bluuebunny/crossref_metadata_2025 huggingface dataset:
17 Challenges and implications of feeding diets with excess concentrations of leucine to growing-finishing pigs
Authors: Tokach Mike D , Cemin Henrique S , Kerkaert Hayden R , Woodworth Jason C , Dritz Steve S , DeRouchey Joel M , Goodband Robert D
Published: November 2020

Excess dietary leucine stimulates the key enzymes involved in branched-chain catabolism causing breakdown of all branched-chain amino acids, including isoleucine and valine. Branched-chain amino acids share a common brain transporter with other large neutral amino acids (LNAA). Excess levels of one of the LNAA increases brain uptake of that amino acid and decreases the uptake of the other LNAA, including tryptophan. Thus, excess leucine can impact the requirements for many amino acids. From a practical basis, this effect was first demonstrated with diets containing blood meal, but was thought to be of limited concern unless high blood meal diets were fed. Use of corn dried distillers grains with solubles (DDGS) or high protein DDGS in corn-based diets results in diets containing excess leucine. These high leucine levels are of limited concern if adequate levels of other branched-chain amino acids and LNAA are fed, which is often the case if the diet consists largely of intact protein sources. Feed grade amino acids, such as L-lysine, L-threonine, L-tryptophan, DL-methionine, L-valine, and L-isoleucine have been widely adopted as a means to lower nitrogen excretion and diet cost. Including these amino acids in diets containing corn products reduces dietary leucine; but the resulting diets are formulated near the requirement for the first 6 limiting amino acids, including valine, isoleucine, and tryptophan, while still being high in leucine. The excess leucine increases the requirements for valine, isoleucine, and possibly other LNAA, such as tryptophan and possibly others. The exact relationship between these amino acids and how to handle them in practical diet formulation is still being elucidated; however, recent meta-analysis and experimental data confirm the importance of these ratios and provide useful direction for future research.
112 Young Scholar Presentation: Protein and Amino Acid Nutrition in Fresh Cows
Authors: Tebbe Alex , Weiss Bill
Published: November 2020

During the 4 weeks after parturition, postpartum dairy cows (i.e., fresh cows) have the highest risk of disease and metabolic disorders. This is largely because nutrient requirements for lactation outweigh the cow’s metabolizable intake. As a result, cows enter negative nutrient balances and mobilize endogenous protein and energy stores to meet demands. Although negative energy balance, in terms of mass, is more negative than protein balances over this time frame, intake of metabolize protein (MP) and its amino acid (AA) profile may influence the performance and health of fresh cows more than increasing energy intake. Better performance from greater MP and AA supplies may also carry over and enhance milk production further into lactation. In our recent experiment, increasing MP supplies to fresh cows by feeding a greater rumen undegradable protein concentration (RUP; 7 vs 10% of DM) also increased milk and milk component yields. However, when the AA profile of the supplemental RUP was optimized to mimic the AA profile of casein, the greater yields were sustained much further into lactation. This may be because fresh cows fed the “casein like AA profile” had improved health and less body protein catabolism than cows fed a similar MP concentration. However, production responses with a greater MP intake depended on what the RUP replaced in the diet and on parity. When replacing forage fiber with RUP instead of nonforage fiber, multiparous cows had a reduction in milk and milk fat yields whereas primiparous cows performed similarly regardless of what type fiber was replaced. This suggested reducing forage fiber in a high MP diet will not increase overall MP intake, and multiparous cows may require more forage fiber during the fresh period than primiparous cows. Overall, MP intake and the AA supply is important for the health and production of fresh cows.
193 Equine teaching programs – where do they fit?
Authors: Anderson Kathy
Published: November 2020

Equine teaching programs in Animal Science Departments throughout the Midwest region land grant institutions have greatly expanded over the past 20 years. However, private schools with equine programs focused on large equitation programs have shown a reduction in recent years. Most indicated cost and reduced student numbers as factors to the decline. In evaluation of 12 land-grant institutions in the Midwest Animal Science region, 100% offer one or more equine Animal Science courses with a range of 1 to 16 different equine focused courses. Nearly all schools offer a combination of lecture and “hands-on” courses. Lecture courses focused on management, nutrition, evaluation, etc. were offed at all 12 institutions with most offering between 2 to 4 equine lecture type courses. Enrollments in these courses range between 10 – 50 students or more. However, highly popular hands on courses covering training, equitation, and handling have lower enrollment limits (10-15), lab fees, and schools offer between one to 6 different courses. Makeup of students enrolling in all courses is highly diverse from students with extensive prior horse skills and experience, to those with minimal experience. Furthermore, all of the institutions evaluated used the equine courses within their Animal Science major and three offered an Equine Option within Animal Science. However, this may be reflective of the structure of each Animal Science Department. Equine courses tend to be highly popular and attract students from various majors across intuitions. Offering courses to serve and attract this diverse student population is a challenge to departments, especially with the increased cost of maintaining herds for highly popular hands on courses. However, departments must strive to find a balance between lecture/distance and hands-on courses to provide students the educational experience exposing them to the equine industry and future careers.
99 Breed authentication of five lines comparing Structure, Admixture, and an allele frequency method
Authors: Putz Austin M , Charagu Patrick , Huisman Abe
Published: November 2020

