bluuebunny/crossref_metadata_2025 huggingface dataset:
76 Cattle Production’s Response to Packing Capacity Disruption
Authors: Holland Ben P , Wesley Kaitlyn R , Word Alyssa B , Maxwell Casey
Published: October 2021

In August 2019, a fire at Tyson’s Finney County, Kansas, beef plant removed approximately 5% of U.S. beef packing capacity for 3 months. Subsequent COVID-19 pandemic-related precautions and workforce illness caused multiple packing plants across the country to decrease or stop production in the spring of 2020. Both events resulted in feedlots being unable to ship cattle at optimal finish points or according to projection. Estimates of the number of cattle backlogged during 2020 approach 1 million. Producers were faced with decisions on how to manage finished animals that could not be shipped while considering economic, animal welfare, and animal health outcomes. Many factors further complicated the situation including highly volatile markets, the possibility employee quarantine due to personal or family illness would cause operations to be under-staffed, and shortage of available pens for new cattle. Feeders had the option to slow the rate of growth of finished cattle due to the ability of ruminant animals to utilize low-energy feedstuffs or by calculating programmed rates of gain using the net energy system. Instead, many producers chose to attempt maximal rates of gain hoping persistent growth and feeding margins would offset discounts due to heavy carcass weights and excess fatness when the supply chain began moving again. Regarding new placements, the structure of the beef industry is uniquely developed to absorb cattle in stocker and backgrounding operations. This presentation will review the factors impacting cattle production and provide case-studies related to feeding at maintenance and growth rates, efficiencies, and carcass outcomes of held cattle from an operation and industry level.
92 Maternal Nutrient Restriction of Primiparous Beef Heifers During Late Gestation Decreases Colostrum Yield and Reduces Calf Vigor
Authors: Wichman Lindsey G , Redifer Colby A , Davies Shelby L , Meyer Allison M
Published: October 2021

We hypothesized that late gestational nutrient restriction (NR) would reduce colostrum yield and impair offspring transition to postnatal life. Primiparous, fall-calving crossbred beef heifers (BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) were individually-fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Delivery duration was determined as minutes from first fetal feet expulsion to birth. Calves were reared naturally by their dams and monitored for times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores (1 = very weak, 5 = extremely vigorous) were assigned at 2, 5, 10, and 20 min of age. Total colostrum from one rear quarter was collected pre-suckling. Calf rectal temperatures were recorded at 0, 6, 12, 24, and 48 h postnatally. Data were analyzed with the fixed effects of treatment (single point) or treatment, hour, and their interaction (over time, using repeated measures). Date of calving was a fixed effect; calf sex was included when P < 0.25. Heifers fed CON had greater (P = 0.04) colostrum weight and volume than NR. Although gestational nutrition did not affect (P = 0.72) calf birth weight, calves born to CON heifers had faster (P = 0.02) times to stand and tended to have faster (P = 0.09) times to attempt to stand. Calves from CON heifers had greater (P = 0.05) 20 min vigor scores. Rectal temperatures at 0 h were greater (P = 0.02) in CON calves, but at 24 h were greater (P = 0.04) in NR calves. These data indicate that heifers nutrient restricted during late gestation have reduced colostrum yield and less vigorous calves, which may influence postnatal calf survival.
89 Relationships Among Measures of Efficiency with Body Weight, Frame Score, and Body Volume in Lactating Multiparous Crossbred Beef Cattle
Authors: Mosher Macie K , Olorunkoya Samuel , Bhowmik Nayan , Ringwall Kris A , Hanna Lauren L Hulsman , Swanson Kendall C
Published: October 2021

Sixty cows of varying frame scores (FS; 5.17 ± 1.38) were used to examine relationships between body size [BW, FS, and body volume (V)] and cow efficiency. Dry matter intake (DMI) and BW change were monitored over 64 days starting 1 month before bull turnout. Cows were fed a forage-based diet and DMI monitored using the Insentec system. Average BW (ABW; 662 ± 93.3 kg) was calculated by averaging 2-d beginning and end BW. Measurements (body length, hip height, hip width, and heart, mid, and flank girth) were collected at the beginning and end of the experiment and average V (628 ± 96.4 L) calculated. Calf BW was recorded at weaning (WW). Pearson partial correlations between body size characteristics and efficiency measures were determined using GLM (SAS) and the MANOVA/PRINTE statement. There was positive correlation (P < 0.001; r = 0.84, 0.74, 0.81) between DMI (kg) and ABW, FS, and V. There was a tendency for negative correlation (P = 0.08, 0.09; r = -0.24, -0.23) between DMI (% of BW) and ABW and V. There was positive correlation (P ≤ 0.05; r = 0.33, 0.28, 0.26) between WW (kg) and negative correlation (P < 0.001; r = -0.63, -0.57, -0.65) between WW (% of ABW) and ABW, FS, and V. There was positive correlation (P = 0.04; r = 0.26) between calf ADG and ABW, and a tendency for positive correlation (P = 0.09; r = 0.23) between calf ADG to weaning and FS. The observed correlations suggest that larger cows consume more kg of feed and wean heavier calves with greater ADG to weaning, whereas smaller cows tend to consume more feed as a percentage of BW and wean a greater percentage of cow BW. Further research is needed on the complex relationship between cow size and efficiency.
88 Impacts of Body Condition Score at Initiation of the Breeding Season on Reproductive Performance and Overall Productivity of Bos Taurus and B. Indicus Beef Cows
Authors: Brandão Alice , Cooke Reinaldo F , Lamb G Cliff C , Vasconcelos José Luiz , Pohler Ky G
Published: October 2021

