bluuebunny/crossref_metadata_2025 huggingface dataset:
342 Sow weight development: A pragmatic approach to crossbred and selection populations
Authors: Bergsma Rob , Lei Huaigang , Yang Chengbo , Knol Egbert F
Published: September 2024

Feed used for maintenance in sows is around 1% of their live weight, and a 10 kg greater sow body weight (BW) from first lifetime insemination onwards requires 36.5 kg extra feed for maintenance annually, which increases the feed cost for a 1,000-sow operation unit by approximately $15,000 CAD per year. Genetic selection, through emphasis on feed efficiency, changes body development year after year. Phenotypic sow development should allow for adequate litter weight, litter size and longevity for an optimum lifetime production. In this study we wanted to understand sow mature weight and its variation. Sow BW (n = 14,554 of 5,292 sows) around farrowing and litter weights were collected on two crossbred and one purebred farm with industry accepted feeding protocols; that is, limited feeding at the different stages of production. Sow BW were corrected for stage of gestation and realized litter weights to represent empty BW at the day of farrowing. Body weight at the age of first insemination was added. When estimating genetic parameters, the statistical model for sow BW included, in addition to Line and HerdYearSeason, a rate parameter as a covariate (b1*AGE -1) within Farm. A bivariate analysis applying a repeatability model for the BW of purebred and crossbred animals yielded similar heritabilities (h2 = 0.58 ± 0.05 and h2 = 0.55 ± 0.05, for purebred and crossbred, respectively), and greater relevant genetic variances (335 ± 40 and 166 ± 13 kg2) with a clearly positive, but not significant genetic correlation of 0.49 ± 0.46. The (random) effect of a permanent environment was not significant for either characteristic. A second analysis in which genetic parameters were estimated simultaneously for the plateau and the rate parameter showed that genetic selection based on the repeatability model for BW only, affected both the plateau and the rate parameter. Only crossbreds were included in this analysis because the minimum required BW observations per sow were not met for purebred animals. Selection for mature BW might affect other key traits. The phenotypic correlations between the EBVs for the BW of crossbred sows and litter weight, litter size and longevity were -0.15, -0.02 and +0.02, respectively. Genetically heavier or smaller animals do not have better production with heavier ones possibly having slightly decreased performance. However, if animals are treated as equally and uniformly as possible, it is reasonable to assume that genetically heavier animals use more feed for growth, instead of for reproduction, given equal feeding rations. Heritability estimates point to a clear genetic drive to BW development. This study shows the relevance of weight observations at nucleus level and the necessity to estimate genetic correlations with production traits.
344 Preliminary heritability estimate of liver abscess incidence in beef on dairy heifers
Authors: Zuvich Miranda L , Enns R Mark , Wilson Reese , Woerner Dale R , Theurer Miles , Cleveland Matthew , Speidel Scott E
Published: September 2024

This preliminary study aimed to estimate the heritability of liver abscess incidence in fed, beef on dairy crossbred progeny. Liver abscesses affect approximately 20% to 30% of livers at slaughter. They are commonly identified during viscera inspection at slaughter due to difficulty with antemortem diagnosis. All livers with abscesses are condemned, causing a profit loss for producers. This loss is increased when the abscesses are ruptured or adhered to the gut due to additional condemnation of the gut. The most common prevention techniques include antimicrobial feed additives and nutritional management; however, mitigation has not been highly effective. Few studies have attempted to ascertain if a genetic component for liver abscess incidence exists. Determining if there is a genetic component to liver abscess occurrence could enable the ability to utilize genetic selection as a preventative measure. Liver abscess scores were collected on 1,492 crossbred beef on dairy heifers at slaughter. Cattle were harvested in Kansas. Individual livers were scored using the Elanco scoring system of 0, A-, A, A+. Scores of A+, A+AD, and A+O were combined into the A+ category. A score of 0 indicates a normal liver, as scores of A-, A, and A+ indicate increasing severity of abscesses. Scores of A+AD and A+O represent animals with adhesion to the gut or ruptured abscesses, respectively. In the dataset, the distribution was 903, 168, 69, and 352 for scores of 0, A-, A, and A+, respectively. Overall, the prevalence of liver abscesses was 39.5% in this sample. All 1,492 heifers had recorded sire information, but no dam information existed other than knowing they were of dairy origin. In total, 19 unique sires were represented in the data, with six of the sires producing 89.4% of the heifers. A 3-generation sire pedigree was built from the data, and heritability was estimated using a sire model and the statistical software package ASReml 3.0. Fixed effects included the number of bovine respiratory disease treatments, age in days, and a contemporary group consisting of kill lot and treatment type. These cattle were part of an additional study evaluating the effectiveness of various treatment regimens for mitigating the incidence of liver abscesses. There were three treatment groups, one control and two treatments. Genetic and phenotypic variation for this model was estimated to be 2.70 × 10-7 ± 9.99 × 10-9 and 1.58 ± 5.86 × 10-2, respectively. With such a small genetic variance estimate, the heritability of liver abscesses was effectively 0 (1.70 × 10-7), which suggests the lack of a genetic component for liver abscesses in these data. This was a preliminary study that had limited sire variation. Currently, dam information is being accumulated in an attempt to account for dam genetic variation.
312 Leveraging digital phenotyping from research to implementation: Insights from a pig breeding company
Authors: Chen Ching-Yi , Psota Eric , Valente Bruno , Knap Pieter , Holl Justin W
Published: September 2024

