bluuebunny/crossref_metadata_2025 huggingface dataset:
PSVIII-3 Can the fermentation of insoluble corn fiber be improved in the pig? – An investigation into the in vivo mode of action of xylanase
Authors: Petry Amy , Koester Lucas , Schmitz-Esser Stephan , Huntley Nichole , Bedford Mike , Patience John
Published: November 2020

Xylanase may improve fermentability of corn co-products through the alteration of hemicellulose, but the mode of action (MOA) is incompletely understood. The experimental objective was to investigate the in vivo MOA of xylanase in growing pigs fed insoluble fiber. Sixty gilts (25.4 ± 0.9 kg BW; L337 X Camborough), were blocked by weight, housed individually, and randomly assigned to one of four dietary treatments: a low-fiber control (LF; 8.45% NDF), a 30% corn bran high-fiber control (HF; 24.5% NDF), HF + 100 mg of xylanase/kg (HF+XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg of arabinoxylan-oligosaccharide/kg (HF+AX; 3-7 degrees of polymerization). Gilts were fed ad libitum for 36 d, followed by 10-d of metabolism crate housing and limit feeding (80% of average ad libitum intake). On d 46, pigs were necropsied and ileal, cecal, and colonic digesta were collected for short-chain fatty acid (SCFA) analysis, and 16s rRNA gene amplicon sequencing. Data were analyzed as a mixed model with random effects of replicate and block, and fixed effect of treatment. Differences in individual operational taxonomic units (OTUs) were compared using Linear Discriminant Analysis Effect Size. Acetate, propionate, butyrate, and total SCFA in the ileum did not differ (P >0.05), but HF+XY had 10 significantly different OTUs compared to HF in the ileum (P< 0.05). In the cecum, compared to LF, HF reduced total SCFA concentration (91.7 vs. 82.8 mM/L; P< 0.01). However, HF+XY and HF+AX increased total SCFA concentration by 23% and 12% over HF, respectively (P< 0.05). This is likely due to increased cecal acetate concentration (54.0, 53.2, 74.4, 61.2 mM/L for LF, HF, HF+XY, and HF+AX, respectively; P< 0.01). Total colonic SCFA concentration did not differ (P=0.72), but xylanase increased molar proportions of butyrate (P< 0.01). One MOA of xylanase could be the release of fermentable substrates from insoluble fiber.
PSVIII-2 Dietary supplementation of Bacillus subtilis altered metabolites in the intestine of weaned pigs
Authors: He Yijie , Kim Kwangwook , Jinno Cynthia , Li Xunde , Liu Yanhong
Published: November 2020

This experiment aimed to investigate the effects of dietary supplementation of Bacillus subtilis probiotics on metabolites in the intestines of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli (E. coli). Forty-eight weaned pigs (6.17 ± 0.36 kg BW) were individually housed in disease containment rooms and randomly allotted to one of four dietary treatments: negative control (NC, control diet without E. coli challenge), positive control (PC, control diet with E. coli challenge), and supplementation of 50 mg/kg of carbadox or 500 mg/kg of Bacillus subtilis probiotics. The experiment lasted 28 days with 7 days before and 21 days after the first E. coli inoculation. The F18 E. coli were given to pigs at 1010 CFU/3 mL dose for three consecutive days. At the end of the experiment, all pigs were euthanized to collect ileal mucosa and colon digesta for the analysis of metabolomic profiles by gas chromatography time of flight-mass spectrometer (GCTOF-MS). All data were analyzed by an online MetaboAnalyst tool (https://www.metaboanalyst.ca/). Statistical significance was declared at P < 0.05 and the false discovery rate–adjusted P value (q value) < 0.20. A total of 282 (141 identified and 121 unidentified) and 196 (127 identified and 69 unidentified) metabolites were detected in ileal mucosa and colon digesta, respectively. Forty-nine identified metabolites in ileal mucosa significantly differed among experimental groups (P < 0.05; q < 0.20). The most impacted metabolic pathways were galactose metabolism, aspartate and glutamate metabolism, fructose and mannose degradation, pentose phosphate pathway, and urea cycle. However, in colon digesta, only 7 identified metabolites differed among experimental groups (P < 0.05; q < 0.20) and the majority of them were involved in purine metabolism. Results of metabolomics indicated that supplementation of Bacillus subtilis or antibiotics altered metabolites in the intestines of weaned pigs. In particular, more treatment impacts were observed in the metabolite profiles in ileal mucosa compared with colon digesta.
PSVI-16 Effects of feeding spices on heifer gains and potential as tick management
Authors: Farney Jaymelynn
Published: November 2020

