bluuebunny/crossref_metadata_2025 huggingface dataset:
PSXIV-18 Fit of the Zero-Inflated Negative Binomial Model to Analyze Fecal Egg Counts
Authors: Gunes Hilal Yazar , Howard Réka , Fudolig Miguel , Burke Joan M , Lewis Ronald M
Published: November 2023

Fecal egg count (FEC) is used as an indicator of parasite infection level in sheep. The distribution of FEC is non-Gaussian and typically overdispersed, often with an excess in zero counts. Quantifying the extent of inflation of zero counts can be difficult. Our objective was to assess the potential zero-inflation problem in FEC resulting from variation in infection with gastrointestinal nematodes by using a generalized linear model approach. The zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models are useful techniques to analyze count data with excess zeros; ZINB also handles overdispersion. The ZINB model has the potential to delineate ‘true’ zeros, in this case, animals resistant to parasitism and thereby with zero FEC, from ‘false’ zeros, animals never or minimally exposed to a parasite challenge. By distinguishing false zeros, those animals expressing parasite resistance may be more clearly identified. Two datasets on Katahdin sheep, a hair breed known to express resistance to gastrointestinal nematodes, were investigated; a smaller set (n = 3,048) with FEC and FAMACHA (FAM) scores, a subjective measure of anemia indicative of parasitism by Haemonchus contortus, a blood sucking helminth; and a larger set (n = 14,405) with FEC and a contemporary group (CG) designation, assigned based on the flock, birth year, management group, and FEC recording date of the animal. Among animals with FAM recorded, 14% had scores indicative of at least border line anemia. Amongst the 410 CG, 22% had mean FEC more than 500 egg/g, a threshold value routinely used to indicate a substantial infection level with H. contortus. For each dataset, the Poisson, Negative Binomial, ZIP, and ZINB models were fit and compared using R (pscl package) and SAS software, with the ZINB providing the best fit. In the models considered, FEC was the response variable and either FAM or CG was the explanatory variable, depending on the dataset. Despite evidence of parasite challenge, the true and false zeros could not be delineated in both data sets using these models. The estimated proportion of false zeros due to inflation did not differ from the proportion of zeros observed in the data set. Either all zeros coincided with no infection, which seems unlikely in Katahdins, or neither FAM nor CG provided sufficient information to distinguish resistant from uninfected individuals. Alternative or additional explanatory variables, such as packed cell volume or immunoglobulin concentrations indicative of parasitic infection, may be necessary to separate true from false zero FEC in sheep challenged with gastrointestinal nematodes using the ZINB model.
PSXIV-25 Investigating the Relationship Between Maternal Protectiveness and Temperament in Beef Cattle
Authors: Rogers Corley D , Grandin Temple , Engle Terry E , Archibeque Shawn L , Garry Franklyn B
Published: November 2023

Observations were made on 73 dams on two ranches in Colorado and one in Wyoming during the spring 2022 calving season to investigate the relationship between temperament and calf protection. The objective was to compare temperament scores to the distances of protective behavior performed by the dam as the observer moved closer to the pair. The protective actions of the cow were: Approach (alerted by raising her head to presence of the observer), Protective (moved between observer and calf), Vocalization (called to calf), and Closest (closest distance the observer reached before the pair moved away). Temperament scores included chute score, exit score, exit velocity, and blood lactate. One hundred percent of the dams alerted to the presence of the observer, twenty-five percent (n = 18) moved between the observer and the calf, and sixty-three percent (n = 46) vocalized to their calf. Thirty-five (47.9%) dams allowed the observer to touch the calf, categorized as Touch, while the other thirty-eight (52.1%) walked away from the observer before contact with the calf, categorized as No Touch. In a linear model using Touch/No Touch as the predictor and the continuous variables of Approach, Protect, Vocalize, Closest, exit velocity, and blood lactate; only closest (P < 0.001) and exit velocity (P = 0.011) had significant differences (P < 0.05) between the means. Dams that allowed the observer to touch the calf, on average, exited the chute with greater velocity (P = 0.01). Blood lactate and exit velocity were predictors in a mixed model with Ranch as a random factor with Touch/No Touch as the outcome; no significant difference was found (P > 0.05). The Kruskal-Wallis test was performed individually on Approach, Protection, Vocalization, and Closest with predictor values of Ranch, date of birth (DOB), and hair whorl. A significant difference (P = 0.04) appeared between the medians of Closest when grouped by hair whorl; dams with abnormal hair whorls moved away from the observer at a greater distance. When divided by Ranch, there were differences (P < 0.001) in the average chute score. This study suggests that dams with a faster exit velocity are approachable in the field. Exit velocity is not a good indicator of how close an observer can get to a calf in the field. Attraction to novelty could have a larger role than previously thought in temperament. No impactful relationships were observed between the temperament of a dam and her maternal protectiveness. Ranchers can continue selecting for docile temperament without fear of decreasing maternal protection.
PSXIV-28 Post-Confluence Cell Age Affects Lipopolysaccharide-Induced Interleukin-8 Secretion in Ipec-J2 Cells
Authors: Simmons Julie , Woodward Adrienne , Lu Hang , Horn Nathan
Published: November 2023

