bluuebunny/crossref_metadata_2025_split huggingface dataset:
PSVI-15 Effect of direct-fed microbials on fecal characteristics during an acidosis induction
Authors: Huizenga Kaylie , Tondini Sara , McCann Joshua C 
Published: November 2020

Abstract
The objective was to investigate the effects of two direct-fed microbial dosing strategies on fecal characteristics of beef cattle during an acidosis challenge. Ruminal acidosis is a metabolic disorder in beef cattle that may contribute to hindgut acidosis. Eighteen ruminally cannulated steers (BW = 328 ± 20 kg) were used in a completely randomized design with 6 steers in each period. Two steers in each period were randomly assigned to one of three treatments: blank media (NCON), a single strain of Megasphaera elsdenii at 108 CFU (DFM1), and a combination of Megasphaera elsdenii and proprietary microbial strains at 1010 CFU per dose (DFM2). On d 1, DFM1 was dosed once and DFM2 and NCON were dosed daily at 0700 on d 1-15. A basal diet (45% forage) was fed ad libitum on d 1-7. To induce acidosis, steers were fasted for 24 h on d 8 and were fed the challenge diet (10% forage) ad libitum on d 9-15. Fecal pH was measured throughout the challenge and total feces was collected on d 11-14 to determine washed fecal particle size and observe mucin casts. Fecal pH and mucin cast score was not affected (P ≥ 0.29) by treatment. Fecal particle size in DFM1-treated steers was greater (P = 0.01) than NCON and DFM2. Fecal particle size tended (P = 0.06) to increase over time. Fecal particle size was not correlated (P ≥ 0.56) to ruminal or fecal pH. Fecal mucin cast score was positively correlated to dry matter intake (P &lt; 0.01) and mean ruminal pH (P = 0.06). Mucin cast score may help in monitoring ongoing bouts of ruminal acidosis. Overall, results indicate direct-fed microbial treatment affected fecal particle size but not fecal pH and mucin cast score during an acidosis challenge.
PSVIII-20 Impact of soybean meal inclusion in late gestation on sow productivity and litter performance
Authors: Loucks Abigail , van Sambeek Dana , Hines Elizabeth A 
Published: November 2020

Abstract
Soybean meal (SBM) provides essential nutritional components to the pig beyond amino acid profile. However, the expense of SBM has led to reduced use or elimination from diets of pre-farrowing sows. Therefore, the objective of this project is to investigate the impact of variable SBM inclusion rates of late gestation diets on sow productivity during farrowing and lactation. Sows were assigned to one of four diets, two weeks prior to farrowing: A (n=15; 0% SBM, 13.5% crude protein (CP), B (n=17; 10% SBM, 13.5% CP), C (n=15; 0% SBM, 21.5% CP), D (n=15; 30% SBM, 21.5% CP). At farrowing the total born (TB), born alive (BA), mummies (MM), stillborn (SB), and birth weights (BW) were recorded. After farrowing, piglet weights were recorded daily until d 10 of lactation, and then weekly until weaning. No significant effect of SBM inclusion was observed for MM, SB, or BW (P &gt; 0.44). A numerical increase in TB (P = 0.36) and BA (P = 0.11) was observed in litters produced from sows on diet D, with TB at 13.9 ±1.3, and BA at 13.3 ± 1.1, while diets A, B, and C had TB and BA ≤ 11.3 ± 1.6, and ≤ 10.2 ± 1.1, respectively. Litter BW, wean weight, and average daily gain were not different across diets (P ≥ 0.47). These results suggest that the inclusion rate of SBM has minimal impact on overall performance, however, continued research is needed into understanding the nutritional needs of a sow during late gestation.
PSV-22 Use of weekly quizzes in a graduate-level physiology course does not enhance student learning but may help regulate study time
Authors: McFee Renee M , Bidne Katie 
Published: November 2020