Alternative methods to antibiotics/chemical usage in cattle production has been of interest in recent years and essential oils/spices have been promoted to fill this niche. The purpose of this research was to evaluate effect of feeding spices on heifer gains and as control method for ticks. Eight bromegrass pastures were stocked (March to November) with four heifers per pasture to compare control mineral (CON) to mineral containing spices (SPICE; garlic + proprietary blend of 4 spices). Mineral (113.4 g/hd/d) was blended in dried distillers grains (DDGs) and total blend was supplemented daily at 0.5% of BW. Heifers were weighed on two consecutive days at the start and end of the study and every 28 d. Weekly (1st 10 weeks), ticks were counted and removed from every heifer. Gains evaluated using MIXED (SAS 9.4) as completed randomized design with subsampling where pasture was experimental unit and heifer within pasture as subsample. Ticks/heifer was evaluated similarly using GLIMMIX with binomial distribution. Average daily gain was increased by 0.7 kg/d with the SPICE mineral (P = 0.04) and heifers on SPICE gained 15 kg more over the entire grazing period (P = 0.04) than heifers on CON. The gain advantage for SPICE was observed within the first 28 d (P = 0.05). Overall, these pastures had a low tick population (137 total ticks collected). Even so, there was a tendency (P = 0.09) for a treatment x week interaction, where in weeks 2 and 3, SPICE heifers tended (P = 0.12) to have more ticks/heifer than CON heifers, yet at weeks 8 and 10 SPICE heifers tended (P = 0.07) to have less ticks/heifer than CON. SPICE in a mineral blended with DDGs increase heifer gains and appear, after a minimum of 4 weeks of consumption, to show some repellent effects to ticks.
PSVI-17 Effects of increasing doses of trenbolone acetate and estradiol on sera metabolites following implantation during the finishing phase in beef steers
Authors: Smerchek Dathan , Smith Zachary K
Published: November 2020

Continental × English crossbred beef steers (n = 240; allotment BW = 365 kg [SD 22.5]) were used in a randomized complete block design feedlot study designed to evaluate the effects that increasing doses of trenbolone acetate (TBA) and estradiol-17β (E2) have on sera urea-N (SUN) and sera insulin-like growth factor I (IGF-I). Steers were allotted to 30 pens (n = 8 steers/pen) at the Ruminant Nutrition Center (RNC) in Brookings, SD; and were then assigned to 1 of 3 treatments: 1) No implant (NI), 2) Synovex Choice [100 mg TBA + 10 mg E2; CH], or 3) Synovex Plus [200 mg TBA + 20 mg E2; PL] administered 124 days before harvest. This study was part of a factorial experiment that included bedding application. No interactions were detected (P ≥ 0.26). Blood samples were collected and harvested as sera during the weighing process on d 1, 28, 56, and 84 prior to feeding from sentinel steers (n = 2 steers/pen) and pen served as the experimental unit. An implant × day interaction (P = 0.05) was noted for SUN. On d 28, NI cattle had the greater SUN (P = 0.05) compared to PL and CH was intermediate to NI and PL. No implant × day interaction (P = 0.52) was detected for sera IGF-I. However, sera IGF-I was increased (P = 0.01) 14.7% and 18.7% for CH and PL respectively compared to NI. Sera IGF-I also increased as days on feed increased (P = 0.01). Increasing doses of TBA and E2 resulted in increased anabolism as indicated by a reduction in SUN 28 d after implantation and increased sera IGF-I post-implantation.
PSVI-23 Effects of a vitamin and mineral supplement and an energy supplement on concentrations of glucose and non-esterified fatty acids in artificially inseminated beef heifers up to d 84 post-insemination
Authors: Sauer Laura I , Neville Tammi L , Kassetas Cierrah J , Baumgaertner Friederike , Kirsch James D , Dorsam Sheri T , Borowicz Pawel , Reynolds Lawrence P , Ward Alison K , Christopher Forcherio J , Scott Ronald , McCarthy Kacie L , Dahlen Carl R , Caton Joel S
Published: November 2020

Objectives were to determine the influence of a vitamin and mineral supplement (VTM), an energy supplement (NRG), and day post-artificial insemination (DPAI) on concentrations of glucose and non-esterified fatty acids (NEFA) in beef heifers. Cross-bred heifers (n = 72; initial weight = 351.2 kg) were assigned to 4 treatments arranged as a 2 × 2 factorial with main factors of VTM and NRG supplement. Treatments were: 1) control (no VTM or NRG), 2) VTM (initiated 71 to 106 before breeding) only, 3) NRG (initiated at breeding) only, and 4) VTM and NRG. Heifers were synchronized then bred via artificial insemination on d 0. Blood was drawn on d -9, 14, 28, and 42 from all heifers and on d 56, 70, and 84 from pregnant heifers (n = 31). Plasma samples were analyzed for concentrations of glucose and NEFA. Data were analyzed using the MIXED procedure in SAS. There were no interactions between VTM, NRG, or DPAI (P > 0.05). In addition, pregnancy status did not influence concentrations of glucose or NEFA (P > 0.05). There were no effects (P > 0.35) of VTM on glucose or NEFA concentrations. Energy supplementation increased (P = 0.012) glucose and decreased (P = 0.013) NEFA concentrations. Glucose concentrations were greatest at d -9, decreased through d 42, and then, on d 70 and 84 increased to levels similar to d -9 (81.9, 76.1, 73.6, 73.7, 74.3, 76.2, and 78.4 ± 2.97 for d -9, 14, 28, 42, 56, 70, and 84, respectively). Concentrations of NEFA were greater (P < 0.01) at d -9 compared with 14, 28, 42, 56, and 70, and concentrations on d 84 were greater (P < 0.01) than all other days. In conclusion, glucose and NEFA were affected by NRG and DPAI, but not VTM.
PSVI-19 Evaluating the addition of an alpha-amylase enzyme to two bulk-flake density weights of corn fed to beef finishing steers
Authors: Lockard Caleb , Lockard Cathy , Smith Wyatt , Campbell Brian , Jennings Jenny
Published: November 2020

