bluuebunny/crossref_metadata_2025 huggingface dataset:
112 Effect of an Oral Joint Supplement on Gait Kinematics and Biomarkers of Cartilage Metabolism and Inflammation in Mature Riding Horses
Authors: Much Mattea L , Leatherwood Jessica L , Martinez Rafael E , Silvers Brittany L , Basta Casey , Gray Lydia
Published: November 2020

Twenty stock-type horses (589 ± 126 kg BW; 13 ± 8 yr) were utilized in a completely randomized design for a 28-d trial to evaluate a joint supplement on gait kinematics, inflammation and cartilage metabolism. Horses were stratified by age, sex, body weight (BW), and initial lameness score and were randomly assigned to 1 of 2 dietary treatments consisting of either a 100 g placebo top-dressed daily to 0.6% BW (as-fed) commercial concentrate (CON; n = 10), or an oral joint supplement (SmartPak Equine LLC) containing glucosamine, chondroitin sulfate, hyaluronic acid, methylsulfonylmethane, turmeric, resveratrol, collagen, silica, and boron (TRT; n = 10). Horses had ad libitum access to coastal bermudagrass hay (Cynodon dactylon) and exercised progressively 4 d/wk, for 45 min/d. On d 13 and 27, blood was harvested following a 19.3 km exercise stressor. Every 14 d, blood was collected for plasma prostaglandin E2 (PGE2), and serum collagenase cleavage neopeptide (C2C), carboxypropeptide of type II collagen (CPII), and chondroitin sulfate 846 epitope (CS846). Gait kinematics were analyzed every 14 d (Kinovea v.0.8.15) to determine stride length (SL) and range of motion (ROM) of the knee and hock at the walk and trot. Data were analyzed using PROC MIXED of SAS. Hock ROM increased in TRT (P ≤ 0.02) at the walk and tended to increase at the trot (P = 0.09). At the walk, SL and knee ROM increased (P ≤ 0.01) in all horses. C2C and CPII increased over time (P ≤ 0.05) and no effect was observed for CS846 or PGE2 (P > 0.12). In response to the exercise stressor, CPII and PGE2 decreased (P ≤ 0.05) from d 13 to 14, and CS846 and PGE2 tended to decrease (P ≤ 0.10) from d 27 to 28, independent of diet. In conclusion, hock ROM at the walk and trot was the most sensitive to TRT, but biomarker concentration of collagen metabolites and systemic inflammation was not altered in 28 d.
111 Grazing behavior of horses managed on legume-grass mixed pastures
Authors: Vasco Ana Caroline Cerqueira de Melo , Arias-Esquivel Ana Margarita , Seals Emma , da Rosa Fabiane Quevedo , Wallau Marcelo , Warren Lori K , Wickens Carissa
Published: November 2020

Intercropping legume into grass pastures improves pasture quality and decreases the need for nitrogen (N) fertilizer, while providing a more heterogenic grazing environment. This study aimed to evaluate the effect of rhizoma peanut (RP, Arachis glabrata) intercropped into bahiagrass (Paspalum notatum) pasture on horse grazing performance. Unfertilized bahiagrass (UNF) with no N fertilizer, bahiagrass with 120 kg N ha-1 (FER), and bahiagrass with RP and 30 kg N ha-1 (RP) pastures were evaluated using twelve mature Quarter Horses continuously stocked for 84 days in a randomized block design with two blocks. Grazing, activity and leisure behaviors were recorded every 10 minutes for 24 hours on day 35 and 70 using scan sampling. Chew (CR, chew/min) and bite (BR, bite/min) rates were counted for five consecutive 1-min intervals on days 36 and 71. Data were analyzed using a repeated measure mixed model ANOVA. Pasture did not affect (P > 0.05) total time spent on grazing (13.57 ± 1.81 h, mean ± SD), leisure (9.64 ± 1.64 h), and activity (0.79 ± 0.60 h). Pasture x time of day interaction (P < 0.05) was significant for grazing, leisure and activity. Horses grazing FER spent more time grazing between 1100 and 1700 h, whereas horses grazing RP spent more time grazing between 2300 and 500 h when compared to horses grazing FER. Horses grazing FER spent more time in leisure between 2300 and 700 h. No day or pasture effects were observed for BR (30.8 ± 6.3 bites/min, mean ± SD), but a pasture x day interaction was observed for CR. On day 36, CR of horses grazing FER was similar to RP (50.8 and 53.8 chews/min), but lower than RP on day 71 (41.4 and 61.3 chews/min). Intercropping RP into bahiagrass pastures does not affect total grazing, leisure and activity time of horses.
128 Growth performance, blood urea nitrogen and gut morphology of nursery pigs fed a novel, plant-based protein
Authors: Holt Jonathan P , Sundstrom Ylva , Hash Sara
Published: November 2020

