bluuebunny/crossref_metadata_2025 huggingface dataset:
37 Opportunities for using a functional chip in beef
Authors: John Pollack E
Published: July 2019

Adoption of DNA technology in the beef industry has experienced an accelerating trajectory. The well-accepted and adopted applications are now parentage testing and, more recently, the inclusion of marker data into genetic evaluation systems to produce “genomic enhanced EPDs” (GE-EPD). Neither of these applications requires the markers to be functional variants; however, to produce GE-EPD’s does require the traits (or correlated traits) be in the suite of traits for which EPDs are produced. This does not allow for expansion of the use of the technology to several novel, economically important characteristics. To do so requires discovery populations closely related to the target population if typical marker panels are used and would require retraining as the target population moves away from the discovery population in its degree of relatedness. Knowledge of functional mutations is hypothesized to eliminate the necessity of a closely related population to the point of potentially universal application (across breeds) of the variant contribution to the phenotype(s) of interest. Applications that would then represent significant contribution to the genetic and management programs in beef production would be in the segments of the industry “downstream” of the seedstock industry. Breed independent predictive panels for commercial heifer replacement selection, for feedlot animal management and for product characteristics are fertile ground for the use of functional variants. These applications would target predicting animal performance, and as such would also allow for non-additive effects to be considered. If the variant tool is built as one panel including traits of interest to each segment of the industry, then valuable information becomes available each time ownership of the animal, or products derived from harvesting that animal, occurs.
33 Young Scholar Presentation: Expression quantitative trait loci and allele-specific expression exhibiting joint association with polygenic trait phenotypes in pigs
Authors: Velez-Irizary Deborah , Casiro Sebastian , Daza Kaitlyn R , Bates Ronald O , Raney Nancy E , Steibel Juan P , Ernst Catherine
Published: July 2019

Advancements in sequencing technology, improvements in genome annotation, and development of quantitative genetic models have been instrumental to the significant genetic gains achieved in pork production. Several quantitative trait loci (QTL) have been identified for growth, meat quality and carcass composition (GMC) phenotypes, however, the biological mechanisms underlying most QTL remain unknown. Functional genomic analysis can reveal insights on the genetic architecture of complex traits, and transcriptomic profiling of skeletal muscle during the conversion of muscle to meat can identify critical regulators of GMC phenotypes. Gene transcripts obtained with RNA-seq of longissimus muscle from 168 pigs were used to estimate gene expression variation subject to genetic control by mapping expression QTL (eQTL) and allele-specific expression (ASE). A total of 334 eQTL were mapped (FDR≤0.01) and joint association of eQTL with phenotypic QTL (pQTL) segregating in our population revealed 16 genes significantly associated with 21 pQTL for GMC phenotypes. ASE analysis facilitates the identification of cis-acting regulation of transcript abundance. We tested for ASE in 69,502 coding SNP (cSNP) and a total of 18,234 cSNP with significant ASE were identified (FDR≤0.01). A gene-wise conditional analysis fitting all ASE cSNP per gene for each phenotype identified 60 genes associated with GMC phenotypes. A comparison of eQTL with ASE cSNP showed an overlap of 136 genes. Pearson correlations of peak eQTL SNP with ASE cSNP was significant for 51% of these genes. The ASE analysis showed more precision in the identification of cis-acting effects than the genome-wide eQTL analysis; however, both approaches provide valuable information on the regulation of transcript abundance. For instance, we observed 24 genes associated with distant eQTL (trans effects) and exhibiting ASE. This study provides new information on the complex regulation of the pig longissimus muscle transcriptome and associations with measurable differences in economically important phenotypic traits.
42 Advancements in silage management and technology for beef and dairy cattle
Authors: Ramirez Hugo , Branstad Emily , King Layla
Published: July 2019

In 2017, 2.6 million ha of American farmland were destined for corn silage production, which was estimated at 116.5 million tons. Data for 2018 are yet to be compiled but field observations provide insight of a difficult year for growing and harvesting conditions. In recent years, there has been a renewed interest in making the most efficient use of forage resources. Since corn silage is a predominant forage for beef and dairy cattle, most advances have focused on improving harvesting, storage and feeding methods of this crop. The harvesting process has been modified with the introduction of various designs of kernel processors; commercial laboratory data show a trend towards greater and more uniform processing score since 2010. Furthermore, the degree of processing can now be objectively evaluated by combining hydrodynamic separation and image processing software to obtain a kernel processing score in real time in field conditions. Applications of plastic film technology, such as oxygen barriers, to seal and maintain an anaerobic environment, have aroused interest due to the possibility of reducing spoilage with a concomitant increase in recovery of dry matter from the uppermost layer of a silage pile. Throughout the storage phase, it has been recognized that starch digestibility increases over time due to prolamin solubilization. Recent work with reconstituted high-moisture corn demonstrated that bacterial proteolytic activity contributes 60% to protein solubilization and that fermentation acids play a minor role in this process. The field of inoculants has also seen innovations in terms of application equipment and species and strain selection, with Lactobacillus buchneri becoming relevant for certain conditions that require longer aerobic stability. During feed-out, dry matter monitoring can be done with instant measurements using NIR technology in various applications ranging from tractor-mounted instruments to hand-held devices. Even though silage making has been a longstanding practice, specific aspects of the process have evolved over time and are worthy of consideration to improve forage management and quality in support of ruminant nutrition.
45 Opportunity with functional role of supplemental amino acids
Authors: Shen Yanbin , Kim Sung Woo
Published: July 2019