Porcine intestinal epithelial cell line IPEC-J2 is routinely used to investigate epithelial cell interactions with common enteric porcine antigens and pathogens. Lipopolysaccharides (LPS) are bacterial antigens metabolized from Gram negative bacteria that can induce a cellular inflammatory cascade, resulting in changes to cell structure and integrity, and are often used to challenge IPEC-J2 cells. Although numerous investigators employ the IPEC-J2 LPS model, consistent methodology regarding cell culture conditions and treatment times is not well defined. The objective of the current study was to determine the optimal post-confluence cell age for LPS induction of Interleukin-8 (IL-8) secretion and related cell integrity changes. For this study, cells were seeded at 2x104/cm2 in 24 well plates on day zero and incubated at 37°C, 5% CO2 for 3 days (confluence) prior to treatment in complete growth media (CGM) containing 5% fetal bovine serum. One day prior to treatment, CGM was removed and replaced with serum free (SF), phenol red-free media. On days 0, 5, 7, 12, 14 and 18 post confluence, cells were treated with LPS (0 or 10μg/mL) in SF and phenol red-free media for 24 hours. There were 5 replicates per treatment per timepoint. Lactate dehydrogenase (LDH) release, trans-epithelial electrical resistance (TEER), and IL-8 secretion were measured at each experimental timepoint. Data were statistically analyzed for the effect of time, treatment, and the subsequent interactive effect. There was no effect of treatment, time or their interaction on LDH release (P > 0.05), indicating cellular health was maintained over time and 10μg/ml LPS did not influence cellular toxicity. There was an effect of treatment, time and the respective interaction that showed IL-8 secretory responsiveness was increased with LPS challenge (P < 0.01), was increased on d 7 regardless of LPS challenge (P < 0.01) and peaked on d 5 post-confluence (P < 0.01). Furthermore, TEER was maximized at d 5 post-confluence and remained consistently greater relative to the d 0 baseline throughout the experiment (P < 0.01). These data indicate that LPS-induced IL-8 secretion and related cellular integrity are optimized at d 5 post-confluence in IPEC-J2 cells. In conclusion, in-vitro research utilizing the IPEC-J2 LPS model should allow cells to age 5 days post-confluence to maximize responses.
PSXIV-13 Evaluation of On-Animal Sensors for Monitoring Diurnal Physical Activity of Beef Bulls During the Breeding Season
Authors: Rykaczewski Caleb , Bello Nora , Kieffer Justin , Chang Anita Z , Trotter Mark G , Garcia-Guerra Alvaro
Published: November 2023

Applications of on-animal sensors (OAS), commonly used to monitor behavioral patterns in livestock, remain largely undeveloped for extensively managed beef bulls. Thus, the objective of this study was to characterize and compare two OAS types for monitoring bull activity during the breeding season. Angus and Angus crossbred beef bulls (n = 50) aged 1 to 8 years, from six cow-calf operations in Ohio were placed into multi-sire breeding groups (n = 19) with a bull-to-female ratio of 1:25 (range 1:16 to 1:31). Bulls were placed with a female group from day 10 (range day 5 to 12) until day 60 after fixed-time artificial insemination. Before turnout, each bull was subjected to a breeding soundness examination and fitted with a collar-mounted GPS and an ear tag-mounted triaxial accelerometer (AX3). Raw GPS and AX3 activity measurements, namely speed (m/s) and motion intensity (g), were converted to standardized Z-scores and summarized to an hourly resolution by computing the median hourly activity over a 24-hour cycle at early (day 13 to 28) and late (day 34 to 49) stages of the breeding season. Linear mixed models were fitted to standardized activity measurements (expressed in log scale) to assess the dynamic effect of OAS type throughout the day at early and late stages of the breeding season. Size of the breeding group (males and females), bull age, scrotal circumference, and body condition score were evaluated as potential explanatory covariates using stepwise selection. Diurnal activity curves followed a pattern of relative inactivity overnight from hours 21 to 5 and relative activity during daylight from hours 6 to 20. For both OAS, mean activity early in the breeding season was ~47% greater (P < 0.01) than late. At both breeding season stages, mean activity of bulls differed between OAS types (P < 0.01) at hours 2, 3, 4, 5, and 6 by at least 38%, with greater activity from GPS than AX3 (P < 0.05 in all cases). Conversely, at hours 13, 14, and 16, activity derived from AX3 was greater than from GPS by at least 2.5-fold (14: P < 0.01; 13 and 16: P < 0.1). There was no evidence (P > 0.1) for differences between bull activity derived from GPS or AX3 during the remaining overnight (21-1) and daytime (7 to 12, 15, and 17 to 20) hours. In conclusion, this study provides evidence that simultaneous assessment of bull activity using independent OAS, differed between technologies throughout a 24-h day. Additionally, over the course of the breeding season, both OAS indicated a decline in activity. Bull breeding activities are expected to be less frequent as the breeding season progresses; thus, these may explain the observed differences between stages of the breeding season. Further exploration of benchmarks for bull activity may yield useful tools for the identification of health and reproductive-related behaviors.
PSXIV-20 Genetic Differences Related to Beef Production Traits in Bos Taurus Or Bos Indicus Influenced Cattle
Authors: Okamoto Lillian , Stegemiller Morgan R , Reichhardt Caleb , Alberto Anthony F , Motsinger Laura A , Bayles Sarah A , Roholt Bryce W , Garcia Matthew D , Murdoch Brenda M , Thornton Kara J
Published: November 2023