In pig breeding, the integration of phenotypes into genetic improvement has been employed for decades. With today’s advancements in modern sensors, digital phenotyping provides a promising avenue for further enhancing accuracy through genomic selection. This integration also creates opportunities to study areas that used to be challenging due to limitations in data collection. We present four examples of digital phenotypes to illustrate how a company may leverage digital phenotyping for genetic implementation: individual feed intake, computer vision leg scoring, behavior, and metabolomics. Phenotypes recorded using automated electronic devices such as feed intake devices enable continuous tracking and recording of individual feed intake events when animals enter the feeder station during performance testing. The full series of events is often condensed into a single average per individual prior to genetic evaluation. By implementing computer vision, the precision of leg scoring phenotypes has increased from subjective, human-measured categorical scores of 1 to 9 to objective, camera-based continuous assessments. We have implemented convolutional neural networks (CNNs) to predict leg scores in our selection process. Using automation, the camera-based leg scoring system enables us to extend the scale of data used in genetic evaluations to improve animal welfare and longevity. Digital phenotyping holds promise for behavioral studies. Traditional methods of phenotype collection for individual behavior have been hindered by challenges such as the difficulty of capturing individual identification and the time-consuming nature of data collection. We have developed a proprietary, custom ear tag reading method and tracking algorithm that enables the automated identification of unique pigs even in visually challenging conditions. The method estimates behavior traits including time spent eating, drinking, lying, sitting, standing, and meters of distance traveled. These are used for genetic parameter estimation with investigations on association with production traits. Understanding metabolic profiles of pigs offers the potential to uncover new traits that were previously difficult to measure, and to identify biomarkers associated with traits. In conclusion, the integration of digital phenotyping into pig breeding programs offers a path toward more precise and efficient genetic improvement. Digital data capture yields a large amount of data which still provides novel opportunities for research and application.
275 Frequency of chronic passive congestive livers at harvest in the Texas Panhandle and the association with carcass outcomes
Authors: Eckhardt Megan E , Lawrence Ty , Lucherk Loni W , Schwartz Trent
Published: September 2024

Chronic passive congestive (CPC) livers are reported as one of the most common clinical signs of right-sided Bovine Congestive Heart Failure (BCHF). Frequency of CPC livers at harvest and the associated loss of offal and carcass value does not appear in the literature. Our objectives were to 1) quantify the frequency of CPC livers at harvest within the Texas Panhandle, and 2) evaluate the association with offal and carcass outcomes. Audits were performed over the duration of a production week (both harvest shifts) per each large commercial beef processing facility (4 total) in the Texas Panhandle. West Texas A&M University trained personnel identified CPC (large blue) livers at evisceration and documented heart score (HS; scale 1 = normal to 5 = extreme structural changes), liver weight, USDA-FSIS inspection fate (U.S. Inspected & Passed; U.S. Condemned) of the liver, remaining viscera, and carcass. Other visual observations (sex, predominant black hair coat color, carcass/visceral edema, liver abscesses) were noted. 1) Frequency data were documented among cattle-type populations: sex (steers, heifers, cows, bulls), and phenotype [native, dairy-cross, dairy, category-B (Mexico-origin)]. 2) Carcass and lot identification were collected for the purpose of tracking and obtaining carcass grading data. Of carcasses deemed wholesome-U.S. Inspected & Passed, USDA yield and quality metrics [hot carcass weight (HCW), 12th-rib fat thickness (FT), ribeye area (REA), marbling score (MS)] of those identified with CPC, as well as data for the balance of respective lots were collected. Carcass outcomes of those exhibiting a CPC liver were compared with the outcomes of remaining lot. Frequency data were analyzed via chi-square. Carcass data were analyzed using mixed models, where occurrence of CPC liver was the fixed effect; facility, cattle type, and sex were random effects. A total of 83,527 animals were audited, with a CPC liver frequency of 0.17% (n = 144). Frequencies among sex (steer = 0.16%; heifer = 0.17%; cow = 0.33%; P < 0.01) and phenotypes (native = 0.15%; category-B = 0.04%; dairy cross = 0.14%; P = 0.01) were documented. Heart scores ranged from 1 to 4, with HS 3 occurring most frequently [HS 1 (n = 2); HS 2 (n = 39); HS 3 (n = 62); HS 4 (n = 17)]. Weights of CPC livers ranged from 7.3 kg to 34.4 kg; the heaviest CPC livers were recorded in cows (mean = 17.2 kg; P < 0.01). Despite USDA-FSIS guidelines, 2.08% of CPC livers were U.S. Inspected & Passed, along with 16.90% of viscera and 84.03% of carcasses. Cow carcasses encountered the greatest U.S. Condemn-rates (38.24%) among the sex categories. Within the fed-beef population, natives were the only category resulting in U.S. Condemned carcasses (10.64%). All carcass outcomes were decreased (P ≤ 0.01) by CPC livers.
330 Growth performance, incidence of scours, and plasma metabolites in beef × dairy crossbred calves transported at 2, 4, 8 and 14 d of age
Authors: Chibisa Gwinyai E , Konetchy Denise , Chahine Mireille , Murdoch Gordon K , Adams-Progar Amber , Christensen Lauren
Published: September 2024

