bluuebunny/crossref_metadata_2025 huggingface dataset:
147 Nutritional advances in fetal and neonatal development: Mineral nutrition
Authors: Meyer Allison M
Published: November 2020

Mineral nutrition during pregnancy has long been known to impact fetal growth and development. This is evidenced by a multitude of mineral deficiency-related causes for embryonic loss, abortion, stillbirth, or neonatal death, including poor or inappropriate fetal development that can be either reversible or irreversible postnatally. Both macro and trace mineral needs of the dam are known to increase with the fetal growth of advancing gestation due to greater metabolic stress and demand, as well as tissue development and deposition in the fetus. Fetal deposition of many trace minerals is especially important for neonatal use while consuming milk with low mineral concentrations and facing a multitude of immune challenges. In the last 2 decades, many laboratories have focused on “developmental programming,” or the effects of maternal nutrition on fetal and neonatal development and ultimately long-term health and productivity of livestock. Despite this, the role of macro and trace minerals in short-and long-term consequences of developmental programming is still unclear for many minerals and species. Taken together, research in ruminants and swine demonstrate that mineral intake and source during pregnancy can have a large effect on fetal growth and development that lasts into the neonatal and pre-weaning periods. Some studies suggest that supra-nutritional mineral intake may have a positive benefit during gestation or neonatal periods. Moreover, some data suggest that mineral requirements may be greater than currently thought to accommodate the rapid fetal growth and preparation for lactation that occurs during late gestation. Continued research is necessary to determine mineral requirements of livestock during pregnancy, especially when considering their long-reaching subsequent effects on offspring. Additionally, increased understanding of perinatal transfer of trace minerals can aid in our management of pregnant dams and their offspring.
240 Enhancing beef production and quality using big data analytics and computer vision techniques
Authors: Rosa Guilherme J , Aiken Vera C , Fernandes Arthur , Dorea Joao R
Published: November 2020

In this presentation we will discuss our current research on computer vision techniques for optimized management of feed bunks and prediction of live weight in beef cattle. The combination of these two techniques allows not only an enhanced nutritional management in feedlots, but also the determination of economically optimal harvest time for maximized returns. In addition, we will discuss computational and data analytics strategies for integration and analysis of large datasets from multiple sources, including operational farm data, weather and economics, for aiding data-driven decisions to improve beef cattle production.
108 Effect of Revalor-XH, Revalor-200, and combination Revalor-IH/Revalor-200 on Yearling Heifer Growth Performance and Carcass Characteristics
Authors: Carlson Zachary , Coulson Caitlin , Erickson Galen E , Jordon D J , Cooper Rob , Scott Tony , Bundy Sheri , Nuttelman Brandon
Published: November 2020

A commercial feedlot trial utilizing 1,728 crossbred heifers (initial BW = 410; SD = 10 kg) examined three implant strategies on growth performance and carcass characteristics. Treatments included: 1) Revalor-200 (REV-200) on d 1; 2) Revalor-IH on d 1 and Revalor-200 on d 56 (REV-IH/200; range 54-58 d) to target approximately 80 d with terminal implant; and 3) Revalor-XH (REV-XH) on d 1. Heifers implanted with REV-IH/200 combination had greater carcass-adjusted final BW and G:F compared to REV-200 and REV-XH (637 vs. 630 and 630 kg; 0.146 vs. 0.140 and 0.140, respectively; P ≤ 0.05). There were no differences (P ≥ 0.24) observed for live performance including final BW, DMI, or ADG on a live basis among implant strategies. Hot carcass weights and LM area improved for REV-IH/200 implanted heifers relative to REV-200 and REV-XH implanted heifers (397 vs. 393 and 393 kg; 90.9 vs. 87.7 and 88.7 cm2, respectively; P ≤ 0.05). Dressing percent was greater for REV-IH/200 implanted heifers compared to REV-200 and REV-XH (62.7 vs. 62.1 and 62.2 %, respectively; P = 0.01). Marbling score and 12th-rib fat thickness were not different (P ≥ 0.12) among implant treatments. Calculated yield grades improved for REV-IH/200 compared to REV-200 (3.63 vs. 3.82, respectively; P = 0.05). Heifers implanted with REV-IH/200 had a significant (P < 0.01) shift to a lower calculated yield grade distribution compared to REV-200 and REV-XH implanted heifers. The REV-IH/200 combination provided 280 mg of trenbolone acetate (TBA) and 28 mg estradiol (E2), while total active ingredient doses for REV-200 and REV-XH are 200 mg TBA and 20 mg E2. Thus, the greater concentration of TBA and E2 provided by REV-IH/200 combination improved carcass adjusted growth and carcass performance compared to the non-coated REV-200 implant and partially coated REV-XH implant.
151 Effect of enhanced organic acid supplementation in late gestation and lactation of sows on body weight change, litter performance and wean to estrus interval
Authors: Lugar Drew W , Ramirez Shelby , Rickard Justin , Earing Jennifer
Published: November 2020