Global climate change has had, and will continue to have, a negative impact on cattle production. With the global population expected to exceed 9 billion people by 2050, improving production efficiency is imperative to optimizing use of available land and natural resources. One potential method of doing so is to increase the percentage of Bos indicus (BI) genetics in the US beef herd. Compared with Bos taurus (BT) cattle, BI influenced cattle are better adapted to nutritional stress, consume less water, are more heat resistant, and have increased resistance to parasites. The objective of this study was to examine the phenotypic and genotypic outcomes of introducing BI genetics into a BT herd in a temperate climate setting. This study included a live animal trial that utilized a total of 115 steers of two different breeds: Angus (AN; n = 83; 100% BT) or Santa Gertrudis influenced (SG; n = 32; 19% BI, 81% BT). All steers were fed a typical feedlot ration for the area in pens equipped with Vytelle units, weighed every 28 d throughout the trial, and harvested at a commercial facility once industry backfat standards were achieved. Breed did not have an effect (P >0.10) on dry matter intake, average daily gain, gain to feed, ribeye fat thickness, hot carcass weight, or USDA yield grade. Intramuscular fat was increased (P = 0.002) in AN steers, and there was a tendency (P = 0.09) for SG steers to spend more time with their heads down during bunk visits. To better examine the genomic differences between the two beef breeds, DNA from 88 (AN = 58, SG = 30) of the 115 steers was isolated. A Bovine GGP 100k assay was completed commercially, and data were analyzed using Excel and the Multi-Locus Mixed Model of SVS. The traits that were analyzed include average daily gain, gain to feed, dry matter intake, hot carcass weight, marbling score, cold camera ribeye size, ribeye fat thickness, and cold camera yield grade. For each trait, further evaluation was done on SNP markers with the greatest P-values. Differences in allelic combinations that contributed to statistical significance was observed in data attained from dry matter intake, hot carcass weight, marbling score, and cold camera yield grade. Further analysis suggested a potential breed effect on marbling score, cold camera yield grade, and cold camera ribeye size. Additional research is warranted to better understand the relationship between genetics and the observed phenotypic traits, as well as conducting similar analysis on feeding behavior characteristics.
PSXI-18 Prediction of Fecal and Urinary Nitrogen Excretion in Growing Pigs Based on the Ingredient Composition
Authors: Kim Hansol , Yoo Seung B , Kim Beob G
Published: November 2023

The objective was to develop prediction models for estimating fecal and urinary nitrogen (N) excretion from growing pigs based on ingredient composition. Ninety-three observations were collected from 23 studies that determined fecal N excretion (ranging from 3.6 to 11.6 g/d) and urinary N excretion (2.5 to 54.7 g/d) from pigs with a mean body weight (BW) ranging from 20 to 105 kg. Average daily feed intake (ADFI; 0.7 to 3.2 kg/d) and ingredient composition data were also collected. Fecal N excretion can be estimated based on the apparent total tract digestibility (ATTD) of N in the ingredients used for a diet. As the NRC (2012) provides only apparent ileal digestibility (AID) of N, the ratio of ATTD of N to AID of N (NATTD:NAID) is essential to accurately estimate fecal N excretion unless ATTD values of N are available. Based on the NATTD values for 93 diets obtained from the 23 studies in the literature, and the NAID values for the same diets calculated using the NAID for each ingredient in the NRC, NATTD:NAID linearly increased with increasing ADFI: NATTD:NAID = 0.088 × ADFI + 0.917 with r² = 0.42 and P < 0.001. To predict urinary N excretion, it is necessary to determine the limiting standardized ileal digestible (SID) indispensable amino acid (IDAA) order and convert the dietary concentrations of the first-limiting SID IDAA expressed as a percentage of the pig's requirement (IDAA1st, %). The SID IDAA requirements in the 23 studies were calculated using the NRC models. The NRC feed ingredient tables were used to calculate total N, SID IDAA, and SID dispensable AA (DAA) in the diet for these studies. Utilized all SID AA can be estimated using the SID AA intake and urinary N excretion. Assuming that all SID IDAA are utilized up to 100% of their requirements when IDAA1st exceeds 100% of the requirement and that all SID IDAA are utilized up to IDAA1st of their requirements when IDAA1st is lower than 100%, the urinary N excretion can be predicted by estimating the ratio of utilized SID IDAA to utilized all SID AA (SID IDAA:SID all AA, %). Based on the urinary N excretion, IDAA1st (12.5 to 170%) and SID IDAA:SID all AA (31.6 to 84.6%) in the 93 diets, a prediction equation for SID IDAA:SID all AA was developed: SID IDAA:SID all AA = 52.0 + 0.510 × (54.7 – IDAA1st) where IDAA1st is less than 54.7%, with R2 = 0.85. Overall, NATTD:NAID increases linearly with an increase in ADFI. When the IDAA1st exceeds 54.7%, the SID IDAA:SID all AA reaches a plateau of 52.0%, corresponding to a SID IDAA:SID DAA of 52:48.
PSXIII-7 Effect of Dietary Supplementation of Lactobacillus Rhamnosus on Blood Profiles, Intestinal Morphology, Immune Responses, and Gene Expression of Tight Junction Proteins and Cytokines of Weaned Pigs
Authors: Ahn Jinmu , Kyoung Hyunjin , Park Kyeong Il , Kim Yonghee , Lee Jae In , Ha Sewon , Nam Jinwook , Kim Kimoon , Kang Yonggu , Park Youngmin , Shin Ikcheol , Song Minho
Published: November 2023