This experiment was conducted to determine a recommended inclusion level of a novel protein source, MrFeed® Pro50, for nursery pigs. 192 pigs (BW 6.41 kg ± 0.11) were blocked by weight and placed four pigs per pen for 35 d. Dietary treatments included a commercial diet with antibiotics (AB) or diets containing 0 (CON), 5%, 10%, or 15% Pro50, fed in three phases. Pigs and feeders were weighed every 7 d. On d 0, 14 and 35, blood samples were collected via vena cava puncture. On d 35, ileum samples were collected from 48 pigs. From d 0 to d 7, ADG was greater (P < 0.001) for pigs fed AB (0.15 kg/d) compared to pigs fed other treatments (: 0.09 kg, 5%: 0.09 kg/d, 10%: 0.1 kg/d, 15%: 0.09 kg/d). This is due to a greater (P = 0.002) ADFI for pigs fed AB (0.31 kg/d) compared to CON (0.26 kg/d), 5% (0.25 kg/d), 10% (0.27 kg/d) and 15% (0.27 kg/d) during the same time period. From d 28 to d 35, ADG for pigs fed AB (0.67 kg/d) or CON (0.69 kg/d) was greater than pigs fed 10% (0.56 kg/d) or 15% (0.57 kg/d), with 5% being intermediate (0.65 kg/d). At d 35, AB fed pigs (23.35 kg) weighed more than all other treatments (CON: 21.4 kg, 5%: 21.0 kg, 10%: 19.4 kg, 15%: 18.6 kg; P = 0.002). On d 35, BUN was greater (P = 0.005) for CON (14.5 mg/dL) and AB (16.5 mg/dL) fed pigs compared to 5%, 10% and 15% fed pigs (5.66 mg/dL, 6.33 mg/dL, 7.75 mg/dL, respectively). No differences (P > 0.05) in villi height or crypt depth were observed. The optimal inclusion level of MrFeed® Pro50 is 5% for nursery pig diets.
146 Prematurity Blunts the Protein Synthetic Response of Skeletal Muscle to Insulin and Amino Acids
Authors: Davis Teresa A , Rudar Marko , Naberhuis Jane , Suryawan Agus , Fiorotto Marta
Published: November 2020

Livestock animals are important dual-purpose models that benefit both agricultural and biomedical research. The neonatal pig is an appropriate model for the human infant to assess long-term effects of early life nutrition on growth and metabolic outcomes. Previously we have demonstrated that prematurity blunts the feeding-induced stimulation of translation initiation and protein synthesis in skeletal muscle of neonatal pigs. The objective of this study was to determine whether reduced sensitivity to insulin and/or amino acids drives this blunted response. Pigs were delivered by caesarean section at preterm (PT, 103 d gestation) or at term (T, 112 d gestation) and fed parenterally for 4 d. On day 4, pigs were subject to euinsulinemic-euaminoacidemic-euglycemic (FAST), hyperinsulinemic-euaminoacidemic-euglycemic (INS), or euinsulinemic-hyperaminoacidemic-euglycemic (AA) clamps for 120 min, yielding six treatments: PT-FAST (n = 7), PT-INS (n = 9), PT-AA (n = 9), T-FAST (n = 8), T-INS (n = 9), and T-AA (n = 9). A flooding dose of L-[4-3H]Phe was injected into pigs 30 min before euthanasia. Birth weight and relative body weight gain were lower in PT than T pigs (P < 0.001). Plasma insulin concentration was increased from ~3 to ~100 µU/mL in INS compared to FAST and AA pigs (P < 0.001); plasma BCAA concentration was increased from ~250 to ~1,000 µmol/L in AA compared to FAST and INS pigs (P < 0.001). Despite achieving similar insulin and amino acid levels, longissimus dorsi AKT phosphorylation, mechanistic target of rapamycin (mTOR)·Rheb abundance, mTOR activation, and protein synthesis were lower in PT-INS than T-INS pigs (Table 1). Although amino-acid induced dissociation of Sestrin2 from GATOR2 was not affected by prematurity, mTOR·RagA abundance, mTOR·RagC abundance, mTOR activation, and protein synthesis were lower in PT-AA than T-AA pigs. The impaired capacity of premature skeletal muscle to respond to insulin or amino acids and promote protein synthesis likely contributes to reduced lean mass accretion. Research was supported by NIH and USDA.
144 Proof of concept for bilateral twin pregnancies in Trio allele carriers
Authors: Madureira Guilherme , Gomez-León Victor , Grillo Gustavo Fernandes , Andrade João Paulo Nascimento , Lett Beth , Moghbeli Sadrollah Molaei , Wiltbank Milo C , Kirkpatrick Brian W
Published: November 2020

Bovine twin birth is associated with detriments including increased embryo/fetal losses, malpresentation and dystocia. Incidence of these is lessened in bilateral versus unilateral twin pregnancy. This study was undertaken to assess use of follicular ablation by aspiration to create bilateral twin pregnancies in females with genetic potential for ~3.5 ovulations per cycle (Trio allele carriers). In Experiment 1, carriers (n = 30) and non-carriers (n = 10) were synchronized for ovulation and timed artificial insemination (TAI). Follicles (> 5 mm) in excess of one per ovary were aspirated ~16h preceding TAI. Follicle count for females with follicles on only one ovary was reduced to two. Blood was sampled 2 weeks post-TAI to assess progesterone (P4) concentrations; fetal count was determined by ultrasound 6 weeks post-TAI. P4 concentration post-TAI was significantly (P < 0.001) associated with both genotype and subsequent pregnancy status (pregnant non-carriers, 7.06 ± 0.68 ng/mL; pregnant carriers, 5.54 ± 0.55 ng/mL; non-pregnant non-carriers, 5.22 ± 1.05 ng/mL; non-pregnant carriers, 3.13 ± 0.42 ng/mL). Experiment 2 was undertaken to offset negative effects of follicular aspiration on subsequent P4 concentration observed in Experiment 1. Carriers (n = 38) and non-carriers (n = 32) were submitted to fixed-TAI and follicle ablation as described. Additionally, accessory corpora lutea were induced by administration of hCG (carriers) at d6 post-TAI. Consequently, P4 concentration post-TAI was significantly (P < 0.05) associated with subsequent pregnancy status (pregnant, 8.48 ± 0.61 ng/mL; non-pregnant, 6.70 ± 0.63 ng/mL) but not with genotype (carrier, 8.01 ± 0.59 ng/mL; non-carrier, 7.17 ± 0.64 ng/mL). Fetus number was greater in carriers (Exp1, 1.64 ± 0.81; Exp2, 1.45 ± 0.09) versus non-carriers (1.00 ± 0.00, both Experiments). Singles, twins, and triplets occurred in carriers in Experiment 1, whereas multiples in Experiment 2 were limited to twins. Genotype effects on pregnancy rate were not significant (P > 0.10) in either experiment. Results suggest follicular ablation to create bilateral twin pregnancies in Trio carriers is feasible but requires induction of accessory corpora lutea to offset the negative effects of follicular aspiration on subsequent P4 concentration.
374 Early embryonic loss is an important mechanism for maximizing litter size in the pig
Authors: Geisert Rodney D , Meyer Ashley E , Pfeiffer Caroline A , Johns Destiny N , Prather Randall S , Spencer Thomas E
Published: November 2020