Transportation can compromise health and production performance in young calves. Although widely accepted that the younger calves are, the greater the probability of negative outcomes, there still is a lack of evidence-based recommendations on the minimum age at transportation. Our objective was to evaluate the impact of transport age on growth performance, incidence of scours, and plasma metabolites over the first 28 d post-transport in Charolais × Holstein crossbred calves. Calves (n = 36) ages 2, 4, 8 and 14-d old were transported in summer from a commercial farm to an on-campus calf rearing facility (410 miles). Calf body weight (BW) was recorded before departure, on arrival and d 28 post-transport. Dry matter intake (DMI) and fecal scores were recorded daily. Blood samples collected prior to transportation, on arrival, and d 7 and 28 post-transport were used for targeted metabolomics analysis (Biocrates MxP Quant 500 kit). Growth performance and fecal score data were analyzed using PROC MIXED (SAS) whereas R was used for predictive modeling of metabolomics data. Over the 28-d period post-transport, DMI was greater (P < 0.01) for 14 d than 2 and 4 d old calves; however, it did not differ between 2, 4, and 8 d old calves. Average daily gain (ADG) and feed efficiency (FE) were also greater (P < 0.01) for 14 d than 2, 4, and 8 d old calves. During wk 1 post-transport, the total number of days calves had scours was least (P < 0.01) for 2 and 14 d, intermediate for 4 d, and greatest for 8 d old calves. During wk 2, the total number of days with scours was less (P < 0.01) for 8 and 14 d (average of 2 d) compared with 2 and 4 d old calves (5 d). Additionally, the total number of days calves had scours during the first 2 wk post-transport tended (P = 0.08) to be greater for 2, 4, and 8 d than 14 d old calves. However, during wk 3 and 4 post-transport, there were no differences (P ≥ 0.58) in the total number of days with scours across transport age. Arginine methylation, d 7 of measurements, carnitine uptake defect, phosphatidic acid 16:0:18:2, methylenetetrahydrofolate reductase, sodium, triglyceride 18:2:34:4, threonine, α-aminobutyric acid, and glycolithocholic acid 3-sulfate were the most important features in terms of predicting the occurrence of scours. Overall, DMI, ADG and FE were less for calves transported at 2, 4, and 8 d than at 14 d of age, which could partially be attributed to differences in the incidence rate of scours. In addition, several plasma metabolites could be good predictors of scours in transported calves.
335 Effects of feeding an immunomodulatory feed additive (NutraGen) on serum cytokine and antibody concentrations in calves following exposure to a combination bovine respiratory disease challenge
Authors: Markey Jazmin A , Rudd Jennifer , Snider Tim , Montelongo Marie , Humphrey Brooke , Chapman James D , Sharman Evin D , Garcia Miriam , Reuter Ryan R , Beck Paul A , Foote Andrew P , Wilson Blake K
Published: September 2024

Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW = 251 ± 38.2 kg were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Cytokine data were tested for normality using the Shapiro-Wilk test, determined to be non-normal, and logarithm (base 10) transformed as a result prior to statistical analysis. Multiple time effects and treatment × time interactions occurred for serum MH, BVDV 1, and BVDV 2 antibody concentrations in both experiments (P ≤ 0.05). In Exp 1, there was a tendency for an overall treatment effect for calves assigned to the CON treatment to exhibit the greatest MH serum antibody concentrations (P = 0.06). While no differences were detected between treatment groups, BVDV 1 and BVDV 2 antibody concentrations peaked on the same day in both experiments, d 28 post-challenge. There were no treatment × time interactions, treatment effects, or time effects for serum TNF-α, IFN-γ, or IL-17A concentrations (P ≥ 0.13) in either experiment. In Exp 1, there was a treatment effect for serum IL-10 (P ≤ 0.0001), where calves assigned to the PREC treatment had increased serum IL-10 concentrations when compared with calves in the other treatment groups. In Exp 2, there was a tendency for a treatment effect for IL-10 concentrations, where calves assigned to the PREC treatment displayed decreased IL-10 concentrations when compared with calves in the other treatment groups (P = 0.07). These data suggest that feeding NG to calves prior to a stress experience may alter cellular responses. Overall, these experiments suggest that NG impacted antibody concentrations and cytokine expression during a bovine respiratory disease challenge.
334 Metagenomic- and culture-based characterization of the ocular microbiome in cattle with infectious bovine keratoconjunctivitis
Authors: Amat Samat , Luecke Sarah M , Holman Devin B , Anas Muhammad , Stokka Gerald
Published: September 2024