The technological advancement in production of crystalline amino acids has driven the cost of crystalline amino acids down significantly and facilitated the wide use of crystalline amino acids in food animal production. The primary reason of use of crystalline amino acids in am animal’s diet is to provide dietary essential nutrients for protein synthesis and to balance the diet and reduce dietary cost. Extensive researches with amino acids have greatly enabled such use. As a result, most swine diets today are formulated with 3 or 4 supplemental amino acids. However, the economical return on including beyond 4 supplemental amino acids becomes low and thus discourages the use of more than 4 supplemental amino acids for dietary saving purpose. The use of the functional role of amino acids might bear the new opportunity for amino acids. Tryptophan has unique physiological functions involving synthesize serotonin in the body. Increasing tryptophan intake is shown to elevate serotonin synthesis in the brain of pigs and reduce stress and improve performance of pigs under social stress. Research shows that methionine is used as a precursor of glutathione to protect intestinal mucosa from oxidative damages during weaning stress. Arginine, glutamine, and glutamate are shown to have functions in cell proliferation, potentially improving intestinal and immune function of nursery pigs and preventing loss of lean body mass in the sow. Leucine is a ketogenic amino acid. The carbon skeleton of leucine is converted to acetylCoA, which could be used for fatty acid synthesis in muscle tissue. Research showed that intramuscular fat was increased by feeding high dietary leucine levels. Overall, the different functions of individual AA beyond their roles as the building blocks for proteins give additional opportunities of amino acid application in animal production.
49 Fat metabolism and utilization in growing dairy calves and heifers: What do we know and what still needs to be researched?
Authors: Anderson Jill L , Schossow Chelsea R , Rodriguez-Hernandez Karla , Lawrence Rhea D , Senevirathne Nirosh D
Published: July 2019

The objective of this presentation is to discuss and review research on lipid and fatty acid metabolism in growing calves and heifers. The majority of research related to fat metabolism in dairy cattle has been conducted with lactating or transition cows evaluating the effects of diet on milk fat synthesis, energy status, and reproduction. Despite the biological activities of lipids beyond serving as an energy source and their importance in maintaining normal biological function, there is limited understanding of how they are utilized by developing dairy calves and heifers. Additionally, there is limited understanding on the potential impacts of changes in blood concentrations on development and performance of the growing replacements. In recent research studies we have observed that concentrations of circulating lipid metabolites and plasma fatty acids change as calves and heifers develop and mature. Some of these changes are related to the dietary transitions that occur during the first year of life as a calf moves from milk to a concentrate-based diet, followed by a more forage-based diet at several months of age. Additionally, there are major shifts in lipid metabolism as a calf transitions through key developmental changes such as from a pre-ruminant to ruminant and through the critical reproductive stage around the onset of puberty. A better understanding of lipid metabolism and the impacts of supplementation of dietary fats or manipulations of energy sources may offer new ways to enhance development and improve performance of growing replacement heifers through nutritional strategies.
Reducing phosphorus excretion by horses
Authors: Fowler Ashley , Lawrence Laurie M
Published: July 2019

Phosphorus is both a limited, non-renewable resource and also a major factor in water eutrophication. Therefore, dietary P intakes should only provide what an animal requires, reducing unnecessary addition of P to diets and excretion into the environment. Equine feeding programs commonly include inorganic P in excess of requirements, because organic P (e.g. phytate-P) is thought to be poorly digested by the horse. We have observed that 95% of phytate is degraded by the time it reaches the feces, suggesting that phytate-P availability, and thus true P digestibility, may be greater than believed. In other species but not in horses, it is recognized that fecal P excretion is important for maintaining P homeostasis, but can result in low estimates of P digestibility and subsequently greater P requirements. Ideally, P digestibility values used to calculate requirements should only reflect dietary P availability and not fecal P excreted as part of maintaining homeostasis. This research evaluated two factors that could affect P excretion, a change in physiological state (from lactation to post-lactation) and weight loss. We found that post-lactational mares tended to excrete more P than control mares (P = 0.082), but fecal P excretion exceeded P intake for both groups of mares, and mares also lost weight during the study. In the following study, horses fed to lose weight tended to excrete more P than horses fed to gain weight (P = 0.085), suggesting fecal P excretion can be altered by physiological state independent of dietary P availability and is likely the main homeostatic mechanism for P. Previous studies that have not accounted for homeostatic P excretion may have underestimated P digestibility. Thus, requirements could be revised, resulting in a significant reduction in the amount of inorganic P added to equine diets and in the amount of P excreted into the environment. This research suggests that fecal P excretion can be altered due to physiological changes in the horse independent of actual dietary P digestibility and is likely the main homeostatic mechanism for P. Previous studies that have overfed P or failed to account for homeostatic fecal P excretion may have underestimated dietary P availability.
55 Building a production nutrition department in an integrated production company: critical pillars for our success
Authors: Coble Kyle F
Published: July 2019

