggan Kelley L , Holt Timothy N , Speidel Scott E , Enns R Mark , Thomas Milton G
Published: October 2022

Variable precipitation in the western United States impacts forage availability, potentially influencing fertility. Furthermore, producers located above 1,500 meters contend with high altitude disease (HAD) due to reduced atmospheric oxygen, potentially resulting in right sided heart failure. Pulmonary arterial pressure (PAP) score is an indicator trait of HAD. The physiological stress of elevated PAP score could compound environmental stress, such as variable precipitation. Thus, the objective of this study was to investigate the interaction of precipitation and PAP score on beef heifer fertility. Data for this study were sourced from the Colorado State University Beef Improvement Center (CSU-BIC; 1993-2019; n = 3,834; 2,150 to 2,411 m elevation) near Saratoga, Wyoming. Records included identification, birth year, yearling year, yearling weight (YW), PAP, first service conception (FSC), overall heifer pregnancy (HPG) and sire. Precipitation data were sourced from the National Oceanic and Atmospheric Administration. Three classifications were created: cumulative precipitation from birth to breeding, precipitation from heifer birth to weaning, and precipitation from heifer weaning to breeding. Initial models contained sources of variation of precipitation classification, PAP, YW and a PAP by precipitation classification interaction for the response of HPG and FSC. Logistical regression was executed followed by analysis of variance. Yearling weight was a predictor of FSC (P < 0.01) while weaning to breeding precipitation was a predictor for HPG (P < 0.05). In general, the PAP by precipitation interaction was not detected; however, PAP by weaning to breeding precipitation tended to predict HPG (P < 0.10). A favorable, positive relationship was detected between YW and FSC (bi=0.00120 to 00120 to 0.00124; P < 0.01). A favorable, positive relationship also existed between weaning to breeding precipitation and HPG (bi=0.2528, P < 0.05). Those results suggested that increased precipitation during the development period from weaning to breeding was advantageous to HPG. The results also provided evidence to suggest that precipitation and PAP may interact to influence breeding success. Thus, we conclude that increased precipitation during the weaning to breeding period appears advantageous to overall breeding success of Angus heifers in a high-altitude production system.
16 Genetic Parameter Estimates for Age at First Calving in Simmental and Red Angus Heifers
Authors: Giess Lane K , Boldt Ryan J , Culbertson Miranda , Thomas Milton G , Speidel Scott E , Enns R Mark
Published: October 2022

The objective of this study was to determine genetic parameter estimates for age at first calving (AFC) in Red Angus and Simmental heifers. The ability for a heifer to calve earlier has implications on calf performance and the heifer's successive re-breeding. Heifer pregnancy data were obtained from International Genetic Solutions, where females with exposure records were included in the population. Females with a subsequent record of calving between 630 and 810 days of age were included in the analysis. Females with embryo transfer or multiple birth progeny were excluded. Records from single-animal and contemporary groups with no variation were eliminated and after data filtering, there were 149,379 Simmental with a mean Simmental breed proportion of 0.58 ± 0.25, and 83,191 Red Angus records with a mean Red Angus breed proportion of 0.80 ± 0.13. A 3-generation pedigree file containing 291,530 Simmental animals with 25,585 unique sires and 161,921 unique dams, and a 3-generation pedigree file containing 174,914 Red Angus animals with 19,733 unique sires and 99,464 unique dams were used for the separate analysis. The mean AFC in Simmental and Red Angus was 724.8 ± 28.64 d, and 724.2 ± 29.93 d, respectively. Data for each breed were modeled separately using a single trait animal model with random additive genetic and residual effects, and the fixed effect of contemporary group using ASReml 3.0. Contemporary group was defined as breeder, herd, year born, birth group and yearling group. The additive, residual, and phenotypic variances for Simmental were 120.08, 520.37, and 640.45 d2, respectively. For Red Angus, 85.67, 543.56, and 629.24 d2 were the additive, residual, and phenotypic variances, respectively. The heritability estimates of AFC for Simmental and Red Angus were 0.19 ± 0.0059 and 0.14 ± 0.0076, respectively. These results demonstrate AFC in days is lowly to moderately heritable. Lower residual and higher additive variance in Simmental compared to Red Angus may suggest the Simmental population has larger variation for underlying fertility influences such as age at puberty. The mean breeding values for AFC in Simmental was 6.1 ± 8.0, with a minimum of -24.4 and maximum of 54.7. Whereas Red Angus breeding values for AFC resulted in a mean of 4.0 ± 5.6 and a minimum and maximum of -16.1, and 37.3, respectively. The comparable heritability estimates, low standard error, and range in breeding values suggest selection for improved AFC can be attained. It is worth further exploring the impact of breed effects and heterosis influences on age at first calving. While this study does not account for heifers that did not calve in their first year, tandem selection for heifer fertility and age at calving should be heavily emphasized due to the economic importance of both traits.
17 Heritability Estimate of Heart Score
Authors: Kukor Isabella , Enns R Mark , Thomas Milton G , Holt Timothy N , Cleveland Matthew , Holland Ben P , Word Alyssa B , Ellis Guy
Published: October 2022