Responses of Bos taurus (BT) and B. indicus (BI) beef cows were compared according to their body condition score (BCS) at initiation of breeding season. Cows were assigned to an estrus synchronization + AI protocol and classified as BCS < 5.0 (LBCS, BT, n = 158; BI, n = 248) or BCS ≥ 5.0 (HBCS; BT, n = 173; BI, n = 122). Pregnancy status was verified via transrectal ultrasonography at 30 and 40 d after AI for BI and BT cows, respectively. All BT cows were exposed to natural service for 50 d (beginning 18 d after AI), and all non-pregnant BI cows were immediately exposed to natural service for 60 d. Pregnancy rates to AI did not differ (P ≥ 0.16) between HBCS or LBCS cows (60.9 vs. 53.5% for BT; 37.0 vs. 31.4% for BI; respectively). Pregnancy rates to natural service were greater (P = 0.03) in HBCS BT cows compared with LBCS (82.7 vs. 67.9%; respectively) but did not differ in BI cows (78.9 vs. 71.5%; respectively). Calving rate was greater (P < 0.03) in HBCS cows, which also calved earlier (P < 0.01) compared with LBCS (93.7 vs. 85.1% in BT, 83.6 vs. 73.3% in BI; respectively). HBCS Cows weaned more (P ≤ 0.05) calves compared with LBCS, which were older (P ≤ 0.04) (215 vs. 211 d in BT, 219 vs. 209 d in BI; respectively) and heavier (P ≤ 0.09) at weaning (258 vs. 252 kg in BT, 213 vs. 203 d in BI; respectively). Lastly, kg of calf weaned/cow was greater (P ≤ 0.03) in HBCS cows compared with LBCS (221 vs. 200 d in BT, 159 vs. 129 d in BI; respectively). Therefore, HBCS cows had greater reproductive efficiency and overall productivity, and this was observed in both BT and BI.
106 The Effects of Fetal Programming on Offspring Pancreas DNA Methylation
Authors: Hoffman Maria L
Published: October 2021

It has been well documented that fetal programming, caused by changes to the maternal environment during pregnancy, can impact the overall health and growth of the offspring in livestock and non-livestock species alike. These effects are observed in the F1 offspring as well as across subsequent generations; however, the mechanisms by which this occurs are still poorly understood. Epigenetics is one of the many mechanisms that is hypothesized to have a role in fetal programming and may be mediating the observed effects across multiple generations. It has been demonstrated by others that DNA methylation patterns can be altered by an individuals’ diet and that the pancreas is vulnerable to the effects of fetal programming. Therefore, we evaluated the effects of poor maternal nutrition during gestation on the pancreas tissue of lambs. We have demonstrated that maternal under- or overnutrition during gestation alters the DNA methylation patterns of the offspring pancreas tissue with these effects being diet dependent and sex specific. We have also begun evaluating the effects of maternal diet in murine models using whole-genome bisulfite sequencing to compare species differences and determine if there are any changes conserved across species. This will allow us to focus on a smaller number of critical factors in individuals as they age and across multiple generations in livestock species such as sheep and cattle. From these data we will be able to elucidate the role DNA methylation has in mediating the effects of maternal programming in the pancreas tissue.
105 The Epigenetics and Plasticity of CD4+ T Cells in Poultry Health
Authors: Song Jiuzhou , He Yanghua , Ding Yi , Tian Fei , Zhao Keji , Zhang Huanmin , Yu Ying , Yang Ning , Lian Ling , Luo Juan , Mitra Apratim
Published: October 2021

Marek’s disease (MD) is one of the top priority diseases in chicken. The mechanisms through which immune cells react to virus infection and pathway signals represent the fundamental cell biological question to defeat MD. We hypothesized epigenetic status in immune organs and cells is directly associated with how the Marek’s disease virus (MDV) infection influences intrinsic transcriptional and regulatory networks in MD. To investigate the epigenetics in CD4+ T cells induced by MDV infection, we assembled a multifaceted approach with epigenetics, deep sequencing, and computational methods together to explore the roles of epigenetics in unique inbred lines of chickens. First, a genome-wide transcriptome analysis in the immune organs from resistant line 63 and susceptible line 72 chickens was performed to explore disease resistance mechanisms. MDV infection influences both cytokine-cytokine receptor interaction and cellular development in resistant and susceptible chickens. Second, we examined the epigenetic status of CD4+ T cells induced by MDV infection, including DNA methylations, histone modifications, chromatin accessibility, and 3D chromatin structures. Our results revealed more than 5,000 epigenetic modification changes (FDR< 0.01) and methylation changes (>15,000, FDR< 0.01) caused by MDV infection. Only resistant line 63 chickens could initiate robust adaptive immune responses at the transcription level (>200 genes, FDR< 0.05). The increase in chromatin accessibility (P < 0.001) and chromosome reorganization represented by A/B compartment flipping were related to up-regulated genes induced by MDV infection ten days post-infection in line 63 chickens. Our findings provided a deeper insight into the CD4+ T cell commitment and responses toward viral infection. In particular, the identifications of cis-acting and trans-acting regulations and lipid pathways will improve our understanding of the sequence, structural basis of RNA-protein, and RNA-DNA interactions and serve as the impetus for mechanistic studies to refine the genomic and epigenetic control of MD resistance in poultry.
114 Evaluation of Extrusion Processing Method and Protein Source on Standardized Amino Acid Digestibility
Authors: Hsu Clare , Davenport Gary , Rokey Galen , de Godoy Maria R
Published: October 2021