From an outsider’s perspective, internalizing a nutrition department may seem straight forward, although the true pillars for success are not as obvious. While formulating rations is certainly an important function, developing the trust of an entire production team has more direct implication on one’s success than the perfect diet. This is highlighted when describing responsibilities of a production nutritionist which consist of 20% formulation and 80% execution. Getting the right feed, in the right bin, at the right time consists of many moving parts and people, striving to work in harmony. You often see this process overcomplicated and unintentionally driving production in the wrong way due to managing to a level above which is executable. The execution leads to the successful implementation of your perfect diet, and ultimately to the trust and respect of your colleagues on the production team. Gaining their trust and respect is paramount to being successful, as production systems today are complex, and nothing can be accomplished in isolation. Keeping this approach as a nutritionist will instill a positive culture, which is even more relevant today as the industry faces challenges in recruiting and keeping talented teammates. This cannot be accomplished by sitting at the desk, it requires you to be present and seen in the field. People need to know you are accountable. Not being afraid to reach out to others for help is also important, especially to those whom have more specialization in a particular area than yourself. There are great people in our industry willing to help and offering to pass on their teachings. Finally, being disciplined about your time can mean the difference between getting many things done in a day and none. While people all desire a portion of your time, being selective is critical to your output. Being a production nutritionist has been a rewarding career, but it has been necessary to study, find, and act on these important pillars that are proven to work.
56 Observations on pre-weaning piglet mortality
Authors: Ellis Michael , Vande Pol Katherine D , Cooper Naomi , Shull Caleb M
Published: July 2019

Pre-weaning piglet mortality (PWM) is a substantial economic loss and a welfare concern. It is not a new issue; however, there is evidence that levels are increasing in US herds. Genetic improvements in prolificacy have been accompanied with lower average piglet birth weights, increased within-litter variation in birth weight, and an increasing proportion of low birth weight piglets. Low birth weight is a major pre-disposing factor for PWM. In a survey involving over 11,000 piglets (average birth weight 1.44 ± 0.390 kg), PWM for piglets weighing 1.5 kg was 44, 15, and 8%, respectively. However, the percentage of total mortality from these 3 weight groupings was 35, 42, and 23%, respectively. This suggests that efforts to reduce PWM should mainly focus on lightest 50% of piglets in a population. The major causes and timing of PWM have not changed over time. Crushing and starvation are predominant; the majority of losses occur in the first few days after birth. A substantial proportion of dead piglets have empty stomachs. Pre-weaning mortality is multifactorial in origin; reducing levels requires attention to all factors, starting with farrowing accommodation design and basic facility hygiene programs. Minimizing piglet body temperature decline after birth, and encouraging early colostrum and milk intake are critical. Strategies to reduce competition between piglets for access to the udder and/or supplementary feeding programs are important. Cross-fostering is central to maximizing piglet survival; however, there is a dearth of research-based information to use to design the optimum strategy. The potential influence of gestation nutrition on PWM requires clarification. Pre-weaning mortality is strongly influenced by the people managing the farrowing facilities; developing approaches for early identification of at risk pigs would have benefit. Ultimately, minimizing PWM requires systems-based approaches involving all components from genetic selection for survival through to facility and animal management practices.
65 Using 3D images and deep learning to predict feeder occupancy in grow-finish pigs
Authors: Han Junjie , Chewning Sarah K , Wurtz Kaitlin E , Siegford Janice , Steibel Juan P
Published: July 2019

A common source of outlying data in automatic feed recording systems used with grow-finish pigs is multiple pig occupancy of a single space feeder. Tracking these events is difficult and may require continuous observation or time-consuming manual decoding of video recordings. An alternative to manual decoding is use of algorithms for automatic image classification. The aim of this work was to build a hierarchical model to classify images from automatic feeders to discern if the feeder is empty, occupied by one pig, or occupied by more than one pig. An experimental pen was equipped with a ceiling-mounted Intel RealSense D435 camera above an automatic feeder. Images were recorded for 3 consecutive days. Randomly selected Images from d 1 were used for model training (n = 414 and n = 238 for models 1 and 2, respectively). Images from subsequent days were used to test the models (n = 196 and n = 427 for models 1 and 2, respectively). Images were manually labeled as “empty feeder,” “one pig inside the feeder,” or “more than one pig inside the feeder.” Pixel intensity data from depth images were used as predictors of feeder occupancy using a two-step decision tree that consisted of fitting two binary outcome models to a) predict if the feeder was occupied and b) predict if there was more than one pig in the occupied feeder. Both models consisted of a feed-forward artificial neural network. The transfer functions used were the reflected linear unit for deep layers and softmax for the outcome layer. The loss function was the binary cross entropy and the optimizer was the stochastic gradient descent. Accuracy, sensitivity, and specificity were 100% for model 1. For model 2, accuracy=97.7%, sensitivity=97.2% and specificity=98.1%. The proposed models allow accurate, continuous, real-time monitoring of feeder occupancy by no pig, one pig, or more than one pig.
375 Identification of QTL associated with antibody response to common infectious diseases in commercial sows
Authors: Sanglard Leticia Pereira , Canada PigGen , Mote Benny , Willson Philip , Harding John C S , Plastow Graham S , Dekkers Jack C M , Serão Nick V L
Published: July 2019

