bluuebunny/crossref_metadata_2025 huggingface dataset:
PSXIII-8 Determining the effects of selenium content of high-selenium forages on weight gain in growing lambs
Authors: Davis T Zane
Published: September 2024

High selenium (Se) forages grow on seleniferous soils in many parts of the world and upon Se-contaminated rangelands such as in the Western Phosphate Resource Area in the western United States. When consumed in large enough amounts or for extended durations, animals can be poisoned, developing acute or chronic selenosis. Naïve livestock will indiscriminately consume forage with increased concentrations of Se if available. However, most animals upon ingesting a sublethal Se dose will become averted to Se-rich plants and select forages with decreased Se concentrations. The purpose of this study was to determine Se concentrations in feed that cause reduced feed intake and decreased body weight (BW) gain in growing lambs (6 to 8 mo of age). Lambs (n = 5) were randomly divided into four groups and were fed a control pellet (< 1 ppm Se) at 1.5% of their BW and had free choice to a custom Se alfalfa pellet containing < 1 (control), 10, 20, or 40 ppm Se for 8 wk. During the 8 wk period the lambs gained 32.9 ± 4.1, 27.8 ± 1.8, 18.9 ± 9.2, and 7.4 ± 2.8% (mean ±SD) of their initial BW in the < 1 (control), 10, 20, or 40 ppm Se groups, respectively. After the 8 wk were completed, the lambs were fed only the custom Se alfalfa pellets, with < 1 (control), 10, 20, or 40 ppm Se, free choice for four additional weeks. As Se concentration in the pellets fed increased, the feed intake and BW gains significantly decreased. Lambs in the control and 10 ppm Se groups ate approximately 2-fold more than the lambs in the 40 ppm Se group, which lost over 3% of their initial BW. Understanding the concentration of Se in forages and how it affects appetite and BW gain allows range managers to better manage seleniferous or Se-contaminated ranges to safely use sheep on these types of rangelands. Additional work is needed to better understand the management of other livestock species grazing on high Se-containing ranges and pastures.
PSVII-16 Recombinant bovine lactoferrin expressed in Schizochytrium sp. alleviates inflammation and oxidative damage in calf intestinal epithelial cells
Authors: Zhu Yingkun , Meade Kieran , Bu Dengpan , Ma Lu
Published: September 2024

This study aims to generate recombinant bovine lactoferrin (rbLF) by expressing it in Schizochytrium sp. (SZ) and evaluate its effects on calf intestinal epithelial cells (CIECs) exposed to lipopolysaccharide (LPS) or hydrogen peroxide-induced damage. The bovine lactoferrin expression cassette was transfected into Schizochytrium sp. via 18s rRNA gene recombination. Primary CIECs were utilized in this investigation, and the optimal dose of rbLF was evaluated by cell counting kit-8 assay after being treated with different concentrations of rbLF for 24 h. The optimal dose of rbLF was then used as a medium supplement before or after 24 h of 80 μg/mL LPS challenge or 4 h of 400 μM of hydrogen peroxide (H2O2) challenge. Cell viability, gene expression of tumor necrosis factor (TNF) -α, toll-like receptor (TLR) -4, interleukin (IL) -17A, zonula occludens-1 (ZO-1), and claudin-1, as well as protein levels of TNF-α, IL-17A, ZO-1, and claudin-1, were assessed to elucidate the preventive and therapeutic effects of rbLF. Data analysis was performed using SAS 9.4 by F-test, The statistical significance was declared at P < 0.05. Results indicate that rbLF demonstrated no cytotoxicity within the 50 to 1,000 μg/mL range on CIECs. Treatment with 175 μg/mL rbLF for 24 h increased cell viability, expression, and protein concentrations of ZO-1 and claudin following hydrogen peroxide challenge (P < 0.05). Moreover, rbLF pretreatment for 24 hours, despite decreasing cell viability after the H2O2 challenge, increased the expression and protein concentrations of ZO-1 and claudin-1 compared with non-rbLF-treated groups (P < 0.05). When used to prevent LPS-induced inflammation, rbLF enhanced the gene expression and protein concentrations of TNF-α, ZO-1, and claudin-1 compared with controls (P < 0.05). As a treatment for LPS-induced inflammation, rbLF decreased TLR4, TNF-α, and IL-17A expression levels (P < 0.05). These findings suggest that SZ-expressed rbLF is safe for calve intestinal cells and 175 μg/mL of rbLF may mitigate inflammation-induced intestinal barrier dysfunction.
PSLBI-16 Arginine requirements of young adult and senior Labrador retrievers
Authors: Dickerson Sarah M , Timlin Claire L , Fowler Jason W , Coon Craig N
Published: September 2024

