bluuebunny/crossref_metadata_2025 huggingface dataset:
PSIII-17 Relationship of toll-like receptor abundance in the boar reproductive tract with dihydrotestosterone prior to attainment of puberty
Authors: Ognibene Olivia J , McAnally Brooke , Poole Rebecca K , Wiegert Jeffrey
Published: September 2024

Fertile sperm production is crucial to the reproductive efficiency of swine operations; therefore, many factors impair quality semen production including hormonal imbalance and altered immune function. Toll-like receptors (TLRs) are a family of pattern recognition receptors which recognize and protect their host against pathogenic microorganisms through the regulation of inflammatory pathways. Recent data from our lab demonstrated greater expression of TLR2 mRNAs in the testes compared with other reproductive tissues (e.g., epididymis, seminal vesicles, and prostate) of pre-pubertal boars, suggesting TLR2 may aid early-in-life testes function or development. Expression of TLRs in various tissues has been shown to be influenced by hormones in rodents and humans. Dihydrotestosterone (DHT) is a sex steroid hormone and androgen that has a role in sexual development of males. However, little research has related TLRs with hormone concentration, which may help give insight to their physiological significance, particularly in the pre-pubertal male. Therefore, the objective of this project was to characterize relationships between expression of extracellular TLRs (TLR2, TLR4, TLR5 and TLR6) in the reproductive tissues (testes, epididymis, seminal vesicles, and prostate) with DHT concentrations in pre-pubertal boars. Intact reproductive tracts of pre-pubertal crossbred boars (Duroc x Landrace x Yorkshire; n = 4) were harvested at 2 mo of age and tissues were stored at –80°C for RT-qPCR analysis. From each boar, blood was collected postmortem and subsequent plasma samples stored at –20°C. Concentration of DHT in boar plasma was quantified using a competitive ELISA (MyBioSource, San Diego, CA) according to the manufacturer’s instructions. Expression of TLR2, TLR4, TLR5, and TLR6 mRNAs in the pre-pubertal boar tissues were quantified by RT-qPCR. Correlations of DHT concentration and TLR expression were calculated using Pearson Correlation within the PROC CORR function in SAS 9.4. The mean concentration of DHT was 9.32 ng/mL (range of 4.52 to 14.80 ng/mL). In the seminal vesicles, DHT concentration was significantly correlated with expression of both TLR2 (r = 0.95; P = 0.05) and TLR4 (r = 0.96; P = 0.04). In the testes, there was a tendency for a positive correlation between DHT concentration and expression of TLR2 mRNA (r = 0.92; P = 0.08). However, there were no correlations between DHT concentration and expression of any TLRs in the pre-pubertal boar epididymis or prostate (P > 0.10). These results suggest a relationship between androgens and TLR expression, particularly TLR2 and TLR4 mRNAs, in specific reproductive tissues of the pre-pubertal boar. Additional work will investigate TLR expression and androgen concentration in the pubertal boar.
PSIII-6 Multi-sire artificial insemination of beef heifers in the Nebraska Sandhills effect on pregnancy rate compared with single-sire insemination
Authors: Christenson Dempster M
Published: September 2024

The objective of this study was to compare pregnancy outcomes resulting from artificial insemination (AI) with multi-sire semen (MS) compared with single-sire semen (SS) in beef heifers. Another study observed pregnancy and paternity outcomes to sexed MS without a control treatment. In the first study, unrelated ABS Global Angus bulls (n = 3) were selected for AI to 441 (Yr 1) and 391 (Yr 2) Angus crossbred heifers. Heifers were synchronized with the melengestrol acetate – prostaglandin F2α timed-AI protocol. Conventional semen, from each bull, were labeled A, B, or C. Remaining semen was pooled in equal amounts to form conventional MS straws. Heifers were AI using alternating treatment of MS or SS: A, B, or C with one-half of inseminated heifers receiving either MS or SS. The GLIMMIX procedure in SAS 9.4 analyzed responses to treatments using the BIN distribution option and reported as LSMEANS. Contrasts and estimates analyzed responses between treatments. Ultrasound determined SS pregnancy rate averaged 60% (SS-A = 64%, SS-B = 58%, SS-C = 58%) and MS average 62% (P = 0.63). Paternity was determined in 57 MS calves and confirmed in 49 SS calves. In Yr 1, Bull A sired 7%, bull B sired 56%, and bull C sired 37%. Although bull A was much less successful than bull B or C, the values are not significantly different due to the small sample size (P = 0.11 and P = 0.24, respectively). Few conclusions can be made from the ongoing study, but it is hypothesized MS may improve consistency of pregnancy rate by equilibrating semen quality in herds subjected to timed AI. In the observational study, multiple 5-way cross bulls born from the ranch herd were selected for AI of 951 ± 41 heifers for 3 yr. Heifers were synchronized using the previously mentioned protocol with split-time AI. Unequal amounts of semen were collected, pooled, and sexed to favor heifer progeny at an expected ratio of 9:1. Semen from 2 to 4 random bulls were pooled making 3 to 4 MS groups each year. Heifers exhibiting estrus were administered sexed MS, but there was no control treatment. The observed ultrasound determined average pregnancy rate of heifers administered sexed MS was 65% (Yr 1), 75% (Yr 2), and 72% (Yr 3). Previous literature suggests average pregnancy rate to AI with sexed SS is 53%. Paternity testing in Yr 2 found semen contribution mirrored paternity ratios within some groups but the sire group with 2 bulls found one sired 15% and the other sired 85%. This study exemplified a viable method for AI that requires further research. Further research into semen quality of a single sire, and pooled semen could lead to optimization of fertilization among individuals within a herd.
PSIII-2 Exploring differential gene expression and pathways associated with pregnancy outcomes in beef heifers
Authors: Brown Tristan C , Banerjee Priyanka , Rodning Soren P , Dyce Paul W W , Da Diniz Wellison Jarles Silva
Published: September 2024

