bluuebunny/crossref_metadata_2025 huggingface dataset:
13 Innovative Strategies for Managing Swine Welfare During Natural Disasters
Authors: Johnson Anna K , Rademacher Christopher , Eggers Jamee , Gabler Nicholas K , Greiner Laura L , Kaisand Jeffery , Millman Suzanne , Patience John , Schulz Lee , Webb Sherrie , Ross Jason W
Published: October 2021

Coronavirus Disease 2019 (COVID-19) was declared a global pandemic on March 11, 2020, by the World Health Organization. By April 2020, COVID-19 resulted in the simultaneous closure or reduced operations of many processing plants in the upper Midwest, which quickly resulted in supply chain disruptions. Iowa is the leading pork production and processing state, and these disruptions caused producer uncertainty, confusion, and stress, including time-sensitive challenges for maintaining animal care. The Resource Coordination Center (RCC) was quickly created and launched from the Iowa Department of Agriculture and Land Stewardship. The RCC had strategic collaborations with public representation from the Iowa Pork Producers Association, Iowa Pork Industry Center, and Iowa State University Extension and Outreach, and private partners through producers, veterinarians, and technical specialists. The RCC’s mission was four-fold: (1) implement appropriate actions to ensure the health and safety of RCC members, stakeholders, and the public, (2) evaluate and reassess appropriate actions as needed for continuity of pork production operations, (3) provide information to pork producers during supply chain disruptions, and (4) maintain a safe and abundant pork supply for consumers. The command structure included Incident Commanders, Command Staff, and four Section Chiefs whom worked with their respective experts. Sections covered (1) operations, (2) planning, (3) logistics, and (4) finance and administration. As it related to animal welfare, the RCC provided information on management decisions, dietary alterations to slow pig growth, pig movement to increase living space, alternative markets, on-farm euthanasia and mass depopulation. Veterinary oversight was continually maintained. A manual was created to provide up-to-date information to inform producer decisions and aid. Although originally created for swine, the RCC also assisted poultry, cattle and sheep producers. In a crisis, Iowa created a model that reacted to producer’s pragmatic and emotional needs. This model could be replicated for any emergency by other states.
16 Identification of Structural Variants Associated with Mastitis in Holstein Dairy Cows Using Whole Genome Sequencing and RNA-sequencing
Authors: Asselstine Victoria , Medrano Juan F F , Muniz Malane M M , Cánovas Angela
Published: October 2021

For the dairy industry, animal welfare and economic viability are key factors in determining the long-term sustainability of the industry. One challenge in lactating dairy cows is mastitis, as there are significant costs associated with each mastitis case due to treatment, milk loss, and potential cow culling. Differentially expressed (DE) genes, DE mRNA isoforms and DE long non-coding RNA (lncRNA) candidates were previously identified by our group between healthy and mastitic samples from six Holstein dairy cows. In total, 7 candidate genes, 5 mRNA isoforms and 4 lncRNA were targeted as they play an important role due to their association with mastitis or the immune system. The aim of the current research is to identify new structural variants in the transcriptome of these previously identified potential candidates using RNA-Sequencing. These structural variants could occur in both coding and intergenic regions of the genome and potentially impact the amino acid that is transcribed, creating a new functional or non-functional protein. In addition, whole genome sequencing (WGS) analysis was performed using hair samples collected from ten Holstein dairy cows (first lactation). Five of these animals had no previous reports of mastitis and five animals had at least one report of mastitis in her lifespan. The WGS results will be used to identify additional structural variants, especially within introns, of the previously identified candidates that could cause a genetic variation in individuals and an association to their susceptibility to mastitis disease.
23 Exploring the Role of Gut Microbiota in Host Feeding Behavior Among Breeds in Swine
Authors: He Yuqing , Tiezzi Francesco , Howard Jeremy T , Huang Yijian , Gray Kent A , Maltecca Christian
Published: October 2021

The present study aimed to explore gut microbiota’s overall influence on feeding behavior and identify specific microbes associated with the traits in three commercial swine breeds at different growth stages. Feeding behavior measures were obtained from 651 pigs of three breeds (Duroc, Landrace, and Large White) from 67 to 175 days of age. Seven feeding behavior traits cover the information of feed intake, feeder occupation time, feeding rate, and the number of visits to the feeder. Rectal swabs were collected from each pig at 73 ± 3, 123 ± 4, and 158 ± 4 days of age. DNA was extracted and subjected to 16S rRNA gene sequencing. Sequences were analyzed using the QIIME2. The amplicon sequence variant table was constructed using the DADA2. Mixed linear models were used to perform statistical analyses. Differences in feeding behavior traits among breeds and across time periods were found. The proportion of phenotypic variances explained by the microbiome ranged from 0.10 to 0.26, 0.14 to 0.25, and 0.12 to 0.28 in Duroc pigs, from 0.09 to 0.20, 0.10 to 0.23, and 0.12 to 0.23 in Landrace pigs, from 0.10 to 0.17, 0.11 to 0.19, and 0.10 to 0.31 in Large White pigs at three time points, respectively. A total of 21, 10, and 35 amplicon sequence variants were found to be significantly (q-value < 0.05) associated with feeding behavior traits for Duroc, Landrace, and Large White across three time points. This study demonstrated the importance of the gut microbiome composition in influencing the host feeding behavior and identified multiple microbes associated with the feeding behavior of pigs from either Duroc, Landrace, or Large White breeds at three growth stages. Our study provides insight into the interaction between gut microbiota and feeding behavior and highlights the breed effects in swine microbial studies.
28 Optimal Definition of Contemporary Groups for Crossbred Pigs in a Joint Purebred and Crossbred Genetic Evaluation
Authors: Steyn Yvette , Lourenco Daniela , Chen Ching-Yi , Valente Bruno , Holl Justin W , Herring Willian O , Misztal Ignacy
Published: October 2021