Feedlot heart disease (FHD), also known as bovine congestive heart failure, affects feedlot cattle at low to moderate elevations. This disease can cause feedlot death and preliminary research suggests unfavorable influences on performance and carcass quality in those individuals reaching their harvest endpoint. The severity of FHD for an individual animal at harvest can be determined by a heart scoring system that ranges from 1 to 5 corresponding to the increasing degree of heart failure with a score of 1 a normal heart and larger scores indicative of increased malformations. Heart scores (HS) are collected on individual animals at harvest. Previous research indicated that differences exist between sires as to their progeny’s propensity for developing FHD as indicated by HS of 3, 4 and 5. As a result of these sire differences, the objective of this study was to estimate heritability of HS obtained from a group of fattened feedlot cattle. Heart scores, numbers of cattle (Grade 1: 290 ; Grade 2: 728; Grade 3: 340; Grade 4: 64; Grade 5: 0) pedigree, and feedlot pen information were collected from 1,422 individual animals. The pedigree used in the evaluation consisted of the 1,422 individuals and 89 unique sires. No dam information was available on the scored animals. Heritability was estimated using a mixed effect animal model and the statistical software package ASReml 3.0. Fixed effects included scorer, sex, and kill age. Sex was not found to be significant in the model. Individual animal was included as the sole random effect. Scorer (P < 0.05) and kill age (P < 0.1) were found to influence variability in heart score, although kill age was detected as a tendency (P = 0.07). The heritability of HS was estimated to be 0.27 ± 0.10. The genetic variation was 0.15 and the phenotypic variation in the model was 0.40. These results suggest, HS is moderately heritable and has the potential to respond to genetic selection.
19 Heterosis Effects on Pre-Weaning Traits in a Multibreed Beef Cattle Herd in Panama
Authors: Gonzalez Murray Roderick A , Martinez Pedro Guerra , Vigil Virginia , Moreno Edwing , Ramirez Alexandra , Carreño Luis , Vargas Dimas , Lezcano Endhier , Enns R Mark , Speidel Scott E , Thomas Milton G
Published: October 2022

The aim of this study was to estimate the influence of heterosis and breed percentage on birth weight (BW) and weaning weight (WW) in beef cows in a tropical environment. Data from 900 calves and 2,843 individuals in the pedigree, from the multibreed herd of the Panama Agricultural Innovation Institute (IDIAP) in Gualaca, Panama were used. The herd was comprised of the following genetic groups and according to their breed percentage: tropical adapted Brahman (BR), Nellore (Ne), Un define Bos indicus (BI), Guaymi Creole (CR), Senepol (SP) Romosinuano (RS); Bos taurus (BT), Simmental (SM), Angus (A), Red Angus (AR), Limousin (LM), Charolais (CH), Wagyu (Wa), and Others (Oth); crossbreeds (cx), Beefmaster (BF), Three cx(F1 x different BT), R1(Backcross BR), R2 (Backcross BT), Composite (combination of at least 4 different breeds with less than 25% of Zebu), Upgrade (87.5% BR 12.5% BT), B1 (62.5% Zebu + 37.5% BT), B2 (62.5% BT + 37.5% Zebu). A bivariate animal model for BW and WW, was utilized to estimate variance components. Contemporary group was defined as year of birth. The effects of sex, birth season, weaning season, and age of dam were included as categorical fixed effects. Weaning age, degree of outcross and breed percentage were included as linear covariates. The estimated regression coefficient for BW on heterosis was not significant (P > 0.05), and for WW was 0.072 ± 0.027 kg (P < 0.05). Lower BW and WW were observed for the Japanese, and B1, while R2 and Upgrade had the highest average (P < 0.05). Heritability for BW was found to be low (0.14 ± 0.06) and moderate for WW (0.26 ± 0.09). The proportion of variation of WW accounted by maternal permanent environment for WW was (0.2 ± 0.09). The estimated genetic correlation between additive genetic BW and WW was 0.63 ± 0.30, while a negative, additive genetic correlation was observed for WW and WW maternal (-0.43 ± 0.37). These results suggested that heterosis had a beneficial influence on WW but limited effect on BW. Additionally, increasing the percentage of Wa, and BR negatively influenced WW measurements in a multibreed beef cattle herd in Panama.
22 Young Scholar Talk PHD: Investigating Ovine Mastitis: Microbial Sources and Management Methods to Reduce the Prevalence
Authors: Knuth Ryan , Woodruff Kelly , Hummel Gwendolynn , Williams Jordan , Austin Kathleen J , Stewart Whit C , Cunningham-Hollinger Hannah C , Bisha Bledar
Published: October 2022

