bluuebunny/crossref_metadata_2025 huggingface dataset:
269 Copper Methionine Hydroxy Analogue Chelate as a Reduce and Replace Cu Strategy in Growing Pigs
Authors: Lawrence Bradley V , Hintz Alex , Torres David , Fernandez-Dueñas Demian M
Published: November 2023

Research has shown that minerals supplied in the methionine hydroxy analogue chelate (MHAC; MINTREX Trace Minerals [Novus International Inc., St. Charles, MO]) form are more available than inorganic trace minerals. Research in weaned pigs demonstrated improved pig performance when Cu was provided in the Cu-MHAC form compared with inorganic Cu sources. In the growing pig it may be desirable to reduce the amount of total Cu fed to minimize Cu excretion while maintaining animal performance. Data from 8 studies, 4 studies per Cu source comparison, was used to compare 50 mg/kg of Cu as Cu-MHAC with either 125 mg/kg Cu as CuSO4 or 150 mg/kg Cu supplied in the tri-basic copper chloride (TBCC) form. There were 44 pens of 23 pigs per pen for each Cu source in the Cu-MHAC vs TBCC comparison and 39 pens of 22 pigs per pen for each Cu source for the Cu-MHAC vs. CuSO4 comparison. Cu-MHAC was compared with CuSO4 in separate trials from those comparing Cu-MHAC vs TBCC. Trials were conducted across all seasons. Pigs had previously received either CuSO4 or TBCC during the nursery phase. Data were analyzed with the PROC MIXED procedure of SAS using trial as a random effect. Outlier analysis was conducted for each parameter with any observation greater than 3 standard deviations from the treatment mean removed. Pigs in the Cu-MHAC vs CuSO4 comparisons averaged 29.3 + 2.18 kg of BW while those used in the Cu-MHAC vs TBCC comparisons averaged 31.0 + 2.33 kg of BW. Average study duration was 105 days. Average market weight sold was 0.45 kg/pig (P = 0.52) and 0.59 kg/pig (P = 0.46) less for Cu-MHAC than CuSO4 and TBCC pigs respectively. Adjusted feed conversion was 4 points lower (P = 0.12) and 2 points lower (P = 0.25) for the Cu-MHAC vs CuSO4 and TBCC pigs respectively. Removal percentage during the studies ranged from 3.63% to 4.91% with the Cu-MHAC pigs having 0.6 percentage points less removals than the CuSO4 (P = 0.52) and 0.7 percentage points less removals than the TBCC (P = 0.38) treatment. The fewer removals resulted in the Cu-MHAC treatment having 3 points decreased feed conversion (P = 0.25) than TBCC pigs and 6 points decreased feed conversion (P = 0.12) than CuSO4 pigs on a pen basis. The combined Cu-MHAC analysis vs combined inorganic Cu source analysis showed that Cu-MHAC pigs had 4 points less feed conversion on both an adjusted (P = 0.06) and closeout (P = 0.06) basis than pigs fed inorganic Cu. The cumulative removal rate was 0.7 percentage points less for the Cu-MHAC pigs (P = 0.29). These results indicate supplying Cu as 50 mg/kg Cu-MHAC can reduce feed conversion compared with 125 mg/kg Cu as CuSO4 and 150 mg/kg Cu as TBCC in growing-finishing diets.
279 Impact of Increasing Additions of Choline Chloride on Broiler Chicken Body Weight Variability
Authors: Gregg Caroline R , Abascal-Ponciano Gerardo A , Stefanello Catarina , Starkey Jessica D , Starkey Charles
Published: November 2023

Previously, we observed a linear improvement in feed conversion and no difference in body weight (BW) in broiler chickens fed increasing additions of choline chloride in a diet with reduced digestible methionine (dMet) reared under summer environmental conditions. Poor uniformity in broiler carcass weights can negatively impact processing yields and profitability. The objective was to evaluate the impacts of increasing choline concentration on BW variation of broilers from the previous study. Yield Plus × Ross 708 male broilers (n = 2,232) were reared for 41 d on used litter in floor pens (n = 31 birds per 2.3 m2 pen). Birds were fed 1 of 6 corn and soybean meal-based, reduced dMet diets containing 0, 400, 800, 1,200, 1,600, or 2,000 mg added choline chloride per kg of feed (n = 12 pens per treatment). Diets were provided in 3 phases: starter from d 0 to 15 with 0.42% dMet, grower from d 16 to 28 with 0.42% dMet, and finisher from d 29 to 41 with 0.37% dMet. Rearing temperatures began at 34.4 °C, were reduced over 21 d to 26.7 °C and maintained there until d 41. Individual weights were collected at 15, 28, and 41 d. Broilers (n = 10 per pen based on proximity to pen median BW) were processed on d 43. The distance of each bird from both mean and median of the pen, added choline treatment, and whole flock BW over time was calculated. Uniformity was reported comparing within a pen to the pen, treatment, and flock averages. Intra-pen CV was calculated using pen mean and median weights. Data were analyzed as a 1-way ANOVA using SAS PROC GLIMMIX with added choline as main effect. Means were separated at P ≤ 0.05 with tendencies declared at 0.05 < P ≤ 0.10 using the PDIFF option, and orthogonal contrasts were evaluated. Supplementing the diet with choline increased individual bird distance from the treatment and flock average BW from d 15 to 41 (P ≤ 0.0244). Intra-treatment and flock uniformity showed a quadratic response to increasing additions of choline at d 41 (P ≤ 0.0214) as did the CV within pens at d 41 (P = 0.0455). Variability of carcass part weights of birds selected for processing was not impacted by choline addition. While supplementing dMet-deficient diets with choline chloride can improve broiler feed efficiency without impacting BW, it may alter variation among individual birds depending on the concentration in the diet. These results indicate that there is variation in how individual birds respond to choline chloride additions and highlight the importance of analyzing variation as part of comprehensive feed additive evaluation to deepen the understanding of its impacts.
289 Postnatal Obesity Amplifies the Effect of Prenatal Testosterone Excess in Reducing the Progesterone Negative Feedback Sensitivity in First-Generation Ewes
Authors: Gurule Sara C , Sustaita-Monroe Jessica F , King Leslie , Garza Viviana , West Sarah , Weynand Morgan , Ecord Emily , Padmanabhan Vasantha , Cardoso Rodolfo C
Published: November 2023