The objective of this study was to perform genome-wide association studies (GWAS) to identify Quantitative Trait Loci (QTL) associated with antibody response to infectious diseases in commercial sows. A total of 2,848 Large White x Landrace replacement gilts were sourced from 17 high-health multipliers (7 breeding companies; BC) and introduced to 23 commercial farms with a history of common pig diseases, following the standard acclimation procedures with an average of 53 animals per entry group (CG). Serum was used to quantify antibody response to swine influenza virus (SIV), Mycoplasma hyopneumoniae (MH), porcine circovirus type-2 (PCV2), and 8 serotypes of Actinobacillus pleuropneumoniae (APP1-3, 5, 7, 10, 12, and 13) at entry (S/PEntry), following acclimation (S/PAcclimation), and during parities 1 (S/PParity1) and 2 (S/PParity2). All animals were genotyped for 38,191 SNPs. GWAS was performed using BayesB (pi=0.99), with the fixed effect of CG and the random effects of SNPs in the model. For APP, QTL were only identified at S/PAcclimation; on SSC14 (2Mb) for APP3, APP7, APP10, and APP13 that explained 5.6, 4.7, 2.8, and 3.6% of the genetic variance, respectively. A gene within this QTL region is SYK, involved in the control of immune-receptors. For APP5, a QTL that explained 4.2% of the genetic variance was identified on SSC4 (105Mb), which co-localizes with two genes associated with immune-response: SIKE1and NRAS. For SIV, no QTL was identified. A QTL on SSC7 (130-131Mb) was identified for MH (S/PParity1, 5.1%) and PCV2 (S/PEntry, 34%; S/PAcclimation, 43.4%). These results provide new information on the genetic basis of response to infectious diseases in sows. The identified QTL have the potential to be used to select for improved immune response. The authors thanks PigGen Canada, Genome Canada, and the Canadian Swine Health Board for financial support, and the late Dr. Stephen Bishop for his scientific contributions.
63 A comparison of clustering methods for cross-validation of genomic predictors when training on phenotypes or deregressed Estimated Breeding Values
Authors: Baller Johnna , Howard Jeremy T , Kachman Stephen , Spangler Matthew L
Published: July 2019

The objective of the study was to evaluate the impact of clustering methods for cross-validation on the accuracy of prediction of molecular breeding values (MBV) in Red Angus cattle (n = 9,763) and in simulation. Individuals were clustered using seven methods [k-means, k-medoids, principal component analysis on the numerator relationship matrix (A) and identical-by-state genomic matrix (G) as data and covariance matrices, and random] and two response variables [deregressed Estimated Breeding Values (DEBV) and adjusted phenotypes]. Genotypes were imputed to a 50K reference panel. Using cross-validation and a Bayes C model, MBV were estimated for traits including birth weight (BWT), marbling (MARB), rib-eye area (REA), and yearling weight (YWT) for DEBV and BWT, YWT, and ultrasonically measured intramuscular fat percentage and rib eye area for adjusted phenotypes. A bivariate animal model was used to estimate prediction accuracies calculated using the genetic correlation between estimated MBV and the associated response variable. To quantify the difference between true and estimated accuracies, a simulation mimicking a cattle population was replicated five times. The same clustering methods were used as with the Red Angus data with the addition of forward validation and two genotyping methods (random selection and selection of the top 25% of animals). Predicted accuracies were estimated similarly and true accuracies were estimated using the residual correlation of a bivariate model using MBV and true breeding values (TBV). The Rand index was used to quantify the similarity between clustering methods, showing relationship-based clusters were clearly different from random clusters. In simulation, random genotyping led to higher estimated accuracies than selection of top individuals; however, estimated accuracies over predicted true accuracies with random genotyping but under predicted true accuracies with the selection of top individuals. When forward validation was evaluated within simulation, results suggested DEBV led to less biased estimates of MBV accuracy.
59 The Genetic Basis of Natural Antibody Titers and Relationships with Disease Resilience in Pigs
Authors: Chen Yulu , Laura Laura , Ashley Carolyn , Putz Austin M , Lim Kyu-Sang , Dyck Michael , Fortin Frederic , Plastow Graham S , Dekkers Jack C M , Harding John C S
Published: July 2019

Disease resilience is the ability of an animal to maintain performance under pathogen exposure but is difficult to select for because breeding populations are raised in biosecure, high-health facilities. Selection for resilience requires an indicator trait that is easy to measure on healthy young animals, heritable, and genetically correlated with resilience. Our objective was to investigate circulating Natural Antibody (NAb) levels as potential indicators for disease resilience in pigs. Data were from a natural polymicrobial disease challenge, in which batches of 60–75 weaned LWxLR barrows were sourced every three weeks (28 batches, 1799 pigs) from healthy multipliers. NAb and total IgG were evaluated by indirect ELISA in blood samples collected around 35 d of age. Disease resilience data were collected until pigs reached market age. All pigs were genotyped on a 650k panel. Genetic parameters were estimated by univariate and bivariate analyses in ASReml4. Single-marker and Bayesian variable selection methods were used for GWAS. Heritability estimates were lower for IgG NAb (0.03–0.22) than for IgM NAb (0.24–0.42) but maternal effects were larger for IgG (0.49–0.58) than for IgM (0.04–0.12). Phenotypically, IgM titers correlated with each other (0.26–0.71), as did IgG titers (0.40–0.81), but correlations between IgM and IgG were low (0.00–0.13). Genetic correlations showed similar patterns, ranging from 0.44–0.99, 0.45–0.84, and -0.30–0.25 for IgG, IgM, and IgG/IgM, respectively. Genetically, higher levels of NAb tended to be associated with fewer treatments, lower mortality, higher finishing ADG, and lower day-to-day fluctuations in feed intake but SE were large. Phenotypically, pigs that reached market age had significantly higher levels of IgG NAb than pigs that died. GWAS identified several genomic regions for NAb levels. In conclusion, levels of circulating NAb in healthy young piglets are potential indicators of polymicrobial disease resilience. Funded by Genome Canada and Alberta, and by USDA-NIFA.
67 Structural conformation differences between show pigs and commercial genetic lines
Authors: Obermier Dalton R , Peppmeier Zack , Knauer Mark
Published: July 2019