Litter size of commercial dam lines of pigs has seen a significant increase over the last 20 years. Although the current large litter size of gilts and sows can be attributed to improved genetic selection and nutrition, much of the increase in total number born has occurred through the continued increase in ovulation rate over the last four decades. Ovulation rate has increased from 14 in the 80’s to today’s average of 20–25 in commercial dam lines. However, high ovulation rate not only causes increased competition between embryos (uterine crowding), but the number of potential piglets born can out strip the number available teats. In addition, fetal crowding can reduce fetal growth and comprise health and survivability of lighter weight piglets at birth. Since there is usually minimal embryo loss observed up to blastocyst formation and hatching, the majority (20 to 30%) of embryonic loss occurs during Days 10 to 30 of gestation, which encompasses a critical period of conceptus development and differentiation, pregnancy recognition signaling, and onset of implantation. This period of early embryo loss is actually essential for establishing adequate uterine space to support fetal survival for a large litter. The period of rapid conceptus elongation on Day 12 of pregnancy provides a key “selection point” for regulating potential litter size in the pig. Establishing the fundamental roles of conceptus- and uterine-secreted factors is an essential step to develop strategies to increase placental and fetal growth to improve overall health and survivability of piglets before and after birth. During the peri-implantation period of pregnancy, porcine conceptuses produce interleukin-1B2, estrogens, prostaglandins and interferons. CRISPR/Cas9 genomic engineering technology has provided a direct method to evaluate the role of key pig conceptus genes. Loss-of-function studies have increased our understanding of the multiplicity of uterine/conceptus factors that are involved with maintenance of pregnancy.
162 Effects of bedding application on feedlot receiving phase growth performance and estimated maintenance requirement in newly weaned beef steers
Authors: Smerchek Dathan , Smith Zachary K
Published: November 2020

The effect of bedding application on growth performance and estimated maintenance energy requirements during the feedlot receiving phase was evaluated in newly weaned beef steers (n = 162 Charolais-Red Angus cross steers; initial un-shrunk body weight [BW] = 278 ± 13.4 kg). Steers were housed in 18 concrete surface pens (n = 9 steers/pen) measuring 7.62 × 7.62 m at the Ruminant Nutrition Center in Brookings, SD. A corn silage based receiving diet was fed that contained approximately 1.74 Mcal/kg of NEm, approximately 1.12 Mcal/kg of NEg, and monensin sodium at 27.6 g/T. Pens were assigned to one of two treatments: 1) no bedding (NO), or 2) 1.0 kg (as-is basis) of wheat straw bedding/steer/d (BED). The study was conducted from October to December of 2019. Daily ambient temperature (n = 56) averaged -3.0°C [SD 5.5] and windchill averaged -5.1°C [SD 6.1] during the course of the study. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) as a randomized complete block design with pen serving as the experimental unit. An α of 0.05 determined significance and tendencies were declared from 0.06 to 0.10. At study initiation, initial un-shrunk body weight did not differ (P = 0.69) between treatments. Bedding application did not influence (P ≥ 0.66) final body weight (shrunk 4%) or average daily gain. Dry matter intake tended to increase (P = 0.06) by 3.8% in NO compared to BED. Gain to feed was increased (P = 0.01) by 5.6% in BED compared to NO. Maintenance coefficient (MQ) was elevated (P = 0.03) 18.9% for NO compared to BED. These data indicate that bedding application improved feed efficiency and reduced estimated MQ in beef steers during the feedlot receiving phase.
160 Effects of cow-calf management strategies on environmental footprints of beef cattle production in the United States
Authors: Baber Jessica , Wickersham Tryon , Place Sara , Rotz Al
Published: November 2020

As baseline environmental footprints of beef cattle production are established, mitigation strategies through cow-calf dietary and production management can be evaluated. Our objective was to quantify environmental benefits obtained by beef cattle production through implementation of cow-calf management strategies. Ten cow-calf management strategies were identified related to animal performance, feed management, or pasture management. Each strategy was incorporated into 20 representative beef cattle production systems and simulated with the Integrated Farm System Model (IFSM) using local soil and climate data. A combined strategy was identified based upon the results of individual strategies, which was also simulated with IFSM. Farm-gate life cycle assessment was used to estimate carbon (C) footprint, fossil energy use, blue water use, and total reactive nitrogen (N) loss for all production systems and strategy combinations. Averages of each environmental metric for the cow-calf sector were based on weighted averages of regional cow inventory data. National estimates of environmental impacts were based upon number of cattle represented by each production system. Feed efficiency, terminal cross sires, and reduced cow body size strategies had greatest effect on C footprint (reductions of 1.31, 1.15, and 0.71 kg CO2e/kg CW, respectively from a baseline of 16.34 kg CO2e/kg CW). Calving season, reduced cow body size, and improved fiber digestion increased fossil energy use (7.8%), while improved feed efficiency and calf implant use reduced fossil energy use (7.4%). Blue water use was reduced by a greater extent from improved feed efficiency (4.6%) and reduced cow body size (5.3%) compared to other strategies (0.6%). Total reactive N loss was reduced by 7.0 and 6.9% through improved feed efficiency and reduced cow body size, respectively. Combining strategies reduced C footprint (18.2%), fossil energy use (18.6%), blue water use (18.9%), and reactive N loss (16.2%).
161 Effects of management strategies on environmental footprints of cow-calf production in the United States
Authors: Baber Jessica , Wickersham Tryon , Place Sara , Rotz Al
Published: November 2020