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility in women of reproductive age. Women with PCOS exhibit reduced sensitivity of the GnRH neuronal system to the inhibitory effects of both progesterone and estradiol. Additionally, obesity amplifies the severity of the PCOS phenotype. In sheep, testosterone (T) excess during gestational days (GD) 30-90 and 60-90 reduces neuroendocrine sensitivity to the progesterone negative feedback and recapitulates the PCOS phenotype. This study investigated the contribution of postnatal obesity in amplifying or mitigating the effects of mid-gestational T excess in disrupting the responsiveness to progesterone negative feedback in sheep. Suffolk ewes received T propionate (T; 100 mg i.m.) or corn oil (CO; vehicle) twice weekly from GD 60-90 (term = 147 d). At 5 mo of age, F1 T lambs were assigned randomly to either a maintenance (100% of NRC requirements) or overfed diet (130% of NRC requirements) and control lambs were fed the maintenance diet. At 22 mo of age, F1 ewes (n = 8/group) were synchronized with two injections of PGF2α 11 d apart. After the second PGF2α administration, blood samples were collected daily for 14 d and progesterone concentrations were determined via radioimmunoassay. Ewes that were confirmed to be cycling and in the mid-luteal phase based on progesterone concentrations (progesterone ≥ 1 ng/ml on day 10 and ≥ 0.5 ng/ml on days 8-9 and 11-12) were used for LH pulse characterization. On day 10 after PGF2α synchronization (mid-luteal phase), blood samples were collected every 15 min for 6 h to characterize LH pulsatile secretion via radioimmunoassay. Data were analyzed as one-way ANOVA with Tukey's HSD post-hoc analysis. Frequency of LH pulses was greater (P < 0.05) in T maintenance (3.75 ± 0.41 pulses/6h) and T overfed ewes (3.50 ± 0.34 pulses/6h) compared with controls (2.00 ± 0.37 pulses/6 h). Luteinizing hormone pulse amplitude was greater (P < 0.05) in T overfed (2.03 ± 0.15 ng/mL) compared with T maintenance (1.44 ± 0.17 ng/mL), but not to controls (1.74 ± 0.21 ng/mL). Also, average LH concentration was greater (P < 0.05) in T overfed (2.03 ± 0.24 ng/mL), but not T maintenance (1.31 ± 0.35 ng/mL), compared with controls (0.93 ± 0.30 ng/mLl). In conclusion, these findings demonstrate the activational role of postnatal obesity in amplifying prenatal T-induced alterations in tonic LH secretion during progesterone negative feedback. The activational effect of postnatal obesity in increasing LH secretion and consequently thecal androgen production is likely a contributor to the severity of hyperandrogenic status in women with PCOS. Research support: NIH-NICHD (R01HD099096).
329 Evaluation and Prediction of Site and Extent of Protein Digestion of Feedstuffs Commonly Fed in Beef Cattle Finishing Diets
Authors: Proctor Jarret A , Beck Matthew R , Kasuske Zachery A , Foster Ryan C , Long Nathan S , Wickersham Tryon A , Gouvea Vinicius N , Smith Jason K
Published: November 2023