Two commonly used population structure software packages are freely available for breed authentication, Structure and Admixture. Structure uses a Bayesian approach to model population structure, while Admixture uses a frequentist approach. More recently, an allele frequency method has been updated to use quadratic programming to constrain the multiple linear regression coefficients of the regression of genotype count (divided by two) on the matrix of allele frequencies for each known breed or line. This constraint forced coefficients to sum to one and be greater than or equal to 0 and less than or equal to 1. The goal of this research was to compare and contrast these three methods to determine the breed/line authenticity for each of the five genetic lines. These five lines included Large White, Landrace, a lean Duroc, a meat quality Duroc, and a Pietrain line. Only animals with a 50K SNP panel were used in this analysis. Analyses were run five times for Structure and Admixture to check repeatability. The allele frequency method did not need to be repeated because it remains the same as long as the reference allele frequency matrix stays constant. For Structure, results of breed composition were inconsistent across replicates. Structure separated at least one of the maternal lines in three out of the five replicates with only 500 animals and kept the Duroc lines together as one population. Only 500 animals could be utilized in each run of Structure due to computational restraints. Admixture was very consistent across runs for each animal, but also failed to separate the two Duroc lines, instead splitting one of the two maternal lines. Finally, the allele frequency method split all five lines correctly and was 100% reproducible as long as the reference allele frequency matrix stays the same across runs.
98 Using differential evolution to improve predictive accuracy of deep learning models applied to pig production data
Authors: Han Junjie , Gondro Cedric , Steibel Juan
Published: November 2020

Deep learning (DL) is being used for prediction in precision livestock farming and in genomic prediction. However, optimizing hyperparameters in DL models is critical for their predictive performance. Grid search is the traditional approach to select hyperparameters in DL, but it requires exhaustive search over the parameter space. We propose hyperparameter selection using differential evolution (DE), which is a heuristic algorithm that does not require exhaustive search. The goal of this study was to design and apply DE to optimize hyperparameters of DL models for genomic prediction and image analysis in pig production systems. One dataset consisted of 910 pigs genotyped with 28,916 SNP markers to predict their post-mortem meat pH. Another dataset consisted of 1,334 images of pigs eating inside a single-spaced feeder classified as: “single pig” or “multiple pigs.” The accuracy of genomic prediction was defined as the correlation between the predicted pH and the observed pH. The image classification prediction accuracy was the proportion of correctly classified images. For genomic prediction, a multilayer perceptron (MLP) was optimized. For image classification, MLP and convolutional neural networks (CNN) were optimized. For genomic prediction, the initial hyperparameter set resulted in an accuracy of 0.032 and for image classification, the initial accuracy was between 0.72 and 0.76. After optimization using DE, the genomic prediction accuracy was 0.3688 compared to 0.334 using GBLUP. The top selected models included one layer, 60 neurons, sigmoid activation and L2 penalty = 0.3. The accuracy of image classification after optimization was between 0.89 and 0.92. Selected models included three layers, adamax optimizer and relu or elu activation for the MLP, and one layer, 64 filters and 5×5 filter size for the CNN. DE can adapt the hyperparameter selection to each problem, dataset and model, and it significantly increased prediction accuracy with minimal user input.
92 Phenotypic and genomic relationships between vulva score and reproductive performance in first-parity sows
Authors: Corredor Flor-Anita , Sanglard Letícia P , Ross Jason W , Keating Aileen F , Serão Nick
Published: November 2020

Reproductive efficiency is critical to maximizing productivity in the swine industry. A recent study indicated that vulva score (VSC) assessed prior to puberty may be predictive of reproductive performance in sows, in which gilts with greater VSC had greater reproductive performance. The objective of this study was to validate the effect of VSC on reproductive performance, to estimate genetic parameters, and to perform genomic analysis of VSC. A total of 5494 phenotypes and 1326 genotypes (~50K SNPs) from two farms were available for this study. Measurements included VSC assessed using a three-point scale: small (VSC-S), medium (VSC-M), and large (VSC-L), at 15 and 14 weeks of age, for Farm 1 and 2, respectively, and subsequent first parity performance. Genetic parameters were estimated using single-step GBLUP. Genome-wide association study (GWAS) was performed for VSC using BayesB (p=0.999). For Farm1, VSC-L was associated with a greater (P-value=0.04) farrow rate (0.68±0.03) than VSC-S (0.53±0.07). For Farm2, VSC-L was associated with greater (P-value=0.04) number of piglets born alive (NBA; 11.4±0.17) and less mummified fetuses (P-value=0.03; 0.09±0.01) than VSC-S (10.9±0.14; 0.14±0.01). Heritability estimates of VSC were 0.35±0.06 for Farm1 and 0.34±0.05 for Farm2. Moderate genetic correlations between VSC with reproductive traits were found for total number born (0.61±0.21) and NBA (0.62±0.19). The GWAS identified multiple genomic regions associated with VSC. Of these, a QTL located on chromosome 1 at 85Mb accounted for >3% of the genetic variance. This region harbors ADAM21, a gene that has been associated with early embryonic development in pigs. These results validated the use of VSC for prediction of first-parity performance, identified genomic regions controlling VSC, and indicate that selection for increased VSC is possible and could improve reproductive efficiency in swine. We are grateful to Fast Genetics for providing the data and the Iowa Pork Industry Center for financial support.
93 Genomic basis of antibody response to porcine reproductive and respiratory syndrome virus vaccination
Authors: Sanglard Letícia P , Fernando Rohan L , Gray Kent , Linhares Daniel C L , Dekkers Jack , Niederwerder Megan C , Serão Nick
Published: November 2020