Estimates of beef cattle production’s national and regional cradle to farm grate environmental impacts have been quantified. As baseline footprints are now established, cow-calf dietary and production management strategies can be evaluated for their capacity to reduce environmental impacts. Accordingly, our objective was to quantify environmental changes from implementing management strategies in cow-calf production. Ten management strategies were identified, with each related to animal performance, feed management, or pasture management. Each strategy was incorporated into a representative cow-calf operation for each of 6 major regions of beef production in the United States and simulated with the Integrated Farm System Model (IFSM) using local soil and climate data. A combined strategy was also identified based on results of the individual strategies, which was simulated with IFSM. Farm-gate life cycle assessment was used to estimate carbon (C) footprint, fossil energy use, blue water use, and total reactive nitrogen (N) loss for all production systems and strategy combinations. Averages of each environmental metric for the cow-calf sector were based on weighted averages of regional cow inventory data. Averaged across all strategies, the reduction in C footprint was 4.1% and fossil energy use was reduced 3.5% for the cow-calf sector. Improved feed efficiency (8.0%) and terminal cross (7.1%) strategies reduced C footprint to a greater extent than other strategies simulated (2.0%). Fossil energy use was reduced by 8.3, and 6.5% from improved feed efficiency and terminal cross strategies, respectively. Early weaning increased C footprint, fossil energy use, blue water use, and reactive N loss by 13.8, 17.8, 20.2, and 12.7%, respectively. The combined strategy, including improved feed efficiency, improved fiber digestion, calf implant use, increased weaning rate, reduced cow body weight, and terminal cross strategies, reduced C footprint (18%), fossil fuel use (18%), blue water use (23%), and reactive N loss (15%).
172 Enteric methane emissions from pregnant beef heifers as affected by multiple mitigation strategies
Authors: Teranishi Rhea E , McGeough E J , Wittenberg Karin , Crow Gary , Ominski Kim
Published: November 2020

This study was conducted to determine if enteric methane (CH4) emissions from pregnant beef heifers could be reduced by using multiple dietary mitigation strategies. The trial was designed as a 4 x 4 Latin square consisting of a 21-d adaptation phase followed by a 21-d data collection phase. Forty Aberdeen Angus cross pregnant beef heifers were randomly assigned to one of the four dietary treatments (n = 10): i) low protein grass hay (L; 6.1% CP; 1.9% fat); ii) adequate protein grass hay (AD; 10.8% CP; 1.9% fat); iii) AD supplemented with sunflower screenings (ADSS; 9.8% CP; 5.6% fat); and iv) above adequate protein legume grass mix hay (AAD; 12.8% CP; 1.7% fat). Total dry matter intake (DMI) was 32%, 27% and 39% greater (P < 0.0001) for AD, ADSS and AAD respectively, relative to the L diet (6.5 kg d-1). Average daily gain (ADG; kg d-1) was influenced by dietary treatment (P < 0.0001), as heifers offered L, AD, ADSS and AAD diets gained 0 ± 0.2, 0.6 ± 0.2, 0.5 ± 0.2 and 0.7 ± 0.2 kg d-1, respectively. Enteric CH4 emissions (L d-1), were influenced by dietary treatment (P < 0.0001) with 184 ± 18.9, 214 ± 19.0, 204 ± 19.1 and 232 ± 19.1 L d-1 for heifers offered L, AD, ADSS and AAD diets, respectively. Further, heifers offered AD, ADSS and AAD diets emitted 19%, 22% and 14% less (P=0.03) enteric CH4 (% GEI) relative to diet L, respectively. This study demonstrates that supplementation to meet nutrient requirements for protein or increasing the fat content of forage-based diets using low-cost by-products such as sunflower screenings can decrease enteric CH4 emissions without adversely impacting total DMI and ADG.
166 Altering the ruminal microbiota in dairy calves using rumen contents dosing
Authors: Cox Madison S , Weimer Paul J , Steinberger Andrew J , Skarlupka Joseph H , Suen Garret
Published: November 2020

A major goal in dairy research is to improve milk production efficiency (MPE). With the advent of next-generation sequencing, efforts are underway to improve MPE by manipulating the rumen microbiota. MPE correlates to ruminal bacterial community composition (BCC), but the adult rumen microbiota is highly stable and returns to a baseline BCC after heavy perturbation. We seek to influence rumen BCC by early intervention in pre-weaning calves. Two cannulated Holstein donors of disparate MPE were selected. Three cohorts of 6 bull calves were established and dosed by gavage with a rumen inoculum sourced from the high-efficiency donor (HE), the low-efficiency donor (LE), or an autoclaved 50:50 mix as a microbe-free control (C). Dosing occurred at birth, then biweekly through 6 weeks. Feces were collected at each dosing. Daily preweaning intake of calf starter, which correlates to downstream feed efficiency, was greatest in HE calves and lowest in C calves (P < 0.05), though preweaning average daily gain did not differ between cohorts (P = 0.210). Calves were sacrificed at 8 weeks to access rumen contents and rumen wall sections were collected to assess papillation. Fecal and rumen samples were subjected to 16S rRNA amplicon sequencing. BCC differed by cohort in fecal and rumen samples (P < 0.05), with HE calf samples most similar to adult rumen samples and C calves least similar. Additionally, HE calves tended to have elongated papillae (P =0.062), the development of which is dependent on byproducts of microbial metabolism in the rumen and which points to differences in potential absorptive capacity of the epithelium. These data demonstrate that the rumen BCC can be influenced by early intervention. Future work includes expansion of this dosing protocol to a cohort of 60 female calves, following rumen BCC development and the impact on MPE in through the first lactation.
221 Quantifying the relationship between fasting heat production and chemical empty body composition in sheep and cattle
Authors: Lancaster Phillip A
Published: November 2020