An alpha-amylase enzyme has the potential to increase starch digestibility, thus improving feedlot cattle performance and efficiency. The objective of this experiment was to evaluate the addition of an alpha-amylase enzyme on two steam-flaked bulk densities and subsequent performance of finishing beef steers. Forty-eight crossbred steers (325 ± 19 kg), were used in a complete randomized block design with a 2 × 2 factorial treatment design. Factors were corn processing and enzyme addition. Dietary treatments were steam-flaked corn-based diets with two bulk-flake density weights of corn (0.32 kg/L vs. 0.39 kg/L). Experimental treatments were 1) 0.32 kg/L with no enzyme (32NE), 2) 0.39 kg/L with no enzyme (39NE), 3) 0.32 kg/L with enzyme (32E), and 4) 0.39 kg/L with enzyme (39E) on a DM basis. The enzyme was applied at 0.50 kg/T of steam-flaked corn (As-fed basis). Data were analyzed using a mixed model with fixed effects of flake weight, enzyme, and flake weight × enzyme interaction. Throughout the feeding period, starch availability for 0.32 kg/L and 0.39 kg/L corn averaged 60.7% and 42.2%, respectively. Steers receiving the alpha-amylase enzyme had no differences in BW (P ≥ 0.62), ADG (P ≥ 0.55), and DMI (P ≥ 0.56) compared to NE steers. Furthermore, carcass characteristics did not differ (P ≥ 0.26) between E and NE steers. Feeding an alpha-amylase enzyme to finishing cattle had no detrimental effects on performance or carcass characteristics. Overall, a more highly processed corn was observed to decrease dry matter intake and increase the potential for digestive upsets. This may limit the use of the alpha-amylase enzyme to a lesser processed corn.
PSVI-14 Effect of Dietary Nitrates and Sulfates on Enteric Methane Mitigation in Finishing Cattle
Authors: Abdelmoteleb Mohamed , Knoell Allie , Fernando Samodha
Published: November 2020

A study was conducted to determine the effect of nitrate and sulfate supplementation on cattle performance and methane emissions in finishing diets and to identify the effect of nitrate and sulfate addition on rumen microbiota composition and function. One hundred and thirty one day feeding trial was conducted using 24 head of cattle (initial BW = 918 lb; SD = 79 lb) where the cattle received one of four treatments no supplementation (CON), 2.0% dietary nitrate (NT), 0.54% dietary sulfate (SF) or both (COMBO), with 6 steers per treatment. Performance, volatile fatty acid (VFAs) profile and CH4:CO2 emissions data were analyzed using MIXED procedure of SAS. Rumen samples were collected and analyzed through amplicon sequencing targeting the 16S rDNA gene V4 region. Microbiome richness and composition were analyzed using Qiime2. Microbial genes involved in pathways linked to methanogenesis, nitrate, and sulfate metabolism were identified with metagenomic sequencing. Gene prediction, functional profile and pathway mapping were conducted using KEGG database. In diets with only sulfate or nitrate, diet had no impact on CH4:CO2 emissions, but nitrate and sulfate in combination decreased CH4:CO2. However, a reduction in dry matter intake (DMI) (P < 0.01), average daily gain (ADG) (P = 0.07) and gain:feed (G:F) (P = 0.09) was also recorded. Significant increase in bacterial genera with H2 utilization capability e.g. propionate, lactate forming bacteria e.g. Prevotella, Bacteroides, Megasphaera, Selenomonas, Lactobacillus; nitrate and sulfate reducing bacteria e.g. Selenomonas, Desulfovibrio was observed in COMBO diet. Differential gene abundance in metabolic pathways illustrated decrease of enzymes linked to methanogenesis in COMBO diet. This study provides evidence that methane yield is linked to diet type and differential gene abundance in the cattle rumen microbiome.
PSV-21 Assessment of Undergraduate Research Students in the Animal Science Department
Authors: Winkel Shana M , Karr Lisa , Burkey Thomas
Published: November 2020

An assessment of undergraduate involvement in research at the University of Nebraska-Lincoln using participant surveys has shown the benefits of knowledge gained and given insight for design and success of undergraduate participation in research in the animal science department. Current undergraduate students who had participated in some form of animal science research were surveyed with both demographic questions and ones based on intrinsic and extrinsic factors affecting research were evaluated. On the survey, students were asked rank statements on a 1 (strongly disagree) to 5 (strongly agree) Likert-type scale to analyze the impacts of completing undergraduate research and the effects it has on one’s knowledge and ability to use and apply what was taught. A total of 30 students completed the survey. Ten percent of students that participated in the survey were male and the other 90% were female. Students ages ranged from 18-23 with the majority being 20-21 (46%) and seniors (33.3%) as well as a Nebraska resident (78%). Students expressed that they mostly heard about the undergraduate research opportunity from their professor (48%) or an outside source such as pre-vet or class presentations (36%). Sixty percent of individuals indicated that pre-veterinary medicine was their current career choice with only 4% indicating they did not plan to continue a higher degree post undergraduate. Interestingly, undergraduate students felt graduate students had a greater impact on their research compared to the professor (43% vs 36%) while 21% of participants said neither had an impact on their research as an undergraduate. Students felt many benefits from participating in undergraduate research from educational opportunities, such as feeling more prepared/competitive for graduate school to life skills, including greater knowledge, reasoning and problem-solving. In conclusion, from participating in undergraduate research, participants are able enhance their scientific learning skills that will help them in their future.
PSI-8 Evaluation of two burning dates and addition of spices on stocker cattle gains on tallgrass native range
Authors: Toothaker Juliette , Farney Jaymelynn
Published: November 2020