Meeting metabolizable protein requirements of finishing cattle without overfeeding protein requires reliable estimates of site and extent of digestion. Current estimates of rumen degradable (RDP) and undegradable protein (RUP), as well as intestinal digestibility of RUP (dRUP) may be inadequate. Thus, the objectives of this experiment were to quantify RDP, RUP, and dRUP of common feedstuffs and evaluate nutrient composition as a predictor of RDP, RUP, and dRUP. Ruminally cannulated steers (n = 6) consuming a finishing diet were enrolled in replicated 3 × 3 Latin squares. Within each Latin square period, steers were assigned a feedstuff classification for in situ ruminal incubation. Single-source ingredients were classified as grain (steam-flaked and whole-shelled corn, wheat, and milo), protein (wet and dried corn distillers grains, Sweet Bran, cottonseed meal, canola meal, and soybean meal), and roughage (cotton burrs, alfalfa hay, wheat hay, sorghum × sudangrass hay, wheat silage, and corn stalks). Nutrient composition was determined for all feedstuffs using wet chemistry procedures. Feedstuffs were lyophilized, ground through a 2-mm screen, aliquoted into in situ bags, and ruminally incubated for 0, 4, 8, 12, 24, or 48 h. Samples were composited within incubation time point, analyzed for crude protein (CP), corrected for microbial contamination, and fit to non-linear models to estimate RDP and RUP using calculated passage rate. Subsamples of in situ digested feedstuffs underwent in vitro pepsin-pancreatin digestion and CP analysis to estimate dRUP. Statistical analyses were conducted using JMP Pro 16.0 and R (v4.1.0). On average, RUP estimates were 37.0% decreased (P < 0.05) for protein ingredients, yet grains and roughages were not different (P > 0.73) compared with NASEM (2016) empirical values, respectively. However, average dRUP was 11.9% and 33.1% reduced (P < 0.01) for protein ingredients and roughages, yet grain dRUP was not different (P = 0.16) compared with NASEM (2016) values, respectively. Neutral detergent fiber (NDF) and CP explained a substantial portion of the variation in RDP (P < 0.01, R2 = 0.94, RMSE = 2.26). Acid detergent fiber, NDF, and CP explained considerable variation in dRUP (P < 0.01, R2 = 0.91, RMSE = 5.43). Models were predictive when applied to independent data from the literature for estimates of RDP (R2 = 0.93; RMSE = 3.72) and dRUP (R2 = 0.83; RMSE = 6.06). There was slope (-0.09; P < 0.05) and mean bias (-1.30; P < 0.01) for RDP prediction validation but only mean bias (4.90; P < 0.01) in dRUP prediction validation models. Collectively, these data suggest that dRUP of protein ingredients and roughages are less than values reported by the NASEM (2016). Furthermore, CP and NDF may be useful for predicting RDP, RUP, and dRUP.
48 Does Automated Behavioral Monitoring Inevitably Lead to Improved Pig welfare?
Authors: Siegford Janice M
Published: November 2023

Academics, producers, veterinarians, technology developers, and even the general public seem to be talking about using technology to solve agricultural problems. The starting point for many proposed technological solutions to help manage pigs is the automated detection of specific behaviors. These behavioral data then need to be translated into actionable information to assess welfare, and ideally to provide a management solution to ensure good welfare for the monitored pigs. However, detecting behavior of animals, particularly of relatively homogeneous animals living in large groups at high densities, such as pigs on commercial farms, is not a trivial problem. Most functional behaviors are complex and made of multiple smaller elements, including postures and simple motions. Training technology to detect behaviors with accuracy that mimics a human expert is difficult, due to behavioral complexity as well as to variation in how each individual does a behavior and how physical and social environmental context affect performance of a behavior. Disappointingly, many technologies that claim to detect performance of behaviors are in fact only detecting the proximity of the pigs to resources or to each other and then assuming that pig is interacting with the resource or social partner in a particular way. However, a pig standing near a feeder is not always eating, nor is a pig near another pig always deliberately interacting with that other animal. It is necessary to closely evaluate automated behavior detection solutions to determine if these do directly detect the behavioral outcomes of interest. The next problem is connecting the detected behavior to a specific welfare outcome. Animals typically perform behaviors for biologically motivated reasons related to maintaining physiological homeostasis, responding to disease challenges, or to expressing their emotional state. Yet making a direct link between performance of a certain behavior and a subsequent welfare state is not straightforward. For example, grooming is often thought of as a comfort behavior, but animals that are distressed may groom as a displacement behavior. Therefore, context and other measures are needed to complement the behavioral information before drawing a welfare conclusion. A final problem to consider is whether detection of a welfare problem inevitably leads to improved welfare. In some cases, such as when a technology identifies the start of an outbreak of treatable illness, action is possible. In other cases, the technology may detect a more intractable problem, such as lameness in a sow. If we cannot effectively cure the underlying problem or eliminate the associated pain or distress, does this raise ethical dilemmas or reduce trust in the swine industry? While technologies do hold promise to better monitor and manage pigs in labor efficient ways, we must mindfully develop solutions that monitor pigs' behavior and cautiously evaluate their ultimate impacts on pig welfare.
393 Impact of Concurrent Enrollment in Laboratory and Lecture Sections of an Animal Reproduction Course on students’ Final Course Percentages
Authors: Hartman Ashley R , Fike Karol E , Grieger David M
Published: November 2023

As undergraduate animal science student populations shift to more diverse backgrounds, hands-on learning activities have been shown to increase engagement and are necessary for students with diverse backgrounds in animal exposure. Student feedback and engagement in the classroom suggest that students value and seek hands-on learning opportunities. The outcomes of lecture courses with concurrent enrollment in laboratory or hands-on style courses warrant evaluation. Thus, our study aimed to investigate potential impacts of concurrent enrollment in lecture and laboratory sections on final course percentages. Data were collected from students enrolled in the farm animal reproduction lecture and (or) laboratory courses in the spring semesters of 2021 and 2022 including final course percentage in lecture, college classification (sophomore, junior, senior), gender, and degree option (science or production focus). Student learning outcomes and structure of the laboratory course were designed to provide hands-on learning opportunities that coincided with concepts discussed in lecture. A total of 193 students majoring in Animal Science were included in the analysis, of which 65 were concurrently enrolled in the laboratory and lecture, and 128 were enrolled in the lecture alone. Students concurrently enrolled in laboratory and lecture had a greater (P < 0.03) final course percentage in the lecture as compared with those enrolled in lecture alone. Students in the science degree option had a greater (P < 0.01) final lecture course percentage when compared with those in the production degree option. Neither student gender nor college classification affected (P > 0.10) final lecture course percentage. At the end of the semester, students were surveyed about perceived value of the laboratory course on their learning. Among students enrolled in laboratory sections, only 1.6% indicated the hands-on activities did not improve their learning of course concepts in lecture. In 2022, 82.2% of students enrolled in lecture, but not in a laboratory section indicated they wished they had enrolled in a laboratory section, because they believe it would have improved their grade in the lecture course. These student beliefs are supported by our results which indicate that not only did taking the laboratory and lecture together improve student final course percentages, but that students valued the hands-on learning opportunities provided in laboratory sections. Benefits of hands-on learning activities warrant providing student access to these types of activities and incorporating them in lecture courses when laboratory classes are unavailable to improve student performance and experiences.
8 Impacts of Future Climate Scenarios on the Beef Industry of the Great Plains and Western Us
Authors: Place Sara E
Published: November 2023