Subclinical mastitis, a common intramammary disease in sheep production, can be costly to producers due to compromised performance and decreased longevity. Our research focused on preventative and therapeutic measures on mammary health where the objectives were to identify (1) the impact of Zn supplementation on the milk microbiome and (2) the impact of management practices at lambing and weaning on prevalence and cure rate of subclinical mastitis, the milk microbiome, and levels of antimicrobial resistance in milk bacteria. In study 1, the milk microbiome was characterized during the first 3 wk of lactation and at weaning in ewes divergent in dietary Zn supplementation (1× = CON or 3× recommendations = ZnTRT). Mammary health was assessed using somatic cell count (SCC) class. Amplicon sequencing revealed the presence of Staphylococcus, Mannheimia, Corynebacterium, and Pseudomonas, all major mastitis pathogens. Effects of breed, dietary Zn concentration, and SCC class on diversity were limited to early lactation, where CON milk had greater composition stability than ZnTRT milk (P = 0.02). In study 2, milk bacteria were characterized by culture; Staphylococcus spp. and Streptococcus spp. were tested for antimicrobial susceptibility. Subclinical mastitis prevalence ranged from 22–66% where coagulase-negative staphylococci (CoNS; 59%), bacilli (35%), Mannheimia haemolytica (10%), S. aureus (8%), streptococci (5%), and Corynebacterium spp. (5%) were common. Milk samples were compared by jug bedding treatment: jugs were cleaned and dried with barn lime before adding fresh straw (CLEAN) or fresh straw was added atop soiled bedding (SOILED). Bedding had no effect on subclinical mastitis (P = 0.57), but CoNS had greater sulfadimethoxine resistance in SOILED isolates (P = 0.03). Additional mastitis control methods at weaning were evaluated: penicillin injection (PENN), restricted feed access (FAST), or their combination (COMBO). Weaning treatment did not affect cure rate from weaning to 3-d post- weaning (P = 0.21). Further characterization of these samples via microbial sequencing are underway with source tracking analyses to investigate an exogenous route via retrograde transfer and environmental bacteria or endogenous route via an entero-mammary pathway. Results support that breed, animal husbandry, and mammary health variably affect the milk microbiome and provide novel insight to the impact of management practices in a milk microbiome longitudinal study.
1 Characterization of Mature Beef Bull Seminal Fluid and Blood Serum Metabolome During a 65-Day Breeding Season
Authors: Williams Jordan D , Field Catherine E , Dubowsky Jason , Banwarth Megan , Cochrane Tyree , Fanter Rob , La Frano Michael , McFarlane Zachary D
Published: October 2022

The American beef bulls have been neglected in terms of animal science research. Metabolomics is a respected for of science that will aid in developing hypothesis for future research in beef bulls. The objective of this study was to identify metabolites within a 65-day breeding season that were affect by breeding season duration and workload. Over a two-year period, 8 purebred Angus bulls owned and housed by the Cal Poly beef unit were surveyed using serum (collected via the coccygeal vein) and seminal fluid (collected via electroejaculation) at the beginning and end of a 65-day post-AI breeding season. Samples underwent HPLC-MS to observe metabolites within the fluids. Data were stratified for sample day and workload and compared using t-test for day and ANOVA for workload. Within serum, 8 metabolites of interest were observed. Effects included differences between workload groups in the abundance of guanosine (P = 0.01) a metabolite associated with purine metabolism. Within seminal fluid, 13 metabolites of interest were observed including Inosine, a metabolite also involved in purine metabolism and fluctuating based on workload (P = 0.05). Purine metabolism will be of interest to future research of beef bulls.
3 Impacts of Vitamin and Mineral Supplementation to Beef Heifers During Gestation on Performance Measures of the Neonatal Calf, Trace Mineral Status, and Organ Weights at 30 Hours After Birth
Authors: Hurlbert Jennifer L , Menezes Ana Clara B , Baumgaertner Friederike , Bochantin Kerri A , Kirsch James D , Dorsam Sheri T , Sedivec Kevin K , Swanson Kendall C , Dahlen Carl R
Published: October 2022

Objectives were to evaluate the effects of feeding a vitamin and mineral (VTM) supplement to beef heifers during gestation on calf performance, body measurements, trace mineral status, and organ weights at 30 h after birth. We hypothesized that VTM supplementation during gestation would improve mineral status in the neonatal calf but not impact calf performance parameters and body and organ weights at 30 hours after birth. Fourteen Angus-based heifers [initial body weight (BW)] = 273.7 ± 1.10 kg) were randomly assigned to receive either a basal diet (CON; n = 7) or a basal diet plus a VTM supplement (VTM; n = 7; 113 g•heifer-1•d-1, targeting gain of 0.45 kg/day) from 60 d pre-breeding through gestation. Immediately after parturition, blood samples were collected from dams and calves, then calves were separated from their dams. Calves were fed one feeding of colostrum replacer, followed by milk replacer every 12 h, then euthanized at 30 h. Body weight and measurements were recorded, then organs and viscera were removed, weighed, and sampled. Dam serum and neonatal serum, liver, and blood were analyzed for concentrations of minerals. Data were analyzed using the GLM Procedure of SAS with individual animal as the experimental unit. Dietary treatments did not impact calf weight (0 h or 30 h), calf body measurements, or body weight of the dam at calving (P ≥ 0.32). Further, neonatal organ weights were not influenced (P ≥ 0.21) by maternal VTM treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P ≤ 0.02) by VTM treatment; however, concentrations of Cu, Mn, Mo, and Zn in calf muscle, liver, and serum were not impacted (P ≥ 0.07) by VTM treatment. Concentrations of Co in serum of the dam was the only mineral affected by dietary treatments, being greater (P = 0.001) in VTM than CON dams. In the current experiment providing trace mineral supplementation throughout gestation did not impact calf weight or body measurements at birth. However, the implications of altered mineral status of the neonatal calves at birth, and presumably throughout gestation, may have additional postnatal effects that warrant further investigation.
PS-5 In Vitro NDF Digestibility and In Vitro Dry Matter Digestibility and Disappearance Are Similar Between Beef Heifers Differing in Feed Efficiency
Authors: Arellanes Jeff Dominguez , Duran Itzel T , Melchior Emily A , Scholljegerdes Eric J , Ivey Shanna L
Published: October 2022