Burning pastures in April has historically been a method to increase stocker gains for summer grazing in Kansas, yet is becoming an issue from smoke management. Finding alternative burning windows along with feed options that maintain a similar gain to April burns is important from producer’s perspective. Therefore, the purpose of this study is to evaluate spices/essential oils and timing of pasture burning on growing steer gains. 281 steers (292 ± 28 kg) were randomly assigned to one of 8 pasture of tallgrass native prairie in a completely randomized design model. The treatment structure was a 2 x 2 factorial where the first factor was pasture burning date at two levels (March and April) and the second factor was free-choice mineral type (control (CON) or spices (SPICE)). Spices include garlic oil and a 4-spice blend (Solus, Wildcat Feeds LLC, Topeka). Steers were weighed at the start and end of 90 d grazing period. Total gain, average daily gain, and final body weight were evaluated. There was no interaction between burning time and mineral type (P > 0.10) for average daily gain, total gain, nor final body weight. Steers on pastures burned in April had a 0.16 kg/d ADG advantage over burning in March which resulted in 14.3 kg more gain over 90 d (P < 0.0001). Steers on SPICE averaged 0.06 kg/d and gained 5 kg more (P = 0.02) than steers on CON mineral. Burning in April results in greater steer gains than March burning and feeding a mineral with spices increase gains, yet these two are not additive. Addition of SPICE mineral may be one method to allow producers to extend burning window and maintain cattle production.
PSIII-1 A preliminary study to investigate the contribution of different tenderness factors to beef loin, tri-tip and heel tenderness
Authors: Chun Colin , Wu Wanjun , Welter Amelia , O'Quinn Travis , Magnin Geraldine , Chao Michael
Published: November 2020

The objective of this study was to identify the relative contribution of tenderness factors for 3 beef muscles with similar tenderness ratings. Longissimus lumborum (loin), tensor fascia latae (tri-tip) and gastrocnemius (heel) were collected from 10 USDA choice beef carcasses, fabricated into steaks and assigned to a 5 or 21 d aging period (n=60). Heel had the greatest relative troponin-T degradation %, followed by tri-tip and loin (68.10, 53.42 and 35.01 % respectively; P< 0.01). Tri-tip had the longest sarcomere, followed by heel and loin (3.01, 2.59 and 1.71 µm, respectively; P < 0.01), and heel increased in sarcomere length from 5 to 21 d of postmortem storage (2.49 vs 2.70 µm; P< 0.05). As expected, heel had the greatest collagen content, followed by tri-tip and loin (6.06, 3.98 and 2.76 mg/g of muscle tissue, respectively; P< 0.01), and collagen content decreased for all cuts from 5 to 21 d of postmortem storage (4.64 vs 3.90 mg/g muscle tissue; P< 0.05). Out of the 3 cuts, heel had the highest collagen crosslink density (0.20 mol/mol collagen; P< 0.05), while loin and tri-tip did not differ (0.13 and 0.15 mol/mol collagen, respectively; P >0.05). Collagen crosslink density increased for all cuts from 5 to 21 d of postmortem storage (0.14 vs 0.20; P< 0.01). Heel had lower lipid content than the others (2.68 %; P< 0.01), while tri-tip and loin did not differ in lipid content (8.24 vs. 6.99 %; P >0.05). Loin was ranked by the trained panel to have the highest overall tenderness, while tri-tip and heel did not differ in overall tenderness (P >0.05). The overall tenderness value for heel was positively correlated with troponin-T degradation (P< 0.01). On the other hand, overall tenderness value for loin was negatively correlated with lipid content (P< 0.05), and overall tenderness value for tri-tip was negatively correlated with collagen content (P< 0.05). These results indicated that each beef cut had a unique profile of tenderness contributors.
PSIII-4 Effect of Housing System and Supplementation of 25-hydroxicholecalciferol (25-OH-D3) on Performance and 25(OH)D3 Serum Levels of Sows during Gestation and Lactation
Authors: Silva Bruno , Oliveira Nathalia , Sá-Fortes Cristina , Araújo Wagner , Falleiros Francine , Passos Adsos , Gonçalves Mateus , Rebordões Flávio , Ataide Iara , Lima Valesca , Evangelista Rafaela
Published: November 2020

Vitamin D is an essential key modulator of metabolism in pigs. Improvements in sow productivity have raised questions regarding dietary vitamin recommendations. In this sense, vitamin D serum levels could be limiting to attend high demanding phases. The present study aimed to study the impact of housing system with access to sunlight exposure and supplementation of 25(OH)D3 (Hy-D®) on performance and serum levels of 25(OH)D3 in sows during gestation and lactation. A total of 48 mixed parity sows were distributed in a factorial 2 x 2 experimental design (2 housing systems: gestation crates or free-range system with external area for sunlight exposure; and 2 diets: 0 or 50µg of Hy-D® per kg of diet). Sows remained in treatments from insemination until weaning. The housing systems did not influence (P >0.10) performance traits during gestation nor lactation. The use of Hy-D® tended (P=0.052) to improve total born (17.5 vs. 15.4, respectively 50 and 0 µg Hy-D®) and influenced (P=0.046) on number of born alive (13.4 vs. 12.2, respectively 50 and 0 µg Hy-D®). Litter weight at birth was influenced (P=0.01) by Hy-D® supplementation (20.8 vs. 17.5 kg, respectively 50 and 0 µg Hy-D®). Hy-D® supplementation and housing system (free-range with sunlight exposure) tended to increase weaning weight (P=0.07) and litter daily gain (P=0.051) during lactation. Exposure to sunlight and Hy-D® influenced (P=0.008) 25(OH)D3 serum levels when compared to control (without sunlight and 0 µg of Hy-D®) during gestation (132.3 vs. 116.6 ng mL-1, respectively) and lactation (120.3 vs. 92.2 ng mL-1, respectively). In conclusion, our findings showed that the supplementation of Hy-D® during gestation and lactation has a significant impact on performance of sows and their litters. Also, the association of Hy-D® supplementation with exposure to sunlight during gestation improved significantly 25(OH)D3 serum levels and consequently performance traits in gestation and lactation.
33 Genetic parameters for reproductive traits in purebred and crossbred swine
Authors: Kramer Luke M , Wolc Ania , Esfandyari Hadi , Thekkoot Dinesh , Zhang Chunyan , Plastow Graham , Kemp Bob , Dekkers Jack C
Published: November 2020

