bluuebunny/crossref_metadata_2025 huggingface dataset:
159 Design and Development Mechanics of a Random Forest-Based Decision-Tree Model for Sub-Acute Rumen Acidosis Management in Feedlots
Authors: Kaniyamattam Karun , Veettil Vishnudas , Rivera Madeline E , Batista Luiz Diaz , Tedeschi Luis O
Published: November 2023

Sub-acute rumen acidosis (SARA) is a ruminal digestive disorder with a prevalence of 24 to 30% in United States-based feedlots and is responsible for a lost economic opportunity of approximately $1 billion annually. Our objective for this study was to develop a decision tool which feedlot decision-makers could use to make routine managemental interventions that can mitigate the prevalence of SARA. The continuous reduction in rumen pH (pH < 5.6) is the primary causative factor that triggers its onset. However, this prolonged lower rumen pH results from the interaction between multiple other etiological factors. We developed a random forest-based decision tree prediction tool which used seventeen plausible etiological factors, which we broadly classified under four categories, namely 1) animal factors, 2) nutritional factors, 3) environmental factors, and 4) management factors (Table 1), to predict the probability of SARA in a typical US feedlot. A synthetic dataset of 100 observations was created based on a survey conducted among subject matter experts, including ruminant nutritionists, epidemiologists, and decision modelers to chart out the alleged relationship between the above seventeen etiological factors and the probability of a beef cattle population contracting SARA. The random forest model (R, 2021) was used to train as well as test the boot-strapped (80:20 split) synthetic dataset. Ability of random forest to limit overfitting without substantially increasing error due to bias contributed to the high positive predictive value (84%) of the model. Our results indicated that beef yearling cattle with mild temperament, with a rumen pH maintained above 5.6, while being fed three or more times a day, for more than 150 days on concentrate feed, with a stocking density greater than 7 m2, with excellent preconditioning, fed either sorghum or oats which are tempered with a physically effective fiber of 15% and above, under ambient temperature and humidity, along with the feeding of prebiotics, probiotics and ionophores had the least probability to contract SARA. In conclusion, our model can be used by feedlot decision modelers to test different permutations and combinations of these seventeen etiological factors customized to their respective operations to predict the probability of SARA in their herd. Future studies will improve the accuracy of the model by training it on more robust epidemiological datasets sourced from beef herds located in multiple geographic regions.
155 Impact of Ambient Temperature on Bovine Viral Diarrhea Virus and Infectious Bovine Rhinotracheitis Vaccination Response
Authors: Blaske Sarah , Epperson Kaitlin M , Quail Lacey K , Ketchum Jaclyn N , Guy Chloey P , Long Charles R , Perry George A
Published: November 2023

Vaccines are created to help the immune system fight pathogens faster and more effectively, but little is known on how season of the year impacts the immune system response to vaccination. This research was conducted to evaluate how ambient temperature (summer vs fall) impacted antibody production and immune cell type changes in Brahman and Brahman-influenced cows. Cows (n = 18) were immunized (2 mL I.M.) with a combination Modified Live Vaccine for Bovine Viral Diarrhea Virus (BVDV) and Infectious Bovine Rhinotracheitis Virus (IBR) on d 0 in either July 2022 (Summer; n = 12) or November 2022 (Fall; n = 6). Blood samples (30 mL/cow) were collected on d -3, 0, 2, 4, 6, 8, 10, 14 post vaccination and transferred to 50 mL conical tubes containing EDTA to separate plasma and peripheral blood mononuclear cells (PBMC). Density gradient centrifugation was used to isolate PBMC. Serum samples were also collected (10 mL/cow) on d -3, 0, 14. Cells were incubated with propidium iodide and antibody surface cell markers for CD4, CD8, CD25, CD14, CD86, and CD335. An Amnis FlowSight flow cytometer was used to determine the percentage of each cell type in the PBMC. Concentrations of antibodies for BVDV and IBR were determined in serum samples collected pre-vaccination (d -3 and 0) and on d 14. Differences in antibody titers and leukocyte populations were analyzed as repeated measures using the MIXED model procedure in SAS. There were no differences in IBR (P = 0.2) or BVDV (P = 0.47) antibody concentrations between seasons. Percentage of antigen presenting cells (CD14+) was greater in the Summer compared with the Fall (P = 0.01; Summer=11.7 ± 1%; Fall = 7.3 ± 1.1%), but natural killer cells (CD335+) were greater in the Fall compared with the Summer (P = 0.002; Summer = 0.6 ± 0.6%; Fall = 4.4±0.7%). There was a significant treatment by time interaction for antigen presenting cells (P = 0.04), T-helper cells (CD4+; P = 0.01), activated T-helper cells (CD4+CD25+; P ≤ 0.0001), activated cytotoxic T-cells (CD8+CD25+; P = 0.03), activated T-cells (CD25+; P ≤ 0.0001), and natural killer cells (P ≤ 0.0001), but there was no difference between seasons in activated antigen presenting cells (CD14+CD86+; P = 0.19). From pre-vaccination to d 14, natural killer cells were elevated during the Fall compared with the Summer on all days (P = 0.04). Antigen presenting cells were greater in the Summer compared with the Fall on d 4, 10 and 14 (P < 0.02). T-helper cells, activated T-helper cells, activated cytotoxic T-cells, and activated T-cells increased post-vaccination in the Fall, but did not change during the Summer. Thus, ambient temperature (summer vs fall) did not directly impact production of antibodies for IBR or BVDV but did induce changes in specific immune cells following vaccination.
105 The Effects of Roughage Neutral Detergent Fiber Concentration and Bulk Density of Steam-Flaked Corn on Performance, Carcass Characteristics, and Liver Abscesses in Finishing Beef Steers
Authors: McDaniel Zach S , Galyean Michael , Broadway Rand , Burdick Sanchez Nicole C , Carroll Jeff A , Hanratty Ashlee Noelle , Hoffman Ashley A , Dornbach Colten W , Line Dalton J , Smock Taylor M , Hales Kristin E
Published: November 2023