Previous research indicates that animals of similar weight but greater protein mass have greater metabolic rate. The objective was to quantify the relationship between fasting heat production (FHP) and empty body composition in ruminants. A literature search was conducted to compile data on FHP and empty body composition. Seven studies using sheep or cattle consisting of 49 treatment means were found reporting FHP and chemical empty body composition. Data were analyzed with R statistical packages using mixed model methodology with study as a random variable. Given the strong correlations (r > 0.7) and high degree of multicollinearity (VIF > 30) among EBW, empty body protein (EBP) and empty body fat (EBF), LASSO regression was used to reveal that EBP was the important predictor of FHP. Allometric models (a*X^b) gave significant (P < 0.001) values for a and b of 74.3 ± 10.4 and 0.74 ± 0.02 for X = EBW (R2 = 0.963, RMSE = 432 kcal, AIC = 737), 227.7 ± 21.1 and 0.86 ± 0.02 for X = EBP (R2 = 0.972, RMSE = 375 kcal, AIC = 724), and 270.8 ± 75.9 and 0.75 ± 0.07 for X = EBF (R2 = 0.702, RMSE = 1219 kcal, AIC = 839), respectively. Log transformed models (lnFHP = lnX) gave significant (P < 0.001) values for intercept and slope of 4.47 ± 0.13 and 0.69 ± 0.02 for X = EBW (R2 = 0.979, RMSE = 0.088 lnkcal, AIC = -62.6), 5.61 ± 0.11 and 0.74 ± 0.03 for X = EBP (R2 = 0.973, RMSE = 0.096 lnkcal, AIC = -45.1), and 6.44 ± 0.19 and 0.33 ± 0.02 for X = EBF (R2 = 0.894, RMSE = 0.125 lnkcal, AIC = -13.8), respectively. A log transformed model including both EBP and EBF resulted in significant intercept (5.79 ± 0.14; P < 0.0001), lnEBP coefficient (0.56 ± 0.08; P < 0.0001) and lnEBF coefficient (0.09 ± 0.04; P = 0.02) with VIF of 8.3. The R2, RMSE and AIC of this model were 0.970, 0.088 lnkcal and -43.5; not improved over the model with EBP alone. In conclusion, EBP explained the variation in FHP as well or slightly better than EBW, and EBF did not significantly improve the prediction.
215 Supplementation with beta-carotene and vitamins improves pregnancy rate after timed-AI in beef Nellore cows grazed in pasture systems
Authors: Factor Luana , Vasconcellos Guilherme S , Acedo Tiago S , de Carvalho Victor V Valério , Catussi Bruna L , Baruselli Pietro S
Published: November 2020

The aim was to evaluate the effects of beta-carotene and vitamins (A, D3, E and biotin) on reproductive performance of grazing Nellore cows calving in different moments. A total of 497 multiparous cows (5.68 ± 0.11 parities) were homogeneously divided in 4 paddocks (Brachiaria brizantha spp.) according to BCS (2.8 ± 0.27), following a completely randomized design in a 2 x 2 factorial arrangement, being the factors: calving moment [CM = early October (EO; 1st-15th) or late October (LO; 16th-31st)]; and supplementation (SUP): control [(mineral supplementation, Fosbovi® Reprodução; n = 251) or vitamins (control + beta-carotene (150 mg), vitamins A (40.000IU), D3 (5.000IU), E (300 mg) and biotin (20 mg)/cow/day; n = 246)]. Mineral supplement and vitamins were daily offered for 60 days (30d before to 30d after 1st FTAI), and provided by DSM Produtos Nutricionais Brasil S.A. Cows were synchronized (1st FTAI) with a P4/E2-based FTAI protocol, and open cows were resynchronized (2nd FTAI) 30 days after the first insemination. The 1st FTAI conception rate (CR) tended to be greater for vitamins group, compared to control [64.2%(158/246) vs. 56.6%(142/251); P = 0.08], regardless of CM. The CM*SUP interaction was significant for CR at 2nd FTAI, with vitamins presenting higher CR over control in LO moment [52.1% (38/73) vs. 41.4% (24/58), P = 0.0053]. Greater cumulative CR (1st + 2nd FTAI) was observed for vitamins over control [83% (204/246) vs. 79% (198/251); P = 0,058], and for LO compared to EO [86% (157/183) vs. 78% (245/314); P = 0.01], without CM*SUP significance. The BCS was higher for the vitamins group, compared to control, at AI moment (3.00 vs. 2.81, P < 0.0001) and 30 days after AI (3.11 vs. 3.03, P < 0.0001), regardless of CM. The inclusion of beta-carotene and vitamins A, D3, E and biotin in mineral supplements is a tool to optimize reproductive performance and BCS of grazing Nellore beef cows during breeding season.
190 President Oral Presentation Pick: Transit affects metabolic profiles and antioxidant enzyme activity in the muscle of beef steers
Authors: Deters Erin L , Hansen Stephanie L
Published: November 2020

