bluuebunny/crossref_metadata_2025_split huggingface dataset:
243 Ileal Terminal Starch Hydrolytic Activity Is Increased in Association with Improved Growth and Feed Efficiency in Weaning Pigs Fed a Therapeutic Multi-antimicrobial-supplemented Diet
Authors: Chen Jiali , Wang Min , Archbold Tania L , Wang Weijun , Fan Wenyi , Yin Xindi , Cheng Laurence , Fan Ming Z 
Published: November 2020

Abstract
Understanding roles of prescribed in-feed therapeutic multi-antimicrobials in affecting the small intestinal terminal starch digestive enzyme activity in improving weaning pig growth and feed utilization may shed light on developing novel alternative strategies to reduce uses of antimicrobials. A total of 125 crossbred barrows, weaned on d 19–21 with an average initial BW of 6.9 ± 0.1 kg, were randomly assigned to two corn, SBM and dried whey powder based diets for 21 d according to a randomized complete block design. The multi-antimicrobial diet was supplemented with aureomycin 220, tiamulin 31.2 and ZnO 2,358 at mg/kg diet. The growth performances including final BW (control, 13.9 ± 0.2 vs. antimicrobials, 15.0 ± 0.2 kg), ADG (control, 0.307 ± 0.009 vs. antimicrobials, 0.355 ± 0.009 kg/d), ADFI (control, 0.425 ± 0.012 vs. antimicrobials, 0.455 ± 0.013 kg/d) and F:G (control, 1.39 ± 0.03 vs. antimicrobials, 1.28 ± 0.03 kg/kg) were improved (P &lt; 0.05; n = 25 pens; 5 barrows/pen) compared to the non-antimicrobial control diet. The combined enzyme kinetics of the jejunal and the ileal maltase-glucoamylase (MGA) and sucrase-isomaltase (SI) activity were determined with the jejunal and the ileal homogenates by using maltose (0–60 mM in incubation mixture). The combined jejunal and the ileal MGA-SI affinity Km values and the combined jejunal MGA-SI maximal activity Vmax values were not different (P &gt; 0.05) between the two diet groups. However, the combined ileal MGA-SI Vmax (nmol·mg protein-1·min-1) was increased in the antimicrobial diet (P &lt; 0.05; control, 125.6 ± 10.84, n = 13 pigs vs. antimicrobials, 170.8 ± 12.15, n = 11 pigs) in comparison with the control diet. The Pearson’s correlation analyses revealed that the combined ileal MGA-IS Vmax of hydrolyzing maltose was associated with ADG (P = 0.0669; r = 0.38; n = 24 pigs) and feed efficiency (F:G; P &lt; 0.05; r = -0.53; n = 24 pigs). Our results suggest that in-feed therapeutic multi-antimicrobials could improve the distal small intestinal terminal starch digestive enzyme MGA-SI activity, thus improving growth and feed efficiency in weaning pigs.
241 Metoclopramide induces low-level hyperprolactinemia to increase milk production in sows
Authors: Mathews Alice T , Banks Carmen M , Trott Josephine F , Sainz Roberto D , Farmer Chantal , Pendergast Izabella I , Hovey Russell C 
Published: November 2020

Abstract
Inadequate milk production by sows often limits the growth rate of piglets. A successful lactation requires prolactin (PRL)-induced differentiation of the alveolar epithelium within the mammary glands of sows between gestation days 90–110 (G90-110). We hypothesized that late gestational hyperprolactinemia in primiparous sows induced by feeding the dopamine antagonist metoclopramide (MET) would enhance mammary epithelial differentiation, milk yield, and piglet growth rate, and that these effects would carry over into a subsequent lactation. Twenty-six gilts were randomly assigned to receive either MET (n = 13, 0.8mg/kg) or vehicle (CON, n = 13) twice daily from G90-110. On G90, circulating PRL levels peaked 45 min after MET dosing (P &lt; 0.001) then returned to baseline 3 h later. This response occurred daily out to G104 (P &lt; 0.05). Treated gilts had increased alveolar lumen diameter on G110 (P &lt; 0.05), though feed intake, body weight, and carcass fat percent were not different during pregnancy or lactation. Piglets born to treated sows had increased body weight and average daily gain on lactation days 14 and 21 (P &lt; 0.05). Piglet milk intake was estimated from deuterium oxide dilution. While milk intake by piglets nursing MET sows was not statistically different from those nursing CON sows on day 21 of lactation (P = 0.18), there was a greater increase in milk consumption by piglets born to MET-treated sows between days 9 and 21 of lactation than for those in CON litters (P &lt; 0.001). In one group of second parity sows, milk yield was increased during their second lactation with no additional treatment (P &lt; 0.05) and their carcass fat dropped by 14% (P &lt; 0.05). These findings demonstrate that MET-induced hyperprolactinemia in pigs during late pregnancy can increase milk yield and piglet growth rate, and this response can be sustained into a second lactation in some sows.
400 Functional amino acids to improve pig robustness
Authors: Columbus Daniel A 
Published: November 2020