While the majority of dry complete and balanced foods for pet animals are extruded, the interaction between ingredient matrix and processing methods and stages are poorly understood. Thus, the objective of this study was to determine how the use of plant-based and poultry-based proteins processed under different extrusion condition may affect amino acid digestibility in extruded canine diets using a rooster model. Eight diet formulas were made using chicken (CK), chicken byproduct meal (CM), yellow pea (YP), green lentil (GL), and garbanzo bean (GB) as the primary protein sources. These diets were extruded through a single-screw and a twin-screw extruder. Food samples were collected at various stages of processing (i.e., raw, and after preconditioner, extruder, drier, and coating). Four cecectomized single-comb White Leghorn roosters were used for each diet sample. The roosters were fasted for 26 h and then fed with the treatment diets. The excreta were collected 48 h after feeding. Freeze dried excreta were used to calculate standardized amino acid digestibility (SAAD). For all essential amino acids, a significant interaction (P < 0.05) between diet and processing method was observed. The SAAD of arginine, tryptophan, and methionine were greater than 80% for all diets collected at the end of the extruder. The CK diet supplemented with synthetic taurine and processed through twin-extrusion had 70% to 80% SAAD of histidine, isoleucine, leucine, lysine, phenylalanine, threonine, and valine. Overall, twin-screw extrusion resulted in lower SAAD for all essential amino acids (P < 0.05), except for isoleucine and valine. However, the differences were smaller than 2.5%, and therefore may not negatively impact diet formulation and final product nutrient composition or guaranteed analysis. In addition, the extruded canine diets made with plant-based protein did not have lower amino acid digestibility than those made with animal-based protein.
126 Animal Supplements: Market Trends, Benefits and Limitations of Academic Research, and Regulatory Considerations in Product Development
Authors: Bookout Bill
Published: October 2021

Market research shows that U.S. consumers spend approximately $2.5 billion annually purchasing products that are similar to human dietary supplements, but intended for use in dogs, cats, and horses. Demand for these types of products is projected to grow 3% - 5% per year for the next several years. This presentation will examine the animal supplement market and provide insight into the trends that are driving its growth, many of which closely follow trends in human dietary supplements. In addition, this presentation will look at the benefits and limitations of industry sponsored research to verify the safety and efficacy of currently available animal health and nutritional supplements. Three main considerations must be weighed against the exorbitant expense of conducting clinical studies that satisfy the rigors of the scientific community: limitations on claims; lack of intellectual property protection; and the potential influences of similar products that may be available on the human side. Finally, the presentation will delve into the one area that cannot be overlooked when developing new animal health and nutritional supplements—the regulatory requirements that must be satisfied to take a product successfully to market. Any company producing animal health and nutritional supplements should be following current good manufacturing practices (cGMPs), however, since the Dietary Supplement Health and Education Act of 1994 (DSHEA) does not apply to animals, it is important to understand the standards that should be considered when marketing these types of products.
134 Effect of Sow Nutrition on Offspring’s Gut Microbiota
Authors: Everaert Nadia
Published: October 2021

In mammals, fetal development is programmed by the mother’s metabolism, body condition and health status, and thus by her diet. Besides this nutritional programming, the diet of sows has also an impact on her intestinal microbiota and on colostrum and milk production and composition, which may then modulate the microbiota of piglets. Indeed, colostrum and milk are composed of macronutrients, but contain as well immunoglobulins and immune cells, bioactive molecules such as hormones, growth factors, prebiotic and antimicrobial compounds. The latter two also play a role on the establishment of the gut microbiota. Moreover, the contact of the piglets with the faeces of the sows, at birth and during the lactation period, may all affect the composition of their microbiota. As a proof-of-concept concerning this microbiota modulation, it was shown that maternal antibiotic treatment from 10 days before the estimated farrowing date until 21 days after farrowing, transiently modified both mother fecal and offspring ileal microbiota during the first weeks of life, without effects on offspring’s microbiota on a long-term. There is evidence, although limited, that dietary fibers in the diet of the sows modulate the microbiota and gut homeostasis of the progeny. This has been shown by the use of seaweed extracts, short chain fructo-oligosaccharides, wheat bran, resistant starch, or the inclusion of guar gum and cellulose. For example, wheat bran in the diet of sows modulates the microbiota of the sows and piglets differently. Supplementation of the sow’s diet with probiotics (Bacillus subtilis) also revealed that the development of the intestinal microbiota of piglets is modulated, seen by a reduction in pathogenic communities (i.e. Escherichia coli, Clostridium perfringens) in colon and ileum respectively. In conclusion, to optimize piglet’s gut development through the colonization of the microbiota, the diet of the sow should be taken into account.
133 The Potential for Maternal Nutrition to Influence, Health, Development and Subsequent Lifetime Performance of the Pig
Authors: Vigors Stafford , Sweeney Torres , O’Doherty John
Published: October 2021