Antibody (Ab) response to natural infection with porcine reproductive and respiratory syndrome (PRRS) virus has been shown to be highly heritable (~0.40), to be genetically correlated with farrowing performance in PRRSV-infected sows, be controlled by two major QTL on chromosome 7, among others, and have moderate genomic prediction accuracy. However, waiting for PRRS outbreaks to occur to collect data limits the use of Ab response to select for increased PRRS resilience. Thus, we investigated the genomic basis of Ab response to PRRS vaccination with a modified live PRRSV vaccine as a strategy to generate data for this purpose. Nine hundred and six commercial F1 replacement gilts (189±16 days old) were vaccinated with a commercial PRRS modified live virus vaccine. Blood samples were collected 52 days after vaccination to measure Ab response, as sample-to-positive (S/P) ratio using a commercial ELISA, and for SNP genotyping (~50K). BayesC0 was used to estimate heritability for S/P ratio using in a model with contemporary group (CG) as fixed effect and SNP effects as random. Genome-wide association study and genomic prediction for S/P ratio were performed with BayesB (Pi=0.99). For genomic prediction, a three-fold cross-validation was used, in which each CG (n=3) was used as validation dataset. Accuracy of genomic prediction was defined as the correlation between genomic estimated breeding values and phenotypes adjusted for estimates of fixed effects, weighed by the number of individuals in the validation dataset. Heritability of S/P was moderate (0.35±0.04). A QTL was identified on chromosome 7 (25 Mb) explaining ~28% of the genetic variance. Accuracy of genomic prediction was fairly high (0.60±0.15). This is the first study describing the genomic basis of Ab response to PRRS vaccination with modified-live virus vaccine. Additional work is needed to evaluate the genetic correlation of Ab response to vaccination with resilience traits in pigs.
97 An insight into the piglet’s microbial colonization evolution: From birth towards weaning
Authors: García Mireia Saladrigas , Durán Mario , Coma Jaume , Pérez José Francisco , Martín-Orúe Susana María
Published: November 2020

The aim of the present study was to explore the evolution of piglet gut microbiota from birth to weaning. Moreover, it was hypothesized that different farm environments could condition this process. Two farms, distinct in their use of antibiotics, and 10 litters per farm were selected. A total of 100 fecal samples were obtained from the same pig of each litter on d2, d7, d14 and d21 of lactation and d14 after weaning. The DNA was extracted by using the PSP® Spin Stool DNA Kit and sequencing of the 16S rRNA gene (V3-V4 region) performed by Illumina MiSeq Platform. Bioinformatics and biostatistical analysis were performed with QIIME and the open-source software R v3.5.3. (phyloseq package). Alpha diversity was strongly affected by age (P< 0.001), with an increasing richness of species through time. Beta diversity decreased after weaning (P< 0.001), suggesting a convergent evolution among individuals. Regarding the structure of the microbiota, a clear clustering of the samples according to age was observed (P< 0.001). A progressive decrease was observed as the piglets aged for Clostridiaceae, Enterobacteriaceae, Fusobacteriaceae, Pasteurellaceae and Streptococcaceae (P< 0.001). In contrast, Lachnospiraceae (P=0.003), Lactobacillaceae (P=0.003) and Veillonellaceae (P=0.025) increased along the d7–d14 period, but decreased afterwards. Campylobacteraceae, Erysipelotrichaceae, Ruminococcaceae (P< 0.001) and Prevotellaceae (P=0.005) gradually increased with age reflecting the change from a milk-oriented microbiome towards a butyrate-producing one. Regarding the impact of the farm, differences in species richness were found and also a distinct microbial structure (ANOSIM: P=0.025) associated to changes in some particular taxonomic groups. In conclusion, during the transition from birth to weaning, the pig microbiota showed a relevant succession of microbial groups towards a more stable ecosystem better adapted to the dry feed. In this relevant early-age process differences between farms seems to have a limited impact.
51 Intranasal oxytocin improves plasma non-esterified fatty acids but not distance walked or cortisol concentrations at weaning
Authors: Nickles Kirsten , Relling Alejandro E , Parker Anthony J
Published: November 2020

Beef calves express behaviors such as walking and vocalizing to a greater extend during weaning. These behaviors increase production costs due to compromised calf growth, health, and welfare. Oxytocin treatment reduces anxious behaviors and attenuates the HPA axis, thus the objective of this experiment was to evaluate the effects of oxytocin on calf growth, cortisol, and distance walked at weaning. A total of 20 Angus x Simmental heifer calves were randomly allotted to each treatment group (n = 10), intranasal oxytocin or saline (OXT, CON). All calves were administered the respective intranasal treatment at weaning (day 0), and then placed in the same pasture. Calves were weighed and blood sampled on days 0, 1, 7, and 14. Blood samples were used to quantify non-esterified fatty acids (NEFA), β-hydroxybutyrate, and cortisol. Each heifer was fitted with a global positioning system collar that recorded calf location every 10 seconds for 16 h on days 0, 7, and 14. To further evaluate calf behavior, observations were made on days 0, 7, and 14 using instantaneous scan sampling from 0730 to 0830, 1200 to 1300, and 1700 to 1800 h. Data were analyzed using a completely randomized design with repeated measures model (SAS 9.4). Providing calves with intranasal oxytocin on the day of weaning did not have an effect on the distance walked, observed behavior, body weight, β-hydroxybutyrate, or cortisol concentrations, however, there was a day effect (P < 0.05) for these variables. Intranasal oxytocin treatment did affect NEFA concentrations, as calves in the CON group had greater NEFA concentrations on day 1 compared with calves in the OXT group (P < 0.05). These data imply that intranasal oxytocin could have the capacity to decrease mobilization of NEFA, but this change was not enough to affect body weight 14 days after weaning.
49 Solar radiation as a predictor variable for dry matter intake in beef steers
Authors: Yusuf Mustapha , Swanson Kendall C , Hulsman Hanna Lauren L , Degges Ronald , Bauer Marc L
Published: November 2020