This study was conducted to evaluate the effects of an enhanced organic acid formulation (EOA; Biotronic PX Top3; BIOMIN America Inc., Overland Park, KS) on sow farrowing and lactation performance, sow weight and backfat change, and wean to estrus interval. A total of 18 crossbred (Yorkshire x Chester White) sows were randomly allocated to one of two dietary treatments which consisted of control (CNT) and EOA supplemented (n = 9 per treatment). Treatment diets were fed to sows from d 90 of gestation until weaning. Sow body weight gain from d 90 of gestation through weaning was greater in EOA supplemented sows compared than CNT sows (30.9 vs 18.1 ± 2.3 kg, respectively; P = 0.010). Backfat from d 90 of gestation through weaning tended to be affected by dietary treatment (P = 0.051), where EOA supplemented sows had an increase in backfat compared to CNT sows which had a decrease in backfat (0.091 vs. -0.046 ± 0.037 cm, respectively). Total number of pigs born was greater for EOA sows compared to CNT sows (13.1 vs. 8.7 ± 1.1 piglets, respectively; P = 0.047). However, number of liveborn, stillborn, and mummified piglets did not differ among dietary treatments (P ≥ 0.207). Additionally, litter growth rate did not differ among dietary treatments (P = 0.631). Wean to estrus interval was longer for EOA sows compared to CNT sows (5.4 vs. 4.7 ± 0.1 days, respectively; P = 0.008). The present results indicate that addition of this EOA to sow diets in gestation and lactation may be beneficial to maintaining sow body condition.
PSV-12 Evaluator effect on the prediction of genetic merit using subjective measures of beef cattle temperament
Authors: Celestino Elfren F , Hieber Jordan K , Dahlen Carl R , Riley David G , Wagner Sarah A , Hulsman Hanna Lauren L
Published: November 2020

The objective of this study was to determine evaluator effect on genetic predictions of docility score (DS), temperament score (TS), and qualitative behavior attributes (QBA; 6 positive and 6 negative QBA). Weaning age calves (n = 1,542) were evaluated using DS, TS, and QBA scores over 4-year period. Fixed effects included evaluator (n = 11 total), primary breed (n = 2), sex (n = 2), and random effect of calf using repeated measure design (across-evaluator model only). Variance components, heritability, and breeding values (EBV) were estimated using pedigree in ASReml 4.2. Evaluator effect on EBV was based on 1) Spearman rank correlation coefficients (rs) and 2) 3-quartiles change in rankings of calves among evaluators per trait. Results showed evaluator scoring was different in DS, TS, and 12 QBA (P < 0.002). Correlations (rs) on EBV across and within evaluators ranged from 0.52 to 0.84 (DS) and 0.53 to 0.87 (TS) (P < 0.0001). For QBA, all rs on EBV were significant (P < 0.05) and ranged from -0.26 to 0.90 (positive) and 0.11 to 0.82 (negative), except on positively occupied and distressed QBAs (P = 0.46 to 0.65). When comparing evaluator specific EBV to across evaluator model, DS and TS had 1.10% and 1.56% 3-quartiles change, whereas comparison of evaluator to evaluator EBV showed 4.54% and 3.76%. For positive and negative QBA attributes, 3-quartiles change ranged from 0% to 35.13% and 0.52% to 3.76% (evaluator to across-evaluator model); and 1.30% to 21.09% and 3.31% to 13.81% (within evaluators). This illustrates that DS and TS had less variability in EBV prediction compared to QBA. Within QBA, negative QBA had less variability compared to positive QBA. In conclusion, evaluators scored differently using these methods. However, in predicting genetic merit, evaluator has negligible effect for scoring systems already implemented by breed associations.
PSIX-5 Dietary supplementation of Bacillus subtilis modified fecal microbiome of weaned pigs in comparison to antibiotics
Authors: Jinno Cynthia , He Yijie , Li Xunde , Liu Yanhong
Published: November 2020

The objective of this study was to investigate the effects of supplementing Bacillus subtilis on fecal microbiota of pigs experimentally infected with F-18 Escherichia coli (E. coli), in comparison to carbadox. Forty-eight weaned pigs (6.17 ± 0.36 kg BW) were individually housed and randomly allotted to one of four treatment (n =12): negative control (NC), positive control (PC), antibiotics (50 mg/kg of carbadox), and direct fed microbials (DFM, 500 mf/kg of Bacillus subtilis). The experiment lasted 28 days with 7 days before and 21 days after first E. coli inoculation (d 0). Pigs in the NC, PC, and DFM groups were orally inoculated with F18 E. coli for 3 consecutive days with 1010 CFU/3 mL/dose. Fecal samples were collected on d -7 and 0 before E. coli inoculation, and d 7 and 21 post inoculation (PI). DNA were extracted from all fecal samples to perform 16S rRNA gene sequencing at the V4 hypervariable region. All data were analyzed with QIIME2 (2019.4) and R. Chao1 index was greatest (P < 0.05) in feces collected on d 0 before E. coli inoculation and lowest (P < 0.05) on d -7 feces. Pigs supplemented with DFM had lower (P < 0.05) Chao1 index than pigs fed with antibiotics on d 21 PI. Bray-Curtis PCoA displayed separate clusters among days but overlaps among treatments. Bacteroidetes and Proteobacteria were most (P < 0.05) abundant on d -7 and lowest (P < 0.05) on d 21 PI. However, Actinobacteria and Firmicutes were most (P < 0.05) abundant on d 21 PI. Pigs in the NC and DFM groups had greater (P < 0.05) relative abundance of Firmicutes than pigs fed with antibiotics on d 0 and 7. Supplementation of antibiotics reduced (P < 0.05) the relative abundance of Lactobacillaceae compared with other treatments on d 0 PI. In conclusion, both animal age and dietary treatments influenced the fecal microbiome of weaned pigs.
PSVI-8 Mineral composition of feed grade monocalcium phosphate
Authors: Lopez Diego A , Stein Hans H
Published: November 2020