Heifer fertility is a key factor in the success of beef production systems, as the reproductive performance of a heifer correlates with her stayability in the breeding herd. However, despite being reproductively mature and physically healthy, 5 to 15% of these heifers fail to conceive within a designated breeding season. The underlying physiological mechanisms preventing these heifers from achieving pregnancy remain elusive. Therefore, this study aimed to determine differentially expressed genes (DEGs) and biological pathways associated with pregnancy outcomes in beef heifers. Angus-Simmental crossbred heifers were subjected to an estrus synchronization and fixed-time artificial insemination (AI) program (7-d CO-Synch + CIDR) and blood samples were collected at the time of AI for isolation of peripheral white blood cells (PWBC). After pregnancy check, heifers were classified as pregnant (P) and non-pregnant (NP). Based on that, 6 animals per group were randomly selected for total RNA isolation from the PWBC samples, and genome-wide expression was measured through RNA sequencing. The RNA-Seq data were analyzed using an in-house bioinformatics pipeline, with filtered reads aligned to the Bos taurus reference genome using STAR. DEGs were identified using DESeq2, followed by functional analysis using ShinyGO. Our approach unveiled 230 DEGs, comprising 102 up and 128 downregulated genes in the NP group (P-value ≤ 0.05 and |log2FC| > 0.5). Upregulated genes included those from the cytochrome P450 superfamily (CYP27B1 and CYP2U1). The genes SCML2, USIG2, and FBP1 were upregulated and have been associated with immune response and increased PWBC counts. This may be related to the over-representation of biological processes involved in cell division based on the upregulated genes. KEGG pathway over-representation analysis of DEGs retrieved allograft rejection, graft-versus-host disease, type I Diabetes Mellitus, insulin signaling pathway, and transcriptional misregulation of cancer. These pathways included genes such as BOLA-DQB, PRKAR1B, CALML4 and JUP, which were reported as downregulated during times of inflammatory response. Another downregulated gene was GZMB, which is needed for proper cell targeting during immune response. This finding may provide a link between immune function and early pregnancy failure. However, the relationship between the immune system and pregnancy warrants further investigation. Our results shed light on the molecular mechanisms underlying reproductive performance in beef heifers and support previous studies associating immune function with pregnancy outcomes. These differentially expressed genes may be further explored as potential avenues for enhancing fertility in beef production systems.
PSIII-22 Downregulations in the expression of insulin-like growth factor binding proteins in a temporal model of in utero hypothyroidism
Authors: Smith Alyssa A , Rudy Kaylyn , Pasternak J Alex A
Published: September 2024

The insulin-like growth factor (IGF) system is responsible for mediating the effects of growth hormone, which has important roles in regulating fetal development and growth throughout gestation. Prior research suggests a relationship between thyroid hormones and activity of the IGF system; however, the temporal association of this interaction is not well understood. As a result, the objective of the current study was to better characterize temporal dysregulations in the IGF system occurring as a result of induced fetal hypothyroidism in a porcine model. To accomplish this, pregnant gilts (n = 24) were divided evenly into a control (CON) and methimazole (MMI) group. The MMI group was treated daily with 5 mg/kg of oral MMI, a potent antithyroid drug, while the CON received an equivalent sham carrier. The two groups were further subdivided into four timepoints (n = 3/group at each timepoint), with treatment in each group beginning at either d 34, 45, 55, or 65 of gestation. Treatment was continued for 21 d, and gilts were subsequently euthanized to allow for fetal sample collection at d 55, 66, 76, and 86, respectively. Blood samples were collected from the axillary artery of all fetuses (n = 340), and extensive sampling of fetal thyroid, liver (LVR), and kidney (KID) performed on a subset of 4 fetuses per litter (n = 96). Fetuses from the MMI group were confirmed hypothyroid by the presence of goitrous thyroid histology and significantly decreased circulating thyroxine concentrations relative to CON (P < 0.001 for all timepoints). Following confirmation of fetal hypothyroidism, samples of LVR and KID were ground to a fine powder to allow for RNA extraction, reverse transcription, and analysis of gene expression by qPCR. Resultant Ct values were normalized within tissue based on the geometric mean of two stable reference genes, with fold changes calculated using the 2-∆∆Ct method. P-values were calculated within timepoint using a Wilcoxon signed-rank test, with the threshold for statistical significance P < 0.05. IGF2, the major IGF present throughout gestation, was significantly upregulated at d 86 in KID only (P = 0.005). Many significant changes were observed in the expression of the IGF binding proteins (IGFBPs), which modulate the activity of IGF1 and IGF2. In the LVR, both IGFBP1 and IGFBP3 were downregulated at d 76 (P = 0.006 and P = 0.002, respectively). Further, hepatic IGFBP2 was downregulated at all timepoints (P = 0.003, 0.028, < 0.001, and < 0.001, respectively), and hepatic IGFBP4 downregulated at d 66, 76, and 86 (P = 0.020, < 0.001, and < 0.001, respectively). These results indicate that fetal hypothyroidism impacts IGF function via downregulation of hepatic-derived IGFBPs. These changes in IGF activity may alter fetal growth and development, providing a possible explanation for the growth modulations observed in fetal hypothyroidism.
PSIII-16 Evaluating human injury risk during interactions with unhealthy Holstein cows
Authors: Melby Makenzie C , Austin Elena , Swain John , Irlbeck Nancy , Adams-Progar Amber
Published: September 2024