Structural conformation differences between show pig and commercial genetic linesD.R. Obermier, Z.C. Peppmeier, M.T. Knauer North Carolina State University, Raleigh.The objective was to compare the structural conformation of pigs sired by boars from the show pig industry to those sired by modern commercial genetic lines. Data included 174 male pigs from 16 sires and 50 dams. Pigs were sired by Large White (LW) show pig sires (SHOW) or one of two maternal LW commercial genetic lines (W or P). Dams of all pigs evaluated were from line P. Pigs were reared in barns (0.74 m2 per pig) with natural ventilation and totally slatted concrete flooring. Two technicians visually evaluated pigs at five months of age for front leg side view (FSIDEVIEW), rear pastern angle (RPASTERN), rib width (RIB) and locomotion (LOCO). The traits FSIDEVIEW and RPASTERN were scored on a seven point scale where one was soft pasterns, four was normal and seven was buck-kneed and straight pasterns, respectively. Rib width was scored on a five point scale with five being wide ribbed. Locomotion was scored on a seven point scale where one was ideal. Correlations between technicians for FSIDEVIEW, RPASTERN, RIB and LOCO were 0.54, 0.66, 0.77 and 0.72, respectively. Males sired by SHOW had lower (P < 0.01) FSIDEVIEW scores than those sired by W or P (2.2 vs. 3.3 and 3.6, respectively) and softer (P < 0.05) RPASTERN (3.4 vs. 3.8 and 4.2, respectively). Rib width was wider (P < 0.01) for SHOW when compared to W or P (3.7 vs. 2.6 and 2.4, respectively) Locomotion was superior (P < 0.01) for SHOW when compared to W or P (2.6 vs. 3.4 and 3.6, respectively). Line W had lower (P < 0.05) FSIDEVIEW and RPASTERN than P. Yet RIB and LOCO did not differ (P > 0.05) between W and P. Results suggest pigs sired by SHOW had softer pasterns, greater rib width and superior locomotion when compared to those sired by commercial genetic lines.
74 Effects of dietary soy isoflavone supplementation on carcass cutability and meat quality of pigs infected with porcine reproductive and respiratory virus
Authors: Bryan Erin , Smith Brooke N , Honegger Lauren T , Boler Dustin D , Dilger Ryan , Dilger Anna C
Published: July 2019

The objective was to evaluate the effects of porcine respiratory and reproductive syndrome virus (PRRSV) infection and dietary soy isoflavone supplementation on carcass cutability and meat quality of commercial pigs. Barrows were randomly allotted to experimental treatments that were maintained throughout the study: non-infected pigs received an isoflavone-devoid control diet (NC, n = 22), and infected pigs received either the control diet (PC, n = 20) or that supplemented with total ISF in excess of 1,600 mg/kg (ISF, n = 25). Following a 7-d adaptation, weanling pigs were inoculated intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). At 1 d postmortem (192–194 days of age; approximately 120kg BW), left sides were separated between the 10th and 11th rib for determination of loin eye area (LEA), backfat thickness (BF), and loin quality (ultimate pH, instrumental color, drip loss, visual color, marbling, and firmness). Loin chops were aged 14 d postmortem prior to Warner-Bratzler shear force (WBSF) determination. Belly width, length, thickness, and flop distance were determined. Data were analyzed as a one-way ANOVA with a model including effects of PRRSV status and dietary treatment, and also with single-df pre-determined contrasts to compare NC and PC (infection status) and PC and ISF (ISF effect within infected pigs). Carcass yield, LEA, BF, and estimated lean percentage did not differ (P > 0.26) among treatments. Loins from NC pigs had increased ultimate pH (P = 0.01), reduced L* scores (P = 0.005) coupled with darker visual color scores (P = 0.004), were firmer (P < 0.0001), and reduced drip loss (P = 0.01) compared with PC and ISF pigs. However, WBSF did not differ (P = 0.51) among treatments after 14 d of aging. Bellies from NC pigs were more firm compared with bellies from PC and ISF pigs (P < 0.01). These data suggest PRRSV infection and soy isoflavone supplementation do not alter carcass characteristics but may marginally reduce loin and belly quality.
80 Determining the effects of tryptophan biomass on growth performance of 11 to 23 kg nursery pigs
Authors: Wensley Madison R , Woodworth Jason C , DeRouchey Joel M , Dritz Steve S , Tokach Mike D , Goodband Robert D , Haydon Keith D
Published: July 2019

A total of 320 barrows (DNA 200×400, initially 11.3 ± 0.65 kg BW) were used in a 21-d growth trial evaluating the effects of feeding Trp biomass (CJ America-Bio, Downers Grove, IL) as a source of Trp on nursery pig performance. Pigs were weaned at approximately 21 d of age, placed in pens based on initial BW, and fed a common diet. On d 21 after weaning, pigs were weighed and pens were allotted to 1 of 4 dietary treatments with 5 pigs/pen and 16 replicates/treatment. Dietary treatments included a negative control (16% SID Trp:Lys), positive control (21% SID Trp:Lys from crystalline L-Trp), or diets containing Trp biomass to provide 21 or 23.5% SID Trp:Lys (included at 0.104 or 0.156% of the diet, respectively). Diets were corn-soybean meal based and contained 1.25% SID Lys with other AA set to meet or exceed NRC (2012) requirement estimates. The Trp biomass contained 69% Trp. Growth data were analyzed as a randomized complete block design using PROC GLIMMIX of SAS with pen as the experimental unit. Overall (d 0 to 21) pigs fed 21% Trp from L-Trp or Trp biomass had increased (P < 0.05) ADG compared to the control, with pigs fed the 23.5% SID Trp biomass intermediate. Pigs fed the 21% Trp from Trp biomass had improved (P < 0.05) G:F compared to the control with others intermediate. In conclusion, Trp biomass is a viable alternative to crystalline Trp, but further evaluation at higher inclusion levels is needed.
78 Low allergenic full fat soybean as a suitable replacement for fishmeal in weaned pig diets
Authors: Zeamer Katelyn M , Samuel Ryan S , Thaler Robert C , Woyengo Tofuko A , Levesque Crystal L
Published: July 2019