Dietary probiotics were used in the animal feeds because of the beneficial effect of improving gut health and immune responses as one of the potential alternatives to antibiotics. This study was conducted to evaluate the effect of dietary supplementation of Lactobacillus rhamnosus (ILDONG Bioscience Co. Ltd., Pyeongtaek, Republic of Korea) on blood profiles, small intestinal morphology, immune responses, and gene expression of tight junction proteins and inflammatory cytokines in ileum of weaned pigs. A total of 40 weaned pigs [6.21 ± 0.55 kg of initial body weight (BW); 28-day old] were allotted to 2 dietary treatments (4 pigs/pen; 5 replicates/treatment) in a randomized complete block design (block: initial BW) and fed for 4 weeks. Dietary treatments were 1) a commercial basal nursery diet (CON), and 2) CON + 0.02% Lactobacillus rhamnosus IDCC 3201 (PRO). The blood samples were collected from randomly selected 1 pig per pen on day 1, 7, 14, and 28 for blood profiles and immune responses. On the last day of experiment, the pigs were euthanized to collect duodenal, jejunal, and ileal segments for intestinal morphology and gene expression analysis. Intestinal morphology was measured villus height, width, area, crypt depth, villus height to crypt depth ratio, and number of goblet cells by hematoxylin and eosin staining method. The blood profiles were measured by using an automated hematology analyzer. The serum samples were used to measure concentrations of cytokines and cortisol by using porcine immunoassay ELISA kits. The gene expression of tight junction proteins and cytokines were measured by qRT-PCR. Data were analyzed by PROC GLM procedure of SAS. Experimental unit was a pen. Statistical model for blood profiles, immune responses, and intestinal morphology included dietary treatment as a main effect and initial BW as a covariate. The t-test was used for ileal gene expression. Pigs fed PRO had lower (P < 0.05) platelet level, crypt depth in duodenum and ileum, serum tumor necrosis factor-α (TNF-α), and interleukin-6 than those fed CON. The pigs fed PRO downregulated (P < 0.05) TNF-α and interleukin-8 genes compared with those fed CON, but upregulated (P < 0.05) claudin-1 and claudin-2 genes. In conclusion, probiotic Lactobacillus rhamnosus supplementation in nursery diet improved gut health through modulating blood profiles and immune responses, enhancing intestinal morphology, and regulating tight junction protein genes expression in ileum of weaned pigs.
PSXIII-3 Trace Mineral Source Matters to Reduce Trace Mineral Excretion and Maximize Mineral Retention in Growing Pigs
Authors: Camargo Jesus A Acosta , Foran Chelsie K , Provin Ashley , Hancock Deana
Published: November 2023

The study objective was to determine differences between a methionine hydroxy analog chelated trace mineral blend [MHAC; MINTREX Trace Minerals (Novus International Inc., St. Charles, MO)] and sulfate (inorganic) sources of trace minerals (ITM) on the apparent total tract digestibility (ATTD) of dry matter (DM) and mineral utilization in growing pigs. A total of 10 growing gilts (PIC North America, Hendersonville, TN) weighing 50.5 ± 2.6 kg were randomly assigned to either an MHAC or an ITM dietary treatment. Supplemental Zn, Cu, and Mn levels for both treatments were 100, 20, and 40 mg/kg, respectively. Diets were corn-soy-based with phytase added to release 0.09% standardized total tract digestible P. Pigs were housed in metabolism crates for 7-d, including 5 for adaptation and 2 for total fecal and urine collection. Data were analyzed using the MIXED procedure of SAS. Results showed that pigs fed MHAC had a numerical increase in the ATTD of DM compared with ITM (90.9 vs. 89.4%; P = 0.180). Pigs fed MHAC had greater ATTD of Zn than those fed ITM (36.4 vs. 16.8%; P = 0.013), greater Zn retention (87.1 vs. 36.9 mg/d; P = 0.011), and decreased Zn excretion than those fed ITM (159.1 vs. 209.3 mg/d; P = 0.013). Pigs fed MHAC had increased Zn retention:intake compared with ITM (0.353 vs. 0.152; P = 0.014). There was a numerical increase in Zn retention:absorption in pigs fed MHAC compared with ITM (0.977 vs. 0.796; P = 0.128). Pigs fed MHAC had greater ATTD of Cu than those fed ITM (52.5 vs. 30.7%; P = 0.012), had increased Cu retention (25.6 vs. 14.4 mg/d; P = 0.012) and less Cu excretion than those fed ITM (24.1 vs. 35.3 mg/d; P = 0.016). Pigs fed MHAC had increased Cu retention:intake compared with ITM (0.513 vs. 0.293; P = 0.017) and tended to increase Cu retention: absorption (0.980 vs. 0.944; P = 0.057). Pigs fed MHAC had greater ATTD of Mn than ITM (35.8 vs. 14.5%; P = 0.019), had increased Mn retention (42.4 vs. 16.5mg/d; P = 0.017), and less Mn excretion than ITM (77.2 vs. 103.0mg/d; P = 0.017). Pigs fed MHAC had increased Mn retention:intake compared with ITM (0.353 vs. 0.141; P = 0.018). There were no differences between MHAC and ITM in Mn retention:absorption (0.986 vs. 0.986; P = 0.993). Pigs fed MHAC had a numerical increase in the ATTD of P (69.3 vs. 62.9%; P = 0.373), numerically less P excretion (2.94 vs. 3.57g/d; P = 0.348), and numerically greater P retention (6.44 vs. 5.80; P = 0.376) than those fed ITM. In conclusion, pigs fed MHAC had greater Zn, Cu, and Mn availability than ITM. This is likely due to the distribution and utilization of these trace minerals where they are needed. Furthermore, MHAC decreased the excretion of these minerals to nourish the pigs and reduce their impact on the environment through nutrient losses.
PSII-10 Effect of Equine Chorionic Gonadotrophin-Like Glycoprotein Treatment on Fertility in Angus Cows Subjected to a 7-Day Co-Synch Protocol
Authors: Rodriguez Alejandro M , Maresca Sebastian , López-Valiente Sebastian O , Bartolome Julián A , Pérez-Wallace Santiago , Long Nathan
Published: November 2023