The objective of this experiment was to examine the relationship between ambient temperature and solar radiation with dry matter intake (DMI) in beef steers. Daily intake data from 790 beef steers collected from years 2011 to 2017 using an Insentec feeding system were used for this experiment. Data were condensed from daily data into weekly averages (n = 14250 steer-weeks). The variables considered for this experiment include DMI (2.50 to 23.60 kg/d), body weights (197.3 to 796.1 kg), energy density of diets (NEm; 0.7930 to 2.970 Mcal/kg), ambient temperature (-23.72 to 26.40 °C), two week lag of temperature, monthly lag of temperature, solar radiation (30.81 to 297.12 W/m2), two week lag of solar radiation and monthly lag of solar radiation. Residuals of DMI generated after fitting week of year as a fixed effect were used in scatter plots with explanatory variables to identify if non-linear relationships existed. Body weight and energy density were observed to have both linear and quadratic relationships, while the relationship for average temperature and solar radiation vs. DMI were observed to be linear. The MIXED procedure of SAS was used to assess the fit and regression parameters of explanatory variables as fixed covariates. Repeated measures were handled using the REPEATED statement and within-individual relationship were accounted for by autoregressive 1 covariance structure. Absolute average temperature (P = 0.0024) and monthly lag of average solar radiation (P = 0.0014) are the best predictor variables for ambient temperature and solar radiation based on p-values. An interaction (P < 0.001) between average temperature and monthly lag of solar radiation was also observed. The coefficient of determination (R2) for our model was 0.23. This study indicates that monthly lag of solar radiation interacts with ambient temperature in affecting DMI by beef steers and improves DMI prediction equations.
50 Pelleting and Starch Characteristics of Diets Containing Enogen® Feed Corn
Authors: Truelock Courtney N , Tokach Mike D , Stark Charles R , Paulk Chad B
Published: November 2020

This experiment determined the effects of die thickness and conditioning temperature on pelleting and starch characteristics in diets containing conventional or Enogen® feed corn (Syngenta Seeds, LLC). Treatments were arranged as a 2 × 2 × 3 factorial of corn type (conventional [CON] and Enogen® feed corn [EFC]), die thickness (5.6 and 8.0 length:diameter [L:D]), and conditioning temperature (74, 79, and 85°C). Diets were steam conditioned and pelleted (CPM Model 1012-2) with a 4 × 22.2 mm or 4 × 31.8 mm pellet die. Conditioner retention time was set at 30 s and production rate was set at 15 kg/min. All treatments were replicated on 3 separate days. Data were analyzed using the GLIMMIX procedure in SAS (v. 9.4, SAS Institute Inc., Cary, NC). Increasing die L:D improved PDI (P=0.01) and increased (P=0.02) energy consumption. Increasing conditioning temperature from 74 to 85°C increased (linear, P< 0.03) PDI (84.2, 84.9, and 88.2%, respectively) and tended to decrease energy consumption (quadratic, P=0.07). There was a corn × conditioning temperature interaction (P=0.01) for gelatinized starch in conditioned mash. Enogen® feed corn diets steam conditioned at 85°C had the greatest quantity of gelatinized starch. Cooked starch of conditioned mash was greater (P< 0.01) for EFC diets compared to CON diets and increased (linear, P< 0.01) with increasing conditioning temperature. Starch gelatinization was greater (P< 0.01) in pelleted EFC diets (13.4%) compared to CON diets (11.7%) and was increased (linear, P=0.05) by increasing conditioning temperature from 74 to 85°C (12.0, 12.1, and 13.4%, respectively). Pelleted diets containing EFC had increased (P< 0.01) cooked starch compared to CON diets. In conclusion, increasing die L:D and increasing conditioning temperature improved PDI. Starch gelatinization was increased when diets were pelleted at the highest conditioning temperature of 85°C, and EFC diets resulted in greater gelatinized starch.
48 Effects of dietary isoleucine and valine supplementation to excess or low leucine diets on nitrogen balance and metabolism of branched-chained amino acids in growing pigs
Authors: Kwon Woong B , Soto Jose A , Stein Hans H
Published: November 2020

An experiment was conducted to test the hypothesis that Ile and Val supplementation may overcome detrimental effects of excess dietary Leu on N balance and metabolism of branched-chained AA (BCAA) in growing pigs. A total of 144 barrows (28.5 ± 2.5 kg) were housed in metabolism crates and randomly assigned to 18 diets. The basal diet contained 0.98% standardized ileal digestible (SID) Lys and had SID Leu, Val, and Ile ratios to SID Lys of 100, 60, and 43%, respectively. Two levels of synthetic L-Leu (0 or 2.0%), 3 levels of synthetic L-Ile (0, 0.1, or 0.2%), and 3 levels of synthetic L-Val (0, 0.1, or 0.2%) were added to the basal diet for a total of 18 diets in a 2 × 3 × 3 factorial. Urine and fecal samples were collected for 5 d after 7 d of adaptation. Blood, skeletal muscle, and liver samples were collected at the conclusion of the experiment. Data were analyzed as a 2 × 3 × 3 factorial using the PROC MIXED of SAS with concentrations of Leu, Val, and Ile, and all interactions as main effects and replicate as random effect. No interactions among main effects were observed, but excess Leu in diets reduced (P < 0.05) N retention and biological value of diets and increased (P < 0.05) plasma urea N (PUN). However, PUN was reduced (P < 0.05) as dietary Val increased. Concentrations of BCAA in liver were greater (P < 0.05) in pigs fed excess-Leu diets than in pigs fed low-Leu diets, but concentrations of BCAA in muscle were greater (P < 0.05) in pigs fed low-Leu diets. In conclusion, excess dietary Leu reduced N retention and biological value of diets and increased PUN in growing pigs, but Val supplementation may help overcome negative effects of excess Leu.
37 Sibs: an R toolkit for computation of relatedness measures using large pedigrees
Authors: Victor Oribamise B , Hulsman Hanna Lauren L
Published: November 2020