The global population is continuing to grow at a rapid rate leading to increased need for meat and milk products. The pig industry will need to adapt and expand to meet this demand. Improving the productivity of the pig industry is therefore vital in ensuring sustainable growth in the future. The use of dietary additives is a means to improve this animal productivity, however, the most appropriate time to provide dietary additives to ensure maximum benefit with the lowest cost is an area that warrants further exploration. The early-life period is a vital time of physiological, transcriptional, and microbial changes that have a stark impact on lifetime productivity. This early lifetime point provides an opportunity to aid development and impart lifetime alterations and improve animal productivity and health. These changes can be applied by dietary and management interventions to the pig itself or to the dam. The dam is a key influence on the development of the progeny as the primary site of microbial inoculation and is therefore, an interesting target for dietary intervention. With increased legislative and environmental constraints through the ban on antibiotics and the phasing out of zinc-oxide in the EU, there is a need to identify viable natural alternatives to increase productivity particularly in the post weaning period. A wealth of chemodiversity exists in nature in plants and animals developing protective molecules to survive in varying complex biosystems. Our research has established the potential of feeding naturally sustainable bioactives to improve animal performance and health. This talk will explore the strategy of feeding these natural bioactives to the dam to improve lifetime performance of the progeny.
137 Optimizing Animal Welfare in a Socially Acceptable and Sustainable Manner: The ASAS Grand Challenge That Requires Moral Self-reflection and Scientific Calibration
Authors: Daigle Courtney L , Meneses Xandra Christine A , Swanson Janice
Published: October 2021

Animal welfare often engages diverse values and ethics including those of citizens, consumers, scientists, and farmers. Consequently, AW is one of the seven grand challenges (GCs) identified by the ASAS Public Policy Committee (PPC). Societal concerns can lead to public policy decisions at the state or federal level that impact animal agriculture. The ASAS PPC GCs on animal welfare will be examined, progress evaluated, and recommendations made for setting research priorities. Five key questions and their corresponding expected outcomes were identified to advance AW in the GC areas of sustainable management practices, genetic markers, pain mitigation, transportation, and humane euthanasia/depopulation. The diversity of disciplines required to address these key questions is astounding. A five-year window (2015-present) was used to evaluate each key question and outcome. The published peer-reviewed literature and the North Central 1029 and Western 3173 multi-state project station reports served as the foundation for our evaluation. In brief, research opportunities exist to identify new methods and technologies to improve livestock transportation, humane endpoints for emergency depopulation, and management practices enhancing the sustainability footprint of livestock; and there is an urgent need to identify effective preventative measures against heat stress. The investigation of effective methods for species-specific pain assessment and mitigation strategies should continue to be a priority and include the development of alternative practices that avoid pain. Research into genetic markers associated with various aspects of animal wellbeing is growing and offers ample opportunity to improve animal welfare. Animal welfare research also requires scientists to engage with stakeholders to maintain perspective. One example is demonstrated by members of NC 1029 who report engagement in over thirty advisory boards across the supply chain. Through this type of engagement, animal scientists can influence the food supply system and serve as a conduit between social concerns, policy, and science.
135 Grand Challenges in Domestic Agricultural Animal Reproduction
Authors: Spencer Thomas E
Published: October 2021

The ASAS Public Policy Committee (PPC) provides updates of Grand Challenges (GCs) which clearly articulate research priorities while providing science-based information for shaping public policy and enhancing future funding for research and education programs in animal sciences (AS). Among the GCs is reproduction of domesticated animals (cattle, swine, sheep, goats, poultry, horses, and aquatic species) that is integral to sustain and improve global competitiveness of U.S. animal agriculture, understand and resolve complex animal and human diseases, and advance fundamental research in sciences that are critical to understanding mechanisms of action and identify future targets for interventions. Historically, federal and state budgets have dwindled and funding for the United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) competitive grants programs remained relatively stagnant from 1985 through 2010. This shortage in critical financial support for basic and applied research, coupled with the underappreciated knowledge of the utility of non-rodent species for biomedical research, has hindered funding opportunities for research involving livestock and limited improvements in both animal agriculture and animal and human health. In 2010, the National Institutes of Health (NIH) and USDA National Institute of Food and Agriculture (NIFA) established an interagency partnership to promote the use of agriculturally important animal species in basic and translational research relevant to both biomedicine and agriculture. The “Dual Purpose with Dual Benefit” program encouraged One Health approaches for comparative medicine studies that use farm animal models that mimic human developmental, physiological, and etiological processes to promote human and animal health, better understand disease origins, interspecies transmission and mitigation strategies, and improve efficiency of assisted reproduction technologies. This presentation will review the successes of the 9-year Dual Purpose effort and highlight opportunities for tackling GC research in reproduction of domesticated agricultural animals.
146 Specific Gravity as an Objective Assessment of Embryonic Viability to Improve Implantation Rates of Bovine Embryos
Authors: Richardson Katylyn J , Perkins Thomas L , Lust David G , Wells Cara W
Published: October 2021