Global average temperatures have increased by 1.1 degrees Celsius compared with pre-Industrial times and future temperature increases will be driven by anthropogenic greenhouse gas emissions trends. Impacts of climate change vary by geographic regions, with the Great Plains and Western US likely to experience increased temperatures, increased frequency of drought, and more extreme precipitation events. These climate impacts can affect the beef industry in those regions in multiple ways from increasing heat stress, decreasing forage availability, impacting forage quality, and reducing water availability for drinking water and feed production. In the southwestern US, increasing temperatures are likely to increase evapotranspiration, reduce snow cover, and lead to earlier snow melts, all of which can contribute to the aridification of the region. For cow-calf production within the region, aridification will reduce the forage biomass available for grazing cattle operations and reduce carrying capacity, creating potential vulnerabilities to rangeland ecosystems and rural communities dependent upon the cattle industry. Increased incidence of heat waves in the Great Plains and Western US can negatively impact vulnerable cattle populations, such as finishing cattle, particularly those housed in environments with minimal heat stress mitigation measures. Decreased water availability can potentially shift cattle production and feed production away from arid regions dependent upon vulnerable water resources, such as the Colorado River and Ogallala aquifer. In general, the increased climate variability and aridification of some parts of the Great Plains and Western US will create risks for the beef industry that will likely necessitate changes, from shifting cattle population to increased use of heat stress mitigation strategies.
PSVII-5 Detection and Characterization of Copy Number Variation Regions in Three Selection Lines of Nellore Cattle
Authors: Benfica Lorena F , Brito Luiz F F , do Bem Ricardo D , Mulim Henrique A , Braga Larissa G , Cyrillo Joslaine N S G , Mercadante Maria Eugenia Z
Published: November 2023

Copy number variations (CNV) can partially explain phenotypic variability in complex traits. Therefore, we aimed to identify and characterize CNV regions (CNVR) in Nellore cattle from three selection lines. These selection lines were established in 1981 and consist of a line selected based on heavier postweaning weight (NeS, n = 245), a line selected based on heavier postweaning weight and reduced residual feeding Intake (NeT, n = 556), and a line selected based on average postweaning weight (NeC, n = 114). Genotypes (GGP Indicus HD and GGP Indicus 50K panel) of 928 animals were analyzed. The CNV identification was performed per SNP panel using the PennCNV software. After identifying the CNVs, quality control was performed and the following exclusion criteria were used: Log R ratio > 0.30, B allele frequency "drift” < 0.01, and guanine-cytosine wave factor < 0.05. CNVR were determined by grouping individual CNVs with at least one overlapping base pair. The exclusive regions present in at least 10% of the animals from each population were identified. The GALLO R package was used for the annotation of genes in these regions, and the WebGestaltR package was used for the Gene Ontology analyses. Eight-hundred-and-twenty-three CNVRs (143 losses, 650 gains, and 30 mixed), 1,493 CNVRs (327 losses, 1,113 gains, and 53 mixed), and 482 CNVRs (90 losses, 378 gains, and 14 mixed) were identified in the NeS, NeT, and NeC lines, respectively. The CNVRs covered 1.61%, 2.54%, and 0.94% of the cattle genome in NeS, NeT, and NeC, respectively. Only 32 CNVRs were identified in at least 10% of the animals in NeS, 33 in NeT, and 25 in NeC. Of these regions, 2 are NeS exclusive, 4 are NeT exclusive, and 6 are NeC exclusive. Eight candidate genes in NeS, 20 candidate genes in NeT, and 16 genes in NeC overlapped with the exclusive regions. We identified some important genes such as SLC15A1 in NeS herd that have functions associated to nutrient absorption, MAPK1 identified in the NeT population is involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation and development, and IQCA1L in the NeC population is involved in ATP activity. The genes identified are involved in 5 biological processes, such as response to growth factor, in NeT, and in 1 biological process (response to endoplasmic reticulum stress) in NeC. The differences observed in CNVR improve our understanding of the genetic architecture of the three Nellore selection schemes, given that the identification of genes in the CNVR allows the identification of genomic regions and biological processes that could be associated with the phenotypic differences between selection lines.
PSXII-2 Lactation Persistence Analysis and Its Genetic Correlations with Productive, Reproductive, and Health Traits in the First Two Parities in Lucerna Cattle
Authors: Sierra Sergio N Sanchez , Herrera Luis Gabriel Gonzalez , Peñagaricano Francisco
Published: November 2023