Without appropriate relationships present in a given population, identifying dominance effects in the expression of desirable traits is challenging. Including non-additive effects is desirable to increase accuracy of breeding values. There is no current user-friendly tool package to investigate genetic relatedness in large pedigrees. The objective was to develop and implement efficient algorithms in R to calculate and visualize measures of relatedness (e.g., sibling and family structure, numerator relationship matrices) for large pedigrees. Comparisons to current R packages (Table 1) are also made. Functions to assign animals to families, summary of sibling counts, calculation of numerator relationship matrix (NRM), and NRM summary by groups were created, providing a comprehensive toolkit (Sibs package) not found in other packages. Pedigrees of various sizes (n = 20, 4,035, 120,000 and 132,833) were used to test functionality and compare to current packages. All runs were conducted on a Windows-based computer with an 8 GB RAM, 2.5 GHz Intel Core i7 processor. Other packages had no significant difference in runtime when constructing the NRM for small pedigrees (n = 20) compared to Sibs (0 to 0.05 s difference). However, packages such as ggroups, AGHmatrix, and pedigree were 10 to 15 min slower than Sibs for a 4,035-individual pedigree. Packages nadiv and pedigreemm competed with Sibs (0.30 to 60 s slower than Sibs), but no package besides Sibs was able to complete the 132,833-individual pedigree due to memory allocation issues in R. The nadiv package was closest with a pedigree of 120,000 individuals, but took 37 min to complete (13 min slower than Sibs). This package also provides easier input of pedigrees and is more encompassing of such relatedness measures than other packages (Table 1). Furthermore, it can provide an option to utilize other packages such as GCA for connectedness calculations when using large pedigrees.
41 Characterizing the amount and variability of intramuscular fat deposition throughout the loin using barrows and gilts from two genotypes
Authors: Redifer Jack , Beever Jon , Stahl Chad , Boler Dustin , Dilger Anna
Published: November 2020

Pork quality is evaluated by commercial processors along the ventral surface of whole boneless loins. However, in retail settings boneless chops are evaluated individually for quality. The objective was to determine the variability in marbling attributable to chop location, sex, and sire line. The population of pigs evaluated were sired by commercial duroc boars selected for meat quality (MQ; n=96) or lean growth (LG; n=96) and equally split between sexes. Upon slaughter and fabrication, bone-in chops were removed from four locations along the loin (A=6th rib, B=10th rib, C=last rib, D=4th lumbar). Pairs of chops from each location were used for visual color, visual marbling, and subjective firmness, Warner-Bratzler shear force, and determination of moisture and extractable lipid (IMF). Variability across location, sex, and sire line was measured using a Levene’s test and the VARCOMP procedure of SAS was used to evaluate the proportion of variability each contributed to total variance. Barrows produced chops with greater IMF (3.64%) and variability (P< 0.001) than gilts (3.20%; P< 0.001). Chops from MQ pigs exhibited greater IMF (4.02%) and variability (P< 0.001) than LG (2.82%; P< 0.001). Chops from location A (3.80%) and D (3.77%) had greater IMF than B (3.34%; P< 0.001) with all three locations greater than C (2.77%; P< 0.001). Variance (s2) also differed (A=1.44% B=1.59% C=1.05% D=2.18%; P< 0.05) across chop locations. Of the variability in IMF, 33.0% was attributed to sire line, 10.16% to chop location and 4.01% to sex, with 52.83% unaccounted for. Location A chops were the most tender (2.57kg; P< 0.001) and C chops the least tender (2.93kg; P< 0.01). No differences in variability (s2; P=0.40) of tenderness were observed across chop location (A=0.31kg B=0.24kg C=0.24kg D=0.23kg). In conclusion, chop location, sex, and sire line all contribute to the amount and variability of pork loin marbling. Supported by National Pork Board Grant #18-118.
42 Quantifying mammary growth and proliferative effects of estradiol in Holstein heifer calves
Authors: Hardy Nicole R , Enger Kellie , Enger Benjamin
Published: November 2020

Growth of the bovine mammary gland is influenced by estradiol during a heifer’s life. The objective of this study was to determine the effect of estradiol administration on two different mammary parenchymal tissue regions and quantify the response in cellular proliferation between different estradiol treatments and regions. Treatments were administered daily during the 12 days prior to euthanasia at 82 days of age. Holstein heifer calves (n = 12) were divided amongst 3 treatments, control (n = 4, CON), short term (n = 4, SHORT), and long term (n = 4, LONG). CON calves were administered corn oil injections while SHORT calves received 9 injections of corn oil followed by 3 injections of estradiol; LONG calves received 12 injections of estradiol. BrdU was administered 2 hours prior to harvest to label proliferating mammary epithelial cells. Mammary parenchyma was dissected from the right rear gland and separated into two regions, center and edge parenchyma, for further examination. Tissues were examined using brightfield microscopy and fluorescent immunohistochemistry. LONG calves had a greater percentage (P < 0.05) of epithelial tissue area (34.0% ± 1.51) than CON (21.4% ± 1.5) and SHORT (23.0% ± 1.51) calves, and a lower stromal tissue area percentage (63.6% vs 73.9% and 74.0% ± 2.10, respectively; P < 0.05). There was a treatment by region interaction in the cellular proliferation. LONG calves had a greater percentage of proliferating epithelial cells than CON calves in the center (P < 0.05) and edge (P < 0.05) parenchymal regions, and a greater percentage of proliferating cells in the center parenchyma than SHORT calves (P < 0.05). These results indicate that duration of estradiol administration elicits different effects on mammary growth and that mammary epithelial cell proliferation is specific to mammary gland region.
114 Domestic and International Pork Demand and their Implication on Pork Production Practices
Authors: Dennis Elliott J
Published: November 2020