This study sought to elucidate the effects of road transportation on muscle metabolites and antioxidant defense of beef steers. Thirty-six Angus-cross steers (324 ± 36 kg) from a single source were stratified by body weight, then randomly assigned to pens equipped with GrowSafe bunks (6 steers/pen) and treatments (12 steers/treatment): CON = no transit, ad libitum feed and water; DEPR = no transit, deprived of feed and water for 18 h; or TRANS = trucked (1,790 km) with no feed and water for 18 h. Treatments were initiated on d 0 and terminated ~18 h later. Muscle (longissimus dorsi) samples collected from all steers on d -4, 1, and 3 were analyzed for superoxide dismutase (SOD) activity; while d 1 and 3 samples were utilized for complete metabolite analysis via gas chromatography-mass spectrometry. Antioxidant data were analyzed as a completely randomized design using ProcMixed of SAS 9.4 (experimental unit = steer, fixed effect = treatment). Metabolomics data were analyzed with MetaboAnalyst 4.0 where area under the curve (AUC) was used to identify metabolites as potential biomarkers. On d 1, total SOD activity was greatest for TRANS (P = 0.02) driven by a tendency for greater Mn-SOD activity (P = 0.10) and greater CuZn-SOD activity (P = 0.02). On d 3, Mn-SOD activity tended to be least for TRANS (P = 0.07). Metabolites of the pentose phosphate pathway (gluconic acid and D-ribose) were identified as potential biomarkers in TRANS muscle on d 3 when compared to CON (AUC ≥ 0.85) or DEPR (AUC ≥ 0.75). Under conditions of oxidative stress, glucose will be diverted from glycolysis to the pentose phosphate pathway to produce reducing equivalents. Alterations in muscle metabolic profiles coupled with lesser Mn-SOD activity 48 h post-transit may indicate residual oxidative stress, which could negatively affect feedlot performance.
194 Effects of feeding increased roughage to feedlot steers the last 56 days of finishing
Authors: Pierce Kaitlyn N , Foote Andrew P , Beck Paul A , Robison Colton A , Warner Andrea L , Hubbell Don S , Wilson Blake K
Published: November 2020

Finishing cattle are fed high concentrate diets to increase deposition of both muscle and adipose tissue and decrease cost of gain. The objective of this experiment was to evaluate the effects of increased roughage inclusion late in the finishing period on growth performance, carcass traits, and ruminal and fecal characteristics of feedlot steers. Treatments included a control (CON; 6% roughage DM), intermediate (INT; 12% roughage DM), and high (HGH; 18% roughage DM) roughage diets. Crossbred beef steers (n = 54; BW = 289 ± 35.6 kg) were assigned to treatments for the late finishing period in a randomized complete block design (4 pens of INT and HGH, 5 pens of CON; 4 steers per pen). Experimental diets contained prairie hay, Sweet Bran, rolled corn, dry supplement, urea, and a corn steep and molasses-based liquid supplement. The inclusion rate of roughage and rolled corn were adjusted for each treatment diet. Steers in HGH tended to have increased overall DMI (P = 0.07). No differences in final BW, overall ADG, or gain:feed were observed among treatments (P ≥ 0.72). Steers fed HGH had the greatest REA (P = 0.03) and a tendency for a lower yield grade (P = 0.08). Fat thickness, HCW, marbling, liver scores, and KPH did not differ (P ≥ 0.29) among treatments. Steers fed the HGH diet had a lower fecal pH at the end of finishing (P = 0.05) compared to CON and INT steers. Ruminal lactate was increased on d 14 for CON steers compared to other treatments (P < 0.001). No differences were observed for ruminal pH (P ≥ 0.11). Results of this experiment suggest that increasing roughage late in the finishing period does not negatively impact growth performance or carcass characteristics, but may alter ruminal fermentation and post ruminal digestion.
389 Interactions between zinc, copper, and growth promoting technologies in beef cattle
Authors: Genther-Schroeder Olivia N , Carmichael Remy N , Messersmith Elizabeth M , Hochmuth Katherine , Lonergan Elisabeth , Hansen Stephanie L
Published: November 2020

Trace minerals (TM) are required for many biochemical processes and support optimal animal growth. However, as animal genetics and feed technologies in the beef industry have advanced, our understanding of the TM requirements of modern cattle has lagged. Recently, Zn and Cu have emerged as potential targets for better understanding the interaction between nutrition and growth-promoting technologies like anabolic implants and β-agonists (BA). Both Zn and Cu are phosphodiesterase inhibitors, potentially maintaining cAMP concentrations, potentiating the BA signal. Zinc supplementation well above national recommendations can improve ADG or HCW in finishing cattle during the BA feeding period, and N retention is increased by both Zn and BA supplementation, suggesting a major role for Zn is in protein accretion. Interestingly, Cu status of feedlot steers appears to affect ADG during the BA period, where steers with moderate liver Cu and 10 mg Cu/kg diet DM gaining more than steers with high or low Cu status. Anabolic implants likely improve growth through altering protein deposition, degradation and satellite cell proliferation, processes that can be linked to Cu and Zn metalloproteins. Implanting cattle decreases both plasma and liver Zn, and heifers receiving a long-lasting implant had greater HCW when supplemented with 100 mg Zn/kg DM when compared with 30 mg Zn/kg DM. It is apparent Cu status and supplementation also affect the response to hormone implants. Steers supplemented with 20 mg Cu/kg DM had greater liver Cu concentrations and a lesser response to an implant than steers supplemented with 10 mg Cu/kg DM. Current state of knowledge suggests TM status and diet concentrations can impact the response to growth promoting technologies. Much remains to be learned about cattle requirements for dietary TM, and the appropriate TM concentrations to optimize feedlot cattle performance.
237 Evaluation of fleece and fiber characteristics of ultrafine Paco-Vicunas farmed in Missouri
Authors: Wuliji Tumen , Smith Gloria , Smith Don
Published: November 2020