In the pig industry, purebred animals are raised in nucleus herds and selected to produce crossbred progeny for commercial environments. Crossbred and purebred performances are different, correlated traits. All purebreds in a pen are assessed together at the end of a performance test. However, only selected crossbreds are removed (based on visual inspection) and measured at different times, creating many small contemporary groups (CG). This may reduce EBV prediction accuracies. Considering this sequential recording of crossbreds, the objective was to investigate the impact of different CG definitions on genetic parameters and EBV prediction accuracy for crossbred traits. Growth rate (GP) and ultrasound backfat (BFP) records were available for purebreds. Lifetime growth (GX) and backfat (BFX) were recorded on crossbreds. Different CG were tested: CG_all included farm, sex, birth year and birth week, CG_week added slaughter week, and CG_day used slaughter day instead of week. Data of 124,709 crossbreds were used. The purebred phenotypes (62,274 animals) included 3 generations of purebred ancestors of these crossbreds and their CG mates. Variance components for 4-trait models with different CG definitions were estimated with AIREML. Purebred traits’ variance components remained stable across CG definitions and varied slightly for BFX. Additive genetic variances (and heritabilities) for GX fluctuated more: 812±36 (0.28±0.01), 257±15 (0.17±0.01) and 204±13 (0.15±0.01) for CG_all, CG_week, and CG_day, respectively. The predictive ability, linear regression (LR) accuracy, bias, and dispersion of crossbred traits in crossbreds favored CG_day, but correlations with unadjusted phenotypes favored CG_all. In purebreds, CG_all showed the best LR accuracy, while showing small relative differences in bias and dispersion. Different GC scenarios showed no relevant impact on BFX EBV. This study shows that different CG definitions may affect evaluation stability and ranking. Results suggest that ignoring slaughter dates in CG is more appropriate for estimating crossbred trait EBV for purebred animals.
35 Detecting Effective Starting Point of Genomic Selection by Divergent Trends from BLUP and ssGBLUP
Authors: Abdollahi-Arpanahi Rostam , Lourenco Daniela , Misztal Ignacy
Published: October 2021

Genomic selection has been adopted nationally and internationally in different livestock and plant species. However, understanding whether genomic selection has been effective or not is an essential question for both industry and academia. Once genomic evaluation started being used, estimation of breeding values with pedigree BLUP became biased because this method does not consider selection using genomic information. Hence, the point of divergence of genetic trends obtained with BLUP and Single-step genomic BLUP (ssGBLUP) may indicate the start date of genomic selection. This study aimed to find the start date of genomic selection for a set of economically important traits in pigs and Angus cattle by comparing genetic and Realized Mendelian sampling (RMS) trends obtained using BLUP and ssGBLUP. In pigs, the genetic trends from ssGBLUP and BLUP diverged for all traits with different intensity. In beef cattle, the trends started diverging in 2009 for weaning weight and in 2016 for postweaning gain, with little divergence for birth weight. In pigs, the RMS trends from ssGBLUP and BLUP diverged strongly for one trait and weakly for another trait. In beef cattle, the RMS trends started diverging in 2009 for weaning weight and in 2016 for postweaning gain, with little trend for birth weight. Divergence of the genetic trends from ssGBLUP and BLUP indicate onset of the genomic selection. Presence of trends for RMS indicates selective genotyping, with or without the genomic selection. The onset of genomic selection and genotyping strategies agree with industry practices across the two species. In summary, the effective start of genomic selection can be detected by the divergence between genetic and RMS trends from BLUP and ssGBLUP.
48 Genomic Studies of Feed Efficiency and Component Traits in American Mink
Authors: Davoudi Pourya , Ngoc Do Duy , Hu Guoyu , Ardestani Siavash Salek , Miar Younes
Published: October 2021