Assessment of embryo quality and viability has traditionally been based on morphological evaluation. However, morphological evaluation, though somewhat reliable, is subjective in nature and varies greatly depending upon the skill and experience of the evaluator. Although research has been conducted with the goal of identifying more accurate and objective methods of evaluation, the issue of repeatability and consistency in predicting the likelihood of a successful pregnancy remains. Previous research has proposed the ability to utilize specific gravity to predict developmental energy reserves based on embryonic weight, theoretically identifying those embryos with an increased chance of success following standard embryonic transfer. The objective of this study was to determine if specific gravity could accurately identify those embryos that were most likely to succeed in generating positive pregnancies. Bovine embryos (n = 20) were dropped through media in a specific gravity chamber. Utilizing an embryo tracking software program, researchers recorded the time elapsed as the embryos descended 1 cm through the media. Embryos were then transferred into recipient cattle, and pregnancy was detected via ultrasound approximately 40 days post transfer. Of the 20 embryos transferred, 12 resulted in positive pregnancies. Descent times of these positive pregnancies ranged from 25.96 to 90.27 seconds, with an average descent time of 59.72 seconds. An analysis of the relationship between descent time and pregnancy outcome showed no significant difference (P > 0.05). Although there was no significance in the findings of this study, additional trials will be performed to thoroughly evaluate the potential of this technology as an objective measurement of embryonic viability.
152 Comparison of an Antioxidant Source and Antioxidant Plus BCAA on Athletic Performance and Post Exercise Recovery of Horses
Authors: Hess Tanja , Kent Emily , Casagrande Renan Regatieri , Levihn Christine , Romo Grace , Coloman Stephen J , Herkelman Kevin
Published: October 2021

Antioxidant supplementation has been shown to decrease post exercise oxidative stress but can lead to decreased post-exercise muscle protein synthesis. The objective of this study was to compare the effects of the supplementation with a control feed with low antioxidant content (CONT) to a high antioxidant feed (AO), versus a high antioxidant and branched chain amino acid feed (BCAO) on post-exercise protein synthesis and oxidative stress. Our hypothesis is that supplementing AO with BCAO will reduce oxidative stress without hindering muscle protein synthesis. Eighteen mixed breed conditioned polo horses were assigned to one of the three treatments. All horses consumed CONT for 30 days and were then submitted to a lactate threshold test (LT). One hour after this and all LT, each group was assigned and given their treatments. LT were done at 15 and 30 days of supplementation. Blood was collected before, two and four hours after LT, and analyzed for oxidative stress based on glutathione peroxidase, superoxide dismutase and malondialdehyde concentrations by ELISA. Muscle biopsies were taken before and 4 hours after LT and analyzed for the expression of protein synthesis by RT-PCR. Results were analyzed in a mixed model by ANOVA and compared by LSM. A reduction of oxidative stress was found over time (P < 0.050) with no treatment effect (P >0.50). An upregulation of protein synthesis after exercise was found for muscle primers CD36, CPT1, DK4, MyF5, and Myogenin (P < 0.050). There was a treatment by time effect for MyoD (P = 0.027), where AO was upregulated the most after exercise compared to BCAO and CONT. DK4 had a treatment by time effect trend (P = 0.073), where AO and BCAO were upregulated and CONT was unchanged after exercise. This study demonstrated post exercise muscle synthesis with no advantage of AO plus BCAO compared to AO.
144 The Epidemiology of Hoof-related Lameness in Western Canadian Feedlot Cattle
Authors: Erickson Sarah E , Jelinski Murray , Schwartzkopf-Genswein Karen S , Booker Calvin , Janzen Eugene
Published: October 2021

The epidemiology of hoof-related lameness (HRL) in western Canadian feedlots, with a focus on digital dermatitis (DD), was described and analyzed to help inform recommendations on lameness control and prevention in western Canadian feedlot cattle. The retrospective data in this study were accessed from 28 western Canadian feedlots that placed cattle in 2014–2018, inclusive. The total population for this study was 1,796,176 cattle, with an annual placement average of 12,830 cattle per feedlot. These data were accessed through iFHMS Consolidated Database, provided by Feedlot Health Management Services by TELUS Agriculture, and manipulated using Microsoft® Office Access 365 ProPlus and Microsoft® Office Excel 365 ProPlus. Epidemiological analyses determined that lameness accounts for 25.7% of all treatments in western Canadian feedlots. Of those treatments, 71.7% are localized to the hoof, corresponding to 18.6% of all treatments. The most common HRL diseases are infectious bovine pododermatitis [foot rot (FR)]; digital dermatitis (DD), also known as hairy-heel wart or strawberry foot rot; and toe-tip necrosis syndrome (TTNS). These diseases account for 89.6%, 7.9% and 2.4% of HRL, respectively. Between 2014 and 2018, HRL prevalence ranged between 1.93% and 3.09% of the population, with FR consistently having the highest prevalence and TTNS the lowest. HRL and DD were tested for their associations with several animal-level risk factors using © Ausvet 2021 Epitools software. The resultant crude, univariate odds ratio values, evaluated at 95% confidence, are summarized in Table 1. Based on this analysis, acquisition source has the largest influence on the odds of developing HRL and DD, followed by population size, and placement quarter. Using SAS® (Version 9.4, SAS Institute Inc, Cary, North Carolina) statistical software, these preliminary findings will be subjected to a multivariate statistical model, which will provide adjusted OR values and statistical significance for the data in this study.
161 Epigenetic Changes in Poultry Due to Reprogramming of the Gut Microbiota at an Early Stage of Embryonic Development
Authors: Dunislawska Aleksandra
Published: October 2021