Lactation persistency (LP) is a trait of economic relevance in dairy cattle since persistent cows are more profitable by presenting fewer diseases, requiring fewer inputs, and having better reproductive performance. Therefore, the main objective of this study was to estimate genetic relationships between lactation persistency for mastitis (MT), calving interval (CI), and 305–day milk yield (305M) in first and second Lucerna cattle lactations. Records from 67,952 test–day milk, 7,100 CI, and 1,074 clinical-mastitis evaluations from two Colombian farms of Creole dual-purpose cattle were considered. Five three-parameter equations, as reported in previous literature, were graphically and statistically evaluated for fitting a lactation curve (LC) for each parity. The goodness-of-fit criteria included AIC, BIC, RSS, and R2. The most appropriate equation was identified and implemented for predicting 305M for 4,620 lactations (2,716 and 1,904 from first and second parity, respectively) for which LP was estimated. Bi-trait animal models between LP-MT, LP-CI, and LP-M305 for each parity were executed in the BLUPF90+ software (AI-REML algorithm) to estimate heritabilities (h2) and genetic correlations (GC). Fixed effects of herd, year of calving, season of calving, b0 lactation parameter, and age at calving were included. Estimates of goodness-of-fit criteria for all LC equations varied between R2 (0.29 – 0.68), BIC (132,322 – 207,415), AIC (132,289 – 207,389), and RSS (188,231 – 414,007). The incomplete gamma equation best satisfied the goodness-of-fit-criteria and drew the most accurate LC in both parities. Due to the low data density in this work, estimates involving MT and CI had increased standard deviations; therefore, the interpretation should be considered cautiously. The h2 estimates were 0.0 and 0.24 for MT, 0.02 and 0.09 for CI, 0.18 and 0.36 for M305, and 0.14 and 0.15 for LP, for the first and second parity, respectively. The GC estimates were -0.24 and -0.41 for LP–M305, 0.31 – 0.35 for LP–CI, and -0.76 for LP–MT for each parity, respectively. The results of this study suggest that LP could be considered as a selection target in the farms’ breeding program since desirable relationships were found with all evaluated traits for the first and second parity.
PSI-7 Vitamin a and D Pre-Exposure to Prime Reproductive Success in Breeding Beef Cows
Authors: Fox Amanda K , Hammerich Michael , Bishop Cecily V
Published: November 2023

Vitamins A and D are important for immunity, reproduction, and overall health. The need for supplementation is often overlooked in beef cattle production because it is assumed that beef cows receive adequate amounts of these micronutrients from their environment. However, there is an increasing incidence of vitamin A and D deficiencies in beef cattle due to challenges of environment, forage access and quality. It is well known that nutrition has a major effect on reproduction, but direct effects of vitamins A and D on beef cow reproduction and fertility are understudied. We previously reported increased rates of fertilization after co-culture of bovine embryos with vitamin A and D in vitro. The objective of this study is to determine how vitamin A and D supplementation in mid- to late gestation affects calving ease and birth weights of calves at parturition, as well as cow fertility at the following breeding. Angus and Angus crossbred females (Bos taurus) of first (n = 20) or second (n = 10) parity were selected based on pregnancy status and gestational age and then randomly assigned to treatment groups. Starting in October 2021, pregnant cows were injected monthly with either a vehicle (control) or a commercial supplement made up of 300,000 IU vitamin A and 45,000 IU vitamin D (Vitamin AD, Vet One; n = 15/ treatment group). Blood samples were collected before each injection for analysis of vitamin and hormone concentrations. All cows were monitored from January-April 2022 for signs of parturition to determine calving date and time, calving ease, birth weight, and to provide assistance if necessary. Serum samples were collected from the calves within 12 hours of parturition for analysis of vitamin D concentrations. There was no effect of vitamin A and D treatment on calving ease (Generalized Linear Model analyses; P = 0.58; 1.44 ± 0.2 treated, 1.29 ± 0.19 control group) or on birth weight (Generalized Linear Model; P = 0.52, 32.6 ± 1.24 kg treated, 33.8 ± 1.38 kg control group). Estrus synchronization, additional blood sampling, vitamin/vehicle injections, and artificial insemination (AI) was performed in late April 2022. Conception rates were determined by transrectal ultrasonography 30 to 40 days post-AI. Interestingly, 7 of 15 controls were determined to be pregnant by AI, while this improved to 10 of14 in AD-injected females (one female could not undergo AI due to late calving). Cows not pregnant by AI were pastured with a bull of proven fertility, and rectal palpation was used in the fall to determine overall pregnancy rates and any pregnancy loss. These data suggest a modest increase in serum vitamin A and D will improve pregnancy rates after AI. Additional studies should reveal if these treatments improve markers of calf health. Supported by The Oregon Beef Council (C. Bishop).
PSI-6 Effects of a Postbiotic Program Consisting of Liquid and Solid Saccharomyces Cerevisiae Fermentation Products on Digestibility, Ruminal Fermentation, and Plasma Metabolome of Finishing Beef Steers
Authors: Dhungana Anjan , Odunfa Oluwaseun , Osterman Anthony , Woods Daniel , Cooper Kimberly , Wang Changzheng , Yoon Ilkyu , Jiang Yun
Published: November 2023