We evaluated the effects of dietary neutral detergent fiber (NDF) concentration from alfalfa hay and bulk density of steam-flaked corn (SFC) on growth performance, carcass characteristics, and liver abscesses in finishing beef steers. Crossbred beef steers (n = 214; 60 pens; 10 pens/treatment; initial BW 417 ± 11.9 kg) were blocked by BW and assigned randomly to treatments and fed an average of 112 d. The treatments were arranged as a 2 × 3 factorial and consisted of three NDF concentrations from alfalfa hay (3, 4.5, or 6%) and 335 g/L (10.9 kg/bu) or 425 g/L (14.5 kg/bu) steam-flaked corn (SFC; 33 or 69% starch availability, respectively). Steers were harvested at a commercial abattoir where carcass data and livers scores were collected. Performance and carcass data were analyzed with PROC MIXED of SAS with pen as the experimental unit. Pen quality grade distribution and liver scores were analyzed as binomial proportions using PROC GLIMMIX. No interactions between roughage NDF and bulk density of SFC were noted (P > 0.18); therefore, main effects are presented. Live and carcass-adjusted growth performance did not differ throughout the study (P ≥ 0.28), except for an increase in dry matter intake by steers fed 6% vs. 3 or 4.5% roughage NDF from d 70 to 105 (P = 0.02). Marbling score was greater (P = 0.05) for steers fed 3% than for 4.5 or 6% roughage NDF, and steers fed 335 g/L SFC tended to have a larger longissimus muscle area (P = 0.10) than those fed 425 g/L SFC. Presence of LA at harvest was 17.9 and 23.4% less (P < 0.01) in the steers fed 4.5 and 6% roughage NDF, respectively, than for those fed 3% roughage NDF. Similarly, the presence of A+ abscesses was greater (P = 0.03) in steers fed 3% roughage NDF than in those fed 4.5 or 6% roughage NDF. Liver abscesses were 11.7% less (P = 0.05) in steers fed 425 vs. 335 g/L SFC. Results suggest that increasing roughage NDF and bulk density of SFC are dietary strategies to decrease the presence of liver abscesses at harvest without negatively affecting growth performance.
101 Fusobacteria,Bacteroidetes, and more! Linking the Microbial Communities in Bovine Liver Abscesses to the Gut
Authors: Pinnell Lee , Daniel Young J , Thompson Tyler , Wolfe Cory , Bryant Tony C , Nair Mahesh , Richeson John T , Morley Paul
Published: November 2023

Liver abscesses (LAs) are a common and important problem in cattle because of their association with decreased growth and production, low carcass quality, and the significant economic losses associated with liver condemnation. Fusobacterium necrophorum has traditionally been considered the primary etiologic agent of LA formation in cattle, but recent evidence has demonstrated that LA microbial communities are far more polymicrobial than previously believed. Here, we characterize microbial communities within multiple LAs from the same animal, provide evidence that some LAs may be seeded from the hindgut, identify biomarkers throughout the gut-liver axis that predict the presence of LAs, and demonstrate the impact of tylosin on microbial communities in the rumen, ileum, and colon. 16S rRNA gene sequencing was used to characterize communities from LA purulent material, as well as from the luminal and epithelia, communities in three gut locations (rumen, ileum, colon) within the same animals. A combination of QIIME2 and phyloseq were used to analyze sequence data, and microbial community composition was compared based on generalized UniFrac distances. Taxa discriminant of LA occurrence were identified using linear discriminant analysis effect size (LEfSe). Despite being the most abundant genus when averaged across all LA communities, Fusobacterium spp. was not the predominant taxa in the majority of LAs. In fact, members of Bacteriodetes (largely Bacteroides, Porphyromonas) were the predominant taxa in more than one-half of all LA communities. Importantly, multiple LAs from the same animal had remarkably similar community structure, and multiple taxa including Bifidobacterium spp., widely considered beneficial to gut barrier function in humans, were differentially abundant in both the foregut and hindgut between cattle that did and did not have LAs. Further, tylosin had little impact on the diversity and composition of microbial communities within LAs but did alter communities in the rumen and small intestine. In particular, members of the family Lachnospiraceae were more abundant in the rumen and hindgut of animals given tylosin. Together, these results provide additional evidence challenging the traditional theory of LA etiology (that bacterial translocation occurs exclusively from the rumen) and provides evidence that barrier dysfunction in the gut may be the underlying cause of LA formation.
57 Using an Eid Framework at a Land-Grant, Hispanic Serving and Minority Serving Institution
Authors: Linda Scholz Teresa Maria
Published: November 2023

This session will provide participants with an overview of how an Equity, Inclusion and Diversity framework informs initiatives and strategies at a land-grant, Hispanic Serving and Minority Serving institution. Participants will learn about strategic tools that can guide their equity, inclusion and diversity work across their institutions and community outreach. The session will include interactive participation.
89 Physiological Mechanisms Related to Feed Efficiency of Beef Cattle
Authors: Foote Andrew P , Salisbury Carlee M , McConnell Hunter L , King Mindy E
Published: November 2023