Pinkeye, clinically known as infectious bovine keratoconjunctivitis (IBK), is one of the most highly contagious diseases impacting cattle at all ages. Despite extensive use of antibiotics and vaccines targeting Moraxella bovis, the primary IBK pathogen, the incidence of pinkeye has been increasing in North American beef cow-calf operations. This highlights the incomplete understanding of the pathogenesis of this disease and the need for novel and alternative approaches to control IBK. The objectives of this study were to: 1) characterize the ocular microbiome of beef cattle with and without IBK using shotgun metagenomic sequencing; 2) investigate the genetic diversity of M. bovis, Moraxella bovoculi, and commensal ocular bacterial isolates; 3) evaluate whether selected ocular probiotic candidate strains inhibit Moraxella pathogen growth in the presence of the ocular microbiome in culture using qPCR. A total of 143 ocular swabs were collected from cattle with (n = 102) or without IBK (n = 42) and before antibiotic treatment from beef herds across North Dakota, USA. Fifty samples from IBK (n = 38) and healthy cattle (n = 12) were also subjected to shotgun metagenomic sequencing. Seven bacterial species were relatively more abundant (P < 0.05) in the healthy cattle ocular microbiome including Bifidobacterium globosum, Bacillus licheniformis, Pasteurella multocida, Ruminococcus sp900316555, and Ruminococcus sp900100595. Arthrobacter luteus was the only bacterial species significantly associated with IBK-affected cattle. From the metagenomes, 37 high-quality dereplicated metagenome-assembled genomes (MAGs) were recovered, nearly a third of which were identified as Mesomycoplasma bovoculi (n = 10). M. bovis (n = 5) and M. bovoculi (n = 13) were also isolated from the ocular swabs of both healthy and IBK-affected cattle. These isolates represented 9 M. bovoculi and 5 M. bovis strains (average nucleotide identity < 99.99%). We also isolated and sequenced several potentially beneficial bacterial species from healthy cattle including Bacillus pumilus, Lactiplantibacillus plantarum, Lentilactobacillus buchneri, Levilactobacillus brevis, and Weizmannia coagulans. Four of these probiotic candidates were also tested for their inhibitory effects against M. bovoculi in co-culture with the ocular microbiome after 24 h incubation using qPCR. The B. pumilus, L. buchneri, L. plantarum, and W. coagulans strains, as well as a mixture of all four isolates, significantly reduced the growth of Moraxella. In summary, our results provide important information on the culturable and non-culturable fraction of the bovine ocular microbiome potentially associated with IBK and suggest that certain bacterial species in the eye may inhibit the growth of Moraxella spp.
336 Effects of feeding an immunomodulatory feed additive (NutraGen) on metabolite concentrations and cortisol production in calves following exposure to a combination bovine respiratory disease challenge
Authors: Markey Jazmin A , Rudd Jennifer , Snider Tim , Montelongo Marie , Humphrey Brooke , Chapman James D , Sharman Evin D , Garcia Miriam , Reuter Ryan R , Beck Paul A , Foote Andrew P , Wilson Blake K
Published: September 2024

Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW) = 251 ± 38.2 kg)] were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Multiple treatment × time interactions and time effects occurred for serum glucose, lactate, blood urea nitrogen, and non-esterified fatty acid concentrations (P ≤ 0.003) in both experiments. There was a general trend for serum glucose to decrease over time post-challenge, suggesting increased cellular utilization of glucose in response to the challenge. In Exp 1, treatment effects occurred for serum glucose (P ≤ 0.001) and serum lactate (P ≤ 0.01), where calves assigned to the CHLG treatment displayed the greatest concentrations of the metabolites. Blood urea nitrogen concentrations peaked at h 48 in Exp 1 and h 6 in Exp 2. There were no treatment effects or treatment × time interactions for serum cortisol, hair cortisol, or fecal corticosterone concentrations in either experiment (P ≥ 0.17). There were, however, multiple time effects for serum cortisol, hair cortisol, and fecal corticosterone concentrations in both experiments (P ≤ 0.02), indicating that the challenge directly impacted cortisol and corticosterone production. Serum cortisol steadily increased from h 96 to h 168 in both experiments. Trends in cortisol and corticosterone production were similar in both experiments; however, peak concentration times for these variables occurred later in Exp 2. These data suggest that feeding NG to calves may alter glucose availability and nutrient utilization in response to infection resulting from a bovine respiratory disease challenge.
2 Combining dynamic models with deep learning through time series analysis
Authors: Rekabdarkolaee Hossein Moradi , Menendez Hector M , Brennan Jameson R
Published: September 2024

Time series analysis is a traditional approach to analyzing a sequence of data. This approach allows us to study the trend over time, discover the temporal dependencies, and analyze the fluctuations within the data. An understanding of the underlying data generative process can lead to better forecast and decision-making. The time series application can be found across diverse domains including animal sciences, economics, and environmental sciences. In this talk, we will present the fundamental concepts of time series and traditional and state-of-the-art approaches for analyzing such data. By providing a comprehensive overview of time series analysis, this talk aims to equip the audience with a foundational understanding and practical insights into harnessing the power of temporal data and the use of mathematical models that inform and improve decision-making in animal production settings.
18 Impacts of supplementing sulfate vs. hydroxychloride sources of Cu, Mn, and Zn on heifer growth performance and physiology during feed restriction and high-starch challenge periods
Authors: Souza Isabella , Moriel Philipe , Monar Gabriel , Lima Pedro , Carvalho Andre , Oliva Guilherme , Augusto Karolina , de Porcionato Marco Felício , De Araujo Davi Brito , Vasconcelos Jose
Published: September 2024