For swine breeding programs, testing and selection programs are located in nucleus units that are generally managed differently and with higher health levels than commercial herds where descendants of nucleus animals are expected to perform. This approach assumes that superior animals selected in nucleus herds will have progeny with superior performance at the commercial level. There is clear evidence that this may not be true for all traits of economic importance and thus methods including data collected at the commercial level may increase accuracy of selection at the nucleus level. This study’s goal was to estimate genetic parameters for five reproductive traits between two purebred maternal nucleus populations and their commercial F1 offspring: Total Number Born, Number Born Alive, Number Born Alive > 1kg, Number Weaned, and Litter Weight. Estimates were based on single-step GBLUP in the BLUPF90 programs by utilizing any two combinations of a purebred and the F1 population, and by using all three populations jointly. The genomic relationship matrix between the three populations was generated by using within-population allele frequencies for relationships within a population, and across-population allele frequencies for relationships of the F1 with the purebred animals. The two purebred populations were assumed to be genetically unrelated. The use of two versus three populations did not impact estimates of heritability, additive variance, or genetic correlations. Heritabilities ranged from 0.02 to 0.09 for the F1, from 0.07 to 0.18 for Landrace, and from 0.07 to 0.21 for Yorkshire. Genetic correlations between the same traits in F1 and Landrace ranged from 0.22 to 0.93, and from 0.31 to 0.84 for F1 and Yorkshire. This range of genetic correlations indicates that the use of crossbred information can aid in the selection of purebreds for commercial crossbred performance for some traits. Funded by Genome Canada Genomic Applications Partnerships Program.
18 Predicting monthly total sperm production of dairy bulls using additive and fixed age-based training windows
Authors: Quick Allison , Meronek James , Weigel Kent
Published: November 2020

Selection of elite young bulls using genomic data has shortened the generation interval and increased pressure to collect large quantities of semen at an early age. Younger bulls pose a challenge in forecasting total sperm production, due to non-linear relationships between management factors and semen production. Our aims were to compare prediction methods for forecasting monthly total sperm (TS), evaluate additive versus fixed-window training sets, and identify management factors that improve TS forecasting. Data were from a commercial AI company and included 8,060 monthly collection records from 1,118 Holstein and Jersey bulls between 10 and 28 mo of age. Potential explanatory variables included: year and season of collection; barn location; number of collections per month; breed; scrotal circumference at 10–11 mo of age; TS in three previous collection months; and age at arrival, first collection, and current collection. Training and testing sets were split by age at collection. In the additive approach, all prior data were used as training, while in fixed-window, records from 3 previous months were used. Five-fold cross validation was used to train models (R v3.5.1). Prediction models included linear regression (LM), random forest (RF), and Bayesian regularization neural network (BRNN), with performance measured by root mean squared error (RMSE) and correlation (r) between actual and predicted TS of testing sets. Models with fixed training sets (RMSE = 19.07, r = 0.847) performed better than additive training sets (RMSE = 19.82, r = 0.833). RF (RMSE = 19.25, r = 0.855) performed slightly better than BRNN (RMSE = 19.25, r = 0.828) and LM (RMSE = 19.87, r = 0.836). The most important management variables affecting TS were: collection frequency, TS in previous collection months, and age at collection. Preliminary results suggest fixed-window training of RF models yield best TS prediction.
44 Inbreeding levels of the Line 1 and Line 4 Hereford cattle populations
Authors: Hieber Jordan K , Dafoe Julia M , Parsons Cory T , Anderson Don C , Boss Darrin L , Boles Jane A , Thomson Jennifer M
Published: November 2020

The Line 1 and Line 4 Hereford populations have been linebred for decades. Since these populations share origins but have been managed differently, they offer a unique opportunity to understand molecular mechanisms contributing to inbreeding depression. The study attempted to identify areas of the genome impacting inbreeding depression. Inbreeding was estimated using a complete pedigree (FPED), genomic inbreeding (FG), and genomic pedigree inbreeding (FGPED). Average rate of change in inbreeding per year was evaluated. Runs of homozygosity (ROH) analyses were performed in Golden Helix SVS software, and ROH were defined as a minimum length of 2,500 kb, 250 single nucleotide polymorphism (SNP) appearing in 20 samples. Expected phenotypes for five traits were calculated by adjusting each animal’s individual phenotype with published negative impacts of inbreeding depression. Regression association analyses were performed (Golden Helix) on phenotype and genotype data. Markers above 5 x 10–4 genome-wide significance were considered strongly significant. Line 1 FPED, FG, and FGPED average inbreeding was 42.1% (range 0–71%), 14.4% (range 0–46%), and 31.0% (range 0–63%), respectively. Line 4 FPED, FG, and FGPED average inbreeding was 12.6% (range 0–36%), 12.3% (range 0–49%), and 17.7% (range 0–29%), respectively. Average rate of change in inbreeding per year for Line 1 was -0.03% over 83 yr and 0.03% over 55 yr for Line 4. Fifty ROH regions, 93 strongly significant SNP, three strongly significant SNP within ROH, and some significant SNP within 11 previously identified genes were identified for Line 1. Forty-five ROH regions, 35 strongly significant SNP, three strongly significant SNP within ROH, and some significant SNP within 12 previously identified genes were identified for Line 4. Variation in identified regions of the genome of both lines indicate management is impacting results of inbreeding and the expressed inbreeding depression.
46 Endometrial transcriptome profiles associated with bovine preimplantation pregnancy outcome and parity
Authors: Sweett Hannah , Carvalho Murilo R , Spricigo Jose Felipe W , Ticiani Elvis , Ribeiro Eduardo S , Favetta Laura , Fonseca Pablo Augusto S , LeBlanc Stephen J , Canovas Angela
Published: November 2020