Consumer demand for diets that meet the age-appropriate nutritional needs of their pets has steadily risen in recent years as senior dogs represent an increasing proportion of the pet population. However, few studies have targeted the specific amino acid requirements of the aging canine. In this study, the indicator amino acid oxidation (IAAO) technique was used to compare the arginine (Arg) requirements of young adult and senior Labrador retrievers. After 2-d adaptation to Arg-adequate basal diet (Arg = 0.82% dry matter), dogs underwent individual IAOO studies. In brief, all dogs were randomly fed one of six test diets with varying levels of arginine ranging from deficient to sufficient (final Arg content in experimental diets was 0.25, 0.29, 0.33, 0.71, 0.77 and 0.82% dry matter. Test diet was divided into 13 equal meals; at the 5th meal, a tracer amino acid was supplied (a bolus L-[1-13C] phenylalanine based on body weight was first given, followed by [1-13C] Phe doses every 30 min spanning a 4-h period), and breath samples were collected via respiration mask every 30 min. Total production of 13CO2 during isotopic steady state was determined by enrichment of 13CO2 in breath samples and total CO2 production was measured via indirect calorimetry and isotope ratio mass spectrometry (IRMS). Results for IRMS data were converted to atom percent excess (APE) and analyzed using segmented linear regression. The Four Rivers mean and population requirements for arginine were 1,004 ± 90.5 mg/1,000 kcal ME (mean ± 2 SD) in young adults and 919 ± 69.9 mg/1,000 kcal ME for senior dogs, which are slightly greater than the currently recommended amounts by NRC. As the pet food industry offers more specialized diets for aging canines, updating the amino acid requirements for such animals is increasingly important.
PSLBI-19 Utilization of infrared thermography as a non-invasive method for assessing short-term heat stress in Florida Cracker sheep
Authors: Ikuejamoye-Omotore Sola , Harrison Makenzie , Mills-Widemon Anijia , Reyes Zaira M Estrada , Terrill Thomas H
Published: September 2024

Florida Cracker sheep is a wool sheep breed that was developed under natural selection in Florida, US for more than 5 centuries. The objective of this study was to utilize infrared thermography as a non-invasive method for assessing heat stress in this breed. A total of 14 ewes were allocated to heat stress (HT, n = 7) or cooling (CTL, n = 7) conditions for 6 wk during the summer season. Treatment groups were grouped in concrete floor pens with similar dimensions and characteristics. The HT pen was exposed to regular ambient temperatures and had access to shelter, feed, and freshwater ad libitum. For the cooling pen, an evaporative cooling fan was used. Data for ambient temperature and relative humidity of HT and CTL pens were recorded on a weekly basis to estimate the temperature humidity index (THI). Rectal temperature and infrared images were taken every week with the help of a veterinary thermometer and a handheld portable infrared thermal camera, respectively. For IRT, images of the eye area, forehead, legs (left and right) and flanks (left and right) were taken. A mixed model with repeated measures was used. Fixed effects included treatment (HT or CTL), week (1 to 6), and the treatment x week interaction. Animal was fitted as a random effect and the baseline data were used as a covariate. The THI for the HT group ranged from 81.3 to 89.5. For the CTL group, the THI ranged from 73.5 to 75.6. No significant changes were observed for rectal temperature in the experimental groups. For IRT, significant differences were observed for the forehead, the eye area, and the flanks. In conclusion, IRT can be utilized as a non-invasive method to evaluate short-term heat stress in Florida Cracker sheep.
PSLBI-14 Assessment of the effective tissue concentrations of injectable lidocaine and a lidocaine-impregnated latex band for castration in calves and lambs
Authors: Allan Nick , Ross Joe , Roche Steven , Beaugrand Kendall , Schatz Crystal , Hammad Ann , Ralston Brenda , Hanson Andrea M , Olson Merle
Published: September 2024

Tail docking in lambs and castration in lambs and calves are common husbandry practices, both of which cause pain and discomfort, for which many industries recommend or require pain management. The purpose of this study was to assess the effective tissue concentrations of the current standard of care for pain mitigation in calves and lambs during castration or tail docking (injectable lidocaine) and to assess the ability of a lidocaine-loaded elastration band (LLB) to deliver effective concentrations into the scrotal or tail tissues over time. This work comprised four different field trials (n = 50/trial): 1) effective concentrations of injectable lidocaine in the scrotal tissue of dairy calves; 2) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the calf scrotums; 3) effective concentrations of injectable lidocaine in the scrotal and tail tissue of lambs; and 4) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the lamb scrotums and tails. Sensation in the tissue of interest was assessed by electrocutaneous stimulation. Sensation was correlated to tissue concentrations of lidocaine by analyzing sampled tissue for lidocaine content by High-Performance Liquid Chromatography (HPLC). Injectable lidocaine allowed for short-term anesthesia for up to 60 min calves, highlighting the importance of finding additional strategies to mitigate long-term pain. An effective concentration (EC) yielding 50% reduction in tissue sensation (EC50) of 0.635 (95% CI 0.462 to 0.829) mg/g was calculated for calf scrotal tissue. Based on HPLC data of processed biopsy samples taken over time, the LLBs yielded tissue concentartions of lidocaine that approached EC50 and exceeded EC95 at 2 and 72 h following application, respectively, and remained above those concentartions for at least 28 d after application. In lambs, injectable lidocaine allowed for short-term anesthesia for up to 180 min following injection. An EC50 of 0.174 (95% CI 0.125 to 0.248) mg/g was calculated for lamb scrotal tissue and an EC50 of 0.0765 (95% CI 0.0533 to 0.113) mg/g was calculated for lamb tail tissue. The use of the LLB provided tissue lidocaine concentrations that met or exceeded the EC50 for at least 21 to 28 d and, based on electrostimulation data, provided local anesthesia for at least 3 d when compared with a control band. The use of an LLB could provide a practical, long-duration alternative to injectable lidocaine for pain mitigation during castration and tail docking. Further studies are warranted to compare the use of LLBs to injectable local anesthetics.
PSLBI-22 Identifying plasma metabolites influencing body weight in Salmonella challenged growing pigs: A machine learning approach
Authors: da Valini Graziela Alves Cunha , Hauschild Luciano , Remus Aline
Published: September 2024