Feed efficiency is a critical component of improving beef production. Previous research has indicated that differences among lowly and highly feed efficient animals may be the result of differences in digestibility through the gastrointestinal tract. The objective of this study was to evaluate differences in neutral detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD) in the rumen and cecum over time. To determine feed efficient animals to utilize, 134 yearling heifers were individually fed ad libitum for 84 days using a Calan Broadbent Feeding system (Northwood, NH, USA). Heifers were fed a total mixed ration containing 86% ground brome hay, 10% wet distillers grains with solubles, and 4% mineral supplement. Heifers were stratified by body weight and at the end of the feeding period, and sixteen heifers with the least and greatest average daily gain (ADG) were chosen for sampling. Low ADG heifers (n = 8) gained 0.5 ± 0.6 kg/d and high ADG heifers (n = 8) gained 0.85 ± 1.0 kg/d. Rumen content and cecal content were collected from heifers and incubated to determine in vitro NDF and IVDMD over 0, 6, 12, 24, 36, and 48 hours. Samples were incubated in triplicate in individual conicals utilizing the Tilly and Terry method. After incubation, samples were freeze-dried. After freeze-drying, 0.3g of sample was added to F57 fiber bags for determination of NDF disappearance using the ANKOM 200 fiber analysis system. Samples were grouped by site and time of incubation to avoid errors between samples. Data were analyzed using the MIXED procedure of SAS, with fixed effects of treatment (efficiency), collection site (rumen or cecum), incubation time, and interactions. Significance was determined at P ≤ 0.05 and tendencies at 0.05 ≤ P ≤ 0.10. There was a significant effect of site (P < 0.0001), and incubation time (P < 0.0001), as well as a site × incubation interaction (P = 0.01) for NDF disappearance. Treatment did not impact NDF disappearance (P = 0.53), and site × treatment was not significant (P = 0.26), however a tendency for a treatment × incubation time was observed (P = 0.08). In vitro dry matter digestibility was significantly affected by time of incubation (P < 0.0001), site × incubation (P = 0.01), and site × treatment (P = 0.03). Treatment did not affect IVDMD (P = 0.87), nor did site of sampling site (P = 0.64), and a treatment × incubation effect was not observed (P = 0.14). In conclusion, the efficiency of cattle was determined to not play a role in NDF disappearance or in vitro dry matter digestibility. These data indicate that additional factors, including forage type, microbial communities, and host genetics, play a larger role in influencing differences in forage digestibility.
PSI-1 Effects of Pre-Transit Diets and Road Transportation on Plasma, Salivary Cortisol, and Rumen Environment of Beef Heifers
Authors: Birkenstock Bianca , Figueroa-Zamudio Joaquin J , Soto-Navarro Sergio A , Duff Glenn C , Gouvea Vinicius N , Marks-Nelson Eileen , Yates Dustin T , Akter Afroza , Smythe Brandon G , Smith Kathryn E , Löest Clint A
Published: October 2022

Increased salivary cortisol in cattle may be detrimental to rumen bacterial diversity. Effects of transportation and diet before transportation on plasma and salivary cortisol and on rumen conditions of 20 ruminal-cannulated heifers (346 ± 16 kg BW) were evaluated. Heifers were fed ad libitum 40% Sorghum Sudan grass hay and 60% commercial pellet (64% TDN, 12.4% CP, DM basis) for 13 d before study initiation. Heifers were randomly assigned to a 2 × 2 factorial arrangement of 8-h transportation (TR) vs. no transportation (NT) and 100% Sorghum Sudan grass hay (HAY) vs. 30% hay and 70% pellets (H+P) fed ad libitum for 3 d before transportation. All groups were fasted during the 8-h transit period. Upon feedlot arrival at 8 h, cattle were fasted an additional 4 h. At 12 h, cattle were fed 30% wheat hay and 70% commercial feed (69% TDN, 16.6% CP, DM basis). Blood and ruminal fluid were sampled at 0, 8, 12, 24, 28 and 72 h. No diet × transport interactions were observed for any variable. Plasma cortisol was decreased for HAY vs. H+P heifers at 72 h (P < 0.05, diet × hour). Rumen pH and total volatile fatty acid concentrations did not differ between groups. Molar percentages of acetate increased, molar percentages of propionate decreased, and acetate-to-propionate ratios increased at 0 and 12 h for HAY compared to H+P (P < 0.05, diet × hour). At 0 h, molar percentages of butyrate were less for HAY vs. H+P (P < 0.05, diet × hour). Bacterial phyla richness was decreased for NT/HAY compared to NT/H+P and was increased for TR/HAY compared to TR/H+P heifers (P < 0.05, diet × transport). Proteobacteria relative abundances were less at 0 h for heifers fed HAY vs H+P (P < 0.05, diet × hour). Genera evenness was increased at 8 h for TR compared to NT cattle (P < 0.05, transport × hour). Genera Shannon-wiener indices were greater at 0 and 8 h for cattle consuming HAY compared to H+P (P < 0.05, diet × hour). Genera richness was increased at 0 h for cattle fed HAY compared to H+P (P < 0.05, diet × hour). Prevotella relative abundances were less for cattle fed HAY compared to H+P at 0 and 8 h (P < 0.05, diet × hour). In summary, due to negligible response to transportation, salivary cortisol effect on bacteria population and diversity were presumably minimal.
PSII-4 Effects of Late Gestation Supplementation of Vitamin B Complex for Beef Cows
Authors: Ranches Juliana , Hernandez Gracia M , Rezende Aline , Ferreira Matheus , Bohnert David
Published: October 2022