Feed costs are the largest expense in mink production systems. Therefore, improvement of feed efficiency (FE) is the best way to use limited resources efficiently and increase the mink industry’s sustainability. The objectives of this project are to 1) identify the genetic relationships among different FE measures and their component traits, and 2) discover the genetic architecture of FE and implement genomic selection for FE traits to increase the genetic gain in American mink. Final body weight (FBW), final body length (FBL), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR), residual feed intake (RFI), residual gain (RG), residual intake and gain (RIG) and Kleiber ratio (KR) traits were measured based on the phenotypic records on 1,088 American mink from the Canadian Center for Fur Animal Research (Nova Scotia, Canada). Univariate models were applied to test the significance of sex, color type, age, and nested Row(Year) as fixed effects and random maternal effect. Genetic parameters were estimated via bivariate models using ASReml-R 4. Estimated heritabilities (±SE) were 0.38±0.10, 0.36±0.10, 0.25±0.10, 0.34±0.09, 0.38±0.08, 0.37±0.07, 0.29±0.10, 0.32±0.10 and 0.34±0.10 for FBW, FBL, DFI, ADG, FCR, RFI, RG, RIG and KR, respectively. RFI showed non-significant (P >0.05) genetic correlations with component traits such as FBW (0.00±0.17) and FBL (0.30±0.16) but significant (P < 0.05) high genetic correlation with DFI (0.74±0.09), indicating that selection based on RFI will reduce the feed intake without any negative effects on the size and growth. The estimated genetic parameters for FE traits suggested the possibility to implement genetic/genomic selection to improve the FE in American mink. Consequently, the ongoing project on genetic mapping and genomic selection will enhance the knowledge of FE and improve the efficacy of selection for more feed-efficient mink.
501 Late-Breaking: Search for Genomic Associations with Cryo-resistance of Sperm in Animals
Authors: Nikitkina Elena , Dementieva Natalia , Shcherbakov Yuyriy , Krutikova Anna , Musidray Artem , Pleshanov Nikolay , Samoylov Oleg
Published: October 2021

Genetic resistance to sperm cryopreservation is an important factor in the sires selection. In our study, we studied the cryoresistance of the sperm in Gallus gallus, Bos taurus, Equus ferus caballus. Sperm quality was assessed using computer-assisted semen analysis (CASA). Genetic studies were performed using Affymetrix Axiom®600k Array chips for cocks, Affymetrix Axiom®600k Array for stallions and BovineSNP50 for bulls. For the analysis of genotypes, the GWAS (Genome-Wide Association Studies) was used. The calculations were carried out using the PLINK and EMMAX programs. The candidate genes found as a result of our work were compared with the functions of orthologous genes, according to the publications of other researchers. As a result of comparing different animal species, a common candidate gene was found, localized on chromosome 3 (Gallus gallus) and on BTA9 (Bos taurus) BCKDHB gene encodes the beta subunit E1 of branched chain keto acid dehydrogenase, which is a multienzyme complex associated with the inner membrane of mitochondria. In roosters, it was associated with the preservation of sperm motility after cryopreservation, and it was found in the analysis of the integrity of the sperm head in bulls. The functioning of genes associated with meiosis and sperm maturation is an important condition for maintaining its quality after freezing. The work of genes responsible for the formation of membranes and various cellular structures associated with the functions of spermatozoa is also an important factor in cryoresistance. Another important condition for the functioning of the sperm is the expression of genes that prepare the sperm for fertilization. These are calcium metabolism genes involved in preparation for capacitation. Changes in the structure of proteins can lead to premature capacitation and disruption of sperm integrity. The found molecular genetic markers will be used to select sires whose sperm are suitable for freezing. Project of RSF № 18-16-00071.
43 Single and Multiple-breed Genomic Predictions for Conformation Traits of Canadian Dairy Goats
Authors: Massender Erin , Brito Luiz F , Maignel Laurence , Oliveira Hinayah R , Jafarikia Mohsen , Baes Christine F , Sullivan Brian , Schenkel Flavio S
Published: October 2021

The use of multiple-breed models can increase the accuracy of estimated breeding values (EBV) when few phenotypes are available for a trait. However, pooling breeds is not always beneficial for genomic evaluations due to the low consistency of gametic phase between individual breeds. The objective of this study was to compare the expected gain in accuracy of single-step genomic breeding values (GEBV) for conformation traits of Canadian Alpine and Saanen goats predicted using single and multiple-breed models. The traits considered were body capacity, dairy character, feet and legs, fore udder, general appearance, rear udder, suspensory ligament, and teats, all recorded by trained classifiers, using a 1 to 9 scale. The full datasets included a total of 7,500 phenotypes for each trait (5,158 Alpine and 2,342 Saanen) and 1,707 50K genotypes (833 Alpine, 874 Saanen). Standard errors of prediction (SEP) were obtained for EBV and GEBV predicted using single-trait animal models on full or validation datasets. Breed difference was accounted for as a fixed effect in the multiple-breed models. Average theoretical accuracies were calculated from the SEP. For Saanen, with fewer records, expected accuracies of EBV and GEBV for the validation animals (selection candidates) were consistently higher for the multiple-breed models. Trait specific gains in theoretical accuracy of GEBV relative to EBV for the selection candidates ranged from 30 to 48% for Alpine and 41 to 61% for Saanen. Averaged across all traits, GEBV predicted from the full dataset were 32 to 38% more accurate than EBV for genotyped animals and the largest gains were found for does without conformation records (49 to 55%) and bucks without daughter records (56 to 82%). Overall, the implementation of genomic selection would substantially increase selection accuracy for young breeding candidates and, consequently, the rate of genetic improvement for conformation traits in Canadian dairy goats.
53 Awardee Talk: Implications of the Gut Microbiome for Genetic Improvement of Swine
Authors: Maltecca Christian , Tiezzi Francesco
Published: October 2021