Body weight (BW) is an important component of pig productivity. Understanding the metabolic factors affecting growth rate is key to guiding nutritional strategies and bringing economic benefits to pig farms. Machine learning (ML) algorithms have been used to capture patterns in large datasets and predict animal production traits based on integrated information of performance data and blood records. However, utilizing ML models and metabolomic profiling to predict BW of pigs in small datasets with challenged animals has yet to be reported. Therefore, this study investigated use of plasma metabolites in predicting BW of pigs at the growing stage. This simulation used data from gilts (n = 40; BW = 25.6 ± 2.3 kg) raised over a 28-d trial. Plasma samples and BW were collected on d 0, 14, and 28 after 8 h of fasting. Ninety plasma metabolites were identified and quantified from an untargeted metabolomics assay. The development dataset included 30, and the validation dataset contained 10 unique animals with repeated measures in time. The metabolites were log-transformed, Pareto-scaled and missing values were imputed using the minimum nonzero value method. The BW prediction model was performed in R with the caret package. The optimal hyper-parameter configuration for the random forest and neural network algorithms was evaluated based on repeated cross-validation. The final model was the random forest composed of 400 trees with 45 randomly selected predictors. Model accuracy was estimated on repeated cross-validation with 10-folds and 5 repeats and compared with the validation set based on the coefficient of determination (R2), the root mean squared error (RMSE), and Pearson correlation (r). The metabolites with greater contribution with variable importance score above 10 to the model development were extracted. Aiming to understand differences in BW categories, the model response was visualized with an alluvial diagram for the 3 variables with the greatest metabolite importance, and BW was classified as high, medium, and low. The main metabolites driving BW were lysine, oleic acid, aminomalonic acid, myo-inositol, and linoleic acid. The RMSE after cross-validation was 7.22 kg of BW (r = 0.70), and R2 = 0.39. For pigs with a high BW, the predicted BW was explained by generally less plasmatic concentrations of lysine, oleic acid, and aminomalonic acid. Lysine is the main amino acid for muscle protein accretion, whereas oleic acid is for energy substrate. Aminomalonic acid is a metabolite resulting from glycine metabolism and is important in reversing oxidative damage caused by pathogens. Therefore, decreased plasma lysine, amino malonic acid, and oleic acid may indicate faster growth and lean deposition, leading to heavier BW in pigs. Using random forests helped to connect the plasma dynamics to BW and is a promising avenue to understand the main drivers in BW of group-housed pigs.
PSLBI-2 Alberta lamb producers sheep/goat vegetation management accreditation course
Authors: Hanson Andrea M , Church Cailey B M , Markus Susan , McTaggart Aspen
Published: September 2024

Sheep and goats present land stewards with a unique opportunity to graze areas that cattle cannot access and by consuming plants that cattle find unpalatable. While Alberta has a thriving sheep industry and ranks third in Canadian sheep and lamb inventories, producers continue to seek new opportunities to improve land stewardship and better understand grazing animal management. Resources are limited for flock managers that provide the details necessary to successfully graze sheep or goats and maintain forage health under typical and novel circumstances. These typical and uncommon grazing situations include invasive weeds, solar farms, low-quality marginal lands, forests, inner city vegetation control, and powerline cut blocks. In partnership with Lakeland College, the Alberta Lamb Producers and the Alberta Goat Association obtained funding from Alberta Environment and Parks through their Rangeland Sustainability Program to develop a Sheep/Goat Vegetation Management Accreditation Course. In consultation with some knowledgeable Alberta sheep and goat producers, summer students developed a series of vegetation management modules for Alberta sheep and goat producers to learn best management practices for grazing forages under typical and unique situations. These modules form a vegetation management accreditation program. The modules include 1) Grazing Principles; 2) Grazing Forages – native and tame; 3) Stockmanship and Animal Welfare; 4) Building a Business Case; and 5) Unique Grazing – under solar panels, powerline cut blocks, meeting landscape goals and controlling invasive species, forest grazing, and urban grazing. The course will be offered through Lakeland College in the D2L continuing education platform after a group of sheep/goat producers have gone through the course and provided their feedback. The D2L platform will monitor the number of producers and landowners who complete the course to determine the effectiveness of the project. The modules will educate flock owners and serve as a go-to resource for comprehensive grazing and sheep/goat management under specific situations. Stakeholders requiring or offering vegetation management services using livestock would benefit from these resources for contract and partnership development purposes. The project engages land and animal stakeholders to balance and show both perspectives and needs related to vegetation management.
PSLBI-6 Unveiling the gut mycobiota of pasture- and conventionally raised pigs
Authors: Scott Carolyn , Ibe Angela , Gzyl Katherine E , Holman Devin B , Taheri Ahmad
Published: September 2024