This study evaluated the effects of supplementing different sources (sulfate vs. hydroxychloride) of Cu, Mn, and Zn during feed restriction and high-starch challenge periods on heifer growth performance and physiology. On d 0, Nelore heifers (n = 40) were stratified by body weight (BW = 238 ± 38 kg) and age (21 ± 1 mo), and individually allocated into 1 of 40 drylot pens. The study was divided: washout (d 0 to 27), nutrient surplus (d 28 to 55), nutrient restriction (d 56 to 83), and high-starch challenge (d 84 to 112). The washout period consisted of limit-feeding Tifton hay (2.5% of BW; DM basis) and providing free choice access to white salt only. On d 28, heifers were randomly assigned to receive protein DM supplementation (0.10 to 0.20% of BW) added with sulfate (SUL) or hydroxychloride (HYD) sources of Cu, Mn, and Zn (≥ 260, 200, and 960 mg of Cu, Mn, and Zn per kg of supplement DM) from d 28 to 112 (n = 20 heifers/treatment). From d 28 to 55, heifers were offered ad libitum Tifton hay. From d 56 to 83, heifers were limit-fed 50% of average hay DM intake consumed in the last 6 d of the previous phase (d 50 to 55). From d 84 to 112, each respective protein supplement was mixed with a starch-based total mixed ration (TMR). Heifers were gradually adapted to the starch-based TMR by increasing the concentrate DM amount while simultaneously decreasing the hay DM amount by 20% every 7 d (starting with 35% concentrate and 65% hay on d 84 and ending with 80% concentrate and 20% hay from day 106 to 112). Individual heifer shrunk BW were collected on d 0, 28, 56, 84, and 112, following 12 h of feed and water withdrawal. Effects of treatment × day and treatment were not detected (P ≥ 0.37) for heifer BW, average daily gain (ADG), and dry matter (DM) intake, except for ADG from d 28 to 56, which was less (P = 0.05) for SUL vs. HYD heifers (-0.21 ± 0.05 vs. -0.10 ± 0.05 kg/day, respectively). Effects of day, but not treatment × day and treatment (P ≥ 0.43), were detected for fecal pH, which remained relatively constant from d 0 to 84, and then decreased (P < 0.01) from 7.2 on d 84 to 5.8-6.0 on d 110. Overall, protein supplementation added with hydroxychloride sources of Cu, Mn, and Zn had minor positive effects on heifer growth performance immediately following a washout period, but did not improve heifer growth performance and fecal pH during nutrient restriction and high-starch challenge periods, compared with protein supplementation added with sulfate sources of same metals.
24 Maternal supplementation with different sources of trace minerals to beef cattle and its effects on postweaning responses of the offspring
Authors: Cruz Vinicius Alves , Marques Rodrigo , Kvamme Keenan , Limede Arnaldo C Cintra , Ogg Makayla A , McCoski Sarah , Posbergh Christian , Bradbery Amanda N , Mercadante Vitor R G , Mackey Shea , Pickett Autumn , Cooke Reinaldo F , Farmer Chance G , Heldt Jeff S
Published: September 2024

The goal of this trial was to evaluate the effects of different sources of trace minerals on fetal programing and their impact on cow reproductive and postweaning offspring performance until slaughter. Seventy-two non-lactating, pregnant Angus cows [initial body weight (BW) = 637 ± 13 kg; body condition score (BCS) = 5.5 ± 0.07; and age = 6.1 ± 0.57; exposed to artificial insemination (AI) = 54 and bull = 18] were ranked by BW and BCS and assigned to receive a supplement containing: 1) Cu, Mn, and Zn from sulfate source (INR; n = 24), 2) Cu, Mn, and Zn from organic source (ORG; n = 24), or 3) Cu, Mn, and Zn from hydroxychloride source (HXD; n = 24). From d 0 to calving, cows remained on the same pasture and were fed individually three times a week. After calving, pairs were assigned to the general herd management, including inorganic mineral supplementation. Calves were weaned at 6 mo of age and were managed as a single group on a backgrounding period for 85 d. Calf blood samples were collected on d -15, 0, 4, 8, 15, 20, and 28 relative to weaning to evaluate stress-related markers. After this period, calves were fed to finish in a commercial feedyard. Cattle were then harvested, and carcass data were recorded. Though not the focus of this trial, there was a numerical improvement (P = 0.22) in overall subsequent pregnancy rate for the HDX (92.1%) compared with the ING (74.3%) and ORG (75.2%) cows. Also, the HDX had a tendency (P = 0.07) for improvement in liver Cu status compared with the other treatments. At weaning, no treatment differences were detected (P ≥ 0.88) in calf weaning BW and average daily gain from weaning to feedyard receiving. There were no differences (P ≥ 0.22) in the blood stress-related enzymes and metabolites. However, there was a tendency for a decrease in plasma haptoglobin at day 15 post-weaning (P = 0.07) for the calves from HDX supplemented cows relative to other treatments (Figure 1). Which might indicate potential amelioration of inflammation for the calves from cows supplemented with HDX trace minerals during pregnancy. Feedyard growth performance were similar (P ≥ 0.35) across treatments for the offspring (Table 1). No treatment effects were detected (P ≥ 0.17) for carcass traits between treatments (Table 2). Overall, different sources of trace minerals supplemented to late gestating beef cows yield similar effects on offspring performance from weaning and background period until slaughter, whereas a potential amelioration of inflammation was observed in calves born to HDX cows.
23 Physiological and health implications of trace mineral nutrition
Authors: Marques Rodrigo
Published: September 2024