With the universal adoption of genomic selection as a breeding standard, livestock farming is about to enter a new chapter in which deep phenotyping and multi-omics technologies will enhance the use of molecular data in the selection process. Microbiome composition represents a promising tool in this arena, serving simultaneously as a benchmark of environmental challenge, a predictor of animal physiological status, and a direct target for host selection. Our group has been researching the application of the gut microbiome in swine production, with a particular focus on growth and feed efficiency. We investigated how the microbiome is shaped in different production systems by comparing the microbiome composition of growing/finishing pigs raised in bio-secure nucleus farms and commercial facilities. Results suggested a strong impact of gut microbiome composition on pork production efficiency and a consistent effect of several microbial features across different systems. We found that microbial features associated with animal growth are heritable and identified host genomic markers contributing to their relative abundance. We have found that the microbiota composition is different across breeds but stable within breeds (Duroc, Large White, Landrace). Taxa differently represented among the breeds are also associated with feed efficiency and behavior. We estimated the ‘microbiability’ of meat and carcass quality traits. We found that the gut microbiome composition leaves an identifiable ‘footprint’ on the animal tissue deposition. Following these findings, we elucidated the complex relationship between genomic and microbial variation using structural equation modeling to test a causal path between the host genotype, the gut microbiome composition, and fat deposition. We identified direct and mediated (through microbiome) genomic variants affecting host trait expression, highlighting the potential for the ‘second genome’ to contribute to the recovery of genetic variance.
51 Opportunities to Apply and Learn from Deep Phenotyping in Dairy Cattle
Authors: Koltes James E
Published: October 2021

Data from automated systems including sensors, cameras and high-throughput assays, such as milk testing, generate huge amounts of valuable data for research and on-farm applications. The potential to use data collected from automated systems in real-time for predictive analytics or as indicator traits for genetic selection is an exciting opportunity for the dairy industry to address difficult phenotypes. While high frequency recording of data provides high-resolution views of animal behavior, it also creates logistical challenges for determining what data are most informative, when or if to use repeated measures, and how to integrate these repeated measurements with static or less frequently measured traits of interest. Measuring the precision and accuracy of data from automated systems is also a continued challenge. As feed is the largest cost on commercial dairy farms and intake is difficult to measure, our lab is investigating the use of different wearable and stationary sensors to monitor cow and environmental level measurements to determine their utility as potential indicators of variation in feed intake. Associations of sensor measures with feed intake and relationships with health events have been identified. Ongoing research is evaluating the ability to predict trait phenotypes with various sensor data. Beyond the potential to learning more about trait relationships and underlaying genetics of behavior, there is also the potential to develop precision management tools from sensors for producers. Integrating automated systems measurements with research data (e.g. omics) may help to fuel new discoveries and tool development. Future advances in sensing technologies will require transdisciplinary research to develop new types of sensor measures and data analytics to identify hidden information within the data that may lead to new actionable applications on farm.
66 Blood MicroRNAomes Revealed Signatures of Lameness Phenotypes in Feedlot Cattle
Authors: Li Wentao , O’Hara Eóin , Sun Hui-Zeng , Schwartzkopf-Genswein Karen S , Guan Leluo
Published: October 2021

Lameness is a significant health issue in Canadian feedlots resulting in substantial economic losses. However, the high frequency of misdiagnosis of lameness using traditional methods leads to ineffective treatment, suggesting a new diagnostic method is needed. Growing evidence indicates that microRNAs (miRNAs) can be used as biomarkers for identifying the animals’ physiological status and the diagnosis of certain diseases, but this approach has not been utilized in beef cattle. The objective of this study was to compare blood miRNA profiles between lame and healthy cattle to investigate the relationship between miRNA expression patterns and specific lameness phenotypes. Blood samples were collected from 156 feedlot cattle at 0, 1, 2 and 3 weeks after being diagnosed with either digital dermatitis (DD; n=62), toe tip necrosis syndrome (TTNS; n = 40), or footrot (FR; n = 40) and healthy controls (HC; n = 12) for miRNA libraries construction and sequencing. A total of 314 expressed miRNAs were identified in 89 blood samples collected at week 0 across all groups, with TTN having the largest number of expressed miRNAs (291, P < 0.01) compared to all other groups (HC=276, DD=281, FR=278). Although miRNA profiles did not differ among the lameness types, type-specific miRNAs were identified; 6 in DD, 10 in TTN, 5 in FR and 7 in HC cattle. In addition, 3, 6 and 7 DE miRNAs were detected in DD, TTNS and FR when compared with HC cattle. Most of the DE and group-specific miRNAs are related to inflammation and skin diseases. The DE miRNAs were different between week 0 and all other weeks, indicating miRNA profiles may differ over time and with disease progression and recovery. These findings provide an initial understanding of the relationship between the cattle blood miRNAome and lameness and suggest that miRNA expression holds promise in the discovery of novel biomarkers for identifying lameness.
85 Integrating Mechanistic Models with AI for Precision Feeding of Sows
Authors: Gaillard Charlotte , Gauthier Raphaël , Dourmad Jean-Yves
Published: October 2021