The gut microbiome has a significant role in mammalian health, in pigs it is influenced by factors such as age, diet, stress, environmental conditions, and farming practices. Although studies of the pig gut microbiome typically focus on bacteria, fungal members are understudied although they may have important roles in pig gut health. The objective of this research was to characterize the mycobiota in gastrointestinal tract of swine raised under two very different production systems, either outdoors on pasture or indoors in a farrow-to-finish operation (conventional). Fecal samples were collected from nursery (n = 7) and growing-finishing (n = 17) pigs as well as from sows (n = 11) on each of these conventional and pasture farms. After DNA extraction, the universal fungal internal transcribed spacer 1 (ITS1) region was PCR amplified and sequenced. A total of 353 fungal species spanning 234 genera and 6 phyla, were identified among all samples. Ascomycetes and Basidiomycetes were found to be the relatively most abundant phyla, comprising 96% of the mycobiota. There were 56 fungal species (relative abundance ≥ 0.10%) identified as differentially abundant in the fecal mycobiota of conventionally vs. pasture-raised pigs. Of these, 11 fungal species were relatively more abundant in the conventional pigs and 45 species were enriched in the pasture pigs. Kazachstania slooffiae, Penicillium polonicum, and Vishniacozyma victoriae were most strongly associated with the pigs raised under a conventional system while Enterocarpus grenotii, Leucosporidium escuderoi, and Sagenomella oligospora were among those species linked with pasture-raised pigs. Furthermore, E. grenotii was not detected in any of the conventionally raised pigs and K. slooffiae was not identified in the pigs raised on pasture. Pasture-raised pigs had significantly greater richness (number of amplicon sequence variants) and diversity (inverse Simpson diversity) in their fecal mycobiota compared with conventionally raised pigs (P < 0.05). Given these differences, it is therefore not surprising that the pigs raised under the two different systems had significantly different fungal community structures (R2 = 0.07, P < 0.001). Overall, the large differences observed between the two groups of pigs are a result of differences in diet, environment, and management system. In addition to their grain-based diet, pasture-raised pigs have access to plants and soil which may enrich their gut mycobiota as observed in the present study.
PSLBI-26 Purebred-crossbred genetic parameters for sow pelvic organ prolapse
Authors: Chen Ching-Yi , Knap Pieter , Bhatnagar Adria , Holl Justin W , Tsuruta Shogo , Lourenco Daniela , Misztal Ignacy
Published: September 2024

The incidence rate of sow pelvic organ prolapses (vaginal, uterine, or rectal) has increased in recent years. Using a relatively large dataset, this study aimed to estimate the genetic parameters for sow pelvic organ prolapse in purebred and crossbred sow herds. Data were collected from 2018 to 2023 in 32 purebred and 8 crossbred farms, including records from 75,162 purebred sows of a single maternal line and 18,988 two-way crossbred commercial sows. Pelvic organ prolapse was categorized as either normal or prolapsed at the individual sow level, with average incidence rates of 1.81% and 3.93% for purebred and crossbred, respectively. Prolapses in purebred and crossbred were considered two different traits in the model. The bivariate model included fixed effects of parity group and region, and random effects of contemporary group, additive genetic and residual. The contemporary group was defined as the farm, mating year, and month at the first parity. Genetic parameters were estimated using BLUPF90+ with the AIREML option. Heritability estimates were 0.09 for purebreds and 0.11 for crossbreds, with a genetic correlation of 0.83. Results suggested that selection strategies aimed at reducing prolapse incidence in purebred herds will also benefit crossbred sow herds. Due to the low heritability, reducing the incidence of prolapse will have to rely on genetic improvement and enhanced animal management strategies.
PSLBI-23 Effects of peri-castration pain management strategies on feed and water intake, performance, and blood cortisol concentrations of weaned beef steers
Authors: Brandner Andrea K , Wright Cody , Menezes Ana Clara B
Published: September 2024

Objectives of this study were to identify if pain management strategies at the time of castration impact feed and water intake, performance, or blood cortisol concentrations in weaned beef steers. Black Angus and Simmental Angus cross bulls [n = 30; average age = 8 ± 1 mo, average body weight (BW) = 272 ± 45.5 kg] were randomly assigned to 1 of 3 treatment groups: 1) Control (CON; n = 10 bulls), castrated via banding; 2) Analgesic (M; n = 10 bulls), received an analgesic (meloxicam; 1 mg/kg BW) immediately after banding; or 3) Anesthetic + analgesic (ML; n = 10 bulls), received an intra-scrotal and intra-cord anesthetic (total lidocaine 15 to 20 mL + 10% sodium bicarbonate) injection immediately prior to banding and an analgesic (meloxicam; 1 mg/kg BW) immediately after banding. Blood collections to measure blood cortisol concentrations were taken on d -7, -0, +0 (day of castration pre- and post-procedure, respectively), 1, and 8. Data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, day, and their interaction as fixed effects and animal as a random effect. While administering analgesics or anesthetics may reduce discomfort, the results of this study showed that these pain management practices do not significantly impact (P ≥ 0.07) on feed (CON = 7.41 ± 0.27 kg; M = 7.72 ± 0.27 kg; ML = 8.06 ± 0.27 kg) and water intake (CON = 20.90 ± 0.69 kg; M = 23.04 ± 0.69 kg; ML = 22.58 ± 0.69 kg), performance (CON = 345.40 ± 12.09 kg; M = 356.97 ± 12.09 kg; ML = 331.93 ± 12.09 kg), or blood cortisol concentrations (CON = 1.01 ± 0.19 ug/Dl; M = 1.19 ± 0.19 ug/Dl; ML = 1.38 ± 0.19 ug/DL). These data indicate that peri-castration pain management strategies can be adopted at the producers’ managerial discretion.
PSLBII-12 Cloning and analysis of target-specific CRISPR RNA and screening primers to create β-lactoglobulin knock-out goat fibroblast cell lines for nuclear transfer
Authors: Singh Mahipal
Published: September 2024