Domestic and international demand for pork products drives pork production. Consumers purchase pork products based on their personal tastes and preferences. These tastes and preferences have substantially changed over the last 20 years. Consumers desire to know more information about pork production practices and are willing to pay premiums at grocery stores for adoption of these practices. Producers response to changing consumer demands has important implications for the growth and profitability of the pork industry. I address the current economic understanding of domestic and international consumer demand for pork products and how this demand has and will continue to shape pork production practices.
220 Effects of supplemental leucine in milk replacer on lamb growth performance and carcass characteristics
Authors: Reiners Jessica N , Anderson Steven , Hoffman Travis , Swanson Kendall C
Published: November 2020

Twenty-four fall born Dorset-cross twin or triplet ram lambs were used to determine effects of supplemental leucine in milk replacer fed to neonatal lambs on pre- and post-weaning growth, organ weight, and carcass performance. Lambs were weighed after birth and allowed to nurse on dams for 12 h to allow for colostrum intake. At 12 h post-birth, lambs were assigned to one of two treatments: milk replacer (CON) and milk replacer with leucine added at 3% as-fed (LEU). Milk replacer treatments were offered for ad libitum intake for 42 d through a Lac-Tek milk machine. After 42 d, lambs were weaned and adapted to a finishing diet. Lambs were maintained on a finishing diet until one of two slaughter dates. Lamb weight through the pre- and post-weaning phases, organ weights, and carcass traits were determined. Data were analyzed using the GLM procedure of SAS. Leucine supplementation increased lamb ADG (P = 0.007) in the pre-weaning period. Leucine supplementation did not affect final body weight or ADG for the finishing period. Weight of the rumen tended to increase in LEU lambs (P = 0.09). Carcass weight and backfat were not affected by leucine supplementation. Body wall fat thickness was greater (P = 0.05) in lambs supplemented with leucine. Ribeye area, yield grade, leg scores, and percent of boneless, closely trimmed retail cuts were not affected by leucine supplementation. Neonatal growth in the pre-weaning period was enhanced, but long-term growth and muscle development were not affected by leucine supplementation.
75 Effects of dietary energy and lysine concentration on feed intake and productive performance of lean growing pigs
Authors: Aymerich Pau , Soldevila Carme , Bonet Jordi , Gasa Josep , Coma Jaume , Solà-Oriol David
Published: November 2020

The aim of this experiment was to determine the response of growing pigs to different standardized ileal digestible lysine (SID Lys) and net energy (NE) levels. A total of 1,248 crossbred boars and gilts (Pietrain x (Landrace x Large White)), with an initial body weight of 19.9±4.0 kg, were individually blocked in 3 categories. Pigs were distributed in 96 pens (13 pigs/pen). The experiment consisted on a 2 x 2 factorial design with 2 SID Lys (1.20 vs. 1.00 %) and 2 NE levels (2,550 vs. 2,350 kcal/kg), fed for 26 days. Data was analyzed with a two-way ANOVA. No significant interaction was observed between SID Lys and NE. Increasing SID Lys improved ADG (0.721 vs 0.679 kg/d, p< 0.001) and FCR (1.56 vs. 1.65 kg/kg, p< 0.001). Increasing NE had no impact on ADG (0.706 vs. 0.695 kg/d, p=0.100) but improved FCR (1.58 vs. 1.63 kg/kg, p< 0.001) as a result of reduction in ADFI (1.10 vs. 1.15 kg/d, p< 0.001). Therefore, energy intake increased when increasing the energy content of the diet (2799 vs. 2697 kcal NE/d, p< 0.001) and SID Lys intake was reduced (12.2 vs. 12.8 g/d, p< 0.001). In addition, FCR expressed as energy per kg gain was reduced when increasing SID Lys (3.81 vs. 4.04 Mcal NE/kg gain, p< 0.001) whereas increased when increasing NE density (4.02 vs. 3.82 Mcal NE/kg gain, p< 0.001). Differential analysis for small, medium and large pigs showed an interaction between SID Lys and NE in ADG of small pigs during the first 14 days (p=0.028). Pigs fed high lysine and low energy diet had a greater ADG than the ones in the high SID Lys and NE treatment (0.636 vs 0.595 kg/d, p=0.028). In conclusion, growing pigs showed 1) greater ADG when increasing SID Lys above 1.00% 2) no impact of energy level on growth.
72 Young Scholar Presentation: Use of medium chain fatty acids as mitigation or prevention strategies against pathogens in swine feed
Authors: Lerner Annie B , Cochrane Roger A , Gebhardt Jordan T , Dritz Steve S , Jones Cassandra K , Tokach Mike D , Goodband Robert D , DeRouchey Joel M , Gauger Phillip C , Zhang Jianqiang , Magstadt Drew , Bai Jianfa , Porter Elizabeth , Anderson Joe , Bass Benjamin , Karnezos Theodore , de Rodas Brenda , Woodworth Jason C
Published: November 2020