Trace minerals are often recommended to avoid possible implications for beef cattle productivity. Trace minerals have several roles in livestock species, such as protein synthesis, enzyme activation, and immune functions. The primary trace minerals for cattle include zinc, copper, selenium, iron, manganese, cobalt, and iodine. These minerals serve as cofactors for numerous enzymes involved in metabolic pathways crucial for growth, reproduction, and immune function. Trace minerals such as zinc, copper, and manganese serve as cofactors for enzymes involved in metabolism. They have crucial roles in carbohydrates, protein, and lipid metabolism, facilitating energy production and nutrient utilization. Additionally, zinc, selenium and copper, are essential for maintaining a robust immune system. They are involved in the production and function of immune cells, antibody response, and the regulation of inflammation, thus aiding in the body’s defense against pathogens and diseases. Selenium, copper, and manganese act as cofactors for antioxidant enzymes that help neutralize harmful free radicals in the body. By scavenging free radicals, these trace minerals protect cells from oxidative damage and reduce the risk of chronic diseases such as cancer, cardiovascular diseases, and aging-related disorders. Cattle obtain trace minerals from various sources, including forages, grains, supplements, and water. However, the bioavailability of these minerals can be influenced by factors such as soil composition, forage type, and dietary interactions. Therefore, careful attention to mineral supplementation and management practices is necessary to meet the specific requirements of cattle at different stages of life and production. Furthermore, research continues to elucidate the complex interactions among trace minerals and their effects on cattle health and performance. Strategies such as targeted supplementation, mineral source selection, and dietary manipulation are being explored to optimize trace mineral nutrition in cattle production systems while minimizing environmental impact and economic costs. However, trace mineral sources might vary in water solubility and bioavailability, affecting their reactivity with antagonists and microorganisms in the rumen. Hence, understanding the importance of these micronutrients and implementing appropriate management practices can help ensure optimal performance and well-being of cattle herds, ultimately contributing to the efficiency and profitability of livestock operations.
53 Relationship of Angus yearling bull pulmonary arterial pressure estimates with birth weight, gestation length and growth traits
Authors: Stearns Kaylen A , DelCurto-Wyffels Hannah , Wyffels Sam , Sitz Taylre , Bigler Lauren , DelCurto Timothy
Published: September 2024

Pulmonary arterial pressure (PAP), determines the susceptibility to High Altitude Disease (HAD) of an animal, which causes pulmonary hypertension due to hypoxia. Cattle that reside in elevations greater than 1,500 m are more susceptible to HAD. PAP measures the resistance of blood flow through the lungs and can be used as an indicator of the susceptibility of an animal to HAD. It is estimated that 1.5 million head of cattle are raised in high altitude environments (above 1,500 m) and HAD accounts for 3 to 5% of calf death loss yearly. The objectives of this study were to model the relationship of PAP estimates with birth weight, gestation length and growth traits of developing bulls. PAP estimates were collected from Angus yearling bulls ranging in age from 12 to 18-mo of age from a Montana-based Angus operation (> 1,600 m elevation, 5,400 yearlings/18-mo-old bulls from 2016 – 2023). We hypothesized that the relationship between PAP and performance traits could be described with linear or asymptotic models. We used Akaike’s Information Criterion adjusted for small sample sizes (AICc) to evaluate support for competing models reflecting hypotheses about the effects of bull age at time of testing and performance traits. Models containing an asymptotic relationship between PAP and all measured variables were the best supported from the candidate model sets. Bull age at time of PAP testing was not supported in model selection for any of the performance traits measured. PAP was greater for bulls with greater birth weight (P < 0.01; β = 2.86 ± 0.81; R2marginal = 0.25 %; R2conditional = 0.77 %). PAP was greater for bulls that had greater gestation lengths (P < 0.01; β = 33.74 ± 11.25; R2marginal = 1.40 %; R2conditional = 27.37 %). There were no observed relationships between bull PAP and weaning weight (P = 0.26). PAP was less for bulls that had greater yearling weights (P = 0.04; β = -2.16 ± 1.05; R2marginal = 0.09 %; R2conditional = 0.65 %). In addition, PAP was less for bulls that had greater weaning to yearling gains (P = 0.02; β = -1.21 ± 0.54; R2marginal = 0.12 %; R2conditional = 0.79 %). In summary, PAP was related to birth weight, gestation length, yearling weight, and growth between weaning and yearling; however, these relationships explain very little of the variation of PAP estimates.
260 Industrial hemp (Cannabis sativa) supplementation improved plasma antioxidant enzymes and stress hormones in beef cattle
Authors: Ogunkunle Nathaniel , Simpson Monya , AbdelRahim Gamal Eden , Cebert Ernst , Boateng Judith
Published: September 2024