Data recordings of animal breeding, fleece production, and fiber characteristics in an ultrafine Paco-Vicuna herd farmed at Victory Farm, Missouri were analyzed. A selective mating strategy was applied while establishing an ultrafine fleece growing Paco-Vicuna herd on the ranch over 12 years. The herd size was expanded from five males and one dozen breeding females in 2009 to more than 200 heads in 2016. All animals were recorded for sires, dams, and registered pedigree, birth weight, weaning weight, shearing weight, and fleece weight. Mid-side flank fleece samples were measured for Optical Fiber Diameter Analyser (OFDA) fiber characteristics, including mean fiber diameter, length, and fiber curvature. Live weight, fleece weight, and fiber characteristics were analyzed using SAS® GLM procedures. Mean birth weight, weaning weight, mixed age shearing weight, fleece weight, fiber diameter, coefficient of fiber diameter variation, fiber length, and fiber curvature were 6.82 kg, 25.27 kg, 48.84 kg, 0.85 kg, 16.6 µm, 25.2%, 64.6 mm and 56.9 degree /mm, respectively. The average fiber diameter of herd was 18.3 µm at 2009 clip, which was gradually but significantly (P < 0.05) reduced yearly to 16.4 µm at 2019 clip. In addition, the finest 25 percent of the herd’s fleeces were tested and found to have an average fiber diameter of 14 micron, which was within vicuna fleece fiber diameter ranges. These measures did not significantly increase with ages. Heritability estimates for the fleece weight and fiber diameter, length, and curvature were 0.40, 0.65, 0.29, and 0.50, respectively. The average fiber diameter measurements of Paco-Vicuna herd at Victory Farm were significantly (P < 0.01) finer than the comparable camelid herds in the country. This study found that strict selective breeding is effective for genetic gains in ultrafine fiber diameter and fleece quality in Paco-Vicunas.
234 Woodlands for Expanding the Grazing Opportunity for Small Ruminants in the Southeast: Challenges and Opportunities
Authors: Karki Uma , Paneru Bidur , Bhattrai Shailes , Ellis Nevershi , Karki Lila B
Published: November 2020

Woodlands account for around 60 percent of the land cover in the Southeast and offer a great potential for expanding the grazing opportunity for small ruminants. However, such opportunities and challenges associated with woodland grazing have not been documented well. The objectives of this study were to 1) develop strategies for increasing understory-vegetation biomass and its utilization by small ruminants and 2) identify challenges associated with the use of small ruminants in woodland plots. The study was initiated in 2017 using six woodland plots (0.4-ha each) that consisted of southern pines, as the main timber species, and numerous non-pine species. Each plot was virtually divided into four sections, and each section was randomly allocated to one of the cutting treatments or control. Treatments included the cutting of non-pine species into one of the three heights from the ground surface: 0 m, 0.9 m, or 1.5 m, and the control section did not receive any cut. Samples of understory vegetation were collected during the production period of 2018 and 2019, dried, and weighed. Small ruminants were rotationally stocked in the plots and their behavior (feeding: grazing, browsing; non-feeding: loafing, lying, and debarking) and landscape-use pattern (time spent by animals in different treatments or control in performing various behaviors) monitored. The understory-vegetation biomass increased tremendously in treatments compared to the control (33%-160%), with maximum increment (100%-160%) occurring in the section that received 0-m cut. Animals spent much of their feeding time in sections that received 0-m and 0.9-m cut consuming much of the vegetation available within their reach (goats or goats-sheep mixed: 0–1.5 m; sheep: 0–1.1 m from the ground). They selected dry and less vegetated areas containing shelters and tree shade for resting, visited the least to the control, and did not impose any damage to timber trees.
397 Using nutribiosis to improve robustness in pigs
Authors: Remus Janet C , Parrott Terry , Gruber Jordon
Published: November 2020

Nutribiosis is interaction between nutrition, the gastrointestinal microbiome and gut/immune function. Putting nutribiosis into action means re-considering strategies around nutrition and perhaps even husbandry. Monogastric nutritionists are trained to consider the impact of feed and its nutritive value to the growth and development of the pig. Yet today, nutrition needs to consider not just the impact that feed and nutrient digestibility will have on the pig, but also what could happen with the composition, development and maturation of the microbiome as well as immune function within the gastrointestinal tract. Additionally, the environment the animal is in may influence gastrointestinal microbial composition and immune competence alongside nutrition as the animal matures from neonate to a robust market hog. From an energetics standpoint, how the microbiome develops ultimately impacts maintenance cost of digestion as well as productive energy that the pig will have to support growth and robustness. As such, good nutribiotic management means balancing favorable microbiome development via targeted nutrition that manages both nutrition to the pig as well as nutrient bypass to the microbiota via use of probiotics, feed enzymes and other nutritive tools, with the end goal being a more robust pig.
410 Steroids Regulate SLC2A1 and SLC2A3 to Deliver Glucose into Trophectoderm for Metabolism via Glycolysis
Authors: Johnson Gregory A , Kramer Avery C , Steinhauser Chelsie , Seo Heewon , McLendon Bryan A , Burghardt Robert C , Wu Guoyao , Bazer Fuller W
Published: November 2020