Improving feed efficiency is essential for the sustainability of the US beef production system. However, achieving this goal is challenging due to various factors such as diet types, genetics, environments, and industry segmentation. To address these difficulties, it is critical to have a fundamental understanding of what contributes to efficient nutrient utilization and feed resources, which can guide future genetic selection and production practices. Despite recent progress, the regulation of feed intake in growing and finishing cattle remains incompletely understood, hindering advances in feed efficiency. Recent research has aimed to advance the hepatic oxidation theory to growing and finishing cattle fed high-concentrate diets and explored the control of appetite by gut peptide hormones. Other factors contributing to variation in feed efficiency include nutrient metabolism and hormonal control of metabolism. Previous research is limited by a lack of in-depth analysis of metabolism due to the inability to time sample collection relative to feed consumption and account for correlations among metabolites. The role of fat metabolism in the rumen has been associated with epithelial inflammation, while inflammation of the gut has been identified as a contributing factor to inefficiencies in nutrient utilization. However, there is still a need to further understand the role of fatty acid metabolism in the induction of inflammation. An issue that limits the further understanding of efficiency is that a wide variety of feedstuffs are utilized by the industry and small changes in the nutrient composition of a diet can have large impacts on efficiency. Therefore, it is important to consider the utilization efficiency of specific nutrients rather than general feed efficiency. Nitrogen utilization efficiency is becoming increasingly important due to the significant economic and environmental ramifications of inefficiencies in nitrogen utilization. There is growing evidence that precision feeding of protein to match requirements can reduce nitrogen excretion without compromising growth and efficiency. In conclusion, a better understanding of the underlying biology contributing to nutrient utilization is crucial for improving feed utilization efficiency in the US beef production system, which will enhance the sustainability of the US beef production system.
189 Single-Step Gblup Evaluation for Behavioral Traits in Labrador Retrievers Used as Guide Dogs
Authors: Riser Molly M , Leighton Eldin , Russenberger Jane , Fragomeni Breno O , Moser Caroline
Published: November 2023

The objective of this study was to evaluate the accuracy of prediction in a genomic selection program for behavior traits in a population of Labrador Retrievers used as service dogs. Phenotypic data were collected in 4841 Labrador Retrievers with ages ranging from 3 months to 2.5 years, for 17 phenotypes from the International Working Dog Registry behavior checklist. The behavior checklist is a document that standardizes a scoring system for the reaction of an individual dog to environmental stimulus. Such scores are used to assess behavior and suitability of a dog for training. Pedigree contained 23,593 animals with birth dates ranging from 1991 to 2019. Genomic data were available for 457 individuals and obtained by low-pass whole genome sequences and reduced to a 250K SNP chip. Breeding values were calculated using a single trait animal model that included the fixed effects of sex, year of birth, and a contemporary group that included month/year of behavior test and organization that hosted the test. Variance components were estimated using AIREML. Genomic information was included in the model under a single-step GBLUP (ssGBLUP) approach by substituting the pedigree numerator relationship matrix with a matrix that combined pedigree and genomic relationships. Additionally, the genomic relationship matrix was modified under a weighted ssGBLUP (wssGBLUP) approach that allowed SNPs to have different distributions. Accuracies were evaluated in a 5-fold cross-validation that simulated a forward-in-time prediction. Heritabilities were low to moderate on all traits and varied from 0.025 to 0.37. Prediction based solely on pedigree information averaged 0.49 and ranged from 0.34 to 0.69. ssGBLUP increased the average accuracy to 0.55 and ranged from 0.34 to 0.72. Genomic estimated breeding values were more accurate than those computed with pedigrees for most traits. Gains in accuracy were limited by the small number of genotyped animals and are expected to increase as more animals are genotyped. The differences seen between the ssGBLUP approach and the wssGBLUP were minimal, and accuracies decreased after the second iteration. Those results indicate that behavior traits in this population are likely highly polygenic and would not benefit from weighted approaches. However, interpretation may change, as the limitations of the current study are due to the small number of genotyped individuals. Better SNP weight estimates may occur with more animals enrolled in the program, and with that a better description of the genetic architecture of the traits. The gains in accuracy show that genomic selection can help with improvement by identifying which young dogs have the highest genetic merit for the desired traits and are the best choices to keep as replacement breeders. The use of ssGBLUP is adequate for this canine data where not all animals are genotyped, and its use is recommended in selection programs focused on service dogs.
199 Effects of Dietary Fiber and Biotic Supplementation on Apparent Total Tract Macronutrient Digestibility, Fecal Characteristics, and Fecal Metabolites of Healthy Adult Dogs
Authors: Wilson Sofia M , Swanson Kelly S
Published: November 2023

Synbiotics, or mixtures of live microorganisms and substrates selectively utilized by host microorganisms, may confer complementary or synergistic health benefits to the host. Although synbiotics have demonstrated the potential to modulate the gut microbiome and improve gastrointestinal health in many host species, research trials in companion animal diets are limited. Therefore, this study was conducted to determine the apparent total tract macronutrient digestibility (ATTD) of diets supplemented with fibers or biotics and to evaluate their effects on the fecal characteristics, metabolites, microbiota, and immunoglobulin (Ig) A concentrations of dogs consuming them. Healthy adult female beagles (n = 12; age= 6.2 ± 1.6 yr; BW = 9.5 ± 1.1 kg) were used in a replicated 3 x 3 Latin square design to test three dietary treatments: 1) basal diet based on rice, chicken meal, tapioca starch, and cellulose and without probiotics or prebiotics + a placebo treat (control, CT); 2) diet based on rice, chicken meal, garbanzo beans, and cellulose + placebo treat (GB); 3) diet based on rice, chicken meal, and garbanzo beans, and functional fiber/prebiotic blend (mannanoligosaccharides; fructooligosaccharides, inulin, pea fiber, alfalfa meal, Saccharomyces cerevisiae fermentation product) + probiotic-containing treat (synbiotic treatment, SYN). The probiotic treat contained Bacillus subtilus and Bacillus amyloliquefaciens (2 x 109 CFU/d). In each 28-day period, a 22-day diet adaptation was followed by a 5-day fecal collection phase for measurement of ATTD and fecal characteristics, metabolites, microbiota, and IgA concentrations. Fasted blood samples were collected on day 28 for serum chemistry and complete blood count. All data were analyzed using the Mixed Models procedure of SAS 9.4, with P < 0.05 being significant. ATTD of dry matter (DM), organic matter, and energy were less and DM fecal output was greater in dogs fed SYN than those fed CT or GB, whereas ATTD of crude protein was greater in dogs fed CT and SYN than those fed GB. ATTD of fat was higher and wet fecal output was less in dogs fed CT than those fed GB or SYN. Fecal DM% was greater in dogs fed CT than those fed SYN or GB, and greater in dogs fed SYN than those fed GB. Fecal short-chain fatty acids (SCFA; acetate, propionate, total SCFA) were higher in dogs fed GB than those fed CT or SYN, and higher in dogs fed GB than those fed SYN. Fecal IgA concentrations were greater in dogs fed GB than those fed CT. Serum triglycerides were less in dogs fed GB than those fed SYN or CT. Our results demonstrate that legume-based dietary fibers, with or without prebiotics and probiotics, slightly reduce nutrient digestibility, increase stool output, beneficially shift fecal metabolites, and reduce blood lipids of adult dogs.
427 A Survey of Mississippi Beef Cattle Producer Attitudes, Practices, and Demographics
Authors: Montgomery-Williams Sarah M , Brumbelow Kaitlin , Larson Jamie E , Maples Josh , Karisch Brandi B
Published: November 2023