Industrial hemp is a rich source of antioxidants due to its high CBD but there is little information known about its impact on plasma antioxidant enzyme activity and stress hormone in beef cattle. The objective of this study was to determine the effect of industrial hemp supplementation on plasma antioxidant enzymes and stress hormone of Angus cattle. Black Angus heifers (n = 20) were completely randomized into either control (CON: n = 10, receiving 0 g of hemp) or hemp (HEMP: n = 10, receiving 30 g of hemp in 200 g of commercial concentrate) in a trial that lasted for 6 wk. Each group was replicated twice. Hay and water were offered ad libitum, experimental diets were offered o700 h daily. Blood samples were collected on d 0, 7, 14, 21, 28, 35 of the experiment for enzyme-linked immunosorbent assay to determine enzyme activity using standard kits. Data were analyzed using GLIMMIX procedure for repeated measure in SAS 9.4 with Compound symmetry as covariance structure while means were separated with Tukey at 5% alpha. There was significant (P < 0.05) difference in cortisol with HEMP group having 97.54 ng/mL and 122.23 ng/mL for CON. There was treatment x time interaction in total antioxidant capacity (TAOC) and malondialdehyde, TAOC range was 7.26 to 13.95 U/mL in HEMP group and 7.56 to 11.80 U/mL in CON. In conclusion, industrial hemp improved plasma antioxidant status, reduced lipid peroxidation and decreased stress level thereby improving the performance and welfare of beef cattle
266 Breed differences in feeding behavior measured by two remote monitoring technologies in feedlot steers
Authors: Luke Madison M E , Burgess Jillian E M , Gonzalez Luciano A
Published: September 2024

Estimation of individual dry matter intake (DMI) is required to optimize feed efficiency, carcass endpoint and profitability of feedlot cattle. However, measuring individual DMI is not practical or economically viable in a commercial setting. It is suggested that feeding behavior measured by remote monitoring technologies could be used to predict DMI of feedlot steers in real-time. However, inherent differences between breeds could influence DMI and feeding behavior and therefore these may need to be considered to predict DMI from feeding behavior. The objective of the present study was to assess differences between breeds in DMI and feeding behavior using data collected from radio-frequency identification (RFID) tags linked to electronic feeders and smart ear tags with accelerometers. Twenty-four steers from each breed [Angus, Brahman and Charolais; initial body weight (BW) = 335 ± 25.0 kg/steer) were fed using 10 electronic feeders in a serial slaughter trial for up to 200 d with 50 d slaughter intervals. Data were averaged per animal and ANOVA was performed with fixed effects of breed and length of the feeding period. There was no interaction between breed and length of feeding period (P > 0.05). DMI, feeding time and visit length measured by RFID, were less in Brahman compared with Angus and Charolais steers (P < 0.05). Eating rate (g/min) was not affected by breeds (P > 0.05); however, Brahmans ate faster compared with the other two breeds when expressed as gּ min-1ּ kg BW-1 (P ≤ 0.001). Smart tags showed that daily eating and ruminating times were longest in Charolais and shortest in Brahman (P < 0.05). In contrast, time spent not active was longest in Brahman and shortest in Charolais (P ≤ 0.001). Daily ‘active’ time was longer and ‘highly active’ shorter in Angus and Brahman compared with Charolais (P < 0.001). Differences in feeding behavior suggest that breed should be considered to predict DMI from RFID and smart ear tag technologies.
268 Assessment of antimicrobial exposure on generic Escherichia coli and Enterococcus spp. concentration, prevalence, and resistance to antimicrobials in beef cattle raised with or without antimicrobials
Authors: Dornbach Colten W , Wells Jim E , Broadway Rand R , Hales Kristin E
Published: September 2024

To investigate the effects of antimicrobial exposure, Angus steers [n = 288; initial body weight (BW) = 314 and 300 kg) were sorted into 1 of 2 treatments over 2 consecutive years: steers raised without antimicrobials (NAT) and conventionally raised steers exposed to antimicrobials (CONV). Pens within treatment were adjacent and separated via empty pens from the other treatment. Before cattle arrival, pens were renovated, and soil was replaced from an area not subjected to livestock production. Monensin and tylosin were included in CONV steer diets targeting 250 and 85 mg/steer daily, respectively. On d 123, CONV steers received a metaphylactic antimicrobial; NAT steers received a sterile saline injection. From d 0 to 168, diet and rectal fecal samples were collected longitudinally at 5 timepoints to determine E. coli and Enterococcus spp. concentration, prevalence, and resistance patterns. The MIXED procedure of SAS was used with fixed effects of treatment, day, and treatment × day interaction, and random effect of pen nested within a treatment × year interaction. Feed E. coli and Enterococcus spp. concentrations were greater in NAT diets than CONV diets (P < 0.01). Erythromycin (8ERYR; 128ERYR), tetracycline (TETR), trimethoprim-sulfamethoxazole (COTR), and cefotaxime (CTXR) resistant E. coli concentrations and prevalence were greater in NAT diets than CONV diets (P < 0.02). Fecal E. coli concentrations tended to be greater in NAT steers than CON steers (P = 0.07). A treatment × day tendency was detected for 8ERYRE. coli concentrations (P = 0.06), with NAT steers tending to have greater concentrations on d 64 and 130. Conversely, CONV steers had greater 128ERYRE. coli concentrations on d 130 and 168 than NAT steers (P < 0.01). Fecal TETRE. coli concentrations were greater in CONV steers than NAT steers (P = 0.03). Fecal COTR and CTXRE. coli prevalence had a treatment × day interaction (P < 0.01), with CONV steers having greater prevalence at the beginning of the finishing phase (d 0). Conversely, NAT steers had greater COTR (d 123 and 130) and CTXR (d 130 and 168) E. coli prevalence towards the end of the finishing phase than CONV steers. Fecal Enterococcus spp. concentrations did not differ between treatments (P = 0.11). A treatment × day interaction was detected for 8ERYR and 128ERYREnterococcus spp. concentrations (P < 0.05), with CONV steers having greater concentrations on d 64, 130, and 168 than NAT steers. Overall, these data suggest that antimicrobial exposure does not inherently increase E. coli and Enterococcus spp. concentrations. Treatment differences observed for ERYREnterococcus spp. concentrations are likely a result of tylosin exposure whereas differences in 128ERYR and TETRE. coli concentrations are likely an effect of metaphylactic administration. USDA is an equal opportunity employer.
364 Genetics: How long does it take for genetics to improve carcass characteristics
Authors: Engle Bailey N , Thallman Mark , Snelling Warren M , Wheeler Tommy L , Shackelford Steven , King Andy , Kuehn Larry A
Published: September 2024