Feed phosphates are included in swine diets to meet the requirements of P. Two products are predominantly used for this purpose, commercial monocalcium phosphate (MCP) and dicalcium phosphate (DCP). Theoretically, pure MCP should contain 26.5% P but commercial sources of MCP contain around 21 % P. The reason there is less P in commercial sources is that these sources are contaminated with calcium carbonate and other minerals. In addition, feed grade phosphates called MCP in reality is a mixture of MCP and DCP, which also contributes to the reduced P. To determine the complete composition of commercial MCP, seven sources of MCP were procured. All sources were analyzed for most common minerals that may be present in feed phosphates (Table 1) Results indicate that the composition of minerals is relatively stable among the different sources of MCP, indicating that the process to produce feed grade phosphates does not result in much variability. However, none of the commercial feed grade phosphates contained close to 26.5% P, which would be expected in a pure source.
PSVIII-4 Effect of coarse wheat bran and crude protein level in nursery diets without zinc oxide on pig performance
Authors: Batson Kelsey L , Calderon Cartagena Hilda I , Tokach Mike D , Woodworth Jason C , Goodband Robert D , Dritz Steve S , DeRouchey Joel M
Published: November 2020

A total of 355 pigs (DNA 200x400; initially 5.6 kg) were used to evaluate the effects of coarse wheat bran and crude protein (CP) level in diets without pharmacological levels of zinc oxide on nursery pig performance and fecal dry matter (DM%). Pigs were allotted to 1 of 6 treatments in a completely randomized design with 5 pigs per pen and 12 pens per treatment. Treatment diets were fed in two phases (d 0 to 7 and 7 to 21) followed by a common diet fed d 21 to 45. Treatments included a positive control diet with ZnO, negative control without ZnO, and negative control with 4% wheat bran and formulated to contain 21, 19.5, 18, or 16.5% CP. All diets contained 1.35% SID lysine except the 18 and 16.5% (1.25 and 1.20% lysine) CP diets. Data were analyzed using the lmer function from the lme4 package in R. During the experimental period, decreasing CP decreased (linear, P< 0.05) ADG, G:F, and d 21 BW, but increased (linear, P=0.005) fecal DM%. Pigs fed the diet containing ZnO had increased (P< 0.050) ADG, ADFI, and G:F compared to the negative control and diet with 21% CP and wheat bran. From d 21 to 45, pigs previously fed the 21% CP diet with wheat bran had increased (P< 0.05) ADG compared to the positive control. Fecal DM on d 45 and G:F increased (P< 0.05) for pigs fed the 21% CP, wheat bran diet and negative control compared to those fed the positive control. Overall, pigs fed low CP diets had decreased (P< 0.05) ADG while pigs fed the positive control had greater (P< 0.05) ADG compared to the negative control. Additional research is needed to determine if modifying low CP, wheat bran diets will elicit benefits of increased fecal DM% while maintaining growth performance.
PSVIII-10 Effects of enzyme supplementation in corn distiller’s dried grains with solubles (DDGS) diets on growth performance in broilers: a meta-analysis
Authors: Jang Jae-Cheol , Zeng Zhikai , Urriola Pedro E , Shurson Gerald C
Published: November 2020

The objective of this study was to conduct a meta-analysis to quantitatively summarize the growth responses of broilers fed cDDGS and the efficacy of various types of dietary enzyme supplementation. A total of 12 publications with 69 observations were included in the database. Individual observations were analyzed using a multivariable linear mixed model. The mean differences (MD) of BWG, FI, and gain efficiency (G/F) were calculated by subtracting either the enzyme response in corn-soybean meal (CSB) or CSB+cDDGS based diets to the control, and was expressed as a percentage (MD = (enzyme – control)/control ×100%). A type of exogenous enzymes (xylanase; protease; carbohydrases; cocktail = proteases + carbohydrases), and feeding phase (starter = d 0 to d 21; finisher = d 21 to d 42 or 49; overall = d 0 to d 42 or more) were included as fixed effects. Dietary enzyme inclusion showed significant improvement on BWG (3.19%, P < 0.01) and G/F (5.69%, P < 0.01) in broilers fed cDDGS diet. However, no significant enzyme responses were observed in broilers fed CSB diet on growth performance. Broilers fed cDDGS diet had increased (P < 0.01) BWG with the addition of protease (3.32 %) and cocktail (3.27 %), whereas addition of xylanased improved (P < 0.01) G/F by (3.56 %) and carbohydrases (1.90 %). Broilers fed cDDGS diet with enzyme supplementation showed greater improvement in BWG (3.71 %, P < 0.01) and G/F (3.78 %, P < 0.01) at finisher phase compared with starter phase. Likewise, Broilers fed CSB diet with enzyme supplementation increased BWG (9.40 %, P < 0.01) and G/F (3.11 %, P < 0.01) at finisher phase. In conclusion, supplementation of xylanase and carbohydrases in cDDGS diet improved G/F, and the enzyme response can be maximized when fed during the finisher phase diet compared with the starter phase diet.
PSVIII-17 Assessment of conformational changes across three parities in sows
Authors: Trenhaile-Grannemann Melanie D , Lewis Ronald M , Kachman Stephen D , Stalder Kenneth J , Mote Benny E
Published: November 2020