As input costs increase, producers need to be mindful of management practices to maintain profit margins and it is important to understand current management practices. Therefore, the objective of this study was to investigate current beef marketing strategies and beliefs of beef producers in the state of Mississippi in 2019. This survey was distributed to cattle producers in Mississippi in the June/July issue of “Cattle Business in Mississippi” magazine with return postage. There also was a link included in the “Monday Memo” email sent to members of the Mississippi Cattlemen’s Association. The survey consisted of 22 questions that were divided into three sections: current practices, current cow-calf marketing practice, and general information. Responses from the survey were anonymous and confidential and were received via paper mail or electronic responses. Responses were stored and analyzed using Qualtrics. Data collected from this study were compared with 1999 data from a similar study conducted by Little et al. (2000). Out of 148 respondents, there was a 95% completion rate of surveys taken. Most respondents were 51 years and older with 54% of the respondents being part of the cattle industry for over 31 years. Ninety percent of respondents were members of the Mississippi Cattlemen’s Association and almost 60% were certified in Beef Quality Assurance. The majority, 122 of 148 producers, stated their cattle operation was not the primary source of income for their household. The average number of cows, bulls, stockers/yearling, replacement heifers and cattle on-feed on an operation was greater in the 2019 data compared with 1999. On average, the number of cows per operation increased from 40 to 68 animals, bulls increased from 2 to 5 animals, and replacement heifers increased from 7 to 17 animals from 1999 to 2019. There was also an average increase from 30 to76 animals of stocker/yearling and an increase from 2 to 27 animals of on-feed cattle. Most producers vaccinate (81%) and deworm (85%) according to recommendations and indicated a lack of labor and time as reasons for not implementing some common management practices such as preconditioning. Respondents mainly purchased calves directly from a producer (61%) or from special sales (59%). In 1999, over one-half of respondents purchased from an auction. When it came to selling cattle, 58% of respondents sold at auction regularly in 2019. In 1999, 73% of respondents sold at auctions. In 2019, 72% of respondents stated they did not retain ownership while in 1999 only 58% of respondents did not retain ownership. In conclusion, our results suggest there have been key changes within the cattle industry regarding herd size increases and a shift in selling and purchasing habits since 1999.
244 Fgf-21 Myokine Expression By Cultured Bovine Satellite Cells from 3- and 11-Month-Old Steers
Authors: Shira Katie A , Becker Gabrielle M , Murdoch Brenda M , Thornton Kara J , Chibisa Gwinyai E , Murdoch Gordon K
Published: November 2023

Myokines are proteins produced by muscle cells that regulate muscle growth and metabolism. In livestock species, little is known about most myokines or their physiological impact. While FGF-21 has been examined in humans and model species for its roles in muscle development, regeneration, and metabolism, it is important to characterize its expression in livestock, such as beef cattle. This study assessed the quantity and temporal abundance of fibroblast growth factor 21 (FGF-21) expression, from cultured bovine satellite cells (BSC). BSC were isolated from the semimembranosus muscle of 3-month-old (n = 3) and 11-month-old (n = 3) commercially raised angus-based beef steers. BSC were cultured on Matrigel in Dulbecco’s Modified Eagle Medium with 10% Fetal Bovine Serum until 70% confluency. At this time, the media was replaced with fresh media representing time zero. Cells and media were collected at times 0-, 12-, 24-, 48-, 72-, and 96-hour with zero serving as the baseline. All experiments included three biological and three technical replicates. The content of myokines including FGF-21, were analyzed in the sample’s media using a commercial ELISA kit and cells were collected and stored for gene expression analysis. Statistical analysis was completed using the GLIMMIX procedure in SAS. A repeated measures analysis was used to evaluate the fixed effects of age, time, and age×time interaction. Contrasts were used to identify whether the baseline was statistically different from the other timepoints, and Tukey-Kramer adjustments were made. Significance was determined at P ≤ 0.05. There was an interaction effect between age and time (P < 0.0001). The media from the BSC of the 11-month-old steers had greater (P < 0.0001) FGF-21 concentrations than that of the 3-month-old steers at every time point. When evaluating each time in comparison with the baseline of each age independently, there were differences between 0 and 12 hour (P < 0.0001) and 0 and 24 hour (P = 0.002) for the 3-month-old steer BSC, as well as 0 and 12 hour (P = 0.0003) for 11-month-old steer BSC. This study confirms that the myokine FGF-21 is produced by cultured BSC, and in differing quantities depending on the age of the steer at harvest. The observed differences in FGF-21 production in cultured cells harvested from 3- to 11-month-old steers may in part be responsible for some of the differences in growth patterns in muscle cells at these ages. The authors postulate that these data represent the first report of FGF-21 expression in cultured bovine satellite cells.
259 Genome-Wide Insights into Whole Gut Microbiota of Rainbow Trout,Oncorhynchus Mykiss Associated with Changes in Dietary Composition and Temperature Regimens
Authors: Idenyi John N , Eya Jonathan , Hadimundeen Abdallah , Adeyemi Abigeal
Published: November 2023