Beginning with a large push from consumers to improve meat and carcass quality in the 1990s, through selection, the beef industry has successfully made significant genetic gains towards achieving these improvements. For producers looking to increase the genetic potential of their own herds for carcass quality there are multiple considerations that will inform the time it takes to see improvement. Some of the primary factors influencing the rate of genetic gain for carcass quality phenotypes include: 1) available selection candidates, 2) trait heritability, 3) selection accuracy, and 4) selection intensity. Using the Germplasm Evaluation beef herd at the US Meat Animal Research Center, many of the possible factors influencing this timeline have been evaluated. Collection of carcass quality phenotypes has been an ongoing, long-term objective of the project and has allowed for the estimation of trait heritabilities, breed differences, heterosis effects, and genetic trends over time for this trait complex. Additionally, this herd facilitated the development of decision support tools for creating selection indices and breeding programs, representing the culmination of many of these research outcomes. There are multiple ways to achieve genetic improvement for carcass quality, and our primary objective is to equip producers and other stakeholders with the necessary information to make informed selection decisions. The USDA is an equal opportunity provider and employer.
406 Impacts of drought on long term cow-calf productivity and potential management strategies for producers to overcome these challenges
Authors: Beck Paul A , Beck Matthew R , Gunter Stacey A , Lalman David L , Prather Richard
Published: September 2024

Our climate in North America has shifted to what appears to be a dry cycle reminiscent of the 1930s and 1950s. There are predictions of extended periods of drought and other climate perturbations interspersed with short periods of respite. Drought conditions in the High Plains and Southeastern U. S. in 2011 and 2012 resulted in destocking of cow-calf operations leading to shortages in feeder cattle supplies and record prices in 2015 and 2016, but these high prices were short lived with rapid rebuilding of the cowherd and return to stable cattle numbers. The drought that started in areas of the High Plains in 2021 and intensified throughout the region in 2022 and 2023, has again resulted in massive culling and destocking of the cowherd. Today the U.S. beef cowherd, estimated at just over 28 million cows, is the lowest since 1961. Relief from the low cattle numbers is not in sight because heifer retention numbers are also the lowest since 1950. The reduced cow numbers limit the potential calf crop and available feeder cattle supplies, but the issues can be more intrusive and have long term implications. Data from multiple cowherds in Northwestern Oklahoma (R. Prather, DVM; Ellis County Hospital, Shattuck, OK) shows reductions in AI and overall pregnancy rates as body condition decreases after timed artificial insemination and during natural service breeding in range cows. There are also indications of reduced fertility of replacement heifers retained from these cows in the subsequent year following nutritional and heat stress during pregnancy. Decreasing body condition of cows during late pregnancy decreases the volume and concentration of immunoglobulins in the colostrum, leading to long term health consequences on the offspring. With limited forage resources, calves tend to skip the stocker phase of production and enter feedlots for finishing at younger ages and lighter bodyweights. Research has shown that feeding younger calves decreases performance and body weight at slaughter and produces lighter fatter carcasses. Cows maintained on western rangelands with limited hay feeding are much more susceptible to changing forage conditions than cows maintained in more intensive operations in the eastern U. S., but mature weight of cows is increasing in all regions of the U. S., effectively increasing stocking rates and reducing resilience. Research in Arkansas showed that smaller cows weaned heavier calves and produced more weaning weight per hectare than larger cows during dry years with limited forage availability. Pasture and livestock management plans and nutritional intervention need to be in place in a timely manner to prevent swings in cattle numbers and negative impacts on long-term productivity of feeder calves in response to drought and other climate stressors.
407 Transition from the ranch to the feedyard: Challenges and management strategies to improve calf health welfare and performance
Authors: Schwartzkopf-Genswein Karen S , Meléndez Daniela M
Published: September 2024

The health, welfare and performance of newly received feedlot calves is intricately connected to their pre- and post-weaning management as well as how they are transitioned from the ranch to the feedyard. Industry data suggest that despite prophylactic antimicrobial use in receiving calves the incidence of respiratory related morbidity and mortality has remained unchanged in Canadian feedyards for the past 4 decades. It is well established that any management practice causing stress or pain has an immunosuppressive effect thereby increasing the risk of calf morbidity and mortality and reducing performance efficiency. There are several factors that could contribute to this including, if and or how preconditioning is conducted, comingling at assembly yards or auctions and number of calf sources, and the distance calves are transported and the effects of rest. The impacts of other timely and relevant factors such as environmental conditions (rapid and extreme weather/temperature changes) and cattle type (dairy beef or dairy beef cross) will also be covered. Studies assessing these impacts on receiving calf health, welfare and performance as well as potential strategies for mitigating negative effects will be discussed.