This study evaluated the effect of administering a glycoprotein with equine chorionic gonadotropin like activity produced by recombinant DNA technology (eCG-like) associated with a 7-d Co-Synch protocol on estrus rate (ER) and pregnancy per timed AI (P/TAI). A total of 1,344 suckled Angus cows (primiparous, n = 381; multiparous, n = 963) from 11 herds were scanned at initiation of synchronization protocol by transrectal ultrasonography and the presence of corpus luteum (CL) and uterine tone was used to classify them by cycling. On day -10, cows received 100 μg GnRH analogue and a progesterone intravaginal device (IVD; 1.0g progesterone) for 7 days. At IVD removal, cows were administered 500 μg of cloprostenol and randomly assigned to receive 400 IU of eCG-like glycoprotein (Syntex S.A., Argentina, PCT/EP2019/073277; eCG-like, n = 665) or to remain as untreated (Control, n = 679). Also on day -3, paint was applied on the sacrum to the tail head of each cow. Finally, 100 μg GnRH analog were injected concurrently with TAI on Day 0 (66h after IVD removal) and the ER was evaluated by the degree of paint loss. Pregnancy to TAI was determined on day 30 by transrectal ultrasonography when an embryo and fluid were detected in the uterus. Body condition score (BCS; scale = 1-9) was evaluated on days -10 and 30. Optimal BCS was considered ≥ 5 and BCS balance between days -10 and 30 was classified as negative (lost BCS) or positive (maintained or gained BCS). The associations among treatment, parity, cyclicity at initiation of protocol, optimal BCS on day -10, and their interactions and ER and P/TAI were analyzed by GLIMMIX (SAS 9.3). Estrus expression and BCS balance were also included as effects in the model of pregnancy per TAI. The effect of herd was included as a random effect. The model specifications included an option to retrieve the mean, SEM, and an adjustment for multiple comparisons (Tukey-Kramer). The percentage of acyclic cows was 31.3%. The ER in cyclic cows was 64.9% and the eCG-like treatment increased ER only in anestrus cows (55.8 vs. 44.3%; Treatment x cyclicity interaction; P = 0.03). The percentage of cows with negative BCS balance was 27.2%. The P/TAI in cows with positive BCS balance was 48.4% and the eCG-like treatment increased P/TAI only in cows with negative BCS balance (44.7% vs. 30.5%; Treatment x BCS balance interaction; P = 0.01). In conclusion, the addition of a recombinant eCG-like glycoprotein to a 7-day Co-Synch protocol increased estrus expression in anestrus Angus cows and P/TAI in those with negative body condition score balance. However, this addition did not influence the estrus expression in cycling cows or on P/TAI in those with positive BCS balance.
PSII-8 Comparison of Different Fattening Stages on Rumen Microbiota and Physiological Characteristics in Japanese Black Cattle
Authors: Lee Huseong , Kim Minji , Masaki Tatsunori , Ikuta Kentaro , Iwamoto Eiji , Nishihara Koki , Hirai Makoto , Uemoto Yoshinobu , Terada Fuminori , Roh Sanggun
Published: November 2023

This study aimed to investigate the relationship between rumen microbiota and physiological characteristics in Japanese Black cattle during the fattening period, which are known for their distinctive physiological characteristics due to prominent intramuscular fat deposition. The experimental period was categorized into three stages: early (12 to 14 months of age; T1), middle (15 to 22 months; T2), and late fattening phases (23 to 30 months; T3). We analyzed the rumen microbiota of 21 Japanese Black cattle in each phase using 16S rRNA gene amplicon sequencing. In addition, we examined the correlation between the rumen microbiota and various physiological parameters, such as blood metabolites, hormones, and rumen fermentation characteristics. Our results showed that rumen microbial diversity was greater in T1, and the inter-group distribution of rumen microbiota in T1 was differentiated from T2 and T3. At the genus level, Flexilinea, Streptococcus, Butyrivibrio, Selenomonas and Kandleria were the most abundant in T1. Bifidobacterium, Shuttleworthia and Sharpea were the most abundant in T2. Acetitomaculum, Mycoplasma, Atopobium and Howardella were the most abundant in T3. In correlation analysis, Monoglobus and Olsenella negatively correlated with IGF-1 and positively correlated with cortisol in T1. Firmicutes/Bacteroidota ratio positively correlated with daily gain, blood total cholesterol, and lactic acid dehydrogenase in T3. Planctomycetota correlated with volatile fatty acid components during the entire period, while Verrucomicrobiota positively correlated with carcass traits in T1. Additionally, functional genetic profiles indicated that rumen microbiota related to carbohydrate metabolism and nucleotide biosynthesis was significantly enriched in T1 and T3, respectively. The composition of rumen microbial in Japanese Black cattle varied depending on fattening stages, and this variation is likely attributable to changes in feed composition. Furthermore, specific microorganisms were significantly associated with physiological parameters. Our findings could help in the development of strategies to enhance gut health and productivity by manipulating the rumen microbiota through the changes in diet compositions considering the fattening stages of Japanese Black cattle.
PSII-13 Size and Abundance of Extracellular Vesicles in Cattle During Early to Mid-Gestation Consuming Control Or Restricted Diets
Authors: Pratt Scott , Soyluoglu Meryem , Karanfil Tanju , Delorme Richard , Long Nathan
Published: November 2023