In the United States, the dairy industry has a greater-than-average injury rate on farms. Most injuries are caused by cattle during interactions with dairy workers. Researchers have shown that cow behavior is altered when a cow is unhealthy; however, no studies examined whether these altered behaviors are exhibited during human-cow interactions and how they may pose a risk to workers. The purpose of this study was to evaluate how the health status of dairy cows impacts the safety risk for dairy workers during human-dairy cow interactions. This study was conducted at Washington State University’s Knott Dairy Center in Pullman, WA. Data were collected during Fall 2023 and Winter 2024. Lactating, multiparous Holstein cows (n = 58) were enrolled in the study. Cow health status was determined using CowManager, an electronic ear tag that records activity and ear temperature and uses a proprietary algorithm to alert producers to sick cows. Unhealthy cows (n = 29) enrolled in the study were those whose health status was labelled as ‘suspicious’ by CowManager. A healthy counterpart, not labelled unhealthy but matched with a similar lactation number, reproductive status, and days in milk, was selected for each unhealthy cow. Two Brinno time-lapse video cameras were installed in the holding pen area, and video footage was continuously recorded during morning milkings. Enrolled cows and milkers were fitted with Polar H10 heart rate monitors, and heart rate data were collected while cows and milkers were in the holding pens. Video footage was observed, and behaviors were recorded according to an ethogram. The ethogram included cow behaviors and human behaviors related to low-risk or high-risk potential for human injury. Data were analyzed in SAS (SAS 9.4) using PROC GENMOD, PROC MIXED, and PROC CORR. Unhealthy cows tended to spend a greater percentage of time in the holding pen without a milker present (88 ± 4%) than healthy cows (75 ± 6%, P = 0.09), and milkers spent a greater percentage of their time engaging in high-force tactile (such as pushing) interactions with healthy cows (12 ± 4%) than with unhealthy cows (2 ± 1%, P = 0.08). These results indicate that there are possible risk level differences in interactions with healthy versus unhealthy dairy cows. This information will be used to educate dairy farm employees about these risk differences, with the intention of reducing the number of human injuries caused by interactions with unhealthy dairy cows.
PSIII-18 Effects of dietary exogenous fibrolytic enzymes on ruminal degradation kinetics of beef steers offered a high- and low-quality feedlot growing diets
Authors: Polepalle Bharathwaj , Sarturi Jhones O , Dos Reis Beatriz Q Queiroz
Published: September 2024

The post-consumption effects of dietary pre-treatment with exogenous fibrolytic enzymes on the ruminal degradation kinetics of wheat hay when beef steers were offered high- and low-quality feedlot growing diets were evaluated. Ruminally cannulated crossbreed steers [n = 5; body weight (BW) = 520 ± 30 kg] were used in a 5 × 4 unbalanced Latin square design, in which a 2 × 2 factorial arrangement of treatments was used as follows: a) growing diet quality (high = HQ; and low = LQ); and b) enzyme inclusion (0 or 0.75 mL/kg of diet DM; ABVista, UK). Steers were offered diets to ad libitum intake during four periods. Pre-dehydrated (55 ºC for 72 h) wheat hay substrate was ground (2 mm) and placed into 10 × 20 cm (28 µm) nylon bags (5 g, as-is). Substrate in situ bags were placed within a nylon mesh (with weights) at the ruminal ventral sac and reversely removed at 0, 3, 6, 12, 18, 24, 30, 48, 72, and 96 h after feeding. Samples were removed, rinsed, and dehydrated for 72 h at 55 oC. Residues were composited within the period, steer, and incubation time, corrected for residual moisture, and were used to fit a first-order kinetics model using the NLIN procedure of SAS and the Glimmix procedure of SAS used for the statistical analysis (animal = experimental unit). No interaction (P ≥ 0.35) diet × enzyme was observed for the ruminal effective degradability (ED) fractions of the substrate. Regardless of dietary type, steer consuming diets pre-treated with fibrolytic enzymes increased (P ≤ 0.05) the substrate ED for organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose (HEMI). No interaction (P ≥ 0.09) diet × enzyme was observed for the ruminal rate of degradation (kd) of any fraction. Steers offered feed pre-treated with fibrolytic enzymes, regardless of dietary type, increased the substrate ruminal rate of degradation (P ≤ 0.01) for OM and HEMI, while high-quality diets showed an increase kd for OM and HEMI compared with low-quality diets (P ≤ 0.03). An interaction (P = 0.03) diet × enzyme was observed for OM lag time, in which the enzyme decreased the lag time of the substrate on the high-quality diet, while increasing for steers consuming the low-quality diet. No interaction (P ≥ 0.14) diet × enzyme was observed for the lag time for NDF, ADF, and HEMI. Steers consuming grower diets pre-treated with fibrolytic enzymes had improved ruminal effective degradable fraction of wheat hay substrate, regardless of the grower diet quality offered to animals. A reduction in the lag time does not seem to be a probable cause for such an effect but rather an improvement in the rate of degradation of organic matter, especially hemicellulose.
PSV-12 Evaluating the effect of lyoprotectants in preserving community structure and bacterial viability in the lyophilized fecal community of pigs
Authors: Oladele Paul , Johnson Timothy A
Published: September 2024