Conformation-based sow selection is performed prior to reaching mature size, yet little is known about how conformation changes as growth continues. To assess conformation changes, 9 conformational traits were objectively measured at 12 discrete time points between 112 d of age and parity 3 weaning on 622 sows in 5 cohorts. The 9 traits included 5 body size traits (body length, body depth at the shoulder and flank, and height at the shoulder and flank) and 4 joint angles (knee, hock, and front and rear pastern). Data were analyzed with a repeated measures model (SAS V 9.4) including cohort and time point as fixed effects, sire as a random effect, and heterogeneous compound symmetry as the covariance structure. Sire variance ranged from 0.16 (body depth shoulder) to 2.00 (body length) cm2 for body size traits and 2.28 (rear pastern) to 4.22 (front pastern) degrees2 for joint angles. Cohort had an effect on all traits (P < 0.05). All traits displayed changes over time (P < 0.001). Size traits increased between 112 d of age and parity 3 weaning (64.16 vs. 107.57 cm, 26.62 vs. 44.14 cm, 23.32 vs. 36.92 cm, 46.10 vs. 73.55 cm, 49.36 vs. 77.47 cm for body length, body depth shoulder and flank, and height shoulder and flank, respectively); however, they fluctuated within parity by increasing during gestation and decreasing at weaning. Knee angle decreased (164.12 vs. 150.72 degrees) while fluctuating within parity by decreasing in the second half of gestation and increasing after weaning. Front and rear pastern angles decreased over time (60.89 vs. 53.74 degrees and 64.64 vs. 55.50 degrees for front and rear pastern, respectively), while biologically negligible change was observed in hock angle (148.63 vs. 147.48 degrees). Sow conformation changes throughout life, and these changes may require consideration when making selection decisions.
PSIII-14 The effects of variant auditory stimuli on goat kids’ formant patterns from birth to weaning
Authors: Quandt Rachael C , Bartley Samantha S , Burke Thomas A , Forshey Brandon
Published: November 2020

The objective of this study was to determine if exposure to human voice during early development affected the frequency of vocal formants (peaks in the harmonic spectrum) in Boer goat kids (n=13). The proposed mechanism is due to mimicry and imprinting on human or goat by comparing the developmental changes based on the presence of human vocal frequencies. From birth to weaning at d 60, goat kids were exposed to various ambient sound patterns through 3 treatments and frequency changes were studied to see if there was a change due to the presence of human voice. Treatment 1 was exposed to human voice vocalization via recording (n=5), treatment 2 was exposed to doe vocalization (n=4), and treatment 3 had no human or doe vocalization (n=4). Throughout the study, all kids were located in similarly controlled pen sizes roughly 2.44 x 3.05 m, received the same diets that exceed the NRC requirements for goat kids and ad libitum access to water. Kids were isolated and individually recorded weekly for approximately 120 to 1000 s using VoceVista Software. The software allowed researchers to record the frequency and intensity of kids’ bleats over the 7 wk period. Each goat kid’s fundamental frequency and second through fifth harmonics were collected at 5 locations through each week’s recording. There was no significant difference found between the three treatment groups throughout the study. However, there was a significant difference (P< 0.05) between the fundamental frequency, second, third, fourth, and fifth harmonics over the 7 wk period. The average fundamental frequency for wk 1 was (573 ± 61 Hz) compared to wk 7 (467 ± 47 Hz). The results of this study suggest that as the kids developed their frequencies progressively lowered over the 7 wk and various auditory exposures had no effect on their formant patterns.
PSIII-12 The effect of sodium butyrate and benzoic acid on nutrient digestibility and fecal volatile fatty acid concentrations in nursery pigs
Authors: Bradley Casey L , Watson Alisun , Bottoms Kristopher , Tsai Tsungcheng , Maxwell Charles V
Published: November 2020

A total of 270 weaned pigs (21-d age) were used to evaluate the effects of administering benzoic acid (BA) alone or with sodium butyrate (SB) on nutrient digestibility, fecal VFA concentrations and growth performance. At weaning (age 21-d), pigs were blocked by initial BW (4.7 ± 0.21 kg) and allotted to 1 of 5 treatments with 9 replicate pens per treatment. Pigs remained on the same treatment through three feeding phases: Phase 1 (d 0-7), Phase 2 (d 7-21), and Phase 3 (d 21-40). The treatments were the Control diet without acidifier (C), C with 0.5% BA, and BA with 0.05%, 0.1% or 0.15% of SB to form SBA0.05, SBA0.1, and SBA0.15, respectively. Titanium dioxide was added in phase 3 diets (d21-40). Diets were fed in meal form and sampled at manufacturing and pen fecal samples were collected for two consecutive days at the end (d40). Samples were analyzed for the concentration of DM, GE, N, ash, NDF, ADF, calcium, and phosphorus and the ATTD for each nutrient was calculated. Additionally, fecal VFAs were quantified via gas chromatographic technique. Data were analyzed using Mixed procedure of SAS, with treatment as a fixed effect and initial BW block as a random effect. Level of sodium butyrate was used in IML procedure to generate coefficients for orthogonal contrast for BA, SBA0.05, SBA0.1, and SBA0.15. In feces, absolute butyrate (mM) and total VFA (mM) tended (P< 0.10) to increase quadratically with increasing SB supplementation. Similar to G:F ratio, pigs fed the BA diet had higher ATTD of DM, GE, N, ash, NDF, ADF, and P than pigs fed other treatments. Results suggest that the mechanism on improving growth performance differs among acidifiers.
6 Evaluating the recognition of a large rotated object in domestic horses (equus caballus)
Authors: Corgan Megan E , Grandin Temple , Matlock Sarah
Published: November 2020