The main objective of this study was to evaluate the effects of late gestation and early lactation supplementation of a vitamin B complex on the performance of beef cows and their calves. A total of 48 mature Angus x Hereford cows were randomly assigned (d0) to one of two treatments (1) vitamin (n = 24) or 1) control (n = 24) in early January, allowing for a minimum of 45 days of supplementation before calving and 15 days post-calving. Cows were fed daily with alfalfa hay to the maintenance level. Cows were individually supplemented 3 times weekly (Monday, Wednesday, and Friday) with dried distiller’s grains fortified or not with a vitamin B complex. The vitamin B complex was provided at 2/g daily, and therefore was provided at 4.7g/ feeding event. The vitamin B complex contained pantothenic acid (B5), pyridoxine (B6), folic acid (B9), biotin (B7), and cyanocobalamin (B12). Cows and calves were considered the experiment unit for this study and all data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC, USA). Although all cows were artificially inseminated and pregnancy was checked before the beginning of the study, not all cows enrolled in the study calved within the expected calving range. Therefore, a total of 20 calves were born to cows assigned to control treatment and 19 calves were born to cows assigned to the vitamin treatment. No treatment differences (P ≥ 0.21) were observed for initial (d 0) body weight (BW; 1065 vs.1079 lb, respectively for control and vitamin) or body condition score (BCS; 4.7 vs. 4.8, respectively for control and vitamin) among cows. No treatment differences (P ≥ 0.34) were observed for BW (1168 vs.1161 lb, respectively for control and vitamin) or BCS (5.3 vs. 5.4, respectively for control and vitamin) among cows post-supplementation at turnout (d 90). No differences (P = 0.95) were observed for calf birth weight (81.7 lb); however, calves born to cows supplemented with vitamin tended to be heavier at turnout (P = 0.07; 169.7 vs. 180.5 lb, respectively). These results indicate that supplementation of vitamin B complex to beef cows during late gestation might lead to improved performance of offspring shortly after birth.
PSII-7 Feed Intake and Behavioral Responses of Mature Rams Provided Feed Containing Phenylthiocarbamide
Authors: Southerland Claire N , Yelich Joel V , Taylor Joshua B , Ellison Melinda J
Published: October 2022

Bitter taste perception has been studied in various species, including humans, using the synthetic compound phenylthiocarbamide (PTC). Human perception of PTC is linked to the ability to taste bitter foods. Sheep express varying levels of aversion to PTC delivered in drinking water. The objective of this study was to determine the effects of PTC delivered in feed on dietary intake and behavior in mature rams. We hypothesized that rams previously classified into PTC-taster categories using PTC-spiked drinking water would rank similarly when PTC was added to feed. Mature Targhee, Rambouillet, Polypay, and composite-breed rams, previously classified as either super- (n = 3), intermediate- (n = 5), or non-PTC tasters (n = 4), were subjected to 4-d acclimation and 6-d test phases. Alfalfa (70%), corn (15%), and beat pulp (15%) meal were mixed with ethanol (150 g/kg, as fed) only (control) or PTC solubilized in ethanol (150 g/kg, as fed) to create three pelleted (6.3 mm) test diets (110, 220 and 330 mg PTC/kg feed, as fed). Rams received control and PTC diets (0.87% BW) daily for 30 min in a side-by-side presentation, which was replicated for each PTC concentration. Feeding duration, number of bucket approaches and switches, sniffs, drinks, lip smacks and licks, and head bobs, jerks, and shakes were recorded throughout the trial using video surveillance. For each PTC concentration, consumption of PTC and control diets was similar (P = 0.22) when measured as a percentage of total diet (control + PTC) consumed. Individual PTC diet intakes ranged from 1.5 to 89.8% of total diet consumed. The CV for intake of 110, 220 and 330 mg/kg diets increased from 22.4 to 34.1 to 36.1%, respectively. Intake of total diet offered decreased (P = 0.01) between 110 mg/kg (80.9 ± 3.2%) and 330 mg/kg (72.3 ± 3.2%), while 220 mg/kg (78.4 ± 3.2%) was intermediate (P ≥ 0.06). Rams were classified by average PTC diet consumption relative to ± 1.0 SD of the population mean (50.2 ± 7.5%). Using this method, only 7 of the 12 rams were classified similarly to the former classification established when PTC was added to drinking water. Total feeding duration was less (P ≤ 0.03) when rams were offered 330 mg/kg (805.4 ± 18.2 s) compared with 110 (858.1 ± 19.3 s) and 220 mg/kg (862.7 ± 19.5 s). Rams switched between the control and PTC diets more (P ≤ 0.02) when offered 110 mg/kg (21.2 ± 10.0) than the 220 (16.4 ± 7.8) and 330 mg/kg (18.4 ± 8.4). These results suggest that sheep perceive and exhibit variable responses to PTC when incorporated into a pelleted feed. More research is needed to identify mechanisms by which sheep perceive bitter-tasting feeds.
PSII-8 Impact of Grazing High Nitrate Forages on Serum Nitrate Concentration and Production Performance in Beef Heifers
Authors: Debasitis Catherine , Goddard Sandra , Ellison Melinda J , Chibisa Gwinyai E , Yelich Joel V , Hall John B
Published: October 2022