Epigenetic regulation of the gene expression is an interaction of the external environment with the genetic information. They are potentially heritable changes in the gene expression which does not involve alteration in DNA sequence and can be triggered by microRNA activity and DNA methylation. MicroRNA is fraction of small RNA molecules that have a fundamental impact on gene expression. DNA methylation inhibits DNA transcription by addition of the methyl residues to the cysteine within the CpG islands of the gene promoters. These processes can be modulated by environmental factors, such as intestinal microbiota modification. In poultry, the microbiota can be reprogrammed using in ovo technology at an early stage of embryo development. The intestinal microbiota is therefore stimulated and rearranged by injecting bioactive substances into air chamber of eggs on the day 12 of incubation. We have proved that the administration of lactic acid bacteria strains and galactooligosaccharide in ovo is effective in modulating of the intestinal microbiota. The administration of bioactive compounds has been demonstrated to influence gene expression in immune, intestinal and metabolic tissues. However, it has been noticed that a significant part of genes is silenced. In our experiment after in ovo administration of the substances in different genotypes (chicken broiler and native Polish breed) the range of tissues was collected: liver, caecal tonsils, spleen. By performing the bioinformatic analysis of the expression microarray, silenced genes and active miRNAs were selected. Methylation was analysed using the global and MSP-qPCR method, and analysis of miRNA activity using miRCURY LNA PCR Systems. We confirmed that negative regulation of the gene expression have epigenetic character and its mechanism depends on the genotype and the substance administered in ovo. Epigenetic nature of research is new direction of host-microbiome interaction. Research was financed by grant UMO-2017/25/N/NZ9/01822 funded by National Science Centre (Poland).
177 Ad Libitum Consumption of a 1:1 Blend of inorganic:organic Se by Steers Grazing Endophyte-infected Tall Fescue Increases Serum Prolactin and Alkaline Phosphatase Activity, but Not Average Daily Gain
Authors: Webb Kelsie , Trotta Ronald J , Bridges Phillip , Matthews James
Published: October 2021

To test the hypothesis that average daily gain (ADG) and clinical parameters of steers grazing novel non-toxic (NTE) or toxic KY-31 (TE) endophyte-infected tall fescue would be improved by ad libitum intake of vitamin-mineral mixes (V-M) that contain 27 ppm Se as a 1:1 blend of SELPLEX:sodium selenite (MIX) vs sodium selenite (ISe), 32 TE-naïve beef steers depleted of Se were randomly assigned to ad libitum consumption ISe vs MIX for 35 d and fed enough of a NTE/alfalfa/grain diet to achieve 0.57 kg BW gain/d. Within Se-form treatments, 2 steers were randomly assigned to each of 4, 2-acre NTE (ISe = 316 ± 31 kg, MIX = 315 ± 22 kg) or TE (ISe = 316 ± 37 kg, MIX = 314 ± 39 kg) paddocks for 84 d and had ad libitum access to their respective V-M. The MIXED procedure of SAS was used to assess effects of day, Se-form (ISe, MIX) and endophyte (NTE, TE) treatments, and their interactions. Whole blood Se decreased (P < 0.01) 31% from d 0 to 84 and was 6.2% greater (P < 0.01) for MIX steers. Serum prolactin decreased (P < 0.01) 18% for NTE and 48% for TE steers from d 0 to 84 and was 17% greater (P = 0.01) for MIX vs. ISe TE steers. Alkaline phosphatase activity (AP) decreased (P < 0.02) 27% from d 0 to 84 and was 15% greater (P < 0.02) for MIX steers. Serum urea nitrogen increased (P < 0.02) 8.2% from d 0 to 84 for TE but not NTE steers. Average daily gain (kg/d) was less (P < 0.01) in TE (-0.18) vs NTE (0.09) steers. We conclude that the ad libitum intake of MIX ameliorated the negative effects of consuming TE on serum prolactin and AP but not ADG.
174 Forage Production and Nutritive Value of Alfalfa-bermudagrass Mixtures Managed Under Contrasting Defoliation Strategies in the Southeast US
Authors: da Silva Liliane Severino , Burt Justin C , Mullenix Mary K , Tucker Jennifer J
Published: October 2021