Fecal microbiota transplantation (FMT) stands as a potential method for enhancing pig health. FMT has progressed from the basic delivery of fresh stool, to lyophilized preparations which is beneficial for sample storage, but can damage bacterial cells. This has necessitated the need for lyoprotectants to preserve bacterial viability. However, the ideal lyoprotectant for retaining community structure and viability remains unclear. Furthermore, DNA-based microbial profiling methods such as 16S rRNA and metagenomics sequencing do not distinguish live and dead bacteria, prompting the need for other methods of distinguishing live and dead members of the bacterial community after lyophilization. PMA-seq (propidium monoazide treatment followed by 16S rRNA gene amplicon sequencing) has been shown to differentiate between live and dead bacteria in microbial communities. To refine FMT in pigs, we sought to ascertain the impact of four lyoprotectants on bacterial viability and fecal microbiome structure. Fecal samples from six pigs were treated with mannitol, maltodextrin, trehalose, maltodextrin-trehalose mix (2.5% each) as lyoprotectants or left untreated. Lyophilized fecal samples underwent PMA treatment prior to 16S rRNA sequencing to capture the active community, and total and viable bacterial cells number were quantified. One-way ANOVA was used to analyze total and viable bacterial cells, and richness, while PERMANOVA was used to compare beta diversity. Results revealed no initial differences in total, viable bacteria, or community structure (P > 0.05). However, untreated, and mannitol-treated groups showed significantly reduced total and viable bacterial cells post-lyophilization (P < 0.01), unlike the other lyoprotectants (P > 0.05). Mannitol and the untreated group also displayed decreased richness and beta diversity shifts (P < 0.05). Overall, lyophilization with mannitol or no lyoprotectant notably impacted pig fecal microbiota community structure, while maltodextrin, trehalose, and maltodextrin-trehalose effectively preserved bacterial viability and structure.
PSV-8 Investigation of a haplotype and eQTL analysis of the LCORL-NCAPG locus associated with increased lean growth in beef cattle
Authors: Majeres Leif E , Dilger Anna C , Shike Daniel W , McCann Joshua C , Beever Jon E
Published: September 2024

Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, Charolais-sired calves (n = 34) were whole genome sequenced including 17 homozygous for a long-range haplotype associated with increased growth (QQ), and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814-kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, a previously documented mutation in NCAPG (rs109570900), two coding sequence mutations in LCORL (rs109696064 and rs384548488), and 15 variants located within ATAC peaks that were predicted to affect transcription factor binding. Notably, rs384548488 is a frameshift variant likely resulting in loss of function for long isoforms of LCORL. To test the association of the coding sequence variants of LCORL with phenotype, 405 cattle from five populations were genotyped. The two variants were in complete linkage disequilibrium. Statistical analysis of the three populations that contained QQ animals revealed significant (P < 0.05) associations with genotype and birth weight, body weight, carcass weight, hip height, and average daily gain. Additionally, an RNAseq analysis was performed using 22 of the Charolais-sired calves. This, in conjunction with the WGS data, was used to run an eQTL analysis, which revealed 256 genes whose expression were impacted by eQTL in the region (FDR < 0.05). These findings affirm the link between this locus and growth in beef cattle and describe DNA variants that define the haplotype. However, further studies will be required to define the true causative mutation.
PSV-17 Disease surveillance in feedlot cattle via interactions with a novel cotton rope
Authors: Sundman Emiline R , Dewell Grant A , Dewell Renee D , Johnson Anna K , Millman Suzanne T
Published: September 2024

Disease surveillance in feedlot cattle is vital for minimizing morbidity and mortality and maintaining cattle welfare. Hanging a novel cotton rope for disease surveillance is commonly used in pig production but is less developed for feedlot cattle. The aims of this study were to 1) inform future rope-based disease surveillance methods by describing sick and healthy feedlot cattle behavioral interactions with a novel rope, and 2) evaluate how cattle rope interactions vary with time, environment, and individual animal characteristics. Cotton ropes were hung in feedlot pens for three 30-min sessions over six non-consecutive summer days at two feedlots. At Feedlot 1, a rope was hung in one chronic pen and seven healthy pens, and the observation sessions were: Early Morning (0545 to 0700 h), Afternoon (1245 to 1300 h), and Evening (1845 to 2000 h). Three pens were observed on each of the six days; the chronic pen, one healthy “novel” pen with cattle that had no rope experience that changed daily, and one healthy “repeat” pen that was sampled over all observation periods. At Feedlot 2, the methods were altered slightly to focus on “repeat” pens during times when staff would be at the feedlot. A rope was hung in one chronic pen and one “repeat” healthy pen each day. The observation sessions were: Early Morning (0615 to 0645 h), Late Morning (1015 to 1045 h), and Afternoon (1315 to 1345 h). Direct continuous observation was used to record the number of rope-directed interactions (RDIs) performed by individual cattle. Results are presented descriptively as means ± SD. On d 1 in healthy pens at both feedlots, the average number of RDIs was 164 ± 72, and the Early Morning session was slightly more active than the two later sessions. The Chronic Pens at both feedlots were much less active, with only 3 and 10 RDIs on D 1 in Chronic Pens 1 and 2, respectively. The average number of unique cattle that performed at least 1 RDI in a healthy pen on d 1 was 23 ± 7, with an average of 11 ± 4.6 cattle performing an RDI in each 30-minute session. The Chronic Pens were less active, with only 2 and 3 unique cattle performing an RDI on d 1 in the Chronic Pens 1 and 2, respectively. Overall, in the Chronic Pens, the number of individual cattle RDIs varied greatly, with a few sick cattle performing the majority of RDIs. Healthy cattle RDIs varied with age, time of day, and temperature, and chronic cattle RDIs varied with disease status and proximity to death. These results indicate that there is potential value in these methods for disease surveillance, but that clear consideration for how environmental and individual animal characteristics impact RDIs is imperative for successful disease surveillance.
PSVI-15 Impact of breed composition on hair glucocorticoid levels in beef cattle after extended heat stress
Authors: Rojas Camila Santos , Haimerl Carly , Rafiq Fahad , Zayas Gabriel A , Titto Cristiane Gonçalves , Mateescu Raluca
Published: September 2024