The objective of this study was to compare nitrate concentrations in soil, forage, and the serum of animals grazing high (HNO3) and low (LNO3) nitrate forages. The fall before the study began one-half of a 6-ha field was amended with manure to increase nitrate levels in the soil. Forage barley (Hordeum vulgare L. var. Vernal) was planted in spring at 45 kg/ha. The 6-ha field was divided into twenty-seven 0.2-hectare paddocks (n = 13 HNO3; n =14 LNO3). Twenty-four crossbred yearling heifers were stratified by body weight (389.8 ± 2.8 kg) and randomly assigned to HNO3 (n = 12) or LNO3 (n = 12) with three replicates per treatment. Heifers entered paddocks when forage was 30 to 46 cm tall and removed when residual height was 10 cm. Heifers grazed for a total of 58 days. Each grazing period lasted 7-8 d. Soil samples were collected at the beginning of the study and sent to a commercial laboratory for soil analyses. Forage samples were collected prior to animal introduction to each grazing paddock, and before re-grazing. Heifers were weighed on d1 and every 14 d. Serum samples for nitrate analysis were collected on d 28, 42 and 57 of the trial. Forage samples were analyzed by near infrared spectrometry. Serum samples were analyzed for nitrate concentrations by ion chromatography. Data were analyzed using PROC GLM of SAS. Analysis of body weights and average daily gain included repeated measures. Soil, nitrate-nitrogen (ppm) and nitrate-nitrogen content (kg/ha) were greater (P < 0.001) in HNO3 compared to LNO3 paddocks. Soil P (P < 0.03) and K (P = 0.0002) levels were also greater in HNO3 than LNO3 paddocks. Average forage nitrate ion concentrations were greater (P < 0.0001) for HNO3 (1.58%) compared to LNO3 paddocks (0.42%). Forage nitrate ion concentrations increased (P < 0.002) with increasing grazing days. Peak nitrate ion concentration in HNO3 paddocks was 2.45%. Forage ADF, TDN, NDF, NEm, NEg were similar (P ≥ 0.07) between treatments. Forage crude protein was greater in HNO3 compared to LNO3 paddocks (P < 0.0001). Serum nitrate levels were undetectable (< 2 ppm) regardless of treatment. Heifer bodyweight and average daily gain were similar (P > 0.7) across treatments. Heifers gained an average of 1.1 kg/d resulting in a linear increase (P < 0.04) in body weight. In summary, grazing vegetative forage containing toxic concentrations of nitrate did not result in an increase in the serum nitrate concentration. Animal performance also did not differ across dietary treatments. This is suggestive of adaptive changes that prevented toxicity and compromised production performance for heifers grazing high nitrate forages. Supported by the Mary A. Turner Research Endowment
PSII-10 The Influence of Synovex-C Growth Implants at Weaning with Different Supplementation Levels on Growth Performance and Antral Follicle Counts in Developing Beef Heifers
Authors: Andrews Taylor N , Cushman Robert A , Snider Alexandria P , Cox Shad H , Dunlap Richard L , Anderson Collin , Chavez Maria K , Gallacher Kristie L , Melchior Emily A , Scholljegerdes Eric J , Summers Adam F
Published: October 2022

Dormant forage at weaning in Southwestern rangelands may not be nutritionally sufficient to support growth potential of calves administered a growth promoting implant. Therefore, the objective of this study was to investigate the influence of level of supplementation when heifers were administered a Synovex-C implant at weaning on growth and antral follicle counts (AFC). At weaning (8 months old), heifers (n = 17) were stratified by bodyweights (BW) and AFC and assigned to receive one of two levels of supplement (High or Low) and implant (Implant and No Implant; all heifers received a Synovex C implant at 2 months old). Heifers assigned to the Implant group received a second Synovex-C implant at weaning, thus creating four treatment groups: High Implant (n = 4), High No Implant (n = 4), Low Implant (n = 5), and Low No Implant (n = 4). Heifers were utilized in a complete randomized block design with a 2 x 2 factorial. Heifers were individually fed supplement three times a week for 26 weeks with refusals being weighed after each feeding to determine intake. During the receiving phase High and Low heifers were offered 1.94 kg/h/d and 1.17 kg/h/d, respectively, of 20% CP cube for the first 4 weeks of the study. After acclimation High and Low heifers were offered 1.26 kg/h/d and 0.68 kg/h/d, respectively, of 32% CP cube for the remainder of the study. Biweekly BW and monthly body condition scores (BCS) were recorded. Prior to the start of the project and 45 d before the breeding season, AFC were conducted via transrectal ultrasonography. Average daily gain (ADG), BW, and BCS were analyzed as repeated measures in SAS (PROC MIXED). Antral follicle counts were analyzed using MIXED procedures in SAS. Implant, supplement level, implant × supplement level, and implant × supplement level × week did not impact BW or BCS (P ≥ 0.22). Week (P < 0.0001), implant × week (P < 0.0004), and supplement level × week (P < 0.0001) impacted BW. Week (P < 0.0001), implant × week (P = 0.008), and supplement level × week (P = 0.0005) influenced ADG. Implant heifers tended to have increased ADG (P < 0.09) and High Implant heifers tended to have increased ADG compared to the other implant x supplement level treatments (P ≤ 0.09). Body condition score was significantly different across weeks (P < 0.0001). There was no difference between week (P = 0.64) on AFC. Implant (P > 0.22), supplement level (P > 0.43), and implant x supplement level (P > 0.80) did not influence AFC. In conclusion, administration of a second Synovex-C implant at weaning did not impact AFC and feeding implanted heifers at a higher supplementation level tended to improve ADG.
PSII-11 Using GPS Data and Daily Weights to Estimate Net Energy for Activity in Yearling Steers
Authors: Vandermark Logan R , Brennan Jameson R , Menendez Hector M , Ehlert Krista
Published: October 2022