It is dangerous for both riders and horses when the horse suddenly startles. Sometimes horses do this in a familiar environment, with a possible cause being that familiar objects may look different when they are rotated. The purpose of this study was to determine if a horse that had been habituated to a large object (children’s plastic playset) would perceive the object as novel when the object was rotated 90 degrees. Twenty-four young horses were habituated to one side of the playset and led 15 times by a handler until they showed no behavioral reactions. The behavioral signs observed and analyzed were ears focused on the object, nostril flares, neck raising, obvious exhale, avoid by leaning away, and avoid by moving side. The most common reactions observed were ears focused on the object, nostril flares and neck raising. Reactions were mild, because the horses used were safe to lead and all procedures were done at a walk. When the playset was rotated, the behavioral signs observed were similar to behaviors shown on the first exposure to the playset. An unpaired two-sample Wilcoxon test was performed on the behavioral signs, comparing the number of behavioral signs present on pass 1 compared to pass 16 (rotated). There was a significant difference between the control and rotated group (W = 9.5, P = 0.001572, P < 0.05). Horses previously habituated to a large object perceived the rotated object as novel. Horse safety can possibly be improved by habituating a horse to all sides of a novel object.
32 Cross validation of best linear unbiased predictions of breeding values using an efficient leave-one-out strategy
Authors: Cheng Jian , Fernando Rohan , Dekkers Jack C
Published: November 2020

Efficient strategies have been developed for leave-one-out cross validation (LOOCV) of predicted phenotypes in a simple model with an overall mean and marker effects or animal genetic effects to evaluate the accuracy of genomic predictions. For such a model, the correlation between the predicted and the observed phenotype is identical to the correlation between the observed phenotype and the estimated breeding value (EBV). When the model is more complex, with multiple fixed and random effects, although the correlation between the observed and predicted phenotype can be obtained efficiently by LOOCV, it is not equal to the correlation between the observed phenotype and EBV, which is the statistic of interest. The objective here was to develop and evaluate an efficient LOOCV method for EBV or for predictions of other random effects under a general mixed linear model. The approach is based on treated all effects in the model, with large variances for fixed effects. Naïve LOOCV requires inverting the (n - 1) x (n - 1) dimensional phenotypic covariance matrix for each of the n (= no. observations) training data sets. Our method efficiently obtains these inverses from the inverse of the phenotypic covariance matrix for all n observations. Naïve LOOCV of EBV by pre-correction of fixed effects using the training data (Naïve LOOCV) and the new efficient LOOCV were compared. The new efficient LOOCV for EBV was 962 times faster than Naïve LOOCV. Prediction accuracies from the two strategies were the same (0.20). Funded by USDA-NIFA grant # 2017-67007-26144.
48 Genetic study of horn fly abundance in beef cattle
Authors: Ling Ashley , Krause Taylor , Heins Bradley , Hinkle Nancy , Pringle Dean , Aggrey Samuel E , Rekaya Romdhane
Published: November 2020

Disturbing the non-symbiotic relationship between horn flies and cattle is of economic, health, and animal welfare importance. Reliance on management and insecticides has proven inadequate. In the United States, horn flies are estimated to cause more than $1 billion in economic losses on pastured cattle annually. Although insecticides provide temporary control, their efficacy is hampered by several factors. Intensive insecticide use has led to horn fly resistance and decreased predation on horn flies by other insects. Due to the cost and logistic complexity of measuring fly resistance traits under commercial conditions, the genetic basis of these traits remains largely unknown. Only a few heritability estimates are available based on small-scale studies. Currently, the economic injury threshold (EIT) due to horn fly abundance (onset of production decay) is set at around 200 flies for beef cattle. This threshold is largely heuristically set. Additionally, the rate of decay in performance as a function of fly abundance after injury onset is unknown. It is also likely that EIT is breed and animal specific. Data used in this study was collected during the summer of 2019. Animals were not treated or managed in any way to control horn flies prior to data collection. Animals were assessed subjectively and based on image counts for horn fly abundance. Estimates of heritability of horn fly abundance ranged between 0.14 and 0.22 for subjective and image-based phenotypes. The lowest heritability was for the subjective assessment, likely due to the excessive variation between evaluators. Changepoint model-based analysis showed that EIT is variable between sire families, ranging from 265 to 413 flies. Furthermore, there was significant difference in the decay of performance after the onset of injury. The rate of decay ranged between -0.0003 and -0.00018. Collectively, these results indicate the potential to improve horn fly resistance/tolerance using genetic tools.
20 Vaginal microbiome composition is associated with sow longevity
Authors: Neto José Braccini , Sanglard Leticia P , Schmitz-Esser Stephan , Gray Kent A , Linhares Daniel C , Yeoman Carl J , Dekkers Jack C , Niederwerder Megan C , Serão Nick V
Published: November 2020

The vaginal microbiome of gilts vaccinated for porcine reproductive and respiratory syndrome (PRRS) has been previously associated with first-parity reproductive performance in absence of PRRS outbreak. However, associations using multiparous sows have not been investigated. The objective of this study was to associate the vaginal microbiota of PRRS-vaccinated gilts with longevity. Vaginal swabs from 251 commercial F1 gilts (Landrace/Large-White) were collected on days 4 and 52 after PRRS vaccination (dpv) for 16S rRNA sequencing. Sequences were clustered into operational taxonomic unit (OTU). Sows were assigned to one of four groups according to the maximum parity reached (number of animals): without parity (13), first-parity (45), second-parity (47), and 3 or more parities (146). A negative binomial mixed model including fixed effects of group, dpv, group*dpv, and collection age (covariate), and random effect of animal, was used to identify OTUs with differential abundance. The false discovery rate method was used for multiple test correction. Canonical discriminant analysis (CDA) was performed to classify animals into the four parity groups by including significant OTUs in stepwise selection (P < 0.05) using the whole data. A leave-one-out-cross-validation was used to assess the predictive ability of OTUs to correctly classify animals into the parity groups. Abundance of five and four OTUs was associated (q < 0.05) with group and with group*dpv (q < 0.05), respectively. In the CDA analysis, 220 OTUs identified in the vaginal microbiome were included (P < 0.05). The first and second canonical variables explained 96.6 and 3.4% of the variation, respectively. All animals were correctly classified into their respective parity groups. This study indicates that the vaginal microbiome composition of gilts collected after PRRS-vaccination may be used to predict longevity in commercial sow herds. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (Capes) – Finance Code 001.
24 Structural variants affecting mRNAs isoforms splice sites associated with marbling in Nellore cattle
Authors: Muniz Malane M , Fonseca Larissa Fernanda Simielli , Canovas Angela , Silva Danielly Beraldo Dos Santos , Ferro Jesus Aparecido , Chardulo Artur Loyola , Baldi Fernando , de Albuquerque Lucia Galvao
Published: November 2020