Abstract
Pigs are continuously exposed to pathogens and immune-stimulatory antigens that negatively impact animal productivity. In general, this decrease in productivity is the result of reduced feed intake and increased demand for nutrients to mount an immune response. In addition, immune system stimulation alters amino acid metabolism and utilization, with amino acids redirected from growth towards supporting the immune response. A number of previous studies have shown that nutrient requirements for some amino acids, such as methionine, tryptophan, and threonine, are higher in immune-challenged vs. healthy animals, and supplementation with these “functional” amino acids may improve performance and the immune response. In addition to effects on whole-body growth, both dietary composition and immune challenge result in significant physiological alterations to the gastrointestinal tract, including changes in gut motility, permeability, digestive enzyme secretion, absorptive capacity, and mucin production. Alterations to the gut epithelium induced by dietary protein and/or fiber content may lead to increased susceptibility to pathogens and immune stimulation. Functional amino acids have been shown to be important in the maintenance of gut barrier function as well as immune response. An increased understanding of the interaction of nutrition and the pig’s immune response will be a key component in efforts to reduce feed costs and antibiotic use while improving animal robustness and profitability of the swine industry.
255 President Oral Presentation Pick: Exposing Undergraduate Students to Extension: Delivering Producer Education Presentations
Authors: Bullock Darrh , Lehmkuhler Jeffrey , Anderson Leslie , Arnold Michelle 
Published: November 2020

Abstract
Recent communications with livestock industry employers suggest that students seem to be prepared to publicly deliver scientific information to peers, but struggle to present comprehensible science-based information to lay audiences. Based on this premise, a producer education presentation at local Extension offices was incorporated into the Beef Cattle Science Course. The course has four core areas (health, nutrition, reproduction and genetics) with supporting instructors from meat science, forages, agricultural economics and biosystems/agricultural engineering. Students are presented a case study in each of the four focus areas and are required to submit a written report addressing the issues in the case study. At midterm, students are divided into groups of four or five and assigned to a local county. Students are required to contact the county agent and develop an educational program, with one student presenting on each of the core areas, with environmental stewardship as a fifth option. Each student must first prepare an outline and send it to the corresponding faculty member for feedback prior to developing a 15-minute PowerPoint presentation. Each student is required to deliver their presentation to instructors to receive feedback prior to the Extension meeting. Each student group must develop a promotional flyer for the agent’s use. The producer educational programs are delivered in the evening to 15–50 producers, followed by audience questions. Additionally, students are tasked with developing, administering and summarizing an assessment tool. On the last day of class we have an informal discussion of this experience. For the five years that we have incorporated this into the course, the consensus is that students initially hate the concept but love the experience and appreciate the value after presenting. Agent and producer feedback have been positive.
269 Influence of the maternal rumen microbiome on development of the calf meconium and rumen microbiome
Authors: Woodruff Kelly , Hummel Gwendolynn , Austin Kathleen , Smith Travis , Cunningham Hannah 
Published: November 2020

Abstract
Optimization of host performance may be achieved through programming of the rumen microbiome. Thus, understanding maternal influences on the development of the calf rumen microbiome is critical. We hypothesized that the cow maternal rumen microbiome would influence colonization of the calf rumen microbiome. Our objective was to relate the microbiome of the cow rumen fluid prior to parturition (RFC) and at weaning (RFCw) to the calf’s meconium microbiome (M) and calf rumen fluid microbiome at birth (RFd1), d 2 (RFd2), d 28 (RFd28), and weaning (RFNw). Multiparous Angus crossbred cows (n = 10) from the University of Wyoming beef herd were used. Rumen fluid was collected from the cows prior to parturition and at weaning. Immediately following parturition, meconium and rumen fluid were collected from the calf. Rumen fluid was collected again at d 2, 28, and at weaning. Microbial DNA was isolated and 16S rRNA sequencing was completed on the Illumina MiSeq. Sequence data were analyzed with QIIME2 to determine both alpha and beta diversity by sample type and day. Alpha diversity metrics reported similarities in the early gut microbiome (M, RFd1, and RFD2; q ≥ 0.12) and between the cow and calf at weaning (q ≥ 0.06). Microbial composition as determined by beta diversity differed in the early rumen microbiome (RFd1, RFd2, and RFd28; q ≤ 0.04). There were similarities in composition between M, RFCw, and RFd1 (q ≥ 0.09). These data can be used to develop hypotheses for the pathway of colonization in the early gut and can provide insight into management practices affecting the microbiome, improving host performance.
270 Evidence for the amnion-fetal gut-microbial axis in late gestation beef calves
Authors: Hummel Gwendolynn , Woodruff Kelly , Austin Kathleen , Smith Travis , Cunningham Hannah 
Published: November 2020