Goat milk and meat are primary or additional source of income for small farmers in large parts of the world. Goat farming is increasing in southeastern United States, due to influx of ethnic populations. Goat milk is rich in health promoting nutrients compared with other livestock milk; however, its consumption results in allergenicity in humans due to presence of β-lactoglobulin protein in milk. Although some efforts have been made to eliminate allergenicity by modifying β-lactoglobulin gene, especially in Chinese goats, more research is needed to make it a reality. The objective of this study was to design, clone and characterize CRISPR RNA (crRNA) in a plasmid vector containing Cas 9 expression cassette as well as design and analyze PCR primers for efficient screening of edited genomes as a prelude to create and analyze β-lactoglobulin knock-out goats. Three crRNAs, two from exon 1 and one from exon 2 of goat β-lactoglobulin gene with 5 base hangovers were designed and cloned individually in GeneArt CRISPR Nuclease plasmid Vector. Sequence analysis of selected plasmid clones using U 6 promoter primer, upstream of the crRNA insert, confirmed that at least 3 clones of each crRNA had the right sequence. Additionally, 4 sets (forward and reverse) of primers to amplify 4 loci in β-lactoglobulin gene flanking the crRNA sequences in goat genome were designed. PCR amplification using genomic DNA isolated from goat blood as well as goat skin fibroblasts (GSF) confirmed expected single bands of 655, 812, 502 and 437 bps with respective primer sets. Transfection of 3 crRNA clones in GSF cells and their analysis for site-specific genome modification is in progress. In conclusion, we have designed, cloned, and tested crRNA in a plasmid vector along with 4 sets of PCR primers to screen for edited genomes which will be useful to create β-lactoglobulin edited goats to eliminate milk allergenicity.
PSLBII-23 Effects of alternative production systems on growth and circulating blood profiles in Berkshire grower pigs
Authors: Hollomon Nina , Coble Derrick J
Published: September 2024

In this study, we compared the growth performance and circulating blood profiles of Berkshire grower pigs maintained in two different alternative swine production systems, the dry-lot production system, and the hoop structure production system. This study was conducted during a 75-d period spanning from May to July at the North Carolina Agricultural and Technical State University Swine Facility in Greensboro, N.C. Protein expression profiles associated with growth (FGF-19, PDGF-BB, IGF-1), feed intake (CCK), stress (cortisol) and the ability to handle oxidative stress (T-AOC) were analyzed in blood plasma obtained from 24 Berkshire nursery/grower pigs. Berkshire pigs (n = 12) were managed in a 12.19 m x 18.28 m hoop structure with the end walls removed for ventilation and a straw deep bedding system. Twelve additional Berkshire nursery/grower pigs were managed in a 0.08-ha dry-lot. These animals were provided with a canopy for shade and a wallowing area for evaporative cooling. All animals were provided with ad libitum ration and water. Individual body weights (BW) and blood samples were collected at 25-d intervals throughout the 75-d trial, culminating in three different time points. Plasma was isolated from the blood samples and used for ELISA and colorimetric assays. The BioTek 800 TS absorbance reader and Gen5 Microplate Reader and Imager software (Agilent Technologies, Inc., Santa Clara, CA) were used to obtain and calculate the optical densities of the plasma samples, respectively. The data were analyzed using the two-way ANOVA feature of JMP 17.2.0 software (SAS Institute, Inc., Cary, NC) with production system and growth period considered fixed variables, while either growth rate or protein concentration were considered as the response variable. There were four significant treatment effects observed (P < 0.05). Significantly greater concentrations of IGF-1, CCK, and T-AOC were detected in the plasma collected from Berkshire pigs managed in the dry-lot. Whereas those managed in the hoop structure production system had heavier BW. The results show that exposing pigs to higher temperatures can reduce feed intake and growth rates. However, this same stress elicits the release of hormones that promote growth, while enhancing the total antioxidant capacity in these animals. The results support the adoption of the hoop structure production system over the dry-lot production system when managing swine in regions that experience higher temperatures.
PSLBII-24 Effects of maintaining Berkshire grower pigs in alternative production systems on circulating cytokine profiles
Authors: Hollomon Nina , Coble Derrick J
Published: September 2024