More than one-half of the world’s cattle are maintained in hot environments, making heat stress a significant issue for the beef industry. Around $370 million is lost annually due to reduced performance due to heat stress, which has other detrimental impacts on cattle, such as decreased feed intake, fertility, and immune response. The assessment of hair glucocorticoids (hGC) serves as a valuable tool for evaluating chronic stress levels in beef cattle. Unlike traditional cortisol measurements, which provide only a glimpse of stress at a specific moment, hGCs offer a retrospective view of long-term stress exposure. This makes them particularly valuable for assessing chronic stress, which can profoundly impact animal health, welfare, and productivity. By quantifying hGC concentrations, we gain insights into the cumulative stress experienced by cattle over time, allowing for more comprehensive monitoring and management strategies. This study investigated the relationship between hGC concentrations and breed composition in beef cattle, specifically focusing on whether breed composition influences hGC concentrations after prolonged heat exposure. Animals from the University of Florida’s Multibreed Angus-Brahman herd were used. Hair samples were collected from 240 cows during the summer of 2017 and 2018, with breed compositions ranging from 100% Brahman to 100% Angus. Starting with a 4 mg hair sample, the hGC were extracted and analyzed with the Cortisol ELISA KIT (Neogen Corporation, Ayr, UK). An Analysis of Variance (ANOVA) was conducted to examine the relationship between hGC concentration, breed composition, and batch effect. The results indicated a significant effect of breed composition on hGC concentration (P-value 0.01406). These findings suggest that breed composition influences chronic stress during prolonged periods of heat exposure. However, individual factors like thermotolerance, health status, and social stress may also have a role in chronic stress levels. To better understand these factors, future steps will involve comparing the hGC concentration results between thermotolerant and non-thermotolerant animals. This comparison will provide insights into the potential differences in stress responses between cattle breeds adapted to hot environments and those less tolerant to heat stress.
PSVI-6 Genomic determinants of the rumen microbiome and metabolome in Angus steers
Authors: Henniger Madison T , Rowan Troy N , Beever Jonathan E , Wells Jim E , Kuehn Larry A , Voy Brynn H , Mulon Pierre-Yves , Smith Joseph , Myer Phillip R
Published: September 2024

The rumen microbiome provides approximately 70% of energy required for the ruminant host through fermentation byproducts. Due to microbial impacts on host health and productivity, several studies have associated microbiome and metabolome variation with important sustainability phenotypes, such as feed efficiency and methane emissions. Recent studies have indicated the microbial communities present in rumen fluid are under low-to-moderate host genetic control. However, microorganisms present on the rumen wall have been underrepresented in research, negating their unique role in host-microbiome interactions. Current studies investigating heritability of the rumen planktonic microorganisms are plagued by small sample sizes, high management and breed heterogeneity, and low resolution for classifying microbial communities. To determine the heritability of the rumen fluid and epithelium-associated microbiome and metabolome, Angus steers (n = 350) were enrolled in a 70-d feed efficiency trial, where real-time dry matter intake was measured. Body weights were collected throughout the trial to calculate average daily gain and residual feed intake. Mid-trial, a novel surgery method was used to swab the rumen wall to capture epithelium-associated microorganisms. On d 70, 50 mL of rumen fluid was obtained from steers using orogastric tubing for collection of planktonic microbial communities. Metagenomic DNA extracted from both rumen fluid and epimural samples was used for reduced representation sequencing to predict microbial features such as diversity, composition, and putative function. Genomic DNA isolated from whole blood was used to perform low-pass whole genome sequencing for use in downstream heritability estimates and variant association analyses. Many core microbial abundances are under low-to-moderate host genetic control (h2 > 0.15; P < 0.05); however, many microorganisms had low heritability estimates (h2 < 0.10). Preliminary genome-wide associations studies are vastly underpowered to detect host genetic variants associated with microbial features, but data generated using the total number of animals will better refine these polymorphisms. Several key heritable metabolites were identified in amino acid metabolism pathways in rumen fluid (P < 0.05). The rumen microbiome appears to act as a complex polygenic trait and incorporating microbial features into prediction models may improve feed efficiency estimations. Understanding host genetic control of the rumen microbiome and metabolome may empower downstream applications to enhance genomic and phenotypic predictions for feed efficiency and other sustainability traits in beef cattle.
PSVI-4 Impact of rotational ingredient supplements on canine GI health when exposed to rapid dietary change
Authors: Crowell Cierra N , Perry Erin B , Jenkins Eileen , Kaplan Daisy , Zoran Debra , Moore George , Darling Tracy , Davis Michael , Suchodolski Jan S
Published: September 2024