The mRNA identification and associated splice variants affecting meat marbling in Nellore cattle could contribute to a better understanding of the genetic architecture of this complex trait. Longissimus thoracis samples from the 20 most extreme bulls (out of 80 bulls set) for marbling [high (n=10) and low (n=10) groups] trait were used to perform transcriptomic analysis using RNA-Sequencing. The CLC Genomics Workbench software was used to align the fragments of each sample to the bovine reference genome (ARS-UCD1.2) and to perform differential expressed transcript analysis (DE). An average of 37,000 transcripts and 14 mRNA DE (P ≤ 0.001; FC > 2) were detected in the muscle transcriptome. Among them, three transcripts were up-regulated (COL4A2-202, GHRH-201 and ENSBTAT00000070459.1) and 11 down-regulated (HBB-201, HBA-201, RPL14-202, CATHL1-201, CATHL4-201, MAPKAPK2-204, PCBD1-201, RPL30-203, NEURL1-202, PGLYRP1-201 and ENSBTAT00000038384.2) in high marbling group in relation to low group. Structural variants, including Single Nucleotide Variant (SNV), insertion or deletion were also found in the mRNA DE (4 in high and 6 in low marbling groups), causing possible splice site disruption. For high marbling group, in the COL4A2-202 transcript, three SNVs [one guanine (G) located on chromosome 12 at 85,104,867 bp, two cytosine (C), at the positions: 85,119,139 and 85,145,937 bp] were found. From these, one is a non-synonyms mutation [SNV (G) 85,145,937bp], causing an amino acid change (ENSBTAP00000005916.5: p.Glu1088Asp) in Collagen alpha-2(IV) chain protein (COL4A2). Interestingly, animals with low marbling presented also deletions (85,100,930 pb) in this same gene, causing an amino acid change (ENSBTAP00000005916.5:p.Pro113fs)in the COL4A2 protein. Functional enrichment analysis, using the DE mRNAs list, identified significant metabolic pathways (FDR < 0.05), such as O2/CO2 exchange in erythrocytes, tyrosine biosynthesis and phenylalanine degradation. The results suggest potential key regulatory genes associated with marbling, an economically important trait for the beef industry and for the consumer.

Funding FAPESP (#2009/16118-5, #11/21241-0, #2017/02470-3, #2017/10630–2, #2018/ 20026–8, #2018/11154-2) and CAPES (#001).
64 Immunological, physiological, and behavioral responses to an experimentally-induced respiratory disease challenge in growing steers
Authors: Wottlin Lauren , Carstens Gordon E , Pinchak William E , Washburn Kevin , Lawhon Sarah , Reddy Sanjay , Hanks John , Chen Ian
Published: November 2020

Immunologic, physiologic, and behavioral responses to a combined viral-bacterial respiratory challenge were explored in beef steers (initial BW 293 kg). Steers (n = 24) were inoculated intranasally with bovine herpes virus-1 (2×108 PFU) and intratracheally with Mannheimia haemolytica (MH, 2.15×1010 CFU) on days -3 and 0, respectively, (n = 16; VB), or similarly inoculated with phosphate-buffered saline (n = 8; PBS). Venous and arterial blood were collected on -3, -1, 0, 2, 3, 5, 7, 10, and 14 relative to MH challenge for CBC, haptoglobin, and arterial blood oxygen saturation analysis. Continuously recorded variables included rumen temperature, activity, rumination, DMI, and feeding behavior. Data were analyzed with a repeated-measures mixed model (SAS 9.4) with fixed effects of day, inoculation, and the interaction. Bunk visit frequency and DMI were reduced (P < 0.01) in VB steers throughout the 14 d post-MH period compared to PBS steers. Rumination (days 1, 7) and activity (days 1, 2, 4–8, and 11–13) were reduced (P < 0.03) in VB steers vs PBS steers. Rumen temperature was elevated (P < 0.04) in VB steers until day 6 post MH inoculation. Neutrophil concentrations (days 2 and 3), platelets (days 7–14), fibrinogen (days 2–10), and haptoglobin (days 2–7) were elevated (P < 0.05) in VB vs PBS steers. Hematocrit was depressed (P < 0.05) in VB steers on days 3–10. The VB steers had decreased (P < 0.05) arterial SO2% and pO2 than PBS steers; however, the inoculation × day interaction was not significant. Results indicate that the experimental VB challenge substantially altered rumen temperature, DMI, feeding behavior, rumination and immunological response as expected. Arterial sO2% and pO2 concentrations were reduced minimally by VB challenge, indicating challenges in using blood gas to detect BRD in beef cattle.
71 The relationships of late gestational uterine artery blood flow with calf and placental size
Authors: Redifer Colby A , Meyer Allison M
Published: November 2020