Conventional feeding for sows is usually based on the average herd’s nutrient requirements. Thus, sows can be under- or over- fed leading to extra feed costs and environmental losses. New technologies, as sensors and AI, bring opportunities to measure and integrate individual variability into nutrient requirements estimations. The objective is therefore to go towards precision feeding (PF) combining on-farm data as input for a dynamic nutritional model with smart feeders to provide individual and daily-adjusted rations. As a first step, a mechanistic model (InraPorc) was upgraded and applied to databases to calculate daily nutrient requirements at the individual scale for sows. For lactating sows, it highlighted that milk production and appetite influenced the amount and composition of the optimal ration to be fed to each sow. For gestating sows, it showed that parity, gestation stage, and activity level influenced nutrient requirements. The second step was to develop algorithms to predict the parameters of interest defined in the first step and not measured daily on-farm. For lactating sows, feed intake and litter weight at weaning (as proxy for milk production) were accurately predicted using supervised methods: respectively, clustering k-shape and a linear regression. For gestating sows, an algorithm is being developed to identify individual activities via video recordings. The third step is to test on farm the decision support systems (DSS) composed of the models and algorithms. An interface allows the link between the DSS and the feeders, and another allows the farmers to enter observational data. During on-farm trials, nitrogen and phosphorus excretions as well as feed costs were reduced for sows fed with PF compared to sows fed a conventional diet. To conclude, AI allows mechanistic models and algorithms to be integrated on farm for sows for an on real-time individual adjustment of the nutrient supply.
80 A Brief Overview, Comparison and Practical Applications of Machine Learning Models
Authors: Tulpan Dan
Published: October 2021

This is a hands-on workshop offered as a pre-conference training opportunity for researchers interested in applying machine learning techniques to animal science datasets with the purpose of classifying, clustering, performing linear and non-linear regressions or selecting a subset of features relevant to further studies. The objective of this workshop is to provide the audience with a way to formulate a problem such that it will be solvable by machine learning techniques and apply an exploratory analysis of various machine learning algorithms on different datasets. The workshop is structured in a hands-on format and includes a brief overview of basic notions about machine learning, a description of relevant models and evaluation metrics followed by a practical session. The practical session requires each attendee to bring their own laptop and have already installed the Waikato Environment for Knowledge Analysis (Weka) workbench for machine learning available from https://www.cs.waikato.ac.nz/ml/weka/ and all freely available machine learning models. The Weka installation of freely available machine learning models can be achieved by using the Weka Package Manager available from the Tools menu in the main application. Detailed information will be provided before the beginning of the workshop at the following URL: http://animalbiosciences.uoguelph.ca/~dtulpan/conferences/asas2021_mlworkshop/
91 Assessing Variability of Herd Sire Economic Value for Commercial Operations
Authors: Dodd Logan , Anderson David , Riley David G , Johnson Barton , Herring Andy D
Published: October 2021

Number of calves (n = 596) and weaning calf value (n = 574) from natural service, multi-sire breeding groups were evaluated in a crossbred research herd. Sires and dams that were F1 crosses of Angus (A) and Nellore (N) were mated annually during 60 to 90-day breeding seasons to produce spring-born calves in 2009–2015. Numbers of sires used annually varied from 5 to 9; numbers of females exposed per bull ranged from 14 to 22 across years. Bulls were pastured together throughout the year as well as breeding seasons. Sires were identified based on calf DNA genotyping. Calf number, birth date, birth weight, weaning weight, and economic value were determined per bull annually. Calf value was based on weaning weight and reported prices for respective weaning dates. Calf prices were calculated separately for steers and heifers relative to 22.7 kg (50 lb) increments for corresponding weight class and year. Mixed model analyses were conducted that included fixed categorical effects of calf birth year, type of F1 sire (A-sired vs. N-sired), sire nested within type, calf sex, and the interaction of F1 sire type with calf sex. Covariates of Julian birth date and calf weaning age were included for birth weight and weaning weight, respectively. Large differences in calf numbers and performance (P < 0.05) were observed. Weaned calves produced annually per sire ranged from 0 to 48. Average annual calf performance per sire ranged from 28.4 to 50.8 kg for birth weight and 146.5 to 249.0 kg for weaning weight. Annual economic value per sire ranged from $0 to $30,870 when considering half of each calf’s value as attributed to the sire. Commercial producers should consider potential sire variability for calf numbers, birth date distribution, and ratio of female-to-male calves in combination with calf performance for economic assessments.
96 Assessing the Sustainability of Multiple Grass-fed and Grain-fed Beef Production Systems
Authors: Klopatek Sarah C , Marvinney Elias , Yang Xiang , Kendall Alissa , Oltjen James W
Published: October 2021