Incorporation of alfalfa (Medicago sativa) into bermudagrass pastures improves forage quality and decreases the reliance on synthetic nitrogen fertilizer. The objective of this study was to determine forage mass (FM), nutritive value (NV), and botanical composition of ‘Bulldog 805’ alfalfa and ‘Tifton 85’ bermudagrass (T85; Cynodon dactylon) mixtures managed under three defoliation strategies: 1) hay production (H), 2) grazing (G) or 3) dual-purpose (DP) use. The study was conducted in two locations (Headland, AL and Tifton, GA) using a randomized complete block design with two replicates. In spring 2020, grazed plots were divided in four strips and every 7-d, animals were rotated to a new strip and stocking rate was adjusted. Under DP, plots were grazed until mid-July, then forage was harvested in late August. For H plots, forage was harvested every 28 to 35-d. Forage samples were collected prior defoliation to determine FM and on grazed periods, pre- and post-grazing samples and disk meter measurements were collected. Nutritive value responses were determined using near-infrared spectroscopy. There was no effect of defoliation strategy on FM (P = 0.604; mean 3471 kg DM/ha). Greater FM (P = 0.002) was observed in July and August than June (3531 and 3976 vs 2905 kg DM ha-1, SE= 263). This response was associated with an up to 40% increase of T85 proportion in the mixture (P = 0.001). Alfalfa percentage was 78% greater for DP than G (P = 0.029). There were no differences among treatments for NV responses (P > 0.05). Among defoliation periods, crude protein, neutral detergent fiber and acid detergent fiber concentrations ranged from 14 to 22%, 45 to 58% and 28 to 35%, respectively. These preliminary results demonstrate multi-use options for this mixture in the region while aiming for increased forage nutritive value, and extended growing season, and sustainability of forage-livestock systems.
182 Economic Impact of Bale Grazing on Delayed Feedlot Entry Steer Performance, Carcass Measurement, and Net Return
Authors: Senturklu Songul , Landblom Douglas G , Paisley Steve
Published: October 2021

Senturklu et al., (2018) defined merits of delayed feedlot entry while grazing in an integrated crop-livestock system (ICLS). In a three-year follow up study, yearling steers (n = 144) grazed either an ICLS or a native range system (NR). After 177.9 days, free-ranging ICLS and NR steers were fed cover crop hay bales 43.6 days to determine transition period bale-grazing on finishing performance, carcass measurements, and system net return. ICLS and NR gains did not differ (P = 0.24). ICLS 43.6-day bale grazing gain was greater (1.38 vs. 0.80 kg; P = 0.01). Feedlot arrival weight was greater for ICLS compared to NR (569.3 vs 530.1 kg; P = 0.04) and fed 95.7 days. Systems end weight (P = 0.19), gain (P = 0.57), ADG (P = 0.06), and gain cost (P = 0.71) did not differ. ICLS steer hot carcass weight (HCW: 444.8 vs. 419.2 kg; P = 0.03) and fat depth (1.35 vs. 1.17 cm; P = 0.04) were greater. NR steer dressing percent (62.48 vs. 61.83 %; P = 0.01) and muscling ratio to HCW (3.96 vs. 3.81 sq. cm.; P = 0.007) were greater. Choice quality grade did not differ (98.6 vs. 98.6; P = 1.00). Annual cow and steer winter feed cost were $752.00. ICLS grazing cost for NR was $115.30, pea-barley $74.98, unharvested corn $108.87, and cover crop $58.82 totaled $357.97 compared to $207.77 for the NR system. ICLS and NR steer bale and protein-energy supplement cost was $110.47 vs. 103.05, finishing cost $310.57 vs. 313.67 (P = 0.84), and total expense was lower for the NR system ($1531.01 vs. $1376.49). Carcass value was greater for the ICLS steers compared to NR steers ($2013.93 vs. $1921.67; P = 0.03). ICLS and NR systems’ net returns were ($482.92 vs. $545.18). NR system net return was $62.26 greater.
181 Effect of Application Rate of Sodium Lignosulfonate and Propionic Acid on DM Losses, Nutritional Composition, and Fungal Counts of High Moisture Alfalfa Hay Mini Bales
Authors: Killerby Marjorie A , Oppong Godloves M , Almeida Saulo T , Knight Colt W , Robinson Anna , Ames Kaycee , Ma Zhengxing , Annis Seanna , Wu Changqing , Romero Juan Jose J
Published: October 2021

Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on high moisture alfalfa hay spoilage during storage. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3x10.8x13cm; 346kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. At day 0, no differences were observed for DM (68.5 ± 0.61 %), CP (23.2 ± 0.31% DM), and NDF (42.6 ± 0.66% DM), but NaL had more sugars than PRP (0.99 vs. 0.87 ± 0.66% DM) and PRP at 1% reduced mold counts vs. CON (4.71 vs. 4.97 ± 0.05 log cfu/fresh g). At day 33, DM losses were decreased by PRP at 0.5 and 1% (0.9), relative to CON (6.92) and to NaL (6.63 ± 1.13%). Both TRT decreased NDF at 0.25% (46.3) and furthermore at 1% (44.2) relative to CON (49.4), but overall PRP had lower NDF (45.2) than NaL (47.2± 0.81% DM). No differences were observed for sugars and CP. Visual moldiness (0–10) and mold counts were also decreased by PRP at 0.5% (2.4 and 5.30) and 1% (0 and 2.7) relative to CON (6.0 and 7.13) and NaL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). In conclusion, NaL failed to prevent spoilage of high moisture hay while PRP was effective at doses >0.5%.
187 Forage Agronomists Are Needed in Animal Science Departments
Authors: Looper Michael L , Jennings John A
Published: October 2021