Abstract
As the most immediate membrane surrounding the fetus, the amnion carries great potential as a microbial source of inoculation for the calf’s rumen microbiome. We hypothesize the calf is exposed to a microbial source prior to birth, and that the amnion plays an essential role in inoculation prepartum. Our objective was to isolate and identify microbes of the amniotic fluid and vaginal canal during late gestation and compare these populations to rumen fluid and meconium of newborn calves. Vaginal (VAG) and amniotic fluid (AF) samples were obtained from multiparous beef cows (n = 10) 10 days prior to their expected calving date. Rumen fluid (RF) and meconium (MEC) samples were obtained from each newborn calf immediately following parturition. Microbial DNA was isolated and purified utilizing the QIAmp DNA Stool Minikit (Qiagen) for amplicon 16S rRNA sequencing. All analysis was performed in QIIME2. Alpha-diversity was not different between MEC and AF (q ≥ 0.09) under any metric, but MEC and VAG differed under Faith’s Phylogenetic Diversity (q = 0.03). The MEC, AF, and VAG all differed in beta-diversity (q = 0.003). The degree of similarity between AF and MEC may indicate the AF plays a crucial role in the colonization of the fetal gut prepartum. Each of these lines of evidence outline fundamental aspects of the unfolding amnion-fetal gut-microbial axis, and provide key targets for future research into rumen development and the manipulation of feed efficiency in beef calves.
260 Genetic prediction for first-service conception rate in Angus heifers using a random regression model
Authors: Sánchez-Castro Miguel A , Thomas Milt , Enns Mark , Speidel Scott 
Published: November 2020

Abstract
First-service conception rate (FSCR) can be defined as the probability of a heifer conceiving in response to her first artificial insemination (AI). Given the binary nature of its phenotypes, FSCR has been typically evaluated using animal threshold models (ATM). However, susceptibility of these models to the extreme-category problem (ECP) limits their ability to use all available information to calculate Expected Progeny Differences (EPD). Random regression models (RRM) represent an alternative method to evaluate binary traits, and they are not affected by ECP. Nevertheless, RRM were originally developed to analyze longitudinal traits, so their usefulness to evaluate traits with singly observed phenotypes remains unclear. Therefore, objectives herein were to evaluate the feasibility of a RRM genetic prediction for heifer FSCR by comparing its resulting EPD and genetic parameters to those obtained with a traditional ATM. Breeding and ultrasound records of 4,334 Angus heifers (progeny of 354 sires and 1,626 dams) collected between 1992 to 2019 at the Colorado State University Beef Improvement Center were utilized. Observations for FSCR (1, successful; 0, unsuccessful) were defined by fetal age at pregnancy inspections performed approximately 130 d post-AI. Traditional FSCR evaluation was performed using a univariate BLUP threshold animal model, whereas an alternative evaluation was performed by regressing FSCR on age at AI using a linear RRM with Legendre Polynomials as the base function. Heritability estimates were 0.03 ± 0.02 for the ATM and 0.005 ± 0.001 for the average age at AI with the RRM, respectively. Pearson and rank correlations between EPD obtained with each method were 0.63 and 0.60, respectively. The regression coefficient of RRM predictions on those obtained with the ATM was 0.095. In conclusion, these results suggested that although a RRM genetic prediction for FSCR was feasible, a considerable degree of re-ranking occurred between the two methodologies.
423 WS Young Scholar Talk MS II: Heat stress-induced deficits in growth, metabolic efficiency, and cardiovascular function coincided with chronic systemic inflammation and hypercatecholaminemia in ractopamine-supplemented feedlot lambs
Authors: Swanson Rebecca M 
Published: November 2020