Extracellular vesicles (EVs) are known to be present in cattle blood, and have been shown to contain miRNA; however, little information is available describing the abundance or size of circulating EVs in cattle during gestion. Our objective was to determine EVs size and abundance in maternal circulation during early and mid-gestation. Cattle were blocked by body condition score (BCS) and body weight (BW), synchronized and bred to the same AI sire using male-sexed semen (n = 23). At day 30 post-AI, pregnancy was determined and cattle were allotted to 1 of 3 groups and received a control diet (CON) from d 30 to d 190 of gestation (n = 8), a CON diet from d 30 to d 110 and nutrient-restricted (NR) diet from d 110 to d 190 (CON/NR; n = 8), or an NR diet from d 30 to d 110 and CON diet from d 110 to d 190 (NR/CON; n = 7). BW and BCS were recorded weekly or biweekly, respectively. Blood samples were collected via the coccygeal vein, samples allowed to clot, stored at 4 oC overnight and processed for serum. Serum was stored at -20 oC until used for EVs isolation. Six serum samples were utilized for each diet within each day of gestation. Two samples within each group were pooled giving 3 biological replicates for each group by day combination. EVs were isolated using differential centrifugation procedures, resuspended in 1X PBS and then subjected to nanoparticle tracking analysis (NTA; NanoSight NS300, Malvern Panalytical, UK). NTA established a size range across all samples of 31 to over 400 nm indicating the presence of exosomes and larger EVs. NTA data were subjected to ANOVA where day of gestation, diet treatment, and their interaction were the main effects. Student’s t-test among LS means for particle EVs concentration and size were used to determine significance (P < 0.05). Day of gestation affected EVs concentration with 3.9 x 109 ± 2.1 x 108 particles per ml, 1.4 x 109 ± 2.1 x 108 particles per mL and 2.6 x 109 ± 2.2 x 108 particles per mL, at day 30, 110 and 190 of gestation, respectively (P < 0.05). There was a day of gestation by diet effect for the size of EVs with the largest sizes observed for CON, NR and CON/NR group at day 30 and for NR/CON at day 190 (P < 0.05). The smallest EVs were detected on day 110 of gestation for the NR/CON and the CON groups (P < 0.05). These data indicate that EVs size in maternal circulation can be impacted by diet and day of gestation and this observation is most likely linked to the observations of differential abundance of miRNA previously reported.
PSXI-3 Effects of Limit Feeding Complete Diets to High Risk Receiving Calves
Authors: Johnson Michelle , Shelton Cody , Jones Cyle C , Rivera Daniel
Published: November 2023

Limit feeding cattle may result in more efficient gains, however, limiting intake may result in increased morbidity in higher-risk cattle. The objective of this study was to examine the effects of limit feeding on performance and health of newly received cattle. One hundred sixty-eight crossbred beef steers (BW = 215 ± 21 kg) were purchased from several sale barns in TX and AR and shipped to the University of Arkansas Southwest Research and Extension Center in Hope, AR. One-half the steers arrived one week, and the other one-half arrived the following week. Upon arrival, steers were vaccinated against respiratory and clostridial pathogens, treated with an anthelmintic, and administered a growth-promoting implant (40 mg TBA + 8 mg estradiol). Additionally, each animal was administered a metaphylactic treatment of tulathromycin. Approximately 52% were bulls that were surgically castrated upon arrival. Cattle were stratified by bull status and assigned to pens (n = 7 steers/pen) and pens were randomly assigned to one of three treatments (n = 8 pens/treatment): limit-fed pellet comprised of approximately 12% DDGS and 25% corn gluten feed fed at the rate of 2.25% of BW, without additional hay (NH; 2.25NH); a limit-fed pellet comprised of 12% DDGS and 25% corn gluten feed fed at the rate of 1.75% of BW, without additional hay (1.75NH); or a limit-fed pellet with similar composition as the other two, fed at the rate of 2.0% of BW along with free choice access to long stem hay (H; 2.0H). Cattle were fed diets twice daily at 0800 and 1400 hours, and hay was weighed and offered once per week, with hay refusals weighed back to correct for hay disappearance. Cattle were monitored for symptoms of bovine respiratory disease (BRD), and any symptomatic animals were treated with antimicrobial therapy. Cattle were weighed on d 0, 21, 42, 62, and 63. Data were analyzed using PROC GLIMMIX, pen was the experimental unit, treatment was a fixed effect, and block (arrival date) was considered random. Body weight was affected by treatment (P < 0.05) on d 42 and 63 with cattle fed 2.25NH and 2.0H having greater BW than 1.75NH. Similarly, ADG was greater from d 0 to 42 and d 0 to 63 for 2.0H and 2.25NH compared with 1.75NH (P < 0.05). Cattle fed 1.75NH and 2.25NH had more efficient feed conversion compared with 2.0H for the entire study (P < 0.05). No differences (P = 0.17) were noted for morbidity, mortality (P = 0.63), or treatment success (P = 0.76). Data from this study suggests limit-fed diets based on by-product feeds could be used for diets in high-risk cattle.
PSXI-6 The Effects Cattle Breed (Holstein Vs Angus × Holstein) on Growth Performance, Energetic Efficiency, and Carcass Characteristics of Calf-Fed Steers
Authors: Carvalho Pedro H V , Latack Brooke C , Ferraz Marcos V C , Nolasco Lester J R P , Meireles Willi R , Oliveira Heitor O M , Zinn Richard A
Published: November 2023