Past research has provided the groundwork into determining the impact of daily activity, elevation, and slope on energetic requirements for rangeland cattle. However, there is not a consensus on how to accurately account for this dynamic. Thus, the objectives of this study were to 1) calculate rolling and roughness index and distance traveled respective of elevation change and 2) create a regression analysis from objective 1 and determine differences in precision between the two methods for determining changes in NEmract. This analysis compared two methods to estimate the energetic costs of travel on elevation and slope on net energy for activity (NEmract). The analysis was conducted from a dataset consisting of six herds of yearling steers (n = 127) that grazed native summer pastures from May to August in 2021 at the Cottonwood Field Station (Philip, SD). Pastures were composed primarily of native C3 grasses, Nassella viridula and Pascopyrum smithii, and C4 grasses, Bouteloua gracilis and Buchloe dactyloides. VenceTM collars were set to record GPS fixes at 5-minute intervals. GPS data was coupled with real time weight data collected from Smart Scales (C-Lock Inc, Rapid City, SD) located at the stock tanks within six pastures at three different stocking rates treatments (n = 3, 2 reps per trt). The combination of weight and GPS data allowed for the quantification of how elevation, slope, and daily distance traveled impacted NEmract. The first method to account for daily travel is a quantification of terrain use. This method has two indexes, a roughness index and rolling index, to determine the impact of terrain on grazing distribution. Roughness index is a measure of slope and elevation of an individual animal in comparison to the herd. The rolling index quantifies animal distribution by accounting for distance from water. The second method calculated the distance and elevation changes between successive GPS fixes for individual animals over the course of the summer grazing period. The linear regression was conducted in Program R (P < 0.05) which regressed NEmr plus NEmract calculated using the two methods against back-calculated to NEmr using daily body weight and forage nutrient composition (TDN). The result of this analysis provides levels of precision for different methods when quantifying the daily distance traveled, of steers relative to horizontal and ascending locomotion helping to evaluate trade-offs based on available GPS data (e.g., 5 minutes versus 1 hour recording intervals). Technological advances have allowed unprecedented data collection on individual animals. Results from this study will help refine energetic equations on extensive rangeland systems which is important due to the inherently large travels distances on these production settings.
PSIII-4 Late-Breaking: Genetic Marker Association Study of Heifer Pregnancy in Red Angus Cattle
Authors: Saad Hamad M , Gonzalez-Berrios Carolina L , Speidel Scott E , Enns R Mark , Boldt Ryan J , Hansen Thomas R R , Thomas Milt G
Published: October 2022

Heifer pregnancy (HPG) is lowly heritable, yet economically relevant in beef cattle production systems. Hence, identifying single nucleotide polymorphisms (SNP) associated with phenotype could increase the amount of information used in the genetic evaluation of the trait. Using RNA-sequence data from lactating Holstein cows, a set of SNP (n = 69) were discovered among embryo mortality conceptuses (Conceptus-SNP) associated with maternal recognition of pregnancy on day 16 after artificial insemination (AI). To further study these SNP, our objective was to conduct analyses to identify markers associated with HPG in Red Angus. Phenotypic records and genotypes were provided by the Red Angus Association of America (RAAA). For phenotypes, a total of 59,387 cattle records, from the June 2022 RAAA genetic evaluation, were used in the analysis. For genotype data, a 47,860 SNP panel (excluding SNP on the X-chromosome) were formed by combining the historical RAAA genotype data (96,162 animals with genotypes) and genotypes from whole genome sequence of 30 prominent Red Angus AI sires. Markers were mapped to the ARS-UCD1.2 bovine reference genome and then imputed to 47,860 SNP panel using findhap software. A subset of SNP (n = 2,169 SNP; Conceptus-SNP and the multi-breed selected reduced panel [MSRP]) were extracted from the imputed genotypes file. Using PLINK software, genotype quality control procedure was performed so that animals with call rate < 0.9 were removed. A marker was removed if: it had minor allele frequency < 0.01, not in Hardy–Weinberg equilibrium (P < 0.00001), or in high linkage disequilibrium (r2 > 0.95). The final genotype file contained 96,667 animals with 2,137 SNP. A Bayes Cπ single-step super hybrid model (π = 0.99), using the BOLT software package, was used to estimate marker’s posterior probability of inclusion (PPI), the marker significance criterion in predicting HPG. A marker’s PPI was calculated as the average probability from four different Gibbs sampling chains of 75,000 iterations that included 5,000 iterations as burn-in. Markers rs42576394 (18:60583784) and rs42942055 (14:34249373) had PPI of 25.5 and 7.1%, respectively; suggesting association with HPG. None of the Conceptus-SNP had a detectable association with HPG; however, these Conceptus-SNP may be much more informative for genotype to phenotype association analyses for the trait of stayability. Such a trait would be measured with lactating mature beef cows and potentially more similar to the lactating Holstein cows from which the markers were discovered.
PSIII-6 Late-Breaking: Ground Hybrid Rye as a Partial or Sole Concentrate in Backgrounding Rations
Authors: Tobin Colin , Carlson Zachary , Swanson Kendall C , Hoppe Karl
Published: October 2022