Abstract
Our 1st study evaluated the effects of □-adrenergic agonist (ractopamine) supplementation on growth, health, and wellbeing in heat-stressed feedlot wethers. Chronic heat stress impaired growth, metabolism, and wellbeing even when the impact of reduced feed intake was eliminated by pair-feeding. We observed systemic inflammation and hypercatecholaminemia that were likely mediators of these deficits. Moreover, ractopamine did not diminish any wellbeing indicators and improved muscle growth without worsening the effects of heat stress. Our 2nd study assessed the effects of pubertal cyclicity (weaning to 1st breeding) in cows on myoblast-mediated muscle growth, metabolism, and growth efficiency of their offspring. Maternal fertility and postnatal growth efficiency of offspring are imperative to successful beef cattle production. A maternal condition was previously identified in which cows exhibited irregular cyclicity patterns or were non-cyclic between weaning and 1st breeding. This condition is thought to be associated with high concentrations of androstenedione in their follicular fluid, which causes cows to be sub-fertile but also wean heavier calves when they do become pregnant. We hypothesized that calves from cows exhibiting irregular pubertal cyclicity would have enhanced growth efficiency compared to calves from cows with normal pubertal cyclicity. To test this hypothesis, we evaluated myoblast function, growth, and metabolism pre-weaning, as well as growth efficiency in the feedlot and carcass characteristics at harvest in calves from cows that were previously identified as having typical, start-stop, or non-cycling pubertal cyclicity patterns. Calves from irregular cycling cows had reductions in insulin sensitivity, plasma proteins and lipids paired with increased myoblast function and reduced myoblast glycolytic capacity. Data independently and combined suggest calves from cows with irregular cyclicity from weaning to 1st breeding have chronic inflammation. While the specific mechanism of inflammation is unknown, further research may allow mediators of abnormal cyclicity and offspring inflammation-induced dysfunction to be elucidated.
275 Phenotypic relationships between heart score and feed efficiency, carcass, and pulmonary arterial pressure traits
Authors: Heffernan Kathryn R , Speidel Scott , Thomas Milt , Enns Mark , Holt Tim 
Published: November 2020

Abstract
Pulmonary hypertension (PH) can lead to premature mortality in fed cattle and is often called Feedlot Heart Disease (FHD). To date, pulmonary arterial pressure (PAP) has been the only indicator trait of PH that has been evaluated. The objective of this study was to evaluate relationships between heart score (using heart score as a phenotype for PH) and PAP, carcass, and feed efficiency traits in fattening Angus steers. Our hypothesis was that feed efficiency and carcass traits, along with PAP, would demonstrate a strong relationship with heart score. Feed efficiency, carcass, PAP and heart score data from 89 Black Angus steers from Colorado State University Beef Improvement Center were collected and used for this study. Evaluations were performed using a multiple linear regression model, which included heart score as a categorical fixed effect and age as a continuous fixed effect. Least Square Means, pairwise comparisons, and ANOVA tables were constructed per trait. PAP (P &lt; 0.001) showed an important relationship to heart score and average dry matter (P &lt; 0.10) intake approached importance to heart score. In general, feed efficiency and carcass traits decreased as heart score increased, but PAP was the only trait with a strong relationship to heart score (P &lt; 0.05). This led us to reject our hypothesis.
277 Phenotypic and genetic differences in Rambouillet lines divergently selected for reproductive rate over 50 years
Authors: Murphy Tom , Thomson Jennifer M , Berardinelli James , Roeder Brent 
Published: November 2020

Abstract
A long-term selection experiment was conducted in a Rambouillet flock from 1969 to 2017. The high (HL) and low lines (LL) were divergently selected based on a maternal reproductive index, and an unselected control line (CL) was also maintained. Adult ewe traits considered were NLB, greasy fleece weight (GFW), and body weight after fall weaning of their lambs (BW). Results indicated that NLB was greatest for HL (1.67 ± 0.01), intermediate for CL (1.48 ± 0.02), and least for LL (1.28 ± 0.01; P &lt; 0.001). Ewe GFW was greatest for LL (3.9 ± 0.02 kg; P ≤ 0.01) but not different between HL (3.82 ± 0.02 kg) and CL (3.88 ± 0.02 kg; P = 0.08); whereas, BW was least for HL (61.7 ± 0.19 kg; P ≤ 0.01) and not different between LL (62.9 ± 0.21 kg) and CL (62.6 ± 0.25 kg; P = 0.58). Heritability was estimated to be low for NLB (0.13 ± 0.02) and moderate for GFW (0.55 ± 0.03) and BW (0.46 ± 0.04). Genetic correlations were estimated to be near zero between NLB and GFW (-0.07 ± 0.08) and NLB and BW (0.12 ± 0.08) and low between GFW and BW (0.29 ± 0.06). Trends for NLB predicted breeding value differed among all 3 lines (P &lt; 0.01) and was positive for HL (0.012 ± 0.0002 lambs/birth year), negative for LL (-0.005 ± 0.0002), and small but positive for CL (0.002 ± 0.0002). Inbreeding rates were positive in all lines but greatest for HL (0.45 ± 0.005 %/birth year), intermediate in LL (0.37 ± 0.006), and lowest in CL (0.28 ± 0.006). Results indicated long-term phenotypic selection for reproductive rate was effective and not genetically antagonistic with wool production or mature BW.
282 The Influence of RFI classification and cow age on body weight and body condition change, supplement intake and grazing behavior of beef cattle winter grazing mixed-grass rangelands
Authors: Parsons Cory T , Dafoe Julia M , Wyffels Samuel , Van Emon Megan , DelCurto Timothy , Boss Darrin L 
Published: November 2020