Four experiments were conducted to evaluate: 1) medium chain fatty acids (MCFA) application to swine feed pre- or post-viral contamination with porcine epidemic diarrhea virus (PEDV) measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), 2) MCFA levels and combinations measured by qRT-PCR, and 3) selected MCFA in bioassay. In Exp. 1, treatments were a 2x2 + 1 factorial with the main effects of chemical treatment (0.3% commercial formaldehyde (CF), Sal CURB [Kemin Industries, Des Moines, IA] or 1% MCFA blend (Blend) of 1:1:1 C6:C8:C10 [PMI, Arden Hills, MN]) and timing of application pre- or post-inoculation with PEDV; plus a positive control (PC; feed inoculated with PEDV and no chemical treatment). All combinations of treatment and timing decreased detectable PEDV compared to PC (P< 0.05). Pre-inoculation had decreased PEDV detection compared to post-inoculation (P=0.009). Commercial formaldehyde decreased PEDV detection compared to MCFA (P< 0.001). In Exp. 2 and 3, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, and varying levels (0.125-0.66%) and combinations of MCFA (C5:0, C6:0, C8:0, or C10:0). In Exp. 2, treating feed with 0.33% C8:0 decreased (P< 0.05) PEDV detection compared to all levels of MCFA and PC. In Exp. 3, treating feed with CF, 0.5-1% Blend, all levels of C6:0+C8:0, 0.25% C6:0+C10:0, 0.33% C6:0+C10:0, 0.25% C8:0+C10:0, or 0.33% C8:0 + 0.33% C10:0 resulted in decreased PEDV detection compared to PC (P< 0.05). In Exp. 4, feed was treated pre-inoculation with either 1) no treatment (PC), 2) 0.3% CF, 3) 0.5% Blend, or 4) 0.3% C8:0 and analyzed via qRT-PCR and bioassay. Adding 0.5% Blend or 0.3% C8:0 resulted in decreased PEDV detection compared to PC. All chemical treatments resulted in no evidence of infectivity in the bioassay while the positive control did produce evidence of infectivity. In conclusion, lower levels of MCFA than previously evaluated may provide in-feed protection against PEDV.
159 Effects of mycotoxin challenge on growth and health of weanling pigs with different weaning weights
Authors: Holanda Debora Muratori , Kim Sung Woo
Published: November 2020

This study aimed at investigating the effects of mycotoxin challenge on growth and health of pigs with different initial BW (IBW). One hundred and eight weanling pigs were assigned following a RCBD in a 2 x 2 factorial arrangement on d 0. Factors were: IBW, light (6.9 kg) or heavy (9.8 kg); and dietary mycotoxin challenge, low or high (additional: 0.2 mg/kg aflatoxins, 1.8 mg/kg deoxynivalenol, and 1.9 mg/kg fumonisins). Before allotment, 12 pigs from light and heavy IBW were euthanized to collect duodenum and jejunum. There were 16 replicates per factor and 3 pigs per pen. Fecal score (d 0, 3, 5, 7, 10, 15, and 20) and growth performance (weekly) were recorded. Six pens from lightest, intermediary, and heaviest among treatments were selected and 1 pig (20 kg) per pen was euthanized to collect blood, ileal digesta, duodenum and jejunum. Data were analyzed using SAS mixed procedure. On d 0, heavy IBW increased IL-8 (P < 0.05) in duodenum and jejunum and decreased (P < 0.05) TNF-α in jejunum. Heavy IBW increased (P < 0.05) BW, ADG, ADFI, and G:F. Mycotoxins reduced (P < 0.05) BW, ADG, ADFI, and G:F. Heavy IBW tended to decrease fecal score on d 0 (P = 0.080), d 10 (P = 0.069), and decreased (P < 0.05) on d 15 and 20. Heavy IBW decreased blood ALP (P < 0.05) and increased (P < 0.05) creatinine. Mycotoxins tended to decrease albumin (P = 0.051) and albumin/globulin (P = 0.050). Mycotoxins decreased AID of nitrogen (P < 0.05). Heavy IBW decreased (P < 0.05) malondialdehydes in duodenum and jejunum and IL-8 in jejunum. Mycotoxins tended to increase (P = 0.060) TNF-α in jejunum. In conclusion, pigs with heavy IBW showed lower health impairment, and mycotoxins impaired nutrient digestibility, hepatic function, and growth performance.
169 Standardized ileal digestible amino acids and net energy contents in full fat and defatted black soldier fly larvae meals (Hermatia illucens) fed to growing pigs
Authors: Crosbie Michelina M , Zhu Cuilan , Shoveller Anna Kate , Huber Lee-Anne
Published: November 2020

Two experiments were conducted to determine the standardized ileal digestibility (SID) of AA (Exp. 1) and available energy (Exp. 2) in two black soldier fly larvae meal (BSFLM) sources [full fat (FF) and defatted (DF)] for growing pigs. Two corn starch-based diets were formulated with FF and DF BSFLM as the sole sources of AA. A nitrogen-free diet was also used and the corn starch:sucrose:oil ratio was kept constant among diets to calculate digestible energy. In Exp. 1, 8 ileal-cannulated barrows (25.1±0.41 kg initial BW) were used in a replicated 2 x 2 Latin square design (n = 8). In each period, pigs were adjusted to diets for 5d followed by 2d of continuous ileal digesta collection for 8 h. The SID of AA were calculated using basal endogenous losses for pigs fed a nitrogen-free diet. In Exp. 2, 8 barrows (23.4±0.54 kg initial BW) were used in a partially replicated Latin square design (n=8). In each period, pigs were adjusted to diets for 7d, followed by 5d of total urine and fecal grab sample collection, and 24hr in indirect calorimetry chambers to determine heat production. The SID of Arg, Val, Ala, and Pro tended to be less, and the SID of Met tended to be greater for the FF versus the DF BSFLM (P=0.034, 0.090, 0.053, 0.065, 0.074, respectively). Digestible, metabolizable, and net energy (4101 vs 3257±224 kcal/kg) were greater for the FF versus the DF BSFLM (P< 0.05). The ATTD of phosphorus, neutral detergent fiber, and acid detergent fiber were greater for the FF versus the DF BSFLM (P< 0.05). In conclusion, the SID AA in FF and DF BSFLM were high and similar to those of soybean meal. The FF BSFLM is a better source of available energy for growing pigs compared to DF BSFLM.
163 AviPlus®S improves wean to finish performance in pigs
Authors: Tugnoli Benedetta , Piva Andrea , Grilli Ester
Published: November 2020