The objective of this study was to determine the effects of a postbiotic feeding program consisting of liquid and solid Saccharomyces cerevisiae fermentation products (SCFP) on digestibility, ruminal fermentation, and plasma metabolome of finishing beef steers. Eight Holstein steers (BW 467 ± 13.9 kg) equipped with rumen cannulas were used in a crossover design study, with 21-d per period and 7-d washout period in between periods. Steers were blocked based on initial BW to one of two treatments: 1) Control, basal diet only (CON), or 2) SCFP, one day feeding of LiquiCare RTU (Diamond V, dosed via rumen cannula at 11 mL/100 kg BW) followed by daily feeding of 12 g NaturSafe (Diamond V, top-dressed). Feed and fecal samples were collected during d 17 to 20 for determination of digestibility and fecal excretion of N, P, Cu and Zn using acid-insoluble ash as an internal marker. Blood samples were collected on d 21 before morning feeding. Rumen fluid samples were collected on d 0, 1, 2, 3, 5 and 21 at 0, 4, 8, or 12 h post morning feeding via rumen cannula. Results were analyzed with the GLIMMIX procedure of SAS 9.4 (SAS, 2022). BW, DMI and digestibility were not affected by treatment. There was a tendency of treatment by period interaction (P = 0.09) on feed efficiency, which was improved by feeding SCFP only in period 1. Feeding SCFP did not affect (P > 0.10) ruminal pH. Feeding SCFP tended to reduce ruminal lactate concentration on d 21 (0.09 vs. 0.02 mM, P = 0.10). Supplementing SCFP reduced ruminal NH3-N concentration on d 2 (4.24 vs. 7.31 mg/dL, P = 0.03) and d 21 (4.86 vs. 6.83 mg/dL, P = 0.04). By feeding SCFP, ruminal total VFA concentration was increased 4-h post-feeding on d 5 (139.7 vs. 126.7 mM, P = 0.01) and numerically increased 4-h post-feeding on d 21 (151.2 vs. 133.3 mM, P = 0.12). For VFA composition, no treatment differences were observed on day 21. However, feeding SCFP reduced (P = 0.01) propionate proportion and increased (P = 0.05) butyrate proportion on day 3. The enriched plasma metabolic pathways (P ≤ 0.05) by feeding SCFP are citric acid cycle, pyrimidine metabolism, glycolysis/gluconeogenesis, retinol metabolism, and inositol phosphate metabolism pathways. Overall, our results indicated potential benefits of the SCFP feeding program on improving ruminal fermentation, preventing acidosis and improving N utilization in the rumen. Furthermore, feeding SCFP enriched several important pathways in lipid, protein, and glucose metabolism, which may improve feed efficiency of energy and protein in finishing beef cattle.
PSI-17 Use of Sunn Hemp as Forage for Early-Weaned Beef Calves
Authors: Silva Joao , Vendramini Joao , Silva Hiran , Oliveira Hugo , Garzon Jaime , Cook Daniel , Gardner Dale , Moriel Philipe
Published: November 2023

Sunn hemp (Crotalaria juncea) has been widely used as cover crop in the USA and due to superior biomass accumulation and nutritive value, there is interest from producers to use sunn hemp as forage for livestock. However, sunn hemp has pyrrolizidine alkaloids, which can affect animal performance. The objective of this study was to evaluate the effects of feeding sunn hemp hay to early-weaned beef calves in a dry lot in Florida. The experiment was conducted at the UF/IFAS Range Cattle Research and Education Center, Ona, FL from April to May 2021 (42 d). Treatments were calves receiving sunn hemp or stargrass (Cynodon nlemfuensis) hay distributed in a randomized complete block design with 12 replicates. Calves were supplemented with concentrate at 1.3% BW daily (18% CP and 78% TDN). Twenty-four Angus crossbred calves were weaned with 90 ± 14 kg BW and grazed annual ryegrass (Lolium multiflorum) with 1% BW concentrate supplementation for approximately 60 d. Subsequently, calves were randomly distributed and assigned to experimental units (pen) on 14 April 2021 with initial BW of 184 ± 10 kg. ‘Ubon’ sunn hemp hay was harvested approximately 49 d after seeding when 75% of the plants were initially flowering. Ground hay was fed daily targeting 10% refusals, and the initial CP and in vitro digestible organic matter concentrations of sunn hemp and stargrass hay were 9 and 48%, and 9 and 47%, respectively. The average concentration of pyrrolizidine alkaloids from sunn hemp hay was 58 μg/g DM. Early-weaned calves receiving stargrass had a tendency to have greater ADG than sunn hemp (0.5 vs. 0.4 kg/d, P = 0.09), and had greater forage DM intake (1.2 vs. 1.0% BW, P < 0.01) and total DM intake (2.5 vs. 2.3% BW, P < 0.01). Conversely, diets with sunn hemp had greater in vivo DM digestibility than stargrass (68 vs. 62%, P = 0.04). There was no difference between treatments on parasite egg count (mean = 45 eggs/3 g feces, P = 0.25) and coccidia egg count (log10 eggs/g feces, P = 0.35). Early-weaned calves receiving sunn hemp consumed 0.25 g pyrrolizidine alkaloids/d; however, there was no detectable amount (< 0.05 μg/g DM) of pyrrolizidine alkaloids in the feces. The presence of pyrrolizidine alkaloids in sunn hemp may be the potential cause of decreased early-weaned calves forage intake and animal performance.
PSIII-8 Extra-Label Bisphosphonate Effects on Intra-Articular Inflammation in Juvenile Horses Challenged with Intra-Articular Lipopolysaccharide
Authors: George James M , Leatherwood Jessica , Arnold Carolyn , Glass Kati G , Paris Brittany L , Conrad Matthew B , Martinez Rafael , Hernandez Fernando Vergara , Nielsen Brian D , Colbath Aimee , Welsh Thomas H , Bradbery Amanda N
Published: November 2023