Abstract
Weekly quizzes are a popular method to assess student learning. Their use may increase knowledge retention via the testing effect and encourage spaced rather than massed study habits. We sought to understand the effects of weekly quizzes in a graduate-level systems physiology course. This study encompasses two academic years, 2018-2019 (Year 1, n=27) and 2019-2020 (Year 2, n=28). Four independent course units were utilized, with weekly quizzes and an end-of-unit summative exam administered during two units and just an end-of-unit exam administered during the other two units. Quizzes consisted of lower-level questions (remember, understand) while exams contained higher-level questions (apply, analyze). When weekly quizzes were not administered, lower-level questions were added to the unit exam. Identical quiz and exam questions were used for both years of the study. Treatments were reversed between Year 1 and Year 2 to account for variations in unit difficulty (Table 1). Study time was tracked via weekly student surveys. We observed a difference in quiz and exam scores between units; however, there were no differences from Year 1 and Year 2 within units. Overall weekly and non-exam week study time differed across units in Year 1, with increased study time in the first unit with quizzes. This same effect was not observed in Year 2. Between years, overall weekly and non-exam week study time was greater when quizzes were administered but only for the first unit of the year. No differences were observed between units or years in exam week study time. In both Year 1 and Year 2, hours studied per week correlated strongly with exam administration (r &gt; 0.9) but not with quiz administration (r &lt; 0.2). Overall, these data suggest that weekly quizzes may not enhance academic performance. They may help regulate weekly study time, but do not prevent “cramming’” before exams.
PSI-3 Effects of housing cow-calf pairs in drylots vs pasture during the summer on cow performance
Authors: Sexton Keiffer , Myerscough Megan , Chapple Wesley , Meteer William T , Trennepohl Keela , McCann Joshua C , Shike Daniel W 
Published: November 2020

Abstract
The objective was to evaluate the effects of maintaining cows in drylots vs pasture on beef cow performance. Spring-calving, Simmental × Angus cows (n = 108; 84 ± 11 d postpartum) were stratified by age, BW, BCS, calving date, and sex of calves and allotted to 6 groups. Groups were randomly assigned to 1 of 2 treatments for 110 d: drylot (DL) or pasture (PAST). Drylot cows were limit-fed a ration consisting of corn silage, dried distillers grains, hay, corn stalks, corn, and soybean hulls to meet protein and energy requirements. Cows on pasture were rotationally grazed and offered free-choice mineral. On d 0, cows were artificially inseminated (AI). On d 0, 53, and 110 (weaning), cow BW and BCS were measured. On d 54 milk production was estimated using the weigh-suckle-weigh technique. Data were analyzed using the MIXED procedure of SAS. All binary data were analyzed using the GLIMMIX procedure of SAS. On d 0 and 53, cow BW did not differ (P ≥ 0.73) between DL and PAST. On d 110, DL cows had 74 kg greater (P &lt; 0.01) BW than PAST cows. The BCS did not differ (P ≥ 0.66) between treatments. There was no difference in milk production (P = 0.93); however, drylot cows tended (P = 0.10) to have reduced milk fat percentage and had reduced (P &lt; 0.01) milk urea nitrogen. There was no difference (P ≥ 0.34) in AI or overall pregnancy rates between treatments. There was no difference in foot angle or claw set (P ≥ 0.17) of cows at any time point. There was also no difference (P = 0.17) in foot treatments between DL (39%) and PAST (4%). Housing cows in drylots compared to pasture increased BW, but did not affect BCS, milk production, and pregnancy rates.
PSIII-13 The Effects of Corn Gluten Feed and Corn Dried Distillers Grains as a Replacement for Soybean Meal on Boer Type Goat Diets
Authors: Costigan Samantha , Crane Alison , Lattimer James M , Jones Cassandra K 
Published: November 2020

Abstract
The objective of this study was to evaluate the efficacy of corn dried distillers grains with solubles (DDGS) or corn gluten feed (CGF) as a replacement for soybean meal (SBM) in a Boer goat diet. A total of 75 meat goat kids (26.9 0.2 kg) were placed in 25 pens (3 kids per pen and 5 pens per treatment) for a 35-day experimental period at the Kansas State University Sheep and Meat Goat Center. Kids were allotted to one of the following isocaloric and isonitrogenous diets that varied in protein source: 1) SBM; 2) 100% DDGS/0% CGF; 3) 66% DDGS/33% CGF; 4) 33% DDGS/66% CGF; and 5) 0% DDGS/100% CGF. Diets were pelleted and supplied the sole source of nutrition. Goats and feeders were weighed weekly to determine ADG, ADFI, G:F, cost per kg of diet, and cost per kg of gain. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst., Cary, NC) with pen serving as the experimental unit. Differences were considered significant if P0.05. Treatment did not impact BW (P = 0.999), ADG (P = 0.723), ADFI (P = 0.210), or G:F (P = 0.796; Table 2). While diet cost differed due to differences in price of soybean meal and the corn co-products, there was no evidence (P = 0.941) that cost per kg of gain was less for goats fed the corn co-products. However, feed cost per goat was less (P = 0.0008) with diets containing corn co-products, regardless of level. These data allow producers to make more informed feeding decisions with a broader understanding of potential implications of corn gluten feed use in goats.
3 Changes in growth performance, feeding behaviors, and posture behaviors of growing pigs subjected to low-intensity heat stress
Authors: Anderson Lauren E , Holt Jonathan P , van Heugten Eric , Poole Daniel H 
Published: November 2020