In this study, we compared the cytokine profiles in the blood plasma of Berkshire grower pigs maintained in two different alternative swine production systems, the dry-lot production system and the hoop structure production system. This study was conducted during a 75-d period spanning from May to July at the North Carolina Agricultural and Technical State University Swine Facility in Greensboro, N.C. Cytokine profiles associated with the pro-inflammatory immune response [interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF) -α] and the anti-inflammatory immune response (IL-4, IL-10) were analyzed in blood plasma obtained from Berkshire grower pigs (n = 24). Berkshire pigs (n = 12) were managed in a 12.19 m x 18.28 m hoop structure with the end walls raised for ventilation and a straw deep bedding system. Twelve additional Berkshire pigs were managed in a 0.08-ha dry-lot. These animals were provided with a canopy for shading and a wallowing area for evaporative cooling. All animals were provided with ad libitum ration and water. Blood samples were collected at 25-d intervals throughout the 75-d trial, culminating in three different time points. Plasma was isolated from the blood samples and used for ELISA and colorimetric assays. The BioTek 800 TS absorbance reader and Gen5 Microplate Reader and Imager software (Agilent Technologies, Inc., Santa Clara, CA) were used to obtain and calculate the optical densities of the plasma samples, respectively. In turn, the standard curve was used to obtain the correlated protein concentrations. The data were analyzed using the two-way ANOVA feature of the JMP 17.2.0 statistical software (SAS Institute, Inc., Cary, NC) with production system and growth period considered as fixed variables, while protein concentration was considered the response variable. There were four significant treatment effects observed (P < 0.05). Significantly greater concentrations of IL-1β and IL-10 protein were detected in the plasma collected from Berkshire pigs managed in the dry-lot. Averaged across both production systems, there were greater concentrations of IL-1β and IL-10 protein detected in the blood plasma collected in growth period 1 compared with samples collected in growth periods 1 and 2. The results suggest that exposing Berkshire grower pigs to elevated temperatures during the summer elicits a dynamic immune response that favors an inflammatory response designed to destroy damaged tissues, followed by an anti-inflammatory response designed to promote tissue repair.
PSLBII-30 The effect of different soybean meal batches and protease supplementation on nutrient utilization by broiler chickens
Authors: Vieira Vivian , de Dias Isabella C , Doi Ana C B , Deda Guilherme F , Pereira Ítalo S R , de Neta Suzete P M , Felix Ananda P , Maiorka Alex
Published: September 2024

Soybean meal (SBM) is the major protein source in broiler chicken diets. However, the thermal processing of SBM may have an impact on its protein quality, reducing its solubility when over-processed. In this context, the use of exogenous protease may reduce the negative effects that the over-processing of SBM may have on protein digestibility in broiler chickens. The present study investigated two batches of SBM in broiler chicken diets supplemented or not with protease. One-d-old male Cobb 500 (n = 360) were randomly distributed in a 2 x 2 factorial arrangement (SBM batches: A and B; Protease inclusion: 0 and 50 g/t of diet). SBM protein quality was evaluated through crude protein (CP), KOH solubility, and urease activity test (UA) in batches A and B. Scanning electron microscopy was used to visualize the structural organization of particles from SBM A and B. On d 26, ileal digesta content was collected from 6 broiler chickens that were euthanized to determine the apparent ileal digestibility (AID) of dry matter (DM), crude protein (CP), and ileal digestible energy (IDE). Data obtained were submitted to ANOVA and means were compared by Tukey test with a significance declared of 5% using the GLM procedure on R Software. Protein quality assessment demonstrated KOH solubility of 85% and 75% for SBM from batches A and B, respectively. For UA analysis, SBM batch A presented 0.09 and batch B of 0.01 mg N/g (Table 1). Microscopy images emphasized visual differences in particles from batches A and B. In SBM particles from batch A, disorganized cluster structures and asymmetric pores were observed, whereas in the SBM particles from batch B, insignificant pores and large cluster aggregates were visualized in a denser structure (Figure 1). The SBM batch B presented decreased AID of DM, CP, and IDE (P < 0.05). Protease supplementation improved the AID of CP (P < 0.05) in broilers at 26 d of age, regardless of SBM batches, but no effect was observed for DM and IDE (P > 0.05; Table 2). In conclusion, SBM from batch A had greater values of KOH solubility and UA, suggesting an appropriate thermal process, and ensuring protein quality, which is demonstrated through improvement in nutrient utilization by broiler chickens. The use of 50 g of exogenous protease per t of diet improved the ileal digestibility of CP, regardless of SBM batches.
PSLBII-29 Effects of heat stress mitigation methods on growth performance, environmental, and economic outcomes of feedlot cattle raised in a hot climate
Authors: Turcios Sebastian E Mejia , Rotz Alan , McGlone John J , Rivera Carlos , Mitloehner Frank M
Published: September 2024

The increase in average global temperatures presents a challenge for the beef industry, especially in the feedlot sector where heat stress is a major animal welfare and economic concern. To combat this, shade stands out as one of the most practical methods to mitigate heat stress in feedlot cattle. An experiment was conducted as a completely randomized design with Bos indicus bulls (n = 1,560) with initial body weights (BW) of 287 kg. Three shade structure types were used to investigate the effects of different heat stress mitigation methods on cattle growth performance, environmental, and economic outcomes using live animal data, and a partial lifecycle assessment (LCA) using the Integrated Farm System Model (IFSM). The live animal portion of the experiment was done once a year over a 2-yr period with three pen replications per treatment per year (n = 6 per treatment). Four shade structures used were: conventional shade (SC; steel shade 1.8 m2 of shade/animal), double conventional shade (DS; steel shade 3.6 m2 of shade/animal), dome structures without fans (DSA; 8.5 m2/animal with 98% solar radiation blocked), and domes with fans (DCA; three large sized low-speed fans). Each pen held 65 bulls in an area of 570 m2. Live animal data were analyzed as a completely randomized design using the GLM procedure of SAS (version 9.4) with shade type as fixed effect, pen as the experimental unit, and repetition (year) considered a random effect. Cattle housed under DCA had 22 kg and 20 kg heavier final body BW (P < 0.05) compared with those housed under SC and DS, respectively. Final BW of DCA and DSA cattle were similar (P > 0.10). Average daily gain, feed efficiency, and hot carcass weight (HCW) were greater (P < 0.05) for cattle housed under DCA compared with the rest of the shade types. Dry matter intake was not affected (P > 0.10). When treatment results were extrapolated to the annual feedlot turnover of 209,700 animals, cattle in DSA and DCA versus SC and DS had 3 to 8 % reductions in greenhouse gas and ammonia emissions intensities. Compared with SC, DCA increased profitability by $29.66/animal, followed by DSA and DS with profit increases of $5.79 and $8.90/animal, respectively. Overall, the implementation of advanced shade structures improved cattle performance and profitability while reducing the environmental impact of beef production.
PSLBII-4 The effect of standardized ileal digestible sulfur amino acid intake during late gestation on gilt whole-body nitrogen retention and subsequent litter performance
Authors: Alfonso Cristhiam J Munoz , Huber Lee-Anne , Levesque Crystal L
Published: September 2024