Rotational feeding has been suggested in recent years as a method for improving “food boredom” in dogs. Some owners choose to add diversity to the canine diet for enrichment and potential cognitive benefits. However, little data are available on effects of rotational feeding strategies to gastrointestinal health, gut metabolites, and potential impacts to fecal consistency. The objective of this study was to understand the impact of rotational ingredient exposure on the ability of the dog to withstand an abrupt dietary change based on fecal pH, fecal dysbiosis index (DI), fecal score, calprotectin, and C-reactive protein (CrP). Labrador retrievers [n = 16; 1 to 3 yr of age; body condition scores (BCS) = 5 to 6] enrolled in detection dog training and receiving daily conditioning (exercise), were used in a 120-d study investigating the effects of an abrupt diet change on dogs with and without novel ingredient exposures. Study participants were assigned to one of two treatment groups. Control dogs (CON) received the basal diet and treatment dogs (ROT) received the basal diet along with the addition of rotating supplemental ingredients (2.5% total daily DM intake) over 90 d including oatmeal, blueberries, pumpkin, beef liver, salmon, and rabbit. All dogs were acclimated to the basal diet for 30 d, after which dogs in both groups were exposed to an abrupt (untransitioned) diet change [two meals (am and pm feeding)] on d 0, d 45, and d 90. Morning fecal samples at each timepoint were collected for three consecutive days and analyzed for fecal pH, DI, and calprotectin. Blood samples were collected 6 h following the AM dietary challenge and were used to measure CrP. Statistical analysis was performed using PROC MIXED and significance was set at 5%. Rotational ingredient supplemental did not impact DI (P = 0.0844). Similarly, fecal pH and calprotectin were unaffected by the addition of rotating ingredients (P = 0.7243; P = 0.9356, respectively). Fecal scores did not change by period (P = 0.0768) or by treatment (P = 0.9002). Values for CrP demonstrated no treatment effect on acute phase response (P = 0.8022). Markers of gastrointestinal health remained consistent, and tolerant, of rapid dietary change in both treatment groups. These findings suggest that the inclusion of rotational dietary ingredients may be well tolerated in healthy active canines, thus allowing owners to safely introduce diverse ingredients (at low levels) to the diet of their dog with minimum risk to health challenges.
PSVI-3 Finishing-based diets degradability of beef cows supplemented with a Bacillus-based probiotic
Authors: Limede Arnaldo C Cintra , Marques Rodrigo , Cruz Vinicius Alves , Ogg Makayla A , Cidrini Iorrano A , de Queiroz Amanda Caroliny Marques de Caroliny Marques , Cidrini Fernando , Farias Iasmin , Rodrigues Aline Naime Naime , Motter Alarissa , Cappellozza Bruno Ieda
Published: September 2024

Probiotics, sometimes referred to as direct-fed microbials (DFM), are live microorganisms that, when given in sufficient quantities, confer health benefits to livestock animals. Research has indicated that probiotics based on Bacillus enhance the dry matter and neutral detergent fiber digestibility of various feed sources, animal feed, and commercial total mixed rations (TMRs) in vitro. Given that, the aim of this study was to evaluate the influence of a Bacillus-based probiotic supplementation on nutrient degradability of commercial finishing-based diets. Ruminally fistulated Angus × Hereford cows (n = 15; 6.1 ± 1 yr of age; body weight = 658 ± 57) were used in complete randomized designs and housed in individual pens with water, and forage intake monitored daily. Treatments consisted of 1) 500 g of protein supplement (dry distillers grain + mineral mix) without probiotic (CON n = 8), and 2) 500 g of protein supplement + 3 g of a probiotic containing Bacillus licheniformis and B. subtilis (BOV; n = 7; 2.2 ×109 CFU of the mixture/g; Bovacillus, Novonesis, Hørsholm, Denmark). The experimental period lasted 33 d, consisting of 21 d of adaptation and 12 d of collection. From d 28 to 32, four different commercial finishing diets (4 g; Table 1) were fitted in Dracon bags and incubated in the rumen for 0, 12, 24, 48, 72, and 96 h in reverse order so that all bags were removed at the same time and immediately washed until clear water was obtained. After washing, the bags were dried at 56 ºC for 72 h to determine the dry matter. Subsequently, the NDF and ADF content was determined. A treatment effect was detected (P ≤ 0.05) for dry matter degradability in 3 out of 4 finishing-based diets used herein, which increased by approximately 4% in cows supplemented with BOV vs. CON. Supplementing beef cows with BOV also enhanced (P ≤ 0.05) neutral detergent fiber degradability by 12.1, 22.3, and 24.0% in finishing diets A, B, and C, but not D (P = 0.52), compared with CON cows, respectively (Table 2). Cows receiving BOV had greater (P = 0.04) acid detergent fiber degradability in finishing diet A and a tendency (P = 0.07) for finishing diet C compared with CON cows, whereas acid detergent fiber degradability was similar (P ≥ 0.13) among treatments for finishing diets B and D. In conclusion, Bacillus-based products could be used as a nutritional alternative tool to increase nutrient degradability of finishing-based diets.
PSVI-1 Supplemented milk replacer improves feed transition of dairy bull-calves
Authors: Adelusi Oludotun O , Casper David P , Anele Uchenna Y
Published: September 2024