Abstract
This study was to determine the impact of low-intensity heat stress on frequency and duration of feeding, drinking, ventral lying, and lying lateral lying behaviors. Pigs (n = 64; 24.6 ± 3.7 kg BW) were housed four per pen in thermoneutral conditions (CON; 23.9 °C ± 2.5 °C) or constant high ambient temperatures (HS; 28.7 °C ± 1.3 °C) for 16 d, followed by thermoneutral conditions (24.4 °C ± 1.8 °C) for both groups through d 21, and subsequent heat stress (28.0 °C ± 3.0 °C) for both groups through d 30. Eight focal pigs (2 pens/treatment) were video-recorded on d 3, 6, 10, 13, 20, and 29 at three time periods (morning: 0600-0800, afternoon: 1200–1400, evening: 1800–2000). Heat stress reduced ADG (HS: 1.00 kg/d, CON: 1.13 kg/d; P = 0.020) from d 14 through d 21, tended to reduce ADFI (HS: 2.14 kg/d, CON: 2.24 kg/d; P = 0.085), and increased GF (HS: 0.62, CON: 0.52; P = 0.006) from d 1 through d 7. Surface body temperature from d 2 through d 15 was greater in HS than CON pigs (mean: 39.4 °C, 37.6 °C, respectively), and was lower on d 18 for HS than CON pigs (36.4 °C vs. 37.8 °C, respectively) and d 22 (38.6 °C vs 39.3 °C, respectively). A treatment x day x time interaction for feeding duration (P = 0.003) showed CON pigs spent longer at the feeder in the morning of d 6 than HS (22.70 min, 8.97 min, respectively), but CON spent less time than HS during d 6 evening (8.78 min, 19.57 min, respectively). HS pigs visited the feeder more frequently in the evening (14.4 bouts) than CON pigs (7.8 bouts; P = 0.029). Low-intensity heat stress negatively impacted performance and altered time of feeding duration and frequency, indicating feeding behavior may be a useful heat stress predictor.
41 Estimating the heritability of meat quality traits in turkeys
Authors: Vanderhout Ryley J , Yahiro Michelle , Wood Benjamin , Barbut Shai , Mohr Jeff S , Baes Christine F 
Published: November 2020

Abstract
Genetic selection for improved meat quality traits has been successfully implemented in many livestock species. The objective of this study was to estimate the heritability of several meat quality traits to assess their selection potential in turkeys. Pedigree toms (n = 1,033) were processed at a commercial facility and live weight, breast meat yield (as a percentage of live weight), ultimate pH, color (CIELAB values), drip loss, cooking loss, and shear force were recorded on M. pectoralis superficialis (fillet). White striping was also rated on a 1–4 scale. Heritabilities were estimated using univariate animal models in ASReml version 4.1. Hatch week and age at slaughter were included as fixed effects in the mode,l and 32 generations of pedigree records were used. Breast meat yield (h2 = 0.62; SE = 0.090) showed the highest heritability and was higher compared to previous estimates, probably due to the smaller sample size. Live weight (h2 = 0.31; SE = 0.078), ultimate pH (h2 = 0.36; SE = 0.087), lightness (h2 = 0.28; SE = 0.086), redness (h2 = 0.22; SE = 0.075), and white striping score (h2 = 0.27; SE = 0.085) all had moderate heritabilities. The estimate for ultimate pH was similar to previous studies in broilers but was high compared to previous studies in turkeys. Estimates for color were similar to those found in previous studies involving turkeys. Drip loss and cooking loss had similar heritability estimates of 0.13 (SE = 0.071) and 0.10 (SE = 0.064), respectively, which were akin to previous estimates in pork. Shear force (h2 = 0.02; SE = 0.056) was found to have a very low heritability. In conclusion, the heritability estimates provided in this study show great potential for the inclusion of meat quality traits in selection programs of turkeys. This study is part of a larger project working towards the implementation of genomic information in the selection of turkeys for improved meat quality.
15 Host genetics of antibody response to PRRS vaccination and infection in growing pigs
Authors: Neveau Megan , Sanglard Leticia P , Dekkers Jack C , Little Erin , Dee Scott A , Hanson Dan B , Mathur Pramod , Knol Egbert , Eggert John , Dunkelberger Jenelle , Serão Nick V 
Published: November 2020