Increased demand for grass-fed beef raises many producers’ and consumers’ concerns regarding product quality, economic viability, and environmental impacts that have gone unanswered. Therefore, using a holistic approach, we investigated the performance, carcass quality, financial outcomes, and environmental impacts of four typical grass-fed and conventional beef systems raised in a Mediterranean climate in the western United States. The treatments included: 1) steers stocked on pasture and feedyard finished for 128 days (CON); 2) steers grass-fed for 20 months (GF20); 3) steers grass-fed for 20 months with a 45-day grain finish (GR45); and 4) steers grass-fed for 25 months (GF25). The data were analyzed using a mixed model procedure in R. Data from these beef production systems, a weaning-to-harvest life cycle assessment (LCA) using the SPARKS-LCA model framework, to determine global warming potential (GWP), consumable water usage, energy, smog, and land use footprints. Final body weight varied significantly between treatments (P < 0.001) with CON finishing at 632 kg, followed by GF25 at 570 kg, GR45 at 551 kg, and GF20 478 kg. Dressing percentage differed significantly between all treatments (P < 0.001) with CON at 61.8%, followed by GR45 at 57.5%, GF25 at 53.4%, and GF20 at 50.3%. Breakeven costs with harvesting and marketing for the CON, GF20, GR45, and GF25 were $6.01, $8.98, $8.02, and $8.33 per kg hot carcass weight (HCW), respectively. The GWP for the CON, GF20, GR45, and GF25 were 4.79, 6.74, 6.65 and 8.31 CO2e/kg HCW, respectively. Water consumptive use for CON, GF20, GR45, and GF25 were 933, 465, 678 and 1245 L /kg HCW, respectively. Energy use for CON, GF20, GR45, and GF25 were 18.69, 7.65, 13.84 and 8.85 MJ /kg HCW, respectively. The results from this study indicate that differences in grass-fed beef management can have profound impacts on food security and sustainability.
93 Equivalent Effects of Growing Phase ADG and DOF at Various Placement Weights on Finishing Beef Cattle Performance Using Meta-analysis Approach
Authors: Larson Haley E , Owens Fredric N , DiCostanzo Alfredo
Published: October 2021

A meta-analysis approach was used to interpret effects of growing phase days and rate of gain on finishing performance at theoretically similar maturity using a dataset derived from 53 manuscripts. Growing phase feeding strategies included dry-lot feeding a high-energy finishing diet post-weaning (HG; n = 16), silage (DL-forg; n = 32) or a moderate energy diet (DL; n = 78), stocking cattle on winter wheat (WW; n = 16) or range (GR; n = 43). Independent variables of interest were initial growing phase body weight (initial BW), growing phase average daily gain (ADG), days-on-feed in growing phase (DOF), and final growing phase body weight. Data were analyzed using the PROC MIXED procedure of SAS, with treatment means weighted by experimental units (EU) per treatment. Optimal combinations of growing phase DOF and initial BW differed between models. Yet, for dressing percent (R2 = 0.39), LMA (R2 = 0.55), final finishing BW (R2 = 0.58), and HCW (R2 = 0.54) models, an 80-d growing phase for cattle starting at 240 kg resulted in greatest responses by these variables. Simulations evaluating effects of growing phase ADG on finishing performance (dressing percent; LMA; final body weight; HCW) were set equivalent to simulations evaluating the sensitivity of growing phase DOF in response to initial BW. Solving these simulations generated the initial BW at which cattle were more responsive to growing phase length (DOF) than ADG (LMAcritical point = 255 kg; DPcritical point = 242 kg; Final finishing BWcritical point = 231 kg; HCWcritical point = 233 kg). For finishing performance traits listed, each critical point represents the inflexion at which growing phase ADG exerts greatest influence on each trait modeled. Thus, for example, for cattle starting a growing phase at under 233 kg, faster growing phase ADG results in greater hot carcass weight response.
101 Awardee Talk: Impacts of Gestational and Early-life Nutrition on Productive Responses of Beef Cattle
Authors: Harvey Kelsey
Published: October 2021

Nutritional management during gestation as well as postnatally is critical to optimize efficiency and profitability of beef cattle systems. Two experiments were performed evaluating the effects of trace mineral supplementation during gestation and supplementation with calcium salts of soybean oil (CSSO) to nursing beef steers on performance and physiological responses. In experiment one, the impact of inorganic or organic Co, Cu, Mn, and Zn supplementation to beef cows during gestation were evaluated on parameters associated with offspring performance and physiological responses. One hundred and ninety non lactating pregnant beef cows were assigned to the experiment at 117 ± 2.2 days of gestation (d 0) and received diets containing either 1) sulfate sources of Cu, Co, Mn, and Zn (INR), or 2) organic complexed source of Cu, Co, Mn, and Zn (AAC). No treatment differences were detected (P ≥ 0.19) for calf body weight at birth or at weaning. Heifers born to INR cows had delayed puberty attainment (treatment ×day interaction; P < 0.01), whereas no treatment differences were detected (P ≥ 0.24) for carcass traits when male offspring were reared as feeder cattle. In experiment two, the impacts of supplementing CSSO at 2 months of age via creep-feeding and/or postweaning via preconditioning were evaluated on parameters associated carcass quality and development. Steers receiving CSSO at 2 mo of age had greater (P ≤ 0.01) mRNA expression of genes associated with lipid metabolism in the longissimus muscle later in life, although no treatment differences were detected for performance or carcass traits (P ≥ 0.18). Outcomes of these experiments may be used to develop nutritional strategies to enhance productive efficiency in beef cattle systems. Research is still warranted to examine the effects of such supplementation during these periods of developmental plasticity on cattle productivity.
108 Evaluation of Graded Levels of Grain Distillers Dried Yeast (GDDY) on Apparent Nutrient Digestibility and Stool Quality in Healthy Adult Dogs
Authors: Kilburn Logan , Jolly-Breithaupt Melissa L , Balk Derek , Aldrich Charles G
Published: October 2021