Abstract
behavior of beef cattle winter grazing rangelands in North Central Montana. A herd of non-lactating commercial Angus cows, n = 205 (yr-1) and n = 203 (yr-2), ranging in age from 1 to 9 yr old, grazed rangeland pastures (586 ha) from mid-October to early January of 2018 and 2019. Cows were grouped into 6 age classes to evaluate the effects of RFI and age on average daily individual supplement intake, CV of supplement intake, and intake rate, as well as changes in body weight and body condition during an 84-day grazing period each year. Additionally, 30 cows were stratified by age and RFI and fitted with Lotek GPS collars each year to record distance traveled and time spent grazing. Change in cow weight differed by year where cows in yr-1 gained 26.3 ± 1.96 kg while cows in yr-2 lost 19.2 ± 1.96 kg during the 84-day grazing period (P &lt; 0.01). Change in BCS exhibited an age × RFI interaction (P = 0.05); however, an analysis within age groups did not result in differences between RFI classifications (P ≥ 0.27). There was an interaction between RFI, age and year related to supplement intake expressed as g∙kg cow bw-1∙d-1 where in year 2, 4-yr-old high RFI cattle consumed less supplement than 4-yr-old low and average RFI cattle (P &lt; 0.01). Supplement intake rate expressed as g∙min-1 also differed by year (P &lt; 0.01), with cows in yr-1 consuming less supplement per minute than in yr-2 (29.9 ± 1.81 and 91.8 ± 1.87). There were no effects of RFI, cow age or year on time spent grazing (P ≥ 0.19) with cows averaging 6.1 ± 0.61 hrs per day grazing. In summary, cow age had an influence on supplement intake, change in weight and body condition, and grazing behavior, while RFI classification had minimal effects.
283 Heterosis and its potential influence on pulmonary arterial pressure in beef cattle
Authors: Gonzalez Murray Roderick A , Sánchez-Castro Miguel A , Thomas Milt , Speidel Scott , Enns Mark 
Published: November 2020

Abstract
High altitude disease (HAD) is a hypoxia-influenced pathologic condition experienced by cattle raised at high elevations (&gt; 1,524 m). Pulmonary arterial pressure (PAP) is a common diagnostic tool used as an indicator of susceptibility to develop HAD. Given PAP is moderately heritable, possibilities to genetically reduce the incidence of HAD are feasible. However, an alternative strategy could be given by heterosis, since non-additive genetic effects have been related to survivability and environmental fitness. Therefore, objectives of this study were to determine heterosis and breed percentage effects on PAP measurements. A total of 1,083 cattle with varying percentages of Simmental, Angus, Hereford and Red Angus breeds were used for the study. Such animals’ available information included PAP records, PAP test date, PAP technician, sex, herd of origin and breed percentages of parents. A general linear model was utilized to estimate the effect of heterosis on PAP. Contemporary group (defined as a combination between herd, PAP date, PAP technician and sex) was included as a categorical fixed effect; whereas the age at PAP measurement and the degree of outcross were included as linear covariates. Similarly, breed effects were estimated by including breed percentages of Simmental, Angus, Hereford, Red Angus and “Other” breeds as linear covariates in the model. The general average for PAP measurements in the entire dataset was 41.29 ± 0.22, with range of 26 and 108 mmHg. The estimated regression coefficient for PAP on heterosis was -1.834 ± 1.676 mmHg/percent of outcross (P = 0.276), whereas, the range of breed effects on PAP was 15.08 mmHg. These results suggested that heterosis had no significant effects on PAP measurements. However, further research including other multibreed populations is required in order to better understand if increased levels of heterozygosity could potentially be related to lower PAP scores.