Abstract
Antibody response to Porcine Reproductive and Respiratory Syndrome (PRRS) vaccination and infection has been shown to be highly heritable in gilts and sows. This trait, measured as sample-to-positive (S/P) ratio, has been proposed as a selection tool for improved reproductive performance in sows. However, this novel trait has not yet been explored in growing pigs. Therefore, the objective of this study was to estimate genetic parameters for S/P in PRRS-challenged nursery pigs. A total of 854 PRRS-naïve crossbred barrows and gilts (51.9±4.8 d and 17.8±4.6 kg) were randomly allocated to 54 pens in two rooms and vaccinated with a modified live virus PRRS vaccine. Twenty-eight days later (d0), all animals were experimentally inoculated with a highly virulent strain of PRRS virus. Body weight (BW), S/P, and clinical signs of disease were recorded at this time and again at d13. Average daily gain (ADG) was calculated and used in combination with clinical signs to create two distinct groups, robust (R) and susceptible (S), with ~230 animals each. At d42, S/P was measured only in these classified animals. Genetic parameters and effect of classification were estimated for S/P for each collection day. Heritability estimates for S/P were 0.07±0.06, 0.52±0.09, and 0.43±0.28, for d0, d13, and d42, respectively. Genetic correlation estimates were high between collection days, ranging from 0.91±0.31 (d0 and d42) to 0.98±0.03 (d13 and d42). There was an effect of classification for S/P only at d13 (P=0.024), with R showing greater S/P (1.7±0.03) than S (1.64±0.03). These results indicate that, in PRRS-challenged growing pigs, S/P is highly heritable at later collection days, and differences in S/P exist between robust and susceptible animals.
27 Genomic relationship between antibody response to porcine reproductive and respiratory syndrome virus vaccination and reproductive performance in commercial sows
Authors: Sanglard Leticia P , Fernando Rohan , Gray Kent A , Linhares Daniel C , Dekkers Jack C , Niederwerder Megan C , Serão Nick V 
Published: November 2020

Abstract
Antibody response, measured as sample-to-positive ratio (S/P), to porcine reproductive and respiratory syndrome (PRRS) after PRRS outbreaks has been proposed as an indicator trait to improve reproductive performance in PRRS-infected sows. However, waiting for a PRRS outbreak to occur and having different relationships in healthy pigs may limit the use of this trait. Thus, we proposed to investigate if this relationship also occurs between S/P to PRRS vaccination and reproductive performance in sows without exposure to PRRS. Nine hundred six F1 replacement gilts (139□17 days old) from two commercial farms were vaccinated with a commercial modified live PRRS virus vaccine. Blood samples were collected at 52 days after vaccination to measure S/P to PRRS and SNP genotyping. Reproductive performance included: number born alive (NBA), number of piglets weaned, number born mummified (MUM), number stillborn (NSB), and pre-weaning mortality (PWM) at parities (P) 1 to 3. Average performance was calculated for each trait per sow per year (PSY). Farrowing rate and age at first service were also analyzed. BayesC0 was used to estimate genetic correlations between S/P and reproductive performance. Bivariate genome-wide association studies of antibody response and reproductive traits were performed using BayesB. High genetic correlations between S/P and farrowing performance were identified for NBA_P1 (0.61±0.16), PWM_P2 (-0.64±0.15), PWM_P2 (-0.63±0.20), NSB_P3 (-0.84±0.05), MUM_P3 (-0.83±0.11), and NSB_PSY (-0.90±0.05). A QTL was identified on chromosome 7 (MHC region) for these reproductive traits and for S/P, explaining from 1.2% (PWM_P2) to 22.4% (S/P) of the genetic variance. SNP H3GA0020505 explained most of the variance in this region for these traits. Heterozygote animals for this SNP had overall better performance: greater S/P (P = 0.001), greater (P = 0.06) NBA_P1, and lesser (P = 0.06) MUM_P3 than other genotypes. These results suggest that antibody response to PRRS vaccination may be used as a genetic indicator to improve reproductive performance in commercial pigs.
19 Mature size and other trait differences in cows selected for calving ease and growth
Authors: Bennett Gary L , Keele John W , Thallman R Mark , Snelling Warren M , Freetly Harvey C , Kuehn Larry A 
Published: November 2020