This study evaluated a low allergen (P34 protein) and low anti-nutritional factor (trypsin inhibitor and lectin) in both soybean meal form (LASBM) and full fat ground soybean form (LAGR) as substitutes for fishmeal (FM) in nursery pig diets based on growth performance. Weaned pigs (n = 112; 7.30 ± 0.43 kg BW) were allotted to 28 pens (2 barrows and 2 gilts per pen) by initial BW. Pens (n = 7/diet) were randomly assigned to one of 4 dietary treatments in 2 phases (Ph1 = 5d, Ph2 = 13d): control diet containing FM (7.25%, Ph1; 6%, Ph2), and LASBM, LAGR or conventional SBM substituted for FM to supply an equivalent portion of crude protein. Pigs received a common Ph3 diet (18 d). Pig weight and feed disappearance was determined by phase. Data was analyzed as a one-way ANOVA. Model included main effect of diet with pen as experimental unit. In Ph1, pigs fed FM had lower (P < 0.01) ADG than LAGR or SBM and lower (P < 0.01) ADFI than all diets. In Ph2, SBM-fed pigs had higher (P < 0.01) ADG and ADFI compared to all treatments. Pigs previously fed LAGR tended to have higher gain (P < 0.10) than pigs previously fed LASBM in Ph3. There were no differences in gain:feed between diets. Based on growth performance, LAGR would be suitable replacement for FM in nursery diets.
85 Effects of feed removal on body temperature and intestinal morphology in pigs recovering from acute hyperthermia
Authors: Kpodo Kouassi R , Duttlinger Alan W , Aardsma Matthew P , Maskal Jacob M , Johnson Jay S
Published: July 2019

Feed consumption increases body temperature and may delay a return to euthermia and exacerbate intestinal injury following acute hyperthermia recovery in pigs. The study objective was to evaluate the effects of feed removal on body temperature, feeding behavior, and intestinal morphology in pigs exposed to acute hyperthermia and then cooled. Twenty-four gilts (78.53 ± 5.46 kg) were exposed to thermoneutrality (TN; n = 12 pigs; 21.21 ± 0.31°C) for 6 h, or heat stress (HS; 38.51 ± 0.60°C) for 3 h followed by a 3-h recovery period of cooling (HSC; n = 12 pigs; water dousing and TN conditions). Within each temperature treatment, half the pigs were provided feed (F; n = 6 pigs/temperature treatment) and half were not provided feed (NF; n = 6 pigs/temperature treatment). Gastrointestinal (TGI) and vaginal (TV) temperature were recorded every 15 min and pigs were video-recorded to assess feeding behavior. Immediately following the 6 h period pigs were euthanized, and intestinal samples were collected for histology. During the HS period, Tv and TGI were increased overall (P < 0.01; 1.63°C and 2.05°C, respectively) in HSC vs. TN pigs, regardless of feeding treatment. A temperature by feeding treatment by time interaction was detected during the recovery period where TGI was greater (P = 0.03; 0.97°C) for HSC+F compared to HSC+NF pigs from 45–180 min. Feeding behavior was greater overall (P = 0.02; 223.14%) in F vs NF pigs, regardless of temperature treatment. A decrease (P < 0.01) in jejunum and ileum villus height (24.72% and 26.11%, respectively) and villus height to crypt depth ratio (24.40% and 25.52%, respectively) was observed in HSC vs TN pigs, regardless of feeding treatment. Ileum goblet cells were reduced (P = 0.01; 37.87%) in HSC vs TN pigs, regardless of feeding treatment. No other differences were detected for any parameter. In summary, TGI decreased more rapidly following acute hyperthermia when feed was removed.
87 Bacterial communities of the uterus and vagina between resulting pregnant and non-pregnant postpartum beef cows
Authors: Ault Taylor B , Clemmons Brooke A , Reese Sydney T , Franco Gessica A , Dantas Felipe G , Schneider Liesel G , Smith Timothy P L , Edwards J L , Myer Phillip R , Pohler Ky G
Published: July 2019