Anecdotal assertions that bisphosphonates, such as clodronate disodium (CD), exhibit anti-inflammatory properties has led to extra-label use, despite a lack of scientific evidence of its efficacy. The objective of this study was to determine the effects of CD on intra-articular inflammation, hypothesizing that intra-muscular administration of CD would reduce intra-articular inflammation following an acute inflammatory challenge by lipopolysaccharide (LPS). To test this, 32 yearling Quarter horses were stratified by age (500 ± 13 d), BW (336 ± 26 kg), sex (n = 16 female; n = 16 male) and initial bone optical density into 4 treatment groups. The 140-d study consisted of two phases: Phase 1 (d 0 to 83) and Phase 2 (d 84 to 140) emulated sale preparation and early performance training, respectively. Horses were housed individually (3.6 m × 7.3 m) and fed to meet requirements of growing horses undergoing moderate training. Treatments consisted of control (CON; n = 8; no CD), single-dose (1X; n = 8; d 84), two-doses (2X; n = 8; d 0, 84), and four-doses (4X; n = 8; d 0, 42, 84, 126) of CD. All horses received iso-volumetric intramuscular injections of 1.8mg/kg BW clodronate disodium (OSPHOS) or saline (placebo) on d 0, 42, 84, and 126. Following treatment administration on d 126, radial carpal joints of each horse were injected with 0.8 mL of either 0.5 ng sterile LPS derived from Escherichia coli O55:B5 or sterile lactated Ringer’s solution as a contralateral control. Synovial fluid was collected before LPS injection (h 0) and at 6, 12, 24, and 336 h post injection. Synovial fluid was analyzed using an ELISA for prostaglandin E2 (PGE2), an indicator of joint inflammation. Data were log transformed and analyzed using the MIXED procedure of SAS. There was an h × LPS interaction (P < 0.01) confirming an acute, transient inflammatory response with increased PGE2 at 6, 12, and 24 h compared with the contralateral control joint, and resolved (P = 0.62) by h 336 post-injection. There was a treatment × h × LPS interaction (P = 0.02) in which 1X, 2X and 4X CD groups had greater synovial PGE2 concentrations at 6 h post-injection in the LPS joint compared with CON. In summary, intra-articular LPS induced localized inflammation, and the PGE2 response was greater in all horses treated with CD. The results of this study reject the hypothesis, suggesting clodronate disodium administration does not reduce intra-articular inflammation following acute induced synovitis.
PSIII-16 Application and Economic Analysis of Pooled Genome-Wide Association Studies in Commercial Feedlot Cattle
Authors: Prosser Haleigh M , Arnold Chelsea J , Saatchi Mahdi , Scott Matthew , Perkins Tommy L
Published: November 2023

Genotyping an individual animal provides a specified identity of their genetic makeup, which when used in a commercial beef operation, may allow for precise predictions centered around trait quality and production. However, conventional genotyping occurs at the individual level and is fiscally and logistically taxing for commercial cattle producers for whole-herd testing. Therefore, our research objective was to utilize DNA pooling methodology and genome-wide association studies (GWAS) to introduce economically feasible genomic testing in commercial feedlot cattle. A total of 1,956 commercial mixed-breed feedlot cattle (1,715 steers; 241 heifers) with accompanying complete carcass date were enrolled in the project after having their DNA extracted from tissue sampling units collected during feedlot enrollment. Isolated DNA was stratified into 79 pools (mean pool size = 25 individuals) for genotyping via GGP Bovine 100K array (Illumina); pooling was designed to replicate a prospective timeline, utilizing lot number, arrival date, and feedlot entry weight to stratify DNA pools. Data preparation with outlier filtering (OF) and repeated measures (RM) reduced phenotypic variance within pools by removing pools containing outliers, defined as values greater than 150% of the IQR outside of the IQR, and replicating a pool genotype by the number of individuals in a pool to compare to individual phenotype, relying on the concept that pooled DNA is a proxy average of individual genetic makeup, respectively. To complete the GWAS, phenotype files were built using pool average and individual calculated yield grade (CYG) and marbling (MARB) values. To evaluate economic feasibility, we performed a cost comparison of the pooling process itself as compared with individual genotyping, in addition to a cost-benefit analysis for prospective pooling to display the potential increase in income because of the investment in genotyping. Completed GWAS identified 20, 10, 27, and 16 significant SNPs associated with RM CYG, OF CYG, RM MARB, and OF MARB, respectively (P ≤ 0.001). The estimated total cost of genotyping the pooled DNA in the project ($23,460) was 4.5 times less than the estimated cost of genotyping the same cattle individually ($105,354), and the mean potential benefit-cost ratio of utilizing pooled genotypes to make management decisions was 2.33 (SD = 1.91).Our research demonstrated the successful use of DNA pooling in a commercial feedlot setting and showcased a need for further research and more exploration to better define a successful prospective pooling process. Although the dataset was highly variable, these biologically logical associations signify relative success of utilizing pooled DNA in GWAS. The economic efficiency of the DNA pooling process itself warrants further testing, as the economic benefits the process can provide producers outweigh costs.
PSIII-10 Hepatic Mrna Expression of Genes Related to Innate and Adaptive Immune Genes in Beef Steers with Divergent Residual Body Weight Gain
Authors: Idowu Modoluwamu , Ologunagba Deborah , Taiwo Godstime A , Sidney Taylor S , Treon Emily , Leal Yara , Eichie Francisca , Morenikeji Lanre , Pech-Cervantes Andres A , Ogunade Ibukun M
Published: November 2023