Neonatal calves are affected by pathogenic infections, compounded by stress, leading to enteric and respiratory disorders accounting for about 7.8% mortality rate and annual treatment costs exceeding $250 million. Federal restrictions on antibiotic use due antimicrobial resistance in humans has opened the door for viable alternatives like rumen enhancements which have been reported to aid the establishment of beneficial rumen flora leading to improved health and performance. It is hypothesized that nutritional formulation of milk replacers to help the calf prevent or cope with diarrhea can provide a leeway that will ensure better animal performance and transition to solid feed. The objective of study was to evaluate the performance of dairy bull-calves fed nutritionally supplemented milk replacers. Three milk replacers were tested with or without supplementation of metabolic enhancements (Control: no metabolic enhancer; Added: milk replacer with metabolic enhancer added at the time of mixing milk in shuttle; Composite: produced along with metabolic enhancer. Dairy bull-calves (n = 60; 2 to 5 d-old) were grouped into three treatments of milk replacers. The study lasted for 10 wk; 6 wk of milk-feeding and 4 wk of calf starter feeding. Body weights (BW) were taken on a weekly basis, while calf starter intake was measured daily and data were analyzed using one-way analysis of variance. Calves fed milk replacer with composite metabolic enhancer recorded the greatest intake and final BW over the 10-wk period. Calves fed milk replacer with added metabolic enhancer at the point of milk mixing recorded the poorest data in terms of BW gain and final BW. Calves fed metabolic enhancer, either added or composite recorded a better weaning and transition to solid feed from milk feeding. Calves fed control milk replacer experienced a poor transition from milk feeding to solid feed. It is concluded that composited rumen metabolite enhancers in milk replacer supported greater starter intake, average daily gain and better transition of calves to solid feed, and is recommended for the feeding of neonatal calves.
PSIV-2 Gestational heat stress and its impact on placental weight, colostrum production, and milk production on Columbia-Rambouillet ewes
Authors: Fuentevilla Ela , Rios Andrea , Limesand Sean , Diaz Duarte E
Published: September 2024

Heat stress during pregnancy causes placental insufficiency and resduces fetal growth by reducing the oxygen and nutrients availability. In lactating production animals, heat stress during gestation lowers performance by decreasing milk yield and impairing reproduction. The study objectives were to understand the consequences of the exposure to warm environmental conditions during pregnancy on placental weight, colostrum production, and milk production of ewes utilizing heat chambers. Columbia-Rambouillet pregnant ewes with singletons (n = 11) were assigned to one of two environmental treatments: 1) heat stress (HS) or 2) thermoneutral (TN; 22°C) during mid-gestation (d 40 to 80) for a duration of 40 d. Heat stress consisted of 12 h at 40°C/55% humidity and 12 h at 35°C/45% humidity. Dry matter intake (DMI) and water intake (WI) were measured daily for both treatment groups. Feed and water were given ad libitum for HS ewes and TN ewes were pair fed to HS ewes for the entire duration of study. At lambing, the offspring were separated from dams. Measurements were taken of placental weight and colostrum production. The placental weights from HS ewes had a mean of 218 g compared with the placental weights of the TN group at a mean of 396 g (P < 0.01). Colostrum was measured for the first 24 h post lambing. The mean colostrum production of TN was 718 mL and for the HS group it was 882 mL. The colostrum production differences between control and HS groups were nonsignificant. Following lambing, ewes were milked twice a day for a 21-d period to evaluate milk production. Daily milk production for HS ewes was a mean of 1.16 kg/d while the TN group ewes had a mean of 1.31 kg/d (P < 0.01). Exposure of HS during mid-gestation had a significant impact on placental weight and 21-d milk production.
PSIV-4 Effectiveness of maternal bovine appeasing substance on growth, physiological, and behavioral responses of high-risk stocker cattle
Authors: Johnston Elle P , Kegley Elizabeth B , Powell Jeremy G , Pennicott Chantel , Reynolds Jana L , Cheek Robin A , Weimer Shawna
Published: September 2024

Stocker cattle purchased at auction can be susceptible to disease due to the stressors associated with the auction process. These cattle are labeled “high-risk” due to their decreased immune system during transportation, handling, and vaccination processes. The objective of this study was to determine the efficacy of a maternal bovine appeasing substance, FerAppease, on growth performance and fearfulness of stocker cattle. Male beef calves (n = 80) were purchased at auction and transported to the University of Arkansas Division of Agriculture Savoy Research Complex Beef Stocker Unit. Steers and bulls were of varying age, breed, and temperament. Upon arrival to the facility (d 0), bulls (n = 48) were castrated by banding and cattle were assigned to 8 pens (n = 10 calves/pen; 4 bulls and 6 steers/pen). On d 0, cattle in 4 pens were treated with FerAppease (FA) on the nuchal skin (n = 40) and cattle in the other 4 pens were not treated and served as controls (CON, n = 40). All cattle received commercial clostridial and respiratory vaccines and were treated with an anthelmintic. Cattle were offered bermudagrass hay for ad libitum intake and were fed a grain supplement (1.8 kg/d) to meet or exceed nutrient requirements. To measure growth performance, body weight (BW) was recorded on d 0, 3, 14, 28, 41, 42 of the study and used to calculate average daily gain (ADG). Body weights on d 41 and 42 were averaged to calculate final BW. To measure fearfulness, exit chute velocity (ECV) was measured with a rodeo timer and recorded on d 3, 14, 28, 41, and 42. To measure inflammation, blood was collected from 5 calves/pen (n = 3 bulls and 2 steers/pen) on d 0, 3, 28 and 42 and haptoglobin (Hp) was measured in blood serum. A two-way ANOVA with the fixed effects of sex (arrived as steer or bull) and treatment (FA, CON) and random effect of pen was used for analysis. Serum Hp was log transformed to improve normality. There was not a treatment effect on any of the measures collected. Steers had a greater BW throughout the study (P ≤ 0.05), weighing more than bulls at the end of the study (261 kg vs 241 kg, respectively). Steers also had a greater (P < 0.0001) ADG than bulls (1.14 vs. 0.84 kg/d, respectively). On d 3 and 14, steers exited the chute more rapidly (P < 0.05) than bulls. There was an interactive effect on serum d 28 Hp concentrations (P = 0.04), where CON bulls had greater Hp concentrations (111,261 ng/mL) than CON steers (13,055 ng/mL), with FA steers and bulls intermediate. The results from this study indicate that there was no consistent effect of the treatment on the measures collected.
PSIV-9 Pedigree tracing to determine the origin of the golden coat phenotype within the Golden American Saddlebred horse
Authors: Culwell Julius , North Ed , Nicodemus Molly , Cavinder Clay A , Williams Toree
Published: September 2024