The prevalence of reproductive losses costing 1 billion dollars annually to the beef and dairy industries has led researchers to evaluate strategies to improve reproductive efficiency. The microbiome of the reproductive tract has been a recent focus in humans due to its effects on health and fertility; however, little research has evaluated the uterine and vaginal microbiomes of cattle. The present study evaluated the reproductive tract bacterial communities of postpartum beef cows undergoing estrus synchronization and the differences between cows who became pregnant and those who failed to conceive. Forty postpartum Angus cows were subjected to a 7 Day Co-Synch protocol with a pre-synchronization step 21 days prior (day -21) to artificial insemination (AI). Uterine and vaginal flushes were collected on day -21, -9, and -2 of the protocol for pH and bacterial DNA extraction to sequence the V1-V3 hypervariable regions of the 16S rRNA gene. Transrectal ultrasound was performed 30 days after AI for pregnancy diagnosis. Ten pregnant and non-pregnant animals were selected and used for analysis. Decreased numbers of bacterial species present in the uterus of cows were identified, independent of pregnancy status, leading up to AI with an average of 1180 ± 97 species on day -21 to 427 ± 99 on day -2 (P < 0.0001). Principal coordinate analyses depicted significant clustering of bacterial communities by day in the uterus (P = 0.001) and vagina (P = 0.001) as well as pregnancy status in the uterus at day -2 (P = 0.005). Additionally, at day -2, multiple significantly different uterine bacterial genera were present at >1% in non-pregnant cows while present at <1% in pregnant cows. Uterine pH increased in non-pregnant cows but decreased in pregnant cows. In summary, the results suggest uterine bacterial abundances prior to AI may influence the uterine environment and reproductive outcomes.
88 Effects of cattle breed, Holstein versus Angus, and corn grain processing on diet digestibility and ruminal pH
Authors: Carvalho Pedro , Felix Tara , Silva Flavia Sales
Published: July 2019

Objectives were to evaluate impacts of breed and corn processing on digestibility of DM and starch, and on ruminal pH over time. Cannulated Holstein (n = 6) and Angus (n = 6) steers (BW = 571 ± 39 kg) were assigned into 1 of 3 treatments: Whole corn, cracked corn, or ground corn. All diets contained 81.5% corn, 6.5% soybean meal, 10.0% grass hay, and 2% vitamin/mineral supplement (DM basis), steers were fed ad libitum. Treatments were fed in a 3x3 replicated Latin square split plot design. Each period consisted of 21 d, 14 d diet adaptation followed by 7 d of sample collection. On d 1 of the collection period, rumen contents were sampled to measure ruminal pH at 0, 3, 6, 12, and 18 h after feeding. From d 2 to 7 of the collection period, total fecal excretion, feed, and refusal were collected and frozen. Samples were composited by steer within period and analyzed for DM and starch. Data were analyzed using the MIXED procedures in SAS (v9.4 SAS Inst. Inc., Cary, NC). Repeated measures were used to analyze changes in ruminal pH over time. There were no interactions of treatment by breed (P > 0.51) on DMI, or DM and starch digestibility. Holstein steers had a greater (P = 0.03) DMI than Angus steers, regardless of treatment. Digestibility of DM was least (P < 0.01) when corn grain was fed whole, regardless of breed. Compared to feeding whole corn, starch digestibility improved 2.17% when corn grain was fed cracked or 3.44% when corn grain was fed ground. There was a treatment by breed interaction (P < 0.01) for mean ruminal pH. Mean ruminal pH of Angus steers had a linear decrease as corn processing increased. However, mean ruminal pH was less variable among Holstein steers, regardless of diet. Angus steers were less able to maintain a greater ruminal pH than Holstein steers as processed corn was fed, even though Holsteins ate more grain.
90 The influence of supplemental zinc, zinc source, and dietary energy level on performance measures of beef steers
Authors: Carmichael Remy N , Hansen Stephanie L , Genther-Schroeder Olivia
Published: July 2019

The objective was to determine if steer performance improved with supplemental Zn above recommended concentrations with increasing growth rate. Angus steers (n = 72; 324 ± 2.1kg BW) were blocked by BW within growing diets to one of three Zn strategies (ZNTRT) 1) no supplemental Zn (analyzed 36 mg Zn/kg DM; CON), 2) supranutritional Zn as ZnSO4(CON + 120 mg Zn/kg DM; INZN), or 3) supranutritional Zn blend (CON + 60 mg Zn/kg as ZnSO4 + 60 mg Zn/kg as Zn-amino acid complex; ZNBLD) fed for 60 d, then assigned to dietary energy strategies (ENERGY) targeting growth rates of 1.6 (LOW) or 2 kg/d (HI). On d 60, HI steers were transitioned for 7 d and all animals received respective treatments for an additional 91 d finishing period (n = 12). Data were analyzed as a 3×2 factorial in Proc Mixed of SAS with block as fixed effect; steer was experimental unit. After 60 d of dietary treatment BW tended to be greater in Zn-fed steers vs. CON (P = 0.07). Finishing DMI within HI was similar between INZN and ZNBLD, which were greater than CON, while within LOW no differences were detected due to ZNTRT (ZNTRT×ENERGY; P = 0.01). Neither ZNTRT×ENERGY nor ZNTRT effects (P ≥ 0.37) were detected for finishing ADG, HCW, marbling score, yield grade or backfat. However, finishing period ADG, hot carcass weight, marbling score, yield grade, and back fat were greater in HI vs. LOW (P ≤ 0.05). Plasma NEFA concentrations were lesser for steers receiving HI vs. LOW (P = 0.02), while BUN was unaffected by ZNTRT or ENERGY (P ≥ 0.42). Steer performance was influenced by supranutritional Zn and dietary energy.
96 Effect of 30% wet brewer’s grain inclusion on the growth and carcass performance of finishing cattle
Authors: Belon Danielle , Earing Jennifer , Rickard Justin
Published: July 2019