Yeast and distillers’ grains from ethanol products have been included in pet food for many years. However, their combination has not been evaluated in pet food. Grain distillers dried yeast (GDDY) is a combination of fermented grains which is rich in yeast. The objectives of this study were to determine the effects of increasing levels of GDDY on apparent total tract digestibility (ATTD) and stool quality in adult dogs. Four extruded diets were fed to twelve adult Beagle dogs in a replicated 4 x 4 Latin Square design. The control diet contained 15% soybean meal (15S) and GDDY was exchanged for soybean meal at either 5%, 10%, or 15% (5G, 10G, 15G). Dogs were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1–5 scale, with 1 representing liquid diarrhea. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and dog and period as random effects. No differences (P > 0.05) were observed in wet fecal output or fecal pH (average; 112.74g/d and 5.77). Fecal DM and defecations per day were greater (P < 0.05) at elevated levels of GDDY. Stool scores were higher (P < 0.05) when dogs consumed diets containing GDDY versus 15S (average; 3.85 vs 3.67). Organic matter ATTD was the greatest (P < 0.05) for dogs fed 15S compared to GDDY treatments (average; 87.64% vs 86.67%). Dogs fed 10G had the lowest (P < 0.05) ATTD for crude protein compared to all others (average; 87.92% vs 88.78%). These results suggest that levels of GDDY between 5 and 15% are comparable to soybean meal when fed to adult dogs.
111 Validation of the Indicator Amino Acid Oxidation Technique in the Domestic Cat
Authors: Pezzali Julia Guazzelli , Rafii Mahroukh , Courtney-Martin Glenda , Shoveller Anna-Kate
Published: October 2021

There is a lack of data on the minimum Met or total sulfur AA (SAA) requirements for adult cats. Non-invasive and precise techniques, such as indicator AA oxidation (IAAO) can be used for these purposes. This pilot study aimed to validate the IAAO technique in cats and investigate the effect of dietary Met concentrations and sources on fasted plasma SAA concentrations. Six cats were fed three experimental diets in random order: Met-deficient diet (BASAL; 0.23% Met+Cys-DM) and two Met-sufficient diets in which either DL-Met (DLM) or Met-hydroxy-analogue (MHA) were supplemented, respectively, on an equimolar basis to meet the total SAA requirement (0.34%-DM). After 2d diet adaptation, IAAO studies were performed. Cats were offered 13 ½-hourly small meals. The 6th meal contained a priming dose (4.8 mg/kg-BW) of L-[1-13C]-Phe and the remaining meals the constant dose (1.04 mg/kg-BW). Breath samples were collected ½-hourly to measure 13CO2 enrichment. The following morning after an 16hr fast, blood samples were collected. Isotopic steady-state was evaluated through linear regression models. Plasma AA data were analyzed using PROC GLIMMIX procedure in SAS (Version 9.4). Met concentrations tended to be higher in cats fed DLM compared to BAS (P = 0.0877), but similar to those fed MHA (P > 0.05). Total cysteine plasma concentrations were similar between treatments (P > 0.05). Cats fed BAS had greater concentrations of plasma HCys compared to DLM and MHA (P = 0.0093). Cats did not reach isotopic steady-state in atom percent excess (P >0.05) regardless of the dietary treatment provided. Non-steady-state kinetics models are under development to predict 13CO2 flux. This study indicates that the short-term feeding of a Met-deficient diet in cats results in greater plasma Hcys and a tendency for lower plasma Met concentrations. A higher prime dose of L-[1-13C]-Phe is warranted to achieve isotopic steady-state and successfully apply the IAAO to estimate AA requirements.
118 The Use of Meta-analysis in Companion Animal Research
Authors: Bermingham Emma N
Published: October 2021

In a world of the “Three Rs” (replace, reduce and refine), combined with more research published via open access research journals, there is increasing interest in the statistical analysis of existing literature. Meta-analysis – the combination of multiple studies, can be used to get better oversight into a specific question of interest. Additionally, it can be used to identify gaps in knowledge. For example, while there are a number of publications investigating energy requirements in adult cat and dog, few studies assess older animals. Similarly, in the dog, there is a lack of literature around dogs at the extremes of body size (i.e. giant and toy breeds). Herein, we describe several published examples that have been used to determine energy requirements of cats and dogs, and more recently, the impacts of diet on the microbiome of the cat and dog. This includes the use of Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, research findings and general findings related to research design and quality.
117 Nutrition Modelling: What Can the Pet Field Learn (or Steal) from Recent Directions in Other Species?
Authors: Ellis Jennifer L
Published: October 2021