Objective of the current study was to evaluate the effects of cattle breed (Holstein vs Angus × Holstein) on growth performance, energetic efficiency, and carcass characteristics of calf-fed steers. Eighty Holstein (HOL), initial body weight (IBW) of 128.7 ± 3 kg, and 80 Angus × Holstein cross (CROS) with IBW of 127.1 ± 3 kg, were blocked by IBW and randomly assigned to 40 pens (4 steers/pen; 20 pens per breed). All steers were fed a similar steam-flaked corn-based diet (63.5% steam-flaked corn, 12.0% hay, 17.5% of dry distillers grains with solubles, 4.0% cane molasses, and 3.0% vitamin/mineral supplement). All cattle were slaughtered after 328 days of feeding. There was no effect (P ≥ 0.13) of cattle breed on final body weight (615 ± 22 kg) and overall average daily gain (1.48 ± 0.07 kg/day). However, calf-fed HOL steers had greater (P = 0.04) overall dry matter intake compared with calf-fed CROS steers (8.06 vs. 7.79 ± 0.39 kg/day; respectively). Therefore, calf fed CROS steers had greater (P ≤ 0.01) grain to feed ratio compared with calf-fed HOL steers (0.192 vs. 0.182 ± 0.005; respectively). Moreover, calf-fed CROS steers had greater (P < 0.01) utilization of dietary net energy for maintenance (2.29 vs. 2.29 ± 0.06 Mcal/kg; respectively) and gain (1.51 vs 1.61 ± 0.06 Mcal/kg; respectively) compared with calf-fed HOL steers. Calf-fed CROS steers had greater (P ≤ 0.02) hot carcass weight (HCW; 386.3 vs. 375.2 ± 14.7 kg; respectively), dressing percentage (DP; 62.3 vs. 61.4 ± 1.05%; respectively), longissimus muscle area (LMA; 86.9 vs. 79.1 ± 4.83 cm2; respectively), backfat thickness (0.89 vs. 0.55 ± 0.12; respectively), and marbling score (538 vs. 449 ± 48; respectively). However, there was no effect (P = 0.26) of cattle breed on calculated USDA yield grade (2.94 ± 0.24). Moreover, there was no effect (P = 0.39) of cattle breed on incidence of liver abscesses. Therefore, cross breeding calf-fed Angus × Holstein increased HCW, DP, LMA, and marbling compared with purebred calf-fed Holstein steers. Moreover, regardless of cattle breed, calf-fed steers in the current study had only 3.75% of liver with abscess.
PSXI-7 Sensing of Defecation and Urination Events Through Carbon Dioxide Monitoring
Authors: Wright Ryan , Ganino Alyssa , White Robin R
Published: November 2023

The continued success of livestock production in grazing systems depends on the ability to manage lands sustainably. Non-point-source emissions, particularly defecation/urination events (DUE), are a major cause of soil degradation, runoff into water sources, and nutrient management issues. Monitoring of these emissions from livestock through wearable sensing could support more precision management, but is complicated by the need for individualized sensors, variable signal strength across topographies, and unreliable data transmission in remote locations. The objective of this study was to explore opportunities to use CO2 sensing as an indicator of DUE from cattle on pasture using data obtained from an open-source sensor. The use of tail sensors was implemented to monitor the DUE of horses at various times of the day, ranging from 8 am to 5 pm. The tail sensors were developed using a neoprene base attached to velcro straps that were placed around the tailhead. The sensors themselves were equipped with a SparkFun ESP32 Thing Plus microprocessor connected to a SparkFun CO2 sensor and a lithium ion rechargeable battery that was charged via micro USB (SparkFun Electronics, Niwot, CO). Sensors were placed on 4 horses for 6 hours each collection period and data collection occurred over 9 days. Horses were observed in real time and DUE were recorded at the time of occurrence. Data were collected from the sensors via a Dragino LoRa gateway and a mobile hotspot for wireless connection. Data analysis relied on visual data exploration and targeted assessment of associations using random forest regression, support vector machines, and extreme gradient boosting. The visual data exploration revealed that DUE occurred in much lower frequency than non-events, and so random oversampling and undersampling were used for each classification approach to attempt to improve accuracy. Although CO2 peaks often corresponded to DUE, they also frequently occurred in the absence of DUE. All classification algorithms showed poor accuracies (0.50 to 0.51), which were only marginally improved by over- (< 0.51) and undersampling (< 0.69). This preliminary assessment revealed considerable noise in sensing CO2 emissions in production settings, which may preclude usefulness in DUE sensing.
PSI-29 Effects of Dietary Intake on Amino Acid Composition of Histotroph (Uterine Luminal fluid) in Nonpregnant Cows: Implications for Pregnancy
Authors: Neville Tammi , King Layla , Borowicz Pawel P , Reynolds Larry P , Caton Joel S
Published: November 2023

When the developing embryo enters the uterus, before the placenta develops, the embryo receives nourishment from endometrially derived histotroph produced by the uterine glands that remain functional throughout gestation. Throughout pregnancy, this histotroph remains necessary for proper embryonic development. Maternal nutrition may affect histotroph composition resulting in altered embryo development. The objectives were to determine the effects of dietary intake on histotroph amino acid (AA) concentrations. Eighteen multiparous nonpregnant cows (initial BW = 597 kg) were housed at the North Dakota State University Animal Nutrition and Physiology Center (n = 6 cows/pen). Cows were individually fed a TMR once daily via a Calan feeding system and had ad libitum access to fresh water. Cows were randomly assigned to 1 of 2 treatments (n = 9/treatment): dietary intake designed to maintain body weight (CON) or dietary intake designed to lose body weight at a moderate rate (-0.7 kg/d; NEG), for 63 days. Slaughter group 1 contained 4 CON and 5 NEG cows, and group 2 contained 5 CON and 4 NEG cows. Cows were estrus-synchronized with the Co-Synch + CIDR protocol to ensure a common day of the estrous cycle at the time of slaughter (3 d after completion of the Co-Synch + CIDR protocol). When total uterine histotroph AA was calculated (luteal + non-luteal horns) and analyzed by treatment with group in the model, the differences were: CON > NEG for 1) Trp as % of essential AA, and 2) Ser as % of total AA (P = 0.04 and 0.05, respectively). Tendencies for total tract histotroph were observed for Phe and Trp as a % of total AA (P = 0.07 and 0.06, respectively) for CON > NEG. Luteal histotroph Ser as a % of total AA was greater (P = 0.05) for CON vs. NEG. When evaluating non-luteal histotroph, CON had greater (P < 0.05) Cys as a % of total AA compared with NEG cows. Non-luteal histotroph Arg concentration tended (P = 0.10) to be greater for NEG vs. CON. These results demonstrate that feed intake affects cow AA supply in the uterine histotroph, and these AA (Trp, Ser, Phe, Cys and Arg) may function in critical nutrient pathways, reproductive tract vascularization, and antioxidant production, which are necessary for optimal fetal development.
PSII-25 Use of Energy Dispersive X-Ray Fluorescence for Determination of Indigestible Markers in Digesta Samples
Authors: King Mindy E , Foote Andrew P
Published: November 2023