The objective of this study was to determine the effect of wet brewer’s grain (WBG) inclusion on the growth and carcass performance of finishing cattle. Forty-eight (n = 48; 30 steers [414 kg] and 18 heifers [373 kg]) Simmental-Angus beef calves were finished at the Illinois State University Farm. Calves were blocked by weight within sex, randomly assigned to one of two dietary treatments, and fed for 119 or 154 days in a 2 x 2 x 2 factorial arrangement. Dietary treatments included a corn silage-whole shelled corn finishing diet (CON) and CON + 30% WBG for the first half of the finishing period (WB). Diets were mixed daily and feed was offered once daily. Daily feed offered was adjusted based on biweekly bunk scores and feed refusal data collected every 7 d. Two-day weights were taken every 28 days, averaged, and used to calculate Average Daily Gain (ADG), Average Daily Feed Intake (ADFD), and Gain to Feed (G:F). Cattle were visually appraised for degree of finish by an industry procurement agent, and transported 159km in two groups (119 and 154 days on feed (DOF); average final body weight of 620kg) for processing under USDA-FSIS inspection. Following slaughter, standard USDA carcass data (quality and yield grade) were collected. Statistical analysis was performed utilizing the MIXED procedure of SAS. Feeding WBG improved final live weight (P = 0.008), ADG (P = 0.039), and G:F (P = 0.005) regardless of days on feed. Following WBG inclusion, hot carcass weight increased at 154 DOF (P = 0.0071). Dressing percentage, ribeye area, 12th Rib Fat thickness, marbling score, and yield grade were not significantly impacted by treatment (P > 0.05). In this study, early inclusion of WBG supported growth and carcass performance; however, additional research examining performance differences based on DOF is warranted.
99 Effects of replacing monensin and tylosin in finishing cattle diets with essential oil and/or benzoic acid on meat color and oxidative stability of ribeye steaks and ground beef
Authors: Wang Lydia M , Huang Shiqi , Chalupa-Krebzdak Sebastian , Vasquez Mejia Sandra M , Bohrer Benjamin M
Published: July 2019

This study examined the effects of replacing monensin and tylosin with essential oils and/or benzoic acid in finishing cattle diets on beef color stability and lipid oxidation during a simulated retail display period. The longissimus thoracis (LT) and semimembranosus (SM) muscles were obtained from 63 steers that were fed for 98 days on 1 of 5 finishing diets: no additional supplement (CON), monensin/tylosin (M/T), essential oils (EO), benzoic acid (BA), or a combination of essential oils and benzoic acid (COMBO). Instrumental color measured with a Minolta colorimeter and visual discoloration evaluated by two trained panelists were recorded daily for three beef products placed under simulated retail conditions, until a 60% surface discoloration was observed. The three beef products evaluated were LT steaks, and two types of ground beef patties manufactured with the SM muscles (lean – no additional fat and regular – 25% added fat). The thiobarbituric acid reactive substances (TBARS) assay was used before and after the shelf life display to determine the degree of lipid oxidation for products during the display. Data were analyzed as a randomized complete block design with the GLIMMIX procedure of SAS using repeated measures. Results indicated a treatment by day interaction (P < 0.0001) for visual discoloration and instrumental color of all three products. At the end of the display period, products from the COMBO diet had on average the least amount of visual discoloration and the greatest a* (redness) value, while the CON steaks and M/T ground beef had the most discoloration and the lowest a* values. TBARS values at d 0 and d 7 did not differ (P > 0.23) among treatments for all three products. Overall, supplemental ingredients in feed did not affect the color and degree of lipid oxidation of steaks and ground beef to a level deemed detrimental.
374 Metabolic response of pigs to Porcine Reproductive and Respiratory Syndrome virus infection and nutrient restriction
Authors: Helm Emma T , Curry Shelby , Schweer Wesley , De Mille Carson , Burrough Eric R , Zuber Elizabeth , Lonergan Steven , Gabler Nicholas K
Published: July 2019

Porcine reproductive and respiratory syndrome (PRRS) virus is one of the most economically significant pig pathogens worldwide. The virus infects pigs at all production stages and significantly reduces the tissue accretion of growing pigs. However, the metabolic explanation for these reductions in tissue accretion remain poorly defined. Additionally, PRRS virus infection is often accompanied by reductions in feed intake, making it difficult to discern which effects are virus versus feed intake driven. To account for this, a pair-fed model was employed to examine the effects of PRRS infection and nutrient restriction on skeletal muscle and liver metabolism. Forty-eight pigs were randomly selected (11.34 ± 1.54 kg BW) and allotted to 3 treatments (n = 16 pigs/treatment): 1) PRRS naïve, ad libitum fed (Ad), 2) PRRS-inoculated, ad libitum fed (PRRS+), and 3) PRRS naïve, pair-fed to the PRRS-inoculated pigs’ daily feed intake (PF). At dpi 10 and dpi 17, 8 pigs per treatment were euthanized and tissues collected. Tissues were assayed for markers of proteolysis [longissimus skeletal muscle (LM) only], oxidative stress (LM only), and glycogen levels (LM and liver). Markers of LM proteolysis (calpain, 20s proteasome, caspase 3/7 activities) and mitochondrial reactive oxygen species production did not differ (P > 0.10) between treatment groups at either timepoint. Liver glycogen stores were reduced (P < 0.001) in PRRS+ pigs compared with both Ad and PF pigs, which did not differ from each other. Muscle glycogen did not differ (P > 0.10) between treatment groups. However, liver glycogen stores were completely depleted due to PRRS+, but not pair-feeding, indicating that liver glycogen stores and glucose are preferentially utilized by pigs to produce and support immune components. These data suggest that even under severe viral challenge and feed restriction, the pig does not upregulate LM proteolysis to re-allocate nutrients to fuel the immune response.