The study evaluated the effect of AviPlus®S, a microencapsulated blend of organic acids and nature identical compounds, fed to piglets from weaning through finishing. Ninety pigs (21 days of age, 6.47 ± 0.27 kg) were assigned to 3 diets (5 pigs/pen, n = 6) for a 22-weeks experimental period in 3 phases: weaning (weeks 1 to 6), growing (weeks 6 to 12), and finishing (weeks 12 to 22). The dietary treatments were: CTR, basal diet; AP1, basal + AviPlus®S at 1 kg/MT (weaning phase) and at 0.25 kg/MT (growing and finishing phase); AP2, basal + AviPlus®S at 2 kg/MT (weaning phase) and at 0.5 kg/MT (growing and finishing phase). Growth performance was recorded for each phase. Data were analyzed with ANOVA and differences considered significant at P< 0.05. In the weaning period, AviPlus®S linearly increased ADG and BW (P= 0.006 and P=0.003, respectively) with AP1 and AP2 pigs being heavier than control pigs by 0.44 and 1.1 kg, respectively, at week 6. Growing phase was not affected by treatments. In the finishing period AP2 had significantly higher ADG and G:F compared to control, while AP1 showed intermediate values (P=0.019 and P=0.005, respectively). Overall during the entire trial, AP2 pigs had the highest ADG and G:F, with the final BW being 5.6 kg higher than control at the end of the cycle (114.9 vs 109.3 kg).In conclusion, the supplementation with AviPlus®S allowed to improve growth performance of pigs throughout a production cycle from weaning to slaughter.
161 Dietary oxidized protein result in growth and histology differences in pigs
Authors: Frame Carl A , Huff-Lonergan Elisabeth , Kerr Brian J , Rossoni Serao Mariana C
Published: November 2020

Rendered by-products are common feedstuffs in diets. During processing, these sources have potential to become oxidized. While most research on oxidative stress has focused on dietary oxidized lipids, little research has been done in dietary oxidized proteins and the potential to induce oxidative stress. Recent studies have shown consumption of dietary oxidized proteins resulted in shifts in oxidative status. The objective of this study was to determine the effects of dietary oxidized protein on oxidative stress in pigs as a model for canines. Fifty-six, 3 weeks old pigs (5.55 ± 0.71 Kg) were fed 4 dietary treatments each varying in dietary oxidized protein. Each treatment was fed the same diet, with the exception of the degree of oxidation in chicken by-product meal which was included in the diet at 23 percent to represent typical inclusion levels of a companion animal diet. Oxidation was induced by 2 levels of heating and 2 levels of antioxidants (mixed tocopherol), in a 2 x 2 factorial design. A significant antioxidant effect was observed in villi height (P-value < 0.05) where pigs fed diets without antioxidant had increased villi height (674 μm) compared to those fed diets with antioxidants (576 μm). Additionally, pigs fed diets without antioxidant had significantly greater villi:crypt (3.22) compared to those fed diets with antioxidants (2.84 ; P-value < 0.05). Additionally, feed efficiency measured by gain:feed, was significantly decreased in pigs fed heated protein (0.65) compared to not heated (0.69; P-value < 0.05). Results from this study are consistent with previous studies (Dibner, et al., 1996). Future studies should examine the effects of feeding oxidized proteins in regard to oxidative status, such as markers of protein, lipid, DNA, and antioxidative enzyme damage. In conclusion, dietary oxidized protein can reduce feed efficiency in pigs.
207 Improving Performance of Finishing Pigs with Added Val, Ile, and Trp: Validating a Meta-analysis Model
Authors: Kerkaert Hayden R , Cemin Henrique S , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D , Dritz Steve S , Haydon Keith , Hastad Chad W , Post Zach
Published: November 2020

Based on a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions caused by high dietary Leu in diets containing high levels of corn protein, namely dried distillers grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4×(Fast LW×PIC L02); initially 33.6±0.63 kg) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal-DDGS-based diets as follow: low level of Lys-HCl (SBM), high Lys-HCl and moderate Ile, Val, Trp (NC; AA above NRC 2012 estimates), moderate Lys-HCl and high Ile, Val, Trp (PC), and PC with either increased L-Val (Val), L-Ile (Ile), or L-Trp (Trp). Diets contained 30% DDGS until pigs reached approximately 100 kg and then 20% DDGS until market. Data were analyzed as a randomized complete block design using lmer function in lme4 package in R with pen considered as the experimental unit, body weight as blocking factor, and treatment as a fixed effect with 10 replicates/treatment. Overall final BW and ADG were greater for pigs fed SBM, Val, and Ile diets than the NC with PC and Trp intermediate. Pigs fed the Val diet had greater (R< 0.05) ADFI than the NC with pigs fed SBM, PC, Ile, and Trp intermediate. No differences were detected between treatments for G:F. In conclusion, increasing Val or Ile in high Lys-HCl-DDGS-based diets improved growth performance and final BW compared with pigs fed diets containing high levels of HCl-Lys without added Val and Ile. These results demonstrate that negative effects of high Leu in corn-DDGS-based diets can be overcome by increasing the ratios of Val and Ile to Lys.