Ruminants serve a valuable role in sustainable agricultural systems, specifically in the conversion of renewable resources from grasslands, pasture, and other by-products into edible human food. Recognizing forage and grasses are grown on 25% of arable land, suitable agronomic practices for grazing livestock are necessary to minimize water and soil erosion. Demographics of Animal Science students have changed over the last several years with more students from urban backgrounds and with interests other than traditional animal agriculture. This makes continued emphasis on education programs supporting the grazing livestock industry that much more important. However, for many reasons, universities place less emphasis on training Ph.D. students in forage agronomy. Based on an email survey of 10 land grant institutions, typically one M.S. student/yr and one Ph.D. student/3–4 yr graduates with an advanced degree in forage agronomy. Most departments have experienced dramatic budget reductions. Challenges with funding faculty positions outside of a department’s emphasis area typically results in the question “Should forage agronomy students be trained in Departments of Animal Science or Crop/Soils Science?” It could be argued that either department is the best fit. Forage agronomy requires training in the basics of plant and soil science, but the application of those sciences relate more to animal science and animal production than to traditional crop production such as cereal grains. Departments of Animal Science must communicate the meaningful context of forage agronomy in an active learning environment developing students’ ability to critically think and solve problems. Those providing technical expertise to livestock producers can no longer make recommendations based solely on production efficiency and profitability. Instead, best management practices must include the impact of grazing livestock on the environment. Cooperative agreements between departments should be discussed to adequately support student development in this critical subject matter.
197 Awardee Talk: Novel Management Strategies to Enhance Growth and Development of Feedlot Receiving Cattle
Authors: Cooke Reinaldo F
Published: October 2021

Feedlot receiving is one of the most critical phases within the beef production cycle, when cattle are exposed to several stress and health challenges that impact their welfare and productivity. These stressors include weaning, road transport, and commingling with different animals, which elicit adrenocortical and acute-phase protein responses known to impair cattle immunocompetence and growth. Accordingly, incidence of bovine respiratory disease (BRD) is elevated during feedlot receiving, despite efforts to minimize stress and vaccination protocols against BRD pathogens. With increased restrictions regarding the use of feed-grade antimicrobials in livestock systems, our research group has focused on developing management systems that minimize stress and enhance performance and immunity of receiving cattle. By providing all vaccines against BRD pathogens prior to feedlot entry, our group reported increased (P ≤ 0.05) vaccine efficacy, body weight (BW) gain, feed efficiency, and reduced BRD incidence during the receiving period compared to on-arrival or delayed vaccination. Reducing the number of cattle sources within receiving pens, as a manner to alleviate commingling stress, reduced (P = 0.04) the number of antimicrobials needed for cattle diagnosed with BRD to regain health. Administration of a bovine appeasing substance (BAS) to beef cattle at weaning alleviated (P ≤ 0.05) the resultant acute-phase protein response, enhanced humoral immunity against BRD pathogens, and improved BW gain during a 6-wk postweaning period. Likewise, BAS administration to steers upon feedlot arrival facilitated (P ≤ 0.05) early detection of BRD signs and lessened the BRD recurrence upon first antimicrobial treatment, resulting in improved (P ≤ 0.05) BW gain and feed efficiency during a 45-d receiving period. Collective, vaccinating cattle against BRD prior to feedlot arrival, reducing the number of cattle sources within receiving pens, and the use of BAS during stressful events are favorable strategies to enhance performance and immunity of feedlot cattle.
210 Awardee Talk: The Future of Beef: Improved Eating Quality and Livestock Systems, But No Cultured Meat
Authors: Hocquette Jean-Francois
Published: October 2021

Beef quality includes intrinsic (e.g., safety, palatability, healthiness) and extrinsic traits (e.g., animal health and welfare, environmental impacts). Concerns for extrinsic traits is increasing. In this context, cultured meat is advertised as a good alternative for consumers who want to be more responsible. However, the control of its safety and of its nutritional composition is still unclear, especially for micronutrients. Regarding environmental issues, the potential advantages of cultured meat related to greenhouse gas emissions are a matter of controversy. In this context, improving existing livestock management to have more eco- and animal-friendly systems is a key issue. In addition, communication to consumers about meat production should be more objective and well-balanced. However, there is still a high level of variability in beef palatability, which induces consumer dissatisfaction. Most grading systems describe carcasses using simple traits (e.g., weight, conformation, fatness). In parallel, research has focused on predicting beef palatability using muscle biochemical traits and biomarkers. For this, a precise definition of variables (e.g. tenderness) and repeatability of the measurements are crucial. Strategic choices have been made for the Meat Standards Australia (MSA) grading scheme to consider real consumers’ expectations, not well estimated by lab approaches. Furthermore, the “big data” approach should be encouraged to improve the Findability, Accessibility, Interoperability, and Reusability of data (the FAIR Principles). The ambitions of the International Meat Research 3G Foundation is to set up an international database with a large number of consumers’ scores to offer a predictive model of beef palatability, flexible enough to consider any local characteristics. This approach is supported by the United Nations Economic Commission for Europe to improve transparency and price signaling along the value chain.