Gut microbiomes play a significant role in the growth, metabolism, and health of fish. However, we know very little about interactive effects of variations of dietary composition and temperature on rainbow trout gut microbiota. Exactly 288 rainbow trout weighing 45.6g ± 0.05 (average ± SD) were fed four isocaloric, isolipidic, and isonitrogenous diets comprised 40% crude protein and 20% crude lipid and formulated as 100 % animal-based protein (AP) and blend of 50 fish oil (FO)/50 camelina oil (CO), 100 % AP and100 % CO, 100 % plant-based protein (PP) and blend of 50FO/50CO or 100 % PP and 100 % CO in 14 or 18°C for 150 days. Gut content was analyzed using 16S rRNA gene and shotgun sequencing. The most abundant phyla identified regardless of diet were Tenericutes, Firmicutes, Proteobacteria, Spirochaetes, Bacteroidetes, and Actinobacteria while Aeromonadaceae and Enterobacteriaceae were dominant families in 18°C. Moreover, gut microbes were dominated by genes relating to amino acid, carbohydrate, fat, and energy metabolisms and influenced by temperature. The shared functional profiles for all the diets suggest that plant protein sources in combination with CO could be as good as the fish meal with 50/50 FO and CO in rainbow trout farming.
273 Effects of Xylanase Supplementation in Diets with Reduced Metabolizable Energy and Supplemental Fat on Intestinal Health, Mucosa Associated Microbiota and Growth Performance of Nursery Pigs
Authors: Baker Jonathan T , Elias Duarte Marcos Elias , Kim Sung Woo
Published: November 2023

This study aimed to investigate the effects of reducing metabolizable energy (ME) below the requirement by reducing supplemental fat on intestinal health and growth performance of nursery pigs. One hundred and ninety-two newly weaned pigs at 7.3 ± 0.6 kg BW were allotted in a RCBD with sex and initial BW as blocks. Pigs were assigned to one of 8 dietary treatments with varying ME levels (3,400, 3,375, 3,350, 3,325, and 3,300 kcal/kg ME) by reducing supplemental fat and increasing xylanase (X0: 0, X40: 1,200, X80: 2,400 and X120: 3,600 XU/kg of feed) in ME deficient diets by 100 kcals/kg. Pigs were fed diets for 35 d in 2 phases (14 d and 21 d, respectively) and growth performance was measured at the end of each phase. Phase 2 diet had titanium dioxide (0.4%) as indigestible external marker to measure ileal digestibility of nutrients. At d 35, a pig representing the median BW within each pen from 3 dietary treatments (ME at 3,400 and 3,300 kcal/kg ME with or without xylanase) were euthanized for sampling jejunal mucosa, jejunal tissue, and ileal digesta to analyze intestinal health parameters, mucosa associated microbiota, and apparent ileal digestibility (AID) of nutrients. Data were analyzed using Mixed procedure of SAS 9.4. Overall, reducing ME level had no effect on growth performance of nursery pigs. However, reducing ME by 100 kcal/kg ME below the requirement increased (P < 0.05) digesta viscosity (1.7 to 2.2 cP) and protein carbonyl (0.18 to 0.40 nmol/mg), tended to change the relative abundance of Prevotellaceae (P = 0.062, 49 to 23%) and Lactobacillaceae (P = 0.086, 7 to 19%), reduced (P < 0.05) villus height (467 to 433 µm) and villus height to crypt depth ratio (1.80 to 1.64) in the jejunum, and reduced (P < 0.05) AID of DM (59.5 to 47.3%), gross energy (59.1 to 43.0%), crude protein (63.4 to 44.6%), and ether extract (67.7 to 55.2%). Xylanase supplementation decreased (P < 0.05) digesta viscosity (2.2 to 1.82 cP) and protein carbonyl (0.40 to 0.17 nmol/mg), increased the relative abundance of Prevotellaceae (20.22 to 61.56%), increased villus height (433 to 462 µm) and villus height to crypt depth ratio (1.64 to 1.99) in the jejunum, and increased (P < 0.05) AID of DM (47.3 to 58.7%), and gross energy (42.9 to 56.0%). In conclusion, reducing ME (100 kcal/kg below the requirement) by reducing supplemental fat (by 2% unit) impaired intestinal health, reducing ability of the pigs to digest feeds whereas xylanase supplementation appeared to mediate some of the negative effects seen by energy reduction by improving intestinal morphology, reducing oxidative damage products, and diversity of the mucosa-associated microbiota.
262 Weaning-Induced Changes in Tissue Cysteine Utilization in Pigs
Authors: Gachman Alexandra M , Newell Brooke , Outlaw Alex , Bartosh Julia , Kim Haejin , Rudar Marko
Published: November 2023