Pregnancy failure in dairy cattle appears to be attributable to losses during embryogenesis, mainly within the first month. Models have estimated that pregnancies lost after day 30 of fertilization cost producers US $550/cow. The reasons for these losses are not well understood, and the transcriptome profile of the reproductive tract during the establishment of pregnancy may point to mechanisms. Thirty-eight cows in lactations 1 to 3 were artificially inseminated, and endometrial biopsies were collected on day 15 after artificial insemination to investigate the effect of parity on the preimplantation pregnancy outcome. Pregnancy status was determined by the presence of interferon-tau in the uterine flushing, revealing 19 pregnant (P) and 19 non-pregnant (NP) cows. Nineteen biopsy samples [9 cows in lactation 1 (6 P and 3 NP), 4 in lactation 2 (2 P and 2 NP), and 6 in lactation 3 (3P and 3NP)] with an average RNA integrity number of 7 were selected for RNA sequencing with an Illumina HiSeq analyzer. Sequence reads were assembled to the ARS_USD1.2.99 bovine reference genome using the CLC genomics workbench software. On average, the samples generated ~56 million reads and 94.99% were mapped to the reference genome. Differential gene expression analysis between P and NP cows identified 187, 60, and 136 differentially expressed genes (DEG) in lactation 1, 2 and 3, respectively (P < 0.01, FDR < 0.05, FC > ±2). Metabolic pathway enrichment analysis identified several DEG upregulated in lactations 2 and 3 associated with IL-17 signaling pathway, although expression of IL-17 itself was not different. This pathway is part of the protective response against extracellular bacteria and likely participates in pregnancy maintenance through local regulation of immune function. Further functional genomic analyses will be performed to determine additional metabolic pathways, key regulator genes, and functional SNPs associated with the establishment of pregnancy.
294 Increased fluctuations of genetic evaluations with genomic information
Authors: Lourenco Daniela , Tsuruta Shogo , Hidalgo Jorge , Misztal Ignacy
Published: November 2020

Under traditional BLUP, animals without new data in subsequent evaluations had stable EBV even when its precision was low. However, changes in EBV could still be observed for some animals when fixed effects were redefined, independently of accuracy levels. Given no model changes were made, the high stability of BLUP generated great confidence in the method. With the adoption of genomic evaluations by the livestock industry and the accumulation of genotypes, changes in genomic EBV (GEBV) in subsequent evaluations are being frequently reported; this is true even for animals that have no added phenotypes. Consequently, there are questions about why such changes happen. The main cause is the increase in connectivity among animals. As genomic relationships consider alleles that are identical by state, all genotyped animals can have some level of relationships, even though they do not share common ancestors in the current population. In this way, phenotypes added for a portion of the genotyped animals in the evaluation will be shared among nearly all genotyped animals. Conversely, in BLUP, those phenotypes are shared only with relatives in the pedigree; therefore, fewer changes are observed. Besides the increased connectivity, changes in blending and scaling of the genomic relationship matrix can cause changes in subsequent GEBV. Using real livestock data, we observed average changes of 0.1 additive genetic standard deviation (SDa) when newly recorded phenotypes were added to the genomic evaluation system; however, outliers had changes as high as 1 SDa, which agrees with the normal distribution theory. Although changes under genomic evaluations are more frequent than in BLUP, the observed fluctuations are small compared to the possible changes based on prediction error variance. Making selection decisions based on groups of animals with high average accuracy instead of individual animals may help to offset the impact of fluctuations in genomic evaluations.
59 Autolized yeast reduces microbiological contamination of the carcass in steers finished in a feedlot
Authors: Delazeri Dailis , Bertagnon Heloísa , Bonato Melina A , Borges Liliana L
Published: November 2020