Utilizing crossbred fall-calving beef females over 2 years, relationships of uterine artery blood flow (UBF) with cow BW, calf birth BW, and placental characteristics were investigated. Transrectal color Doppler ultrasonography of both uterine arteries was conducted, and scans were grouped into 80, 60, 40, and 20 ± 5 d prior to calving (DPC; n = 28, 38, 36, and 24, respectively). Placentas were dissected post-expulsion (n = 21, 26, 26, and 19, respectively). Correlation coefficients were determined for UBF with BW and placental measures at each timepoint. Total UBF had a moderate positive (80, 40, and 20 DPC, P ≤ 0.009) or weak positive correlation (60 DPC, P = 0.02) with calf BW. Calf BW had a moderate positive correlation (P ≤ 0.04) with contralateral UBF (80, 60, and 40 DPC). Cow BW was not correlated (P ≥ 0.07) with UBF. Total and contralateral UBF had moderate positive correlations (P ≤ 0.03) with cotyledonary, intercotyledonary and total placental weights at 40 DPC and with intercotyledonary weight at 20 DPC. Contralateral UBF had a moderate positive correlation (P = 0.03) with total placental weight at 20 DPC. Ipsilateral UBF had no relationship (P ≥ 0.06) with calf or placental weights. Cotyledon number had a moderate negative correlation (P = 0.02) with ipsilateral UBF at 20 DPC, but a moderate (60 and 80 DPC) or strong (20 and 40 DPC) positive correlation (P ≤ 0.05) with contralateral UBF. Average cotyledonary size had a moderate positive correlation (P = 0.01) with total UBF at 20 DPC. Ipsilateral UBF had a moderate (80 and 40 DPC, P ≤ 0.04) or strong positive correlation (20 DPC, P = 0.003) with average cotyledonary size. These data suggest that late gestational UBF drives fetal and placental growth. Interestingly, contralateral UBF may have a disproportionately greater contribution.
74 President Oral Presentation Pick: Phenotypic plasticity of heat tolerance in beef cattle
Authors: Mateescu Raluca G , Davila Kaitlyn M Sarlo , Dikmen Serdal , Nunez Andrea , Rodriguez Eduardo , Oltenacu Pascal
Published: November 2020

Bos taurus indicus cattle have superior ability for regulation of body temperature during heat stress due to a number of physiological and cellular level adaptive traits. The objectives of this study were to quantify the change in body temperature in heifers with various proportions of Brahman genes per unit increase in heat stress as measured by THI and to assess the impact of skin properties on the phenotypic plasticity. A total of 299 two-year old heifers from six breed groups ranging from 100% Angus to 100% Brahman were evaluated under hot and humid conditions during 2017 and 2018 summer days. The plasticity in body temperature of breed groups in response to environmental challenges was estimated using a random regression mixed model. Six mm skin biopsies were collected from the right side of sixth thoracic bone of each heifer. Cross-sections of biopsy samples with a thickness of 7 µm were stained with Hematoxilin–Eosin technique. The number and area of sweat and sebaceous glands and the thickness of dermis and epidermis were determined using the ImageJ program. The 100% Brahman group had the lowest intercept and slope (38.66 and 0.18) representing the body temperature under the low THI conditions and the increase in body temperature for 2 units of THI, respectively. Except for the 100% Angus group, which had a slightly higher intercept (38.68), all other breed groups had lower intercepts. Body temperature in the 100% Angus heifers increases by 0.42 for every 2 units of THI. There was a significant linear effect of Brahman percentage on the sweat gland size, with the 100% Brahman having the largest sweat gland size (203.57µm2) and purebred Angus the smallest (94.31µm2). Effective strategies will require the identification of the genes conferring the superior thermotolerance in Brahman cattle.
316 Regenerative grazing: restoring ecosystem function to improve farm profits
Authors: Teague Richard
Published: November 2020

I explore the hypothesis that managing grazing using regenerative grazing principles to improve soil health is a sustainable base to improve net farm profits. Carbon-rich soil is healthy soil and beneficial for the entire ecosystem. Changing current unsustainable high-input agricultural practices to low-input practices that regenerate ecosystem function will be necessary for sustainable, resilient agro-ecosystems. Current reductionist, small-scale, short-term research managed without goals to find what management framework will deliver positive outcomes for ranchers has produced very erroneous conclusions. Healthy ecosystems function by increasing soil carbon to improve water infiltration and retention; soil nutrient access and retention; and the diversity of fungi, microbes, plants, insects, and wildlife that contribute to both improved livestock nutrition and human nutrition. I will give an overview of our research endeavors using a systems-science, multi-discipline framework to find the best grazing management for regenerating: soil health and function; delivery of ecosystem goods and services; and farmer livelihoods and social resilience. To accomplish this, we partner with farmers who have improved the environment and excel financially to convert experimental results into sound environmental, social, and economic benefits regionally and globally.
87 President Oral Presentation Pick: Oral Microbiota Populations of Adult Dogs Consuming Dental Chews Demonstrated to Reduce Dental Plaque and Calculus
Authors: Oba Patrícia M , Carroll Meredith , Alexander Celeste , Lye Lynn , Somrak Amy , Keating Stephanie , Sage Adrianna , Swanson Kelly S
Published: November 2020