Titanium dioxide and chromium ethylenediaminetetraacetic acid are commonly used as indigestible markers for determining passage rates of diets to aid in determination of digestibility. However, commonly used methodology involving acid digestions and utilizing inductively coupled plasma spectroscopy and atomic absorption spectroscopy for both Ti and Cr analysis involves hazardous chemicals, destruction of samples, and low sample throughput. The objective of this experiment was to develop and validate an accurate and precise method for measuring both Ti and Cr using energy dispersive X-ray fluorescence (ED-XRF). Energy dispersive X-ray fluorescence is an analytical technique used for analyzing elements in various sample types. The samples are added to the ED-XRF machine and irradiated with X-rays and the intensity of the X-rays emitted (termed fluorescent X-rays) are used for calculation of the concentration of the element. The method for Ti was constructed using fecal samples from cattle consuming three different diet types (finishing diet, dairy lactation diet, and grazing native range pasture). The Cr method was developed for rumen fluid analysis. To determine accuracy and precision of the method, samples were spiked with various amounts of Ti or Cr and measured for their respective compounds with percent recovery and inter- and intra-assay CV calculated thereafter. Additionally, a regression was performed using PROC REG in SAS 9.4 to determine the relationship between grams of Ti added and grams of Ti recovered for each diet type. The average recovery for Ti across all diet types was 100.3%, and the recovery for Cr in rumen fluid was 95.7%. The average inter- and inter-assay CV for Ti, across all diet types, were 9.70 and 2.16%, respectively. For Cr, the average inter- and inter-assay CV were 5.41 and 8.45%, respectively. Across diet type, the regression for grams of Ti added versus grams of Ti recovered indicated the recovery was not altered by the amount added (P ≤ 0.062). The ED-XRF method requires minimal additional chemicals, is cost-effective, and allows for sample preservation as well as a high throughput of samples. Our results indicate utilization of ED-XRF is an accurate and precise method for determination of Ti in feces and Cr in rumen fluid.
PSIII-30 Effects of a Bacillus-Based Direct-Fed Microbial on in Vitro Gas Production and Fiber Digestibility of Feedstuffs
Authors: Cappellozza Bruno I , Fantinati Paolo , Bodin Jean-Christophe , Joergensen Jens , Vyas Diwakar , Farooq Samia , La Lima ís , de Guzman Carlos , Arriola Kathy , Copani Giuseppe
Published: November 2023

Direct-fed microbials (DFM) support the health and performance of the herd through different modes of action, including improvements on nutrient digestibility. In fact, Bacillus spp. has been identified as an important enzyme-producing bacteria that could benefit overall nutrient utilization by the beef and dairy cattle herd. Based on this rationale, we hypothesized that incubation of a Bacillus-based DFM would improve nutrient digestibility of feedstuffs often fed to ruminants. Therefore, our objective was to evaluate the effects of a Bacillus-based DFM on in vitro nutrient digestibility of different single feedstuffs. Six individual feedstuffs were sampled from China and South Africa and used herein. Feedstuffs were incubated or not (CON) with a Bacillus-based DFM (DFM; BOVACILLUS; B. licheniformis and B. subtilis; 3.2 × 109 CFU/gram; Chr. Hansen A/S., Hørsholm, Denmark) over a 48-h in vitro period. The dose of DFM was adjusted to the volume of the flasks being used and to represent the commercial dose of 3 grams/head per day (9.6 × 109 CFU/head). In vitro gas production, dry matter (DM), and neutral detergent fiber (NDF) digestibility were evaluated at 24 and 48 h. Data were analyzed using PROC MIXED of SAS (version 9.4). Mean total in vitro gas production increased by 5.1 and 6.5% when DFM was incubated at 24 and 48 h, respectively (P < 0.01). At 24 h, NDF digestibility was 12.6% greater for DFM-treated feedstuffs vs. CON (P = 0.02; 27.7 vs. 24.6% for DFM and CON, respectively), but no effects were observed on DM digestibility (P = 0.26). Conversely, 48-h DM and NDF digestibility were greater for DFM vs. CON (P ≤ 0.05), with improvements that were in the order of 3.7 and 15.1%, respectively. In conclusion, we observed greater in vitro fiber degradability and gas production of feedstuffs collected from China and South Africa over a 48-h period when the DFM BOVACILLUS was added at a dose representative of 9.6 × 109 CFU per head. Greater improvements in fiber degradability are likely due to the enzymes produced by the DFM BOVACILLUS.