The use of feed additives based on yeast cell wall has already been studied to favor the growth of beneficial intestinal bacteria to the detriment of pathogenic bacteria in ruminants. This fact reduces diarrhea, increases animal performance, and could promote lesser contamination of the bovine carcass at the time of slaughter, during the evisceration. The present study aims to verify if the yeast cell wall of Saccharomyces cerevisiae autolyzed yeast (AY) reduces total coliforms and Escherichia coli in feces and bovine carcass. Therefore, 36 steers, ½ Angus blood, finished in a feedlot, were submitted to three daily treatments for 105 days: control (diet without yeast), AY 4g (4g/animal/day, 2 x 1010cel/g of a commercial product based on Saccharomyces cerevisiae RumenYeast®), AY 7g (7g/animal/day, RumenYeast®). On days 29 and 90, after beginning in the feedlot, samples of feces were collected for E. coli and total coliforms identifications and counting. On the day of slaughter, 4 points of the carcasses were collected to identify and quantify E. coli, total fecal coliforms, and mesophiles by a petrifilm methodology. There was a reduction in E. coli and total coliforms for the AY 7g in the fecal samples comparing to the other groups (P = 0.0008 and 0.008, respectively), and a trend to reduce E. coli, total coliforms and mesophilic aerobes in the bovine carcass in AY 4g and AY 7g, comparing to the control group (P = 0.06; 0.10, and 0.05, respectively). It was concluded that supplementation with autolyzed yeast, especially when utilized in higher doses (7g), reduced fecal excretion and, consequently, reduce the carcass contamination by E. coli, mesophiles, and, total coliforms in animals during the feedlot period.
305 Awardee Talk: Transferring a culture of biosecurity to the feedmill
Authors: Woodworth Jason C , Gebhardt Jordan T , Jones Cassandra K , Paulk Chad B , Dritz S S , Tokach Mike D , Goodband Robert D , DeRouchey Joel M
Published: November 2020

A culture of on-farm biosecurity has been established and practiced by modern swine production systems for many years. The value of this has been repeatedly demonstrated through improved animal health and performance based on the prevention of disease introduction to the herd. With the introduction of Porcine Epidemic Diarrhea Virus (PEDV) to the US swine industry in 2013, we have learned that feed and feed ingredients can be vectors of disease transmission. Therefore, there is a heightened need to transfer our on-farm biosecurity culture to our feedmills and entire feed supply chain as a way to help prevent disease introduction into swine farms. Feedmills are designed to efficiently and effectively blend feed components into a homogenous batch, and the potential to distribute contaminated feed to multiple farms is significant. While feed and ingredients can be vectors of disease and pathogen transmission, our data continues to show that people are a major risk for pathogen transmission throughout the feed supply chain. Key biosecurity principles such as exclusion, prevention, isolation, mitigation, disinfection, and containment should be adopted and enforced for a strong feedmill biosecurity program. A written feedmill biosecurity plan should be developed and a training program that covers all employees as well as visitors and delivery drivers should be implemented. Continuous risk assessment and environmental monitoring should be utilized to identify new areas of risk and to assess the current status. Unfortunately, feedmills are nearly impossible to completely disinfect and therefore every effort should be made to prevent the introduction of pathogens into the mill. Research that we have conducted with PEDV and African Swine Fever Virus has demonstrated that adopting a culture of biosecurity at the feedmill will reduce risk of disease and pathogen exposure on farms.
309 ASAS-EAAP Talk: Modelling digestion kinetics: the next step in the evaluation of feed ingredients
Authors: Gerrits Walter J , Schop Marijke A , de Vries Sonja
Published: November 2020

There is increasing importance of upcycling of low-opportunity-cost feed, food waste, and food processing byproducts into animal products, strongly increasing the variation in the nutritional quality of feed ingredients. Traditionally, feed ingredients are evaluated based on their measured extent of digestion. Increasing awareness that not only the total yield of nutrients, but also their absorption kinetics, affect their metabolic fate after absorption, and a growing body of evidence of complex interactions taking place inside the gastro-intestinal tract urges development of new approaches. In a recently developed approach (Schop, 2020), we propose a combination of in vitro methodology and dynamic modelling of the digestion process as an alternative to conventional feed ingredient evaluation, and made the first steps in the development of such a system. The digestion potential, evaluated in vitro, is considered as the true property of feed ingredients. Then, prediction of digesta transit, nutrient hydrolysis and absorption, following the intake of a complete feed, determines the extent to which the digestion potential of each ingredient is exploited. The dynamic, mechanistic model developed by Schop for growing pigs comprises 48 state variables representing dietary nutrients, hydrolysis products, endogenous components, and microbial biomass. Driving variables are ingested nutrients from feed ingredients, characterized in vitro (solubility, undegradable fraction, maximum rate of digestion). Passage of digesta is modelled as a function of nutrient solubility, diet viscosity and feed intake. The extent of protein digestion and extent and rate of starch digestion, but not absorption of amino acids, were adequately predicted by the model. Future efforts should focus on modelling digesta properties and transit, translation of in vitro digestion kinetic data and generating reliable in vivo data on nutrient absorption kinetics across feed ingredients. Schop, T.A. 2020 Modelling digestion kinetics in pigs. Predicting nutrient absorption based on diet and ingredient properties. PhD thesis, Wageningen University, Wageningen, NL.
70 Cows housed in muddy environmental conditions during late gestation have lesser body weight and body condition score compared with cows housed on wood chips
Authors: Nickles Kirsten , Relling Alejandro E , Garcia-Guerra Alvaro , Fluharty Francis L , Parker Anthony J
Published: November 2020