Weaning stress in pigs is associated with low and variable feed intake, poor nutrient utilization, and high feed costs. Cysteine is a sulfur amino acid with key roles in pig production, but how cysteine metabolism and requirements are affected by weaning stress should be better defined. The objective of this study was to determine weaning-induced changes in tissue cysteine metabolism. Pigs (initial BW = 7.23 ± 0.68 kg) were either weaned at 21 d age and euthanized at 23 d age (W; n = 9) or remained with the sow and euthanized at 23 d age (NW; n = 9). Weaned pigs were fasted to simulate acute nutritional stress but had free access to water. At euthanasia, blood, liver, jejunum, and ileum tissues were collected. Plasma and tissue amino acids and amino thiols were analyzed by HPLC. The abundance of proteins central to liver cysteine utilization were determined by immunoblot and enzyme activity assays. Glutathione (GSH) concentrations were less in jejunum (1,379 versus 1,720 ± 70 nmol/g; P < 0.01) and ileum (1,497 versus 1,740 ± 74 nmol/g; P < 0.05) in W than NW pigs. However, liver GSH concentration was not different between W and NW pigs (P > 0.10). While cysteine in jejunum and ileum were not affected by weaning (P > 0.10), γ-glutamylcysteine (γ-GC), the immediate precursor of GSH, declined in both jejunum (9.7 versus 14.3 ± 1.4 nmol/g; P < 0.01) and ileum (6.4 versus 11.2 ± 0.8 nmol/g; P < 0.001) in W compared with NW pigs. In liver, cysteine concentration was greater in W compared with NW pigs (417 versus 298 ± 33 nmol/g; P < 0.05). Although liver cysteine was greater in W pigs, liver activity of glutamate cysteine ligase (GCL; 2.49 versus 4.15 ± 0.25 nmol γ-GC/(mg protein•min); P < 0.001) and glutathione synthetase (GSS; 1.54 versus 1.92 nmol GSH/(mg protein•min); P < 0.001), enzymes needed for GSH production, were less in W than NW pigs. Immunoblot analysis of the catalytic subunit of GCL (GCLC; P < 0.05) and modifier subunit of GCL (GCLM; P = 0.057) were also lower in W compared with NW pigs, but GSS was not different between groups (P > 0.10). While plasma taurine was lower in W compared with NW pigs (64 versus 128 ± 7 µmol/L, P < 0.001), liver taurine was greater in W compared with NW pigs (4,726 versus 2,250 ± 471 nmol/g; P < 0.01). Despite an increase systemic and liver availability of cysteine, the rate-limiting amino acid for GSH synthesis, small intestine GSH concentrations decline. This suggests that systemic cysteine is not effectively utilized for gut GSH production in pigs after weaning.
278 Efficacy of Water Application of a Humic Substance, Butyric Acid, Vitamins C, D and E And/Or Electrolytes on Performance and Mortality in Health-Challenged Nursery Pigs
Authors: Edmonds Michael S
Published: November 2023

Health challenges continue to be rampant in nursery pigs which has led to increased industry-wide mortality trends. Therefore, the objective of these three studies was to evaluate a water supplement (HV; HydraVantage, Kent Nutrition Group, Muscatine, IA) which is a proprietary blend of a humic substance, butyric acid and vitamins C, D and E, as well as an electrolyte blend on nursery performance and mortality. Experiment 1 consisted of 196 crossbred weanling pigs (7 pigs/pen with 14 pens/treatment) which were randomly allotted by BW to 2 treatments consisting of control (water for 33 d) or HV at 2 ounces/gallon of stock solution and proportioned through a medicator (1:128) for 11 d followed by water for 22 d. There were no performance differences. However, mortality was reduced (P < 0.01) from 6.12% for the control to 0.00% for HV. In experiment 2, there were 488 weanling pigs (6 to 10 pigs/pen with 14 pens/treatment) which were randomly allotted by BW to 4 treatments in a 34-d trial. Treatment 1 was control (water), Treatments 2 and 4 were HV at 2 ounces/gallon of stock for 11 d and 34 d, respectively. Treatment 3 utilized HV at 2 ounces/gallon of stock during 0 to d 11 with 1 ounce/gallon of stock of HV utilized during d 11 to d 21 followed by water. No performance differences were observed among the 4 treatments. Mortality was 10.89%, 4.82%, 5.54% and 7.26% for Treatments 1 to 4, respectively, with Treatment 1 having a greater mortality (P < 0.05) compared with Treatments 2 to 4. In Experiment 3, a 2 x 2 factorial study was conducted (7 pigs/pen with 14 pens/treatment) in which the treatments were: 1) Water; 2) HV at 2 ounces/gallon of stock for 34 d; 3) Electrolytes at 32 ounces/gallon of stock for 34 d; and 4) HV at 2 ounces/gallon of stock solution and electrolytes at 30 ounces/gallon of stock for 34 d. Overall pen gain tended to be improved (P = 0.09) by 5.23 kg with supplemental HV. Moreover, mortality was reduced (P = 0.06) by 36% (16.86% mortality for Treatments 1 and 3 vs. 10.73% mortality for Treatments 2 and 4). Supplemental electrolytes had no effect on mortality. These data suggest that HV has a positive effect by reducing mortality in pigs undergoing health challenges.
437 Incentivizing and Aligning U.S. Industry to Drive Change
Authors: Wilkinson Leah
Published: November 2023

Climate issues are complex, and the feed industry is tackling them from multiple angles. From innovations in animal food manufacturing to policy activities focused on improving efficiency and effectiveness of regulatory processes, the feed industry is working toward answers that will have an impact for the industry, all of agriculture and for the environment. Learn about recent developments that are setting the direction for sustainable change.
288 Awardee Talk: Vaginal Microbiomes of Lactating Dairy Cattle Bred Utilizing Timed Artificial Insemination Or Estrus Expression
Authors: Soffa Dallas R , McAnally Brooke E , Hickman-Brown Kyle J , Smith Molly S , Spencer Jennifer A , Poole Rebecca K
Published: November 2023