Nutrition modelling has been the cornerstone of feed formulation and diet optimization in animal production systems for decades. Since the 1970s and 1980s, mechanistic models of nutrient digestion, absorption, metabolism, growth and milk/egg production have been developed and implemented to (1) amass our cumulative biological knowledge and develop theories of regulation, (2) identify knowledge gaps, and (3) propose means to manipulate nutrient dynamics in the animal. At the nutrient and metabolite level, many commonalities exist and parallels found between species. In fact, several second generation models originate from other species or research fields, and many current/existing models may be advanced by examination and consideration of models developed in other species. Many such mathematical models are implemented in practice as ‘decision support systems’ or ‘opportunity analysis tools’, in order to examine a variety of (feeding or management) scenarios for their potential outcomes, with the goal of providing targeted nutrition, improving performance, reducing cost and minimizing environmental impact. More recently, partnering artificial intelligence/machine learning modelling methodologies with newly available big data streams has ushered in a new era of possibilities for data extraction and modelling in animal systems. The niche for this type of modelling in animal production appears to be (1) pattern recognition (e.g. disease detection, activity) and (2) strong predictive/forecasting abilities (e.g. bodyweight, milk, egg production). There also appears strong potential for these two seemingly divergent modelling approaches to be integrated – for example, in precision feeding systems, or in utilizing the abundance of sensor data to better drive or develop causal-pathway based mechanistic models. This talk will broadly review trends and advances in agriculture animal species modelling, and suggest what may be borrowed, stolen or serve as inspiration to advance nutrition models in companion species.
122 Bioactive Peptides for Enhancing Intestine Health
Authors: Li Julang , Akhtar Nadeem , Osakowicz Celina , Fletcher Lauren , O Karmin , Nyachoti Martin
Published: October 2021

Intestinal disorders and colitis affect both animals and humans. The pathogenesis behind the inflammation is complex and not entirely understood. Furthermore, the significant rise in antibiotic-resistant bacteria has emphasized an urgent need for alternative anti-infective therapies. Antimicrobial peptides (AMPs) is one of the appealing alternative to antibiotics due to their antimicrobial activity, mode of actions, and potential role in tissue repair. Epidermal growth factor (EGF) plays an important role in intestinal proliferation and differentiation and thus promotes intestinal development. Using food grade microorganisms such as Lactococcus lactis and yeast as hosts, our laboratory has produced recombinant porcine protegrin-1 (PG-1), a pig originated antimicrobial peptide and EGF via fermentation. Oral administration of PG-1 reduced Citrobacter rodentium induced intestinal infection in mice. This was evidenced by reduced histopathological changes in the colon, prevention of body weight loss, milder clinical signs of disease, and ultimately more effective clearance of bacterial infection. On the other hand, animal trials using the recombinant EGF demonstrated that it enhances intestinal development and growth of early weaned pig fed with antibiotic-free diet. Moreover, piglets challenged with enterotoxigenic Escherchia coli (E. coli) K88 showed similar beneficial responses to EGF as those fed diets with antibiotic in terms of improving gain to feed ratio and lowering oxidative stress. Taken together, our findings suggest the potential for cost-effective production and application of recombinant bioactive proteins as alternatives to antibiotics in animal health and production.
131 Can Maternal Nutrition in Dairy Cattle Impact Gut Health in Dairy Calves?
Authors: Cangiano Lautaro Rostoll , Malmuthuge Nilusha , Ma Tao , Guan Leluo , Steele Michael A
Published: October 2021

The nutritional management, health and welfare of the dairy calf has historically received less attention due to limited research, and recommendations largely focused on passive transfer of immunity and early weaning strategies. Gastrointestinal diseases and disorders remain the leading cause of mortality and morbidity in dairy calves worldwide. Despite the recent thrust in dairy calf nutrition research, major knowledge gaps still exist regarding how maternal nutrition during pregnancy and postpartum impact gastrointestinal health and function, especially during the fetal and neonatal stages when the developmental plasticity is highest. Recent research has focused on how prepartum nutrition and management can influence colostrum quality and has characterized numerous bioactive proteins, lipids, and carbohydrates that may play a critical role in gastrointestinal function and development. It has also been shown that colostrum plays a fundamental role in promoting colonization with commensal bacteria; however, delaying colostrum feeding or abruptly transitioning calves from colostrum to milk decreased the colonization of beneficial bacteria and impaired gastrointestinal development. With respect to the maternal nutrient supply via milk, it is important to note that calves have been traditionally fed less than half of voluntary intake or fed milk replacer formulations that can largely differ in composition from that of maternal milk. Recent research indicated that common milk replacer formulations may impair gastrointestinal function, highlighting the need to question existing nutritional regimens. In addition, feeding prophylactic antibiotics in milk, as well as waste milk containing antibiotic residues, are common practices in the dairy industry, despite recent studies reporting that these practices can increase calf susceptibility to infections by disrupting gut microbiome and gut function. Although our knowledge how maternal factors impact the gastrointestinal tract of calves is limited, it is clear there are great opportunities to further develop prenatal and postnatal nutritional programs to improve dairy calf gastrointestinal health.