Future climate predictions suggest greater precipitation events and an increase in mean ambient temperature during winter months, creating wet and muddy conditions during the last third of gestation for spring calving beef cows. Cows housed in these conditions will likely have increased energy requirements; however, there is limited data on cow requirements in such circumstances. The objective of this study was to evaluate the effects of muddy environmental conditions on cow body weight (BW) and body condition score (BCS) in late gestation. Twenty multiparous Angus cows (n = 10/treatment) housed and fed individually were used in this study. Cows were paired based on initial BW, and one cow from each pair was randomly allocated to either the mud (MUD) or control treatment (CON). Cows in the CON treatment were bedded with wood chips and not exposed to mud, while cows in the MUD treatment were housed in mud (23.6 ± 5.8 cm). Cows were fed the same diet, and each pair was fed to the CON cow’s requirements for maintenance and day of gestation. Maintenance requirements were adjusted weekly. From 213 to 269 days of gestation, cows were sampled for BW and BCS weekly. Data were analyzed as a randomized complete block design with repeated measurements, and the SLICE option of SAS was used for mean separation. All cows started at similar BW (P = 0.35) and BCS (P = 0.79); however, cows housed in muddy conditions had lesser BW (P < 0.01) and BCS (P < 0.01) at day 269 compared with CON cows, while there were no dry matter refusals from any animals throughout the study. Therefore, MUD cows weighed 37.6 kg less than CON cows by the end of the study while dry matter intake was the same between treatments, indicating that mud greatly increased cow requirements.
313 New insights on liver abscess syndrome in cattle using metagenomic investigations
Authors: Morley Paul S
Published: November 2020

Liver abscess syndrome (LAS) is a well-recognized and important problem for beef production in all types of cattle. LAS has been shown to be associated with decreased growth efficiency and lower carcass quality, in addition to losses associated with carcass trimming and condemnation of materials at slaughter. The etiopathogenesis of LAS has traditionally attributed a few bacterial species as being the principal causes (Fusobacterium necrophorum, and Trueperella pyogenes), based on the theory that these bacteria are translocated from the rumen into portal circulation, allowing them to seed the liver. Research regarding the pathogenesis and prevention of LAS has long been limited to data derived from culture-based investigations. Advances in genomic sequencing provide tremendous opportunities for re-evaluation of traditional perspectives on LAS. Recent metagenomic investigations of liver abscesses conducted by our research team have found that liver abscesses are far more polymicrobial than previously believed, suggesting that the etiology is more complex than previously believed. This presentation will present data from culture-based investigations and those using metagenomic sequencing as we re-evaluate traditional dogma regarding LAS.
314 Updating the acidosis-rumenitis-liver abscess disease complex dogma of feedlot cattle
Authors: Reinbold Brandon
Published: November 2020

The pursuit of a reduction in liver abscess disease prevalence in feedlot cattle is of great importance to animal health management and beef industry stakeholder profitability. Disease effects are multifaceted, but primarily materialize in lost feedlot performance, liver condemnation, and reduced carcass weight and quality grade. The impact is further magnified by the increased prevalence of severe, A-plus liver score type disease that is associated with carcass trim and condemnation as well as increased days on feed due to reduced average daily gain and diminished feed conversion. Liver abscess disease in cattle has long been considered to be caused by damage to the ruminal lining (rumenitis) subsequent to ruminal acidosis, followed by translocation of bacteria across the ruminal wall into the portal venous circulation, and culminating in colonization of the liver for abscess formation(s). As a result of bacterial culture frequency, Fusobacterium necrophorum ssp. necrophorum is widely considered the primary etiology even though numerous other bacteria have been isolated from liver abscesses. However, the acidosis-rumenitis-liver abscess disease complex is more complicated than the decades-long, widely accepted dogma. Portions of this are still accurate, but there is much to be learned about the pathobiology of this disease relative to where the etiological agent(s) are translocating from the gastrointestinal tract into the portal venous circulation to evade the host immune responses and multiply in the liver to form an abscess(es). To better understand the pathophysiology of this disease, recent research has been focused on model development and monitoring the time course of liver abscess formation in the live animal. Therefore, the objective of this presentation will be to highlight results of model development efforts and diagnostics to help further elucidate the challenges the beef industry faces for improving industry knowledge for the pathogenesis of liver abscess disease in feedlot cattle.
321 ASAS-EAAP Talk: Quantitative proteomics in animal and veterinary science: a pipeline for exploiting advanced analytical technology
Authors: Eckersall David
Published: November 2020

Application of proteomic investigation to veterinary and animal sciences has grown over the last decade, but has still not reached its full potential of application in animal health and production research [1]. Nevertheless, establishing a versatile methodology has allowed the application of quantitative proteomics for increased understanding of physiological and pathophysiological challenges, and especially to identify potential biomarkers of disease in a range of animal species. A pipeline of sample preparation and mass spectrometry followed by statistical, bioinformatic and biochemical analyses has been established to deal with biofluids and tissue samples from cattle, sheep, pigs, chickens, dogs and cats as well as wild animals. Quantitative proteomic investigation of milk in an experimental model of Streptococcus uberis mastitis of dairy cows has identified potential novel biomarkers with implications for diagnosis and treatment of this major disease. Proteins in milk which have potential as disease biomarkers, such as cathelicidin, haptoglobin and mammary associated serum amyloid A3, are significantly increased in abundance during bovine mastitis. Proteomic investigation has confirmed that these biomarkers are also increased in milk during subclinical and clinical mastitis. Proteomic analysis of plasma from chicken following stimulation of the inflammatory response to Escherichia coli lipopolysaccharide endotoxin has characterised major changes in the chicken plasma proteome. Novel biomarker candidates of hemopexin and fatty acid binding protein have been identified. This proteomic pipeline can be incorporated into many areas of research, providing novel findings at the forefront of animal and veterinary science. Such proteomic investigation requires close interdisciplinary collaboration between experts in mass spectrometry, bioinformatics, statistics and animal production in order to fully exploit recent technological advances in the omic sciences.[1] P. Bilic, et al, Proteomics in Veterinary Medicine and Animal Science: Neglected Scientific Opportunities with Immediate Impact, Proteomics. 47 (2018) 1–7. doi:10.1002/pmic.201800047.