Within the cattle industry, implementation of timed artificial insemination (TAI) or estrus detection protocols aid in determining the optimal breeding date. However, previous studies utilizing both breeding strategies have found differences between pregnancy rates, further emphasizing pregnancy establishment as a prominent issue in cattle production systems. Recent research has begun to evaluate the role of the female reproductive microbiome as it pertains to pregnancy establishment in cattle. It has been demonstrated that shifts in the female reproductive bacterial communities may alter pregnancy outcomes in cattle. Therefore, the objective of this work was to evaluate vaginal microbiomes on day of artificial insemination (AI) in dairy cattle bred utilizing either TAI or estrus detection and the impacts on subsequent pregnancy outcomes. Lactating Holstein cows (104 days in milk) were classified into two groups based on breeding protocols: 1) TAI (n = 44), and 2) Heat (n = 9). On day of AI, sterile swabs were inserted into the vagina, rotated eight times, and subsequently stored at -80°C in sterile collection tubes for microbiome analysis. For microbiome analysis, the V4 hypervariable region of the 16S rRNA bacterial gene was targeted. Statistical analysis for microbiome data were conducted using PROC TTEST in SAS where equality of variances was performed. Pregnancy rates by TAI versus Heat were 56.8% and 33.3%, respectively. The phylum Firmicutes had greater relative abundance in cows bred by Heat (64.1 ± 2.3% vs. 53.9 ± 2.5%, respectively; P < 0.01) compared with phyla Proteobacteria (7.1 ± 0.8% vs. 13.7 ± 1.7%), Fusobacteria (0.9 ± 0.3% vs. 5.8 ± 1.5%), and Actinobacteria (1.8 ± 0.3% vs. 3.2 ± 0.5%) which had a greater relative abundance in cows bred by TAI (P < 0.01). Within Firmicutes, genera Ruminococcus (13.0 ± 1.0% vs. 8.5 ± 0.6%), Blautia (10.3 ± 0.7% vs. 8.0 ± 0.5%), Clostridium (5.8 ± 0.2% vs. 4.9 ± 0.3%), Oscillospira (2.2 ± 0.2% vs. 1.7 ± 0.1%), and Caloramator (2.1 ± 0.1% vs. 1.7 ± 0.1%) were all greater in relative abundance in cows bred by Heat compared with cows bred by TAI (P < 0.05). Interestingly, within Fusobacteria, genera Sneathia (0.6 ± 0.3% vs. 3.5 ± 1.0%) and Fusobacterium (0.2 ± 0.1% vs. 1.5 ± 0.5%) were greater in relative abundance in cows bred by TAI (P < 0.01). Within phyla Proteobacteria and Bacteroidetes, genera Gallibacterium and Porphyromonas respectively, were both greater in relative abundance in cows bred by TAI (P < 0.05). Collectively these results indicate that the vaginal microbiomes of lactating dairy cows bred via TAI or estrus expression differs. Additionally, a shift in the vaginal microbiome to a prevalence of the phylum Firmicutes on day of AI appears to be negatively impacting pregnancy outcomes.
25 Role of Kndy and Arcuate Kiss1r-Containing Neurons in the Preovulatory Luteinizing Hormone Surge and Puberty Onset of Female sheep
Authors: Griesgraber Max J , Onslow Kayla M , Shuping Sydney , Bowdridge Elizabeth , Hardy Steven , Aerts Eliana , Coolen Lique , Nestor Casey , Hileman Stanley , Lehman Michael , Goodman Robert
Published: November 2023

Neurons within the arcuate nucleus (ARC) of the hypothalamus containing kisspeptin, neurokinin B (NKB), and dynorphin (KNDy neurons) have an important role in regulating the pulsatile secretion of gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH). In sheep, kisspeptin neurons also contribute to the LH surge, as kisspeptin receptor (Kiss1r) antagonist administration reduces surge amplitude by 50% and KNDy neurons are likely involved, based on increased Fos expression at the time of the surge. However, the extent to which kisspeptin acts within the ARC regulate the GnRH/LH surge remains unclear. Thus, herein we tested the hypothesis that deletion of KNDy or ARC Kiss1r-containing neurons would impair the LH surge. Adult female sheep received bilateral injections targeting the ARC of NKB-saporin (NKB-SAP, n = 8), kisspeptin-saporin (Kiss-SAP, n = 10), or blank-saporin (Blank-SAP, n = 7) as a control. In other work, NKB-SAP lesioned over 90% of ovine KNDy neurons, while Kiss-SAP lesioned 67% of Kiss1r-containing cells without affecting KNDy or GnRH cell number. Ewes were also ovariectomized and a subcutaneous silastic estradiol (E2) implant was inserted at the time of neurosurgery. Two artificial luteal phases were simulated with progesterone-containing CIDRs, immediately followed by E2 treatment via implants to induce an LH surge. Blood samples were collected every two to four hours over two days and analyzed for LH via radioimmunoassay. LH surge amplitude in six of eight NKB-SAP ewes (49.5 ± 11.7 ng/mL) was significantly reduced compared with Blank-SAP control ewes (156.7 ± 20.2 ng/mL, p = 0.0001), a reduction similar to that produced by treatment with a Kiss1r antagonist. Nine of ten Kiss-SAP treated ewes displayed little to no increase of LH at the time of the expected surge (16.6 ± 5.3 ng/mL, p < 0.0001). Lesion effectiveness is currently being assessed by RNAscope, however all Kiss-SAP animals examined to date have significantly reduced ARC Kiss1r cell numbers except a single ewe which exhibited a normal LH surge. Based on these data, we propose that in ewes, KNDy neurons contribute to, but are not required for, the LH surge. In contrast, ARC Kiss1r-containing cells are essential for a functional LH surge. Given these results, we are currently assessing the role of ARC Kiss1r neurons in ovine puberty using a similar approach. Our data to date shows that time to puberty onset is similar for Kiss-SAP, Blank-SAP, and non-surgical control animals as measured by an increase in progesterone (p = 0.35). Blood samples to detect LH pulses and the LH surge are currently being analyzed, as are ARC Kiss1r cell numbers.
311 Evaluation of Post-Transit Growth Performance and Carcass Characteristics of Feedlot Heifers Sourced and Finished in Different Regions of the U.S
Authors: Gubbels Erin R , Dornbach Colten W , Rusche Warren C , Burdick Sanchez Nicole C , Carroll Jeffery A , Hales Kristin E , Broadway Paul R , Smith Zachary K
Published: November 2023