Gestating gilts [n = 27; body weight (BW) = 158 ± 5.5 kg] were used to determine the effect of standardized ileal digestible (SID) sulfur amino acid (SAA) intake during late gestation on whole-body nitrogen (N) retention and subsequent litter performance. Gilts were assigned to one of two experimental diets that provided SAA at 60 or 200 % of estimated requirements during late gestation (0.29 and 0.92 % SID SAA, respectively; n = 15 and 12, respectively; Table 1 and 2). Each gilt received 2.53 kg of the assigned diet between gestation d 90 and farrowing; standard lactation and nursery diets were provided to gilts after farrowing and offspring after weaning, respectively. Gilt whole-body N balance was determined between d 107 and 109 of gestation using total urine collection and fecal grab-sampling. After farrowing, litters were standardized to 13 piglets and were not offered creep feed. Whole-body N retention was greater in gilts fed the diet containing 0.92 vs. 0.29 % SID SAA in late gestation (27.2 vs. 19.3 ± 1.8 g/d; P < 0.05; Table 3), but the number of piglets born alive, litter birth weight, subsequent piglet growth rates, and litter size at weaning were not different between treatment groups. The post-weaning growth performance of offspring was also not influenced by maternal dietary treatment in late gestation (Table 4). At farrowing, the post-absorptive plasma concentration of Cys tended to be less (P = 0.072) and taurine was greater (P < 0.01) for gilts fed 0.92 vs. 0.29 % SID SAA in late gestation; however, there were no differences in plasma SAA metabolites concentrations for gilts at weaning or offspring at birth (Table 5. At weaning, offspring from gilts fed 0.92 % SID SAA had greater plasma homocysteine (P < 0.05) and plasma Cys concentrations (tendency; P = 0.072) vs. offspring from gilts fed 0.29 % SID SAA in late gestation. Three weeks after weaning, plasma taurine concentration was less (P < 0.05) for offspring from gilts fed 0.92 vs. 0.29 % SID SAA in late gestation (Table 6). Six weeks after weaning, plasma glutathione concentration tended to be less (P = 0.057) for offspring from gilts fed 0.92 vs 0.29 % SID SAA in late gestation. When SAA were fed below estimated requirements during late gestation, whole-body N retention was reduced, but fetal growth appeared to be maintained, likely at the expense of maternal N retention. Such divergences in dietary SAA supply in late gestation had no effect on subsequent offspring growth performance, but it appeared that offspring SAA metabolism was impacted until at least 6 wk after weaning. The influence of differences in sulfur AA metabolites on offspring performance beyond the nursery phase remains unknown. Therefore, carry-over effects of maternal SAA supply in late gestation should be considered when developing feeding recommendations for gestating gilts.
PSLBII-2 Impact of controlled feeding on enteric methane production and animal performance
Authors: Salisbury Carlee M , Smith Zachary K , Thompson Logan R
Published: September 2024

The impact ruminants have on environmental sustainability has been of growing concern in recent decades. Many cattle in the northern great plains are fed on family-owned farms and feedlots, highlighting the need for producer-friendly mitigation strategies, such as the established, but not widely adopted management strategy of controlled or precision feeding. The objective of this experiment was to determine the impact of precision feeding on enteric methane (CH4) production and subsequent animal performance. Angus-cross steers [n = 48; body weight (BW) = 447 ± 4.4kg] were blocked by BW and assigned to one of three treatment groups. Treatments consisted of a control (CON) where steers were fed ad libitum, Treatment 1 (TRT1) 96 percent of ad libitum and Treatment 2 (TRT2) 92 percent of ad libitum. TRT1 and TRT2 were adjusted once weekly based on the CON steers average intakes from the previous week. BW was measured on d 0, 1, 28, 56, and 84 and dry matter intake (DMI; kg/d) was measured using an Insentec Roughage Intake Control System (Insentec, Markenesse, The Netherlands). Enteric CH4 and carbon dioxide (CO2) production was determined utilizing 2 GreenFeed emission measurement systems (AHCS; C-Lock Inc., Rapid City, SD). Only visits greater than 3 min in duration were used for analysis. Average Daily Gain (ADG) and gain to feed (G:F) did not differ among treatments (P = 0.17, P = 0.80, respectively), but ADG had a tendency to decrease (linear; P = 0.09). DMI was greatest for CON and least for TRT2 (P ≤ 0.01). CH4 (g/d) output differed between treatments (P ≤ 0.007). There was a tendency for a quadratic relationship for derived methane yield (MY; g/kg DMI) among treatments (P = 0.10). Emission intensity (EI; g CH4/kg gain) was not different across treatments (P = 0.40). These results suggest precision feeding may have a positive impact on methane emissions but could negatively impact performance.
PSLBII-18 Transcriptomic comparison of embryonic tissues between high and low fertility sired pregnancies
Authors: Jiménez Odile Polanco , Melo Gabriela , Ortega Sofia , Oliviera Filho Ramiro V , Franco Gessica , Cerri Ronaldo , Pohler Ky G , Moraes Vasconcelos Jose Luiz M
Published: September 2024