Cereal rye has been utilized in multiple ways within cropping systems in the northern Great Plains. Rye has traditionally not been utilized as a suitable grain for growing and finishing calves. Previously, recommendations have limited the use of rye due to the negative effects of ergot ingestion. Recent hybrid rye germplasms have shown increased yields with decreased incidence of ergot. The aim of this study was to determine the effects of ground hybrid rye inclusion rate on dry matter intake (DMI), growth performance, and feed efficiency in backgrounding beef steers. Two hundred crossbred steers were shipped to the Carrington Research Extension Center near Carrington, ND, stratified by weight, and assigned to one of twenty pens (n = 10 steers/pen). Four treatments were used in a completely randomized block design to evaluate animal performance during backgrounding when fed partial or complete replacement of corn with rye as the concentrate source. Ground hybrid rye was substituted for DRC as follows: a basal diet formulated with 20% DRC: 0% ground hybrid rye (CON), 13.5% DRC: 6.5% ground hybrid rye (RYE1), 6.5% DRC: 13.5% ground hybrid rye (RYE2), or 0% DRC:20% ground hybrid rye (RYE3) on a dry matter basis. Steers were fed for a total of 56 days beginning Oct. 25, 2021. Interim weights were taken on Nov. 22, 2021, and final weights were taken Dec. 20, 2021. At the conclusion of the feeding period, cattle were weighed on two consecutive days to determine final body weight. Performance data including animal live weights, ADG, DMI and G:F ratio were calculated. The use of rye within the diet did not influence steer weight throughout the study (P = 0.11). No differences in ADG were detected throughout the study (P = 0.68). Steers fed diets containing hybrid rye had higher DMI (P = 0.03) and higher F:G (P = 0.04) during the first month of the study. Increased DMI during the initial month of backgrounding may promote improved intake and growth. Results from the study suggest that steers fed rye as a partial or sole grain in a high forage backgrounding diet weighed similar to calves fed corn as the sole concentrate source.
PSIII-8 Late-Breaking: Effect of Feed Additives in Protein Supplements on Reproductive Performance in Young Postpartum Range Cows
Authors: Crouch Josie , King Tasha , Musgrave Jacki , McCarthy Kacie L , Mulliniks Travis
Published: October 2022

Optimizing reproductive efficiency is crucial in sustaining a successful cattle operation. However, optimizing reproductive performance in young range beef cows is often not captured due to an inability to meet the increased physiological demands. The objective of this study was to determine the impact of feed additives on reproductive performance, cow body weight (BW), body condition score (BCS), and calf growth in young, range beef cows. Data were collected from 2- and 3-year-old range cows (n = 189) from the March-calving herd at the University of Nebraska Gudmundsen Sandhills Laboratory (GSL) located near Whitman, NE over a three-year period (2019-2021). Cows were individually supplemented 908 g/d with one of two 30% crude protein supplement treatments with the addition of either: 1) 160 mg·cow-1·d-1 of rumensin (MON; Elanco Animal Health) or 2) 40 g·cow-1·d-1 of propionate salt (CAP; NutroCal 100; Kemin Animal Nutrition and Health). Supplementation was initiated approximately 7 d after calving and continued for an average of 70 d. Cow BW and BCS were collected weekly from calving to the start of breeding and then again at weaning. On approximately d 60 postpartum, milk production was measured by a modified weigh-suckle-weight technique. Cows were exposed to fertile bulls for a 45-d breeding season starting in June of each year. Cow BW (P ≥ 0.19) and BCS (P ≥ 0.11) were not affected by postpartum supplementation during the study. However, cows receiving CAP did lose more BW (P = 0.04; -7 vs -2 kg for CAP and MON; respectively) from calving to breeding than their counterpart. Calf BW at birth, weaning, or 205-d weight were not impacted (P ≥ 0.68) by the postpartum supplementation strategy. Twenty-four-hour milk production and milk components (fat, solids-non-fat, urea nitrogen) were not influenced (P > 0.21) by postpartum supplementation strategy. However, cows receiving CAP supplement had an increase (P = 0.04; 5.40 vs 5.31% for CAP and MON; respectively) in milk lactose percentage and tended (P = 0.06; 2.56 vs 2.68% for CAP and MON; respectively) to have lower milk protein percentage than their counterpart. Cows receiving CAP supplementation had an increase (P = 0.04; 89 vs 80% for CAP and MON; respectively) in overall pregnancy rate. This study implies that young postpartum cows fed additional glucogenic precursors in the form of propionate salts may increase reproductive efficiency without impacting a change in body weight or body condition score.