The objective was to evaluate growth performance and carcass traits following transit of feedlot heifers sourced and finished in different geographical regions in the U.S. Yearling heifers [n = 190; initial body weight (BW) 483 and 425 kg for SD and TX sourced, respectively] were used in a 2×2 factorial arrangement of origin state (SD vs TX) and finishing state (SD vs TX). Heifers were allotted on d -1 into four treatments: sourced from SD and finished in SD (SD-SD), sourced from SD and finished in TX (SD-TX), sourced from TX and finished in SD (TX-SD), and sourced from TX and finished in TX (TX-TX). Heifers were weighed on d -1, 3, 15, 28, 56, 78 (TX-TX and SD-TX) and 90 (SD-SD and TX-SD). On d 0, SD-TX and TX-SD heifers were shipped to the finishing location and weighed the following morning (d 1) to determine transportation shrink. To monitor transportation effects, vaginal temperature probes were inserted into all SD-TX and TX-SD heifers and a portion of SD-SD and TX-TX heifers on d -1 and removed on d 3. Clinical attitude scores (CAS) were recorded on d -1, 0, 1, 2 and 3 for indications of bovine respiratory disease symptoms. The GLIMMIX procedure of SAS was used to analyze growth performance and carcass measures with fixed effects of origin and finishing state. The MIXED procedure was used for CAS and temperature data with the same fixed effects and time as a repeated measure. Transported heifers had reduced temperatures (P < 0.05) during transit and post-transit compared with non-transported heifers. Temperatures of transported heifers increased (P < 0.05) during loading and unloading. On d 0, 1 and 3 there was a shift in the distribution of heifers that had a CAS score greater than 0 for TX-TX, SD-TX and TX-SD. Cattle endured high ambient temperatures (temperature humidity index value > 75) 54% and 18% of the feeding period for TX and SD finished heifers, respectively. All cumulative growth performance measures and carcass trait interactions were statistically significant (P < 0.05) besides initial BW, percent shrink of transported heifers, average daily gain, dressing percent, ribeye area and liver abscess severity, which were similar (P > 0.30). There was a shift in the distribution (P < 0.05) towards a greater proportion of Yield Grade 1 and Select carcasses for heifers fed in TX compared with those fed in SD, likely due to fewer days on feed. Overall, heifers transported to higher ambient temperatures had reduced dry matter intake, quality grades (QG) and limited growth recovery (45 kg lighter) compared with non-transported heifers. Heifers transported to lower ambient temperatures recovered growth and had improved QG at the same level of rib fat compared with non-transported heifers.
314 Dehydrated Garlic Powder Did Not Influence Enteric Gas Fluxes in Feedlot Steers
Authors: Oyedeji Oluwatobi , Lardner Herbert A , Block Hushton , Durunna Obioha N
Published: November 2023

This 2-yr study was conducted to evaluate the biochemical profiles of commercial dehydrated garlic powder (DGP) and its associated influence on enteric gas fluxes, mineral intake, and body performance at a 5% inclusion level. The DGP was assessed for the stability of the bioactive compounds, especially those responsible for garlic flavor. Each year, resealed (NE) and exposed-to-air (E) DGPs were sampled serially in storage at months 0, 1, 2, and 3. Crossbred steers (n = 40 in year 1; n = 80 in year 2) were assigned to either 5%DGP or 0%DGP treatment group in a randomized complete block design, balancing for initial body weight and breed composition. Feed and supplement intakes for individual animals were monitored using an automatic feeding system. Each year, steers were fed high-grain rations in feed bunks separate from mineral supplement bunks on a free-choice basis over 72 and 82 days, respectively. Methane (CH4), carbon dioxide (CO2), oxygen (O2), and hydrogen (H2) fluxes were also measured using an automatic head-chamber emission monitoring system. Data were analyzed using a linear model in R software with year and treatment as fixed effects. Organosulfur compounds were quantified using Ultra-Performance Liquid Chromatography and Gas Chromatography. No differences (P > 0.05) were observed for allicin, allyl methyl sulfide, dimethyl trisulfide, allyl propyl disulfide, diallyl disulfide, and diallyl trisulfide concentrations in NE-DGP. In E-DGP, the greatest (P < 0.05) concentrations of allicin, diallyl sulfide, and 2-vinyl-4H-1,3-dithiin were recorded at month 1, while other compounds remained stable (P > 0.05) throughout storage months. There were no differences (P > 0.05) in dry matter intake, average daily gain, and the gain-to-feed ratio between 5%DGP and 0%DGP groups. Garlic supplementation did not also influence (P > 0.05) body composition (ribeye area, intramuscular fat, rump fat thickness, and rib fat thickness) of steers, but supplement intake was higher (P < 0.0001) in 5%DGP (204.31 gd-1) compared with 0%DGP (148.04 gd-1) group. There were no differences in the enteric fluxes from 0%DGP and 5%DGP groups for CO2 (8854.04 g·d-1, 9322.69 g·d-1; P = 0.12), CH4 (139.75 g·d-1, 154.12 g·d-1; P = 0.29), O2 (6327.84 g·d-1, 9107.30 g·d-1; P = 0.27) and H2 (0.87 g·d-1, 0. g·d-1; P = 0.17). Results suggest that organosulfur compounds in dehydrated garlic powder can be stable and contributed to enhanced mineral supplement intake of feedlot cattle but did not affect enteric gas fluxes and body performance.