The conceptuses (embryo/fetus and placental membranes) of pigs require energy to support elongation and implantation, and amounts of glucose and fructose increase in the uterine lumen during the peri-implantation period. Conceptuses from Day 16 of pregnancy were incubated with either 14C-glucose or 14C-fructose and amounts of radiolabeled CO2 released from the conceptuses measured to determine rates of oxidation of glucose and fructose. Both glucose and fructose transport into conceptuses, and glucose is preferentially metabolized in the presence of fructose, while fructose is actively metabolized in the absence of glucose and to a lesser extent in the presence of glucose. Endometrial and placental expression of glucose transporters SLC2A1, SLC2A2, SCL2A3 and SLC2A4 were determined. SLC2A1 mRNA and protein, and SLC2A4 mRNA were abundant in the uterine luminal epithelium of pregnant compared to cycling gilts, and increased in response to progesterone and conceptus-secreted estrogen. SLC2A2 mRNA was expressed weakly by conceptus trophectoderm on Day 15 of pregnancy, while SLC2A3 mRNA was abundant in trophectoderm/chorion throughout pregnancy. Therefore, glucose can be transported into the uterine lumen by SLC2A1, and then into conceptuses by SLC2A3. On Day 60 of gestation, the cell-specific expression of these transporters was more complex, suggesting that glucose and fructose transporters are precisely regulated in a spatial-temporal pattern along the uterine-placental interface of pigs to maximize hexose sugar transport to the pig conceptus/placenta.
263 Impact of cow milk production on cow-calf performance in the Nebraska Sandhills
Authors: Mulliniks Travis , King Tasha , Musgrave Jacki , Funston Rick N
Published: November 2020

As cow-calf producers focus on greater weaning weights, selection for increased production parameters including milk production and weaning weight have become prevalent. However, increased cow-calf production may not be captured due to environmental conditions and resource availability. A retrospective analysis was conducted to model the impact of milk production on utilizing data collected from a March calving herd (n = 348) from 2000 to 2018 in the Nebraska Sandhills. The objective of this study was to determine the impact milk production has on subsequent cow reproductive performance and calf performance throughout the pre- and post-weaning phases. Cow body weight (BW) and cow age increased (P < 0.01) average milk production throughout the lactation period with body condition score (BCS) decreasing (P < 0.01) as milk production increased. Pregnancy rate and subsequent calf birth date were not influenced (P ≥ 0.80) by level of milk production. Increasing dam milk production resulted in increased (P < 0.05) calf pre-weaning ADG and adjusted 205-d calf weaning BW. In addition, dam milk production positively influenced (P > 0.05) steer progeny final live calf BW and hot carcass weight (HCW). All other post-weaning performance and carcass characteristics were not influenced (P > 0.05) by dam milk production. This study indicates for each additional kg of milk production calf weaning BW increased 6.6 kg. The greater adjusted 205-d calf weaning BW was maintained through the feeding period resulting in greater final live BW and HCW.
271 Beta-adrenergic agonists increase maximal output of oxidative phosphorylation in bovine satellite cells
Authors: Sieck Renae L , Treffer Leah K , Viana Martonio Ponte , Khalimonchuk Oleh , Schmidt Ty B , Yates Dustin T , Petersen Jessica L
Published: November 2020

Beta-adrenergic agonists (βAA) are widely used supplements in beef production to improve feed efficiency and increase lean muscle mass, yet little is known about the molecular mechanism by which βAA achieve this outcome. Our objective was to identify the influence of Ractopamine HCl (RH) and Zilpaterol HCl (ZH) on mitochondrial function in muscle stem cells. Satellite cells were isolated from skeletal muscle of cattle (n = 4) and yak (n = 1) at harvest. Cells were exposed to ZH, RH, or no βAA in replicates of four. Real-time measurements of oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) were recorded using intracellular flux analysis. Incubation of bovine (n = 4) cells with either ZH or RH increased maximal respiration (P = 0.004) and spare respiratory capacity (P = 0.013). When yak cells were included, the response to treatment was similar (P = 0.006 and P = 0.006), but an animal effect was also observed (P < 0.02), presumably due to differences in genetic background. These findings indicate that βAA-treated cells have the capacity to respond more efficiently to increased energy demands than non-supplemented cells. Beta-adrenergic agonists improve the efficiency of muscle stem cells in part by modifying mitochondrial function.
276 Repeated Measures of PAP at Different Elevations in Beef Bulls in Colorado
Authors: Zimprich Taylor R , Speidel Scott , Schafer David , LaShell Beth , Holt Tim , Enns Mark , Cunningham Sam , Thomas Milt
Published: November 2020

High Mountain Disease (HMD) in cattle is a consequence of altitude-induced (> 1500 m) pulmonary hypertension (PH). Pulmonary arterial pressure (PAP; mmHg) is an indicator of PH-HMD and moderately heritable. This study analyzed repeated measures of PAP in growing bulls and estimated correlations across elevations and ages. Data included breed, PAP, elevation, weights and ages in spring-born bulls from the Agriculture Research, Development, and Education Center (ARDEC) in Colorado. Five PAP measurements were collected from each bull: 1) Weaning PAP at ARDEC (1,525 m); 2) Yearling PAP at ARDEC (i.e., gain-test); 3) PAP after acclimating for 28 days at Fort Lewis College (FLC; 2,470 m); 4) before returning to ARDEC from FLC after 110 days of grazing; and 5) after re-acclimating for 57 days to the moderate elevation and feeding systems at ARDEC when bulls were 18 months of age. Across these 5 times in Angus (n = 18) and Hereford (n = 12) bulls, PAP measures were: 1) 37.97 ± 0.37; 2) 40.93 ± 0.77; 3) 46.10 ± 1.48; 4) 45.00 ± 1.11; and 5) 42.23 ± 0.67, respectively. Breed and elevation-age were important (P < 0.05) sources of variation. Also, PAP changed (P < 0.05) across the 5 time periods (i.e., increased with altitude and then declined as bulls returned to moderate altitude). Yearling PAP measurements collected at 1,525 m were highly correlated with PAP measures at 2,470 m, as well as a PAP collected at 18.3 ± 0.1 mo of age at 1,525 m (r = 0.93 to 0.99); therefore, suggesting that the yearling PAP measurement collected at 1,525 m in gain-tested bulls was an adequate predictor of PAP at elevations of 1,525 and 2,470 m as bulls aged to 18 months; however, additional study of bovine PAP across elevations, ages, and rates of gain is warranted.