With the incorporation of the Golden American Saddlebred Horse Association (GASHA) into the American Saddlebred Horse Association (ASHA), breeding specifically for coat color within the breed registry became less of an emphasis for horse breeders. Nevertheless, historical documentation of the horses making up the foundation of the GASHA through the application of pedigree tracing holds value in understanding the origin of the breed and its coat color. This can be of value to horse breeders targeting a specific coat color as the study of coat colors is a relatively new field of research within equine science. Thus, the objective of this study was to document the historical origins of the GASHA through pedigree tracing to determine the influence of the dilution genes that produce the golden coat phenotype. A random sample of 550 horses was obtained from the Official Directory of GASHA. Using the All-Breed Data Base, sampled horses were entered and examined for pedigrees suitable for analysis of color inheritance, and of these, 507 were found to have extended pedigrees with documented coat colors that were used for this study. Results determined that 43% of traced pedigrees carried the champagne gene, 36.1% carried the cream gene, and 20% had pedigrees that were non-informative as these pedigrees went to unknown ancestors or were found to be incorrect as to ancestry. Another 0.9% were determined to be obligate carriers for the cream gene; as the pedigrees presented conflict concerning color designation so that accurate conclusion of coat color phenotype associated with the cream dilution gene could not be verified. Of the 507, all traced back to 6 foundation mares and most of the breed traced back to 2 of these mares; with one mare, Maud, being a champagne mutation and the other, Allens Queen, a cream mutation (Table 1). In conclusion, through pedigree tracing the GASHA origins were documented giving an understanding as to the genetic contributions for today’s GASHA golden coat color. Further, these results will give breeders more input on how they might select for certain coat color phenotypes.
PSIV-3 Quantifying free choice mineral intake in a lamb feedlot setting: Implications for cost of mineral supplementation
Authors: Dooley Elisabeth F , Kersh Aaron J , Laverell Dylan M , Mills Joe B , Scasta John D , Lima Paulo M T , Gifford Cody L , Stewart Whit C
Published: September 2024

The objectives of this study were to assess mineral consumption in feedlot lambs on a pen basis, comparing estimated intakes with the manufacturer’s specified target intake and examining potential influences of environmental variables on free-choice mineral intake. Lambs [n = 93; initial body weight (BW) = 45.68 kg ± 1.51] were evaluated as part of the “Lamb-A-Year” producer discovery program at the University of Wyoming – Laramie Research and Extension Center (Laramie, WY). There were wethers (n = 68) and ewe lambs (n = 25) of diverse breed types (Western white-faced n = 47, black-faced n = 4, crossbred n = 42) sourced from 24 regional sheep producers. Upon arrival, lambs were allocated to eight pens (10 to 12 lambs/pen) and provided ad libitum access to a custom textured ration over a 24-d testing period. Each pen received 1.81 kg of a custom granularized mix containing specified levels of Ca, P, NaCl, Se, vitamin A, and vitamin D daily. Mineral intake was determined by subtracting residual mineral from the 1.81 kg administered the previous day. Individual consumption was calculated by dividing total mineral intake by the number of lambs in each pen. The difference between actual intake and target intake was computed per pen to estimate cost per head based on a $1,440 metric ton (t). A least squares regression analysis was employed to examine the effects of average daily temperature range, minimum temperature, and maximum temperature on mineral intake. Across the 24-d period, mean intake was 46.26 ± 1.9 g/head/d with an upper 95% mean of 50.24 g/head/d and a lower 95% mean of 42.28 gּ lamb-1ּ d-1. The study found that the mean difference between observed mineral intake and the manufacturer’s target intake was 22.4 ± 1.9 gּ lamb-1ּ d-1, with intake exceeding target intake on 23 d out of 24 d. This overconsumption translated to an increased cost of $0.04ּ lamb-1ּ d-1Statistical analysis revealed that neither the average daily temperature range (P = 0.06), minimum temperature (P = 0.36), nor maximum temperature (P = 0.60) adequately explained the variability in mineral intake. These results underscore the importance of addressing overconsumption of free-choice minerals in housed lamb feeding settings, where intake was roughly double the manufacturer’s target. Furthermore, there is a clear need for additional research to quantify the variability in mineral intake in grazing sheep production systems.