Abstract
Cows selected for heifer calving ease and yearling weight might also show changes in other important traits. Cattle from select and control lines within 7 populations were selected for reduced heifer calving difficulty EPD (select) or for average birth weight EPD (control) and for identical yearling weight EPD (select and control). Heifers randomly sampled within sire and born in the 4th and 5th of 7 years of selection were retained until 6 years of age with culling for once open and health, but not for other performance. Both lines were bred to the same bulls for calves born during the 3 years post-selection. Select line heifers were 7% lighter (-2.6 ± 0.5 kg, P &lt; 0.01) at birth and not different at weaning (0.2 ± 1.5 kg) or yearling ages (-2.1 ± 2.7 kg). Select cow mature weights estimated by Brody growth curves were 5.2% lighter (-32.9 ± 3.7 kg, P &lt; 0.01) and heights were 2.2% shorter (-3.0 ± 0.7 cm, P &lt; 0.01) than controls. Calf weaning weights were not different. Interactions between 1st calving select (bred to select bulls) and control heifers (bred to control bulls) vs. older cows (all bred to the same bulls) were significant for survival (P &lt; 0.01) and calving assistance (P = 0.03). Select line heifers increased calf survival (86.8% vs. 70.9%) and had decreased calving assistance (16.4% vs. 39.3%), but differences in cows for these traits were negligible. Calves born per select cow exposed exceeded those born per control cow only for 2nd calving (7.1%, P = 0.04), possibly due to reduced calving difficulty as heifers. Selection for calving ease and yearling weight resulted in cows with smaller mature size and similar or better calving ease, calf survival, and calf weaning weight. USDA is an equal opportunity provider and employer.
295 Parameter estimation under genomic selection
Authors: Misztal Ignacy 
Published: November 2020

Abstract
Genetic parameters are important in animal breeding for many tasks, including as input to a model for genetic evaluation, to estimate genetic gain due to selection, and to estimate correlated response due to selection on major traits. Before the genomic era, parameter estimation was facilitated by sparse structure of mixed model equations. Methods such as AI REML with sparse matrix inversion or MCMC via Gibbs sampling could estimate parameters for populations exceeding 1 million animals. With genomic selection (GS) and single-step GBLUP, the genomic matrices are mostly dense, and costs of parameter estimation increased dramatically. The estimation with 20K genotyped animals can take many days. Details in matching pedigree and genomic information influence estimated parameters. Estimation without the genomic information when GS is practiced leads to biases due to genomic-preselection. Truncating data to too few generations or to only genotyped animals leads to additional biases by excluding data on which the selection was practiced. Current studies indicate strong declines in heritability due to GS. Regular models for parameter estimation compute parameters only for the base population. Models that trace changes of parameters over time, such as random regression model on year of birth or a multiple trait model treating times slices as separate traits, are very expensive. A good compromise in parameter estimation under GS is to use slices of only 2–3 generations, with genotypes of young animals removed. When complete populations are genotyped, estimations with large number of genotyped animals are possible either with a SNP model or with GBLUP (inversion of genomic relationship matrix by APY algorithm). For simple models, Method R can provide estimates for any data size. An indirect indication of changing parameters over time is reduced predictivity or lower genetic trend despite increased data. Parameter estimation in GS would benefit from new, efficient tools.
306 Economic perspectives on biosecurity decision-making
Authors: Schulz Lee , Tonsor Glynn 
Published: November 2020

Abstract
African swine fever and many other livestock diseases present a host of challenges with a myriad of private and public good considerations. Chief among these challenges is identifying what drives livestock producer, self-protecting biosecurity efforts. Biosecurity adoption is an example of a private behavior that generates positive spillovers affecting the supply of a public good, that is, disease prevention. Encouraging producers to undertake specific biosecurity practices has proven useful in containing previous outbreaks of livestock disease in the United States, such as porcine epidemic diarrhea virus. Motivating producers to change production and management practices when a disease is not currently present in the United States can be much more difficult because of the (perceived or actual) lower probability of risk. National surveys of livestock producers were conducted to gain insight into decisions regarding ongoing and prospective biosecurity investment. Findings suggest producer and operation characteristics and diverse views on expected frequency of disease outbreaks, anticipated disease duration, and possible financial impact on operations underlie current and likely future biosecurity adoption. Furthermore, results point to both policy (e.g., indemnity provisions and cost sharing strategies) and market signals (e.g. market access and/or premiums paid or discounts incurred) from upstream livestock buyers have potential to incentivize biosecurity efforts.