Microbiota play a prominent role in canine periodontal disease, but little is known about the oral microbial community of dogs. We aimed to determine the differences in oral microbiota of dogs consuming dental chews demonstrated to improve oral health outcomes. Twelve adult dogs were used in a replicated 4x4 Latin square design consisting of 28-day periods. Control (CT) dogs consumed diet only, with treatment groups receiving one of three dental chews (BC, DL and GR). At baseline, teeth were cleaned. Teeth were scored for plaque, calculus, and gingivitis at the end of each period by a veterinary dentist blinded to treatments. Breath samples were measured for sulfur compounds throughout each period. Plaque [supragingival (SUP) and subgingival (SUB) plaque] and saliva (SAL) samples were collected for microbiota analysis. Total DNA from saliva and plaque samples was extracted, with 16S rDNA V4 region gene amplicons subjected to Illumina sequencing. Data were analyzed using QIIME 2 and SAS. CT dogs had a higher pocket score, breath sulfur concentrations, and plaque and calculus scores compared to those given chews. Bacterial species richness was highest for CT, with unweighted and weighted PCoA plots showed a clustering of CT dogs vs. those given chews. For all sample types, CT dogs had higher relative abundance of potential pathogenic bacteria (Porphyromonas, Tannerella, and Treponema) and lower relative abundance of bacterial genera associated with oral health (Neisseria, Corynebacterium, Bergeyella, and Moraxella) compared to those given chews. DL reduced Porphyromonas in SUP and SUB samples. DL and GR reduced Treponema in SUP samples. DL increased Corynebacterium in all sample types. BC increased Corynebacterium in SAL samples. DL and GR increased Neisseria and Moraxella in SAL samples. Our results suggest that the dental chews tested beneficially shifted oral microbiota populations, which were associated with improvements in plaque and calculus scores.
103 Equine enterocytes actively oxidize L-glutamine but do not synthesize L-citrulline and L-arginine from L-glutamine or L-proline in vitro
Authors: Martinez Rafael E , Leatherwood Jessica L , Bradbery Amanda N , Much Mattea L , Silvers Brittany L , Posey Erin A , Nawaratna Gayan I , Wu Guoyao
Published: November 2020

In many mammals, enterocytes are responsible for the synthesis of L-citrulline and L-arginine from L-glutamine and L-proline. However, there is limited research in the horse to determine de novo synthesis of L-citrulline or L-arginine by the enterocyte, which is the initial step in establishing dietary requirements and comprehending arginine nutrition in horses. We utilized jejunal enterocytes from 20 horses (neonate n = 2, mature n = 16, and geriatric n = 2) to study glutamine and proline metabolism. As a positive control, enterocytes were isolated from 0, 60, and 180-day old pigs (n = 8/age group). Equine or porcine enterocytes were incubated at 37oC for 30 min in oxygenated (95% O2/5% CO2) Krebs bicarbonate buffer (pH 7.4) containing 5 mM D-glucose and either 2 mM L-[U-14C]glutamine or 2 mM L-[U-14C]proline plus 2 mM L-glutamine. Collected 14CO2 was determined by a liquid scintillation counter, whereas amino acids in cells plus medium were analyzed by HPLC. Both equine and porcine enterocytes oxidized glutamine to CO2 but had a limited ability to oxidize proline to CO2, confirming the biochemical viability of the cells in vitro. Enterocytes from neonatal and geriatric horses had lower rates (nmol/106 cells/30 min) of CO2 production (1.10 ± 0.52 and 1.31 ± 0.65, respectively) from glutamine than those (40.9 ± 5.40) from mature horses. Porcine enterocytes synthesized L-citrulline and L-arginine from glutamine and proline (e.g., 4.86 ± 0.26 nmol L-citrulline/mg protein/30 min and 0.85 ± 0.04 nmol L-arginine/mg protein/30 min from glutamine in enterocytes of 60-day-old pigs). In contrast, equine enterocytes did not synthesize L-citrulline and L-arginine from L-glutamine or L-proline. Because L-arginine is an essential substrate for the synthesis of protein, nitric oxide, and creatine, our novel findings on the lack of intestinal synthesis of L-arginine in horses have important implications for their nutrition, metabolism, and health.
357 Early life factors shaping gut development and lifelong disease risk
Authors: Moeser Adam J
Published: November 2020

The first 3–4 months of postnatal life represents a critical period in gastrointestinal (GI) development that shapes lifelong function and disease resistance. During this period, extensive maturation of the immune and nervous systems, and epithelial transport and barrier function, occurs. While some aspects of early life gut development are genetically “hard-wired,” the GI system exhibits a high degree of plasticity, and thus developmental trajectory and long-term function can be significantly modified during this period via host and environmental influences. Stress or adversity during early critical periods of development has been recognized as a significant risk factor for the later-life susceptibility to several GI and systemic chronic inflammatory and debilitating diseases in humans and animals, including functional bowel disorders characterized by dysmotility and neuroinflammation, but also disease associated with systemic inflammation, such as metabolic disorders (obesity and Type 2 diabetes) and neurobehavioral disorders including anxiety and depression. Moreover, early life stressors include routine management practices such as maternal separation and early weaning, social disruption, and early immune activation from disease or vaccination, and thus early life stress is common in animals. While the link between early life adversity and later life disease risk is well-established across species, the mechanisms that link early life stress, gut development and lifelong disease risk are poorly understood, and thus targeted management, therapeutic and nutritional strategies to reduce the negative impacts of early life stress are lacking. This goal of this presentation is to provide a biological framework for understanding how early life environmental and host factors such as stress and biological sex can alter the normal trajectory of GI development and disease risk throughout the lifespan. Ways in which changes in gut development might drive the risk for diseases important to many species, such as metabolic disease, functional/inflammatory bowel disorders and neurobehavioral disorders, will be discussed.