Pregnancy loss is considered one of the main causes of reproductive inefficiency in the beef cattle industry. The objective was to determine the differentially expressed genes (DEGs) between the conceptus and uterus of pregnancies produced by sires of known fertility. We hypothesized that the paternal genome would have a significant effect on transcript abundance between these tissues. The sires used have been previously reported to have significantly different levels of field fertility; however, they had passed all normal quality control standards for frozen thawed semen. Bos indicus heifers (n = 45) were subjected to estrus synchronization and embryo transfer with IVP embryos from either a High Fertility (HF) or a Low Fertility sire (LF), pregnancies were confirmed at slaughter. Samples were collected from the trophectoderm (TE) and caruncle (CAR) on d 25 and 36 of gestation for transcriptome analysis. Total RNA was isolated from tissue samples using the RNeasy kit (QIAGEN; Hilden, Germany) per manufacturer’s instructions. Sequencing was conducted using an Illumina platform. Sequences were aligned to the reference genome ARS-UCD1.2. DEGs between sires and tissue were determined using edge-R package from R. False discovery rate was 0.1. On d 25, out of 15,755 genes expressed in the trophectoderm, 19 genes were downregulated, and 9 genes were upregulated in the LF. In the CAR, 9 genes were downregulated and 7 were upregulated. On d 36, in the TE the LF resulted in 53 downregulated genes and 20 upregulated genes. In CAR there were 18 downregulated genes for the LF whereas 22 genes were upregulated. Gene ontology analysis reported DEGs in the LF compared with the HF were associated with immunology and reproduction. Of particular interest BoLA NC-1
PSLBII-19 Effects of high-forage backgrounding duration on dry matter intake during the early finishing phase
Authors: Pucetti Pauliane , De Filho Sebastiao Campos Valadares , da Silva Julia Travassos , Siqueira Isabelle Pinheiro , Pacheco Renata Pereira , Gandra Livia Moreira , Swanson Kendall C
Published: September 2024

The adaptation of animals to high-concentrate diets is crucial for optimizing performance in the finishing phase. However, the transition to concentrate-rich diets can lead to metabolic disorders and fluctuations in feed intake. Typically, the same adaptation protocol is used regardless of the previous feeding history of the animal. However, it is possible that the backgrounding period duration may influence initial feed intake and subsequently affect animal performance in the finishing phase. Thus, the objective of this study was to evaluate the effects of implementing different high-forage backgrounding (HFB) durations on daily dry matter intake (DMI) and DMI variance over a 28-d period following the 14-d step-up adaptation to the finishing diets of Nellore bulls. Young Nellore bulls [n = 36; average initial body weight (BW) = 265.25 ± 5 kg; age = 7 ± 1 mo] were used in a completely randomized design and assigned to one of four treatment groups (n = 9/group): 0 (HFB), 28 (HFB28), 56 (HFB56), or 84 (HFB84) d of HFB before starting the 14-d step-up adaptation period to the finishing phase. The HFB diet consisted of 800 g/kg of sorghum silage and 200 g/kg of concentrate, while the finishing diet contained 200 g/kg of corn silage and 800 g/kg of concentrate. The diets were formulated according to BR-CORTE (2016) to achieve ADG of 0.4 kg/d during the HFB phase and 1.2 kg/d during the finishing phase. All animals were fed for ad libitum intake in an electronic feeder (INTERGADO, Intergado Ltd., Contagem, MG, Brazil), and individual daily feed intake was recorded. Additionally, DMI variance was calculated for each bull from daily DMI data over the 28 d of the finishing phase after the 14-d step-up period. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) assuming the significance level of 0.05. The Tukey test was employed to compare means. Daily DMI was analyzed as repeated measures. The HFB duration had no influence on average DMI of the first 28 d of the finishing phase (P = 0.10; Averages per treatment (kg/d): HFB0 = 7.34, HFB28 = 6.53, HFB56 = 6.71, HFB84 = 6.02). However, a significant interaction was observed between treatments and day on finishing phase (P < 0.001), indicating that the effects of different HFB duration may vary over time during the finishing phase, influencing the daily DMI. Furthermore, the HFB84 presented a higher DMI variance, while the remaining treatments did not differ significantly among themselves (P < 0.001; Averages per treatment: HFB0 = 0.927, HFB28 = 0.616, HFB56 = 0.980, HFB84 = 3.487). In conclusion, the HFB84 increased the variation in daily DMI after adaptation to the finishing diet, indicating that a longer adaptation period may be needed for animals fed high-forage backgrounding diets for longer durations.