Immune function plays an important role in overall animal health and productivity. In this study, we evaluated the hepatic mRNA expression of genes involved in innate and adaptive immunity in crossbred beef steers with positive or negative residual body weight gain (RADG). Positive-RADG beef steers (n = 8; RADG = 0.34 kg/d) and negative-RADG beef steers (n = 8; RADG = -0.27 kg/d) were selected from a group of 108 growing crossbred beef steers (average BW = 556 ± 38 kg) after a 42-d performance testing period. At the end of the 42-d period, liver biopsies were collected from the beef steers for RNA extraction and cDNA synthesis. The mRNA expression of 84 genes involved in innate and adaptive immunity were analyzed using pathway-focused PCR-based arrays. The mRNA expression of genes with false discovery rate-adjusted P-values (FDR) ≤ 0.05 were considered to be differentially expressed. Out of the 84 genes analyzed, four genes (IL-2, MYD88, CD-80, NFkB-1) were differentially expressed and were all upregulated in positive-RADG, compared with negative-RADG beef steers. IL-2 is a cytokine that plays a critical role in the immune response by activating and proliferating T-cells, which are important for fighting infections. MYD88 is an adaptor protein that is essential for signaling by toll-like receptors, which are involved in pathogen recognition. CD80 is a protein that is expressed on the surface of antigen-presenting cells and plays a critical role in the initiation of an immune response. The activation of NF-κB leads to the production of cytokines and chemokines that help to recruit immune cells to the site of infection. The upregulation of the aforementioned genes in positive-RADG beef steers suggests that they had a better ability than negative-RADG beef steers to quickly recognize pathogens and initiate appropriate responses to effectively fight off infections without causing inflammatory reactions. This is essential to optimize immune function and minimize the impact of immune activation on growth and production. As a result, more energy and nutrients are available to support improved growth rate and feed efficiency.
PSIII-5 Confirmation of Passive Transfer of Anti-Endotoxin Igy in Neonatal Foals
Authors: Conrad Matthew B , Trauner Alex , Hull Jason , Hawkins Michelle , Robley Brian , Bradbery Amanda N
Published: November 2023

Passive immune transfer in a newborn foal is highly dependent upon the quality and concentration of immunoglobulins (Ig) in maternal colostrum, primarily IgG. Anti-endotoxin IgY derived from chicken egg yolks has been used in calves to reduce morbidity and mortality. Its use may provide additional pathogen-specific immune protection to neonatal foals, but passive transfer has not been confirmed. Therefore, the objective of this study was to quantify passive IgY transfer in neonatal foals given an egg-derived anti-endotoxin IgY supplement (Camas, Inc.) and identify effects on passive immunity. To test this, 5 neonatal foals were randomly divided into two treatment groups. Within 20 minutes after first nursing, the treated group (TRT; n = 3) was administered 40 g of the egg yolk supplement diluted in 50 mL water orally via syringe and the control group (CON; n = 2) was given isovolumetric water. At birth, physical measurements including BW, wither height (WH), hip height (HH), body length (BL), and heart girth (HG) circumference were recorded. Serum samples were collected prior to first nursing (h 0) and h 2, 6, 12, 24, 72, 168, 336 post treatment administration. Rectal temperature, heart rate, and respiration rate were recorded at all blood collection timepoints. Serum samples were analyzed for IgG, IgA, and IgY by commercial ELISA. Custom ELISA was used to identify endotoxin-specific IgY for Salmonella and E. coli at h 6. Western immunoblotting was used to confirm that passively transferred IgY was intact. Data were analyzed using PROC MIXED in SAS. Vital signs remained within normal, healthy ranges and physical measurements at birth were similar for all foals (P > 0.26). There was an effect of treatment (P = 0.05), time (P < 0.01), and treatment × time interaction (P < 0.01) for serum IgY concentrations where IgY was only detectable in TRT foals and peaked at h 6 and 12, decreasing thereafter to h 336. Concentrations of IgG and IgA increased from h 0 to 12 (P < 0.01); however, there were no effects of treatment nor treatment × time interactions (P > 0.24) for either Ig. Western immunoblotting confirmed that IgY was transferred intact and custom ELISA identified IgY specific against Salmonella and Escherichia coli. These results confirm the intact passive transfer of IgY in neonatal foals when given an IgY-infused egg yolk supplement with no negative impact on passive transfer of IgG and IgA from maternal colostrum.
PSV-1 Colostrum Quality Differs By Breed and Photoperiod Exposure in Dairy Cows
Authors: Alward Kayla J , Cockrum Rebecca , Duncan Alison
Published: November 2023

Exposing Holstein dry cows to short-day photoperiod (SDPP) of 8 hours per day can improve milk production post-calving by 3.2 kg per day, compared with cows exposed to long-day photoperiod (LDPP) of 16 hours per day. Based on seasonal variations in colostrum quality and quantity, we hypothesized that altered photoperiod during the dry period also impacts colostrum production in dairy cows. Our objective was to study the effect of LD and SD during the dry period on colostrum production in Holstein and Jersey cows. Holstein and Jersey cows (n = 33) dried off 60 days before their due date were exposed to either SD (n = 9 Holstein, n = 8 Jersey) or LD (n = 8 Holstein, n = 8 Jersey) photoperiod at 18.3 °C until calving. Within 1 hour of calving, colostrum production was measured (kg), Brix score was determined and a milk sample was collected to evaluate composition (fat, protein, other solids, lactose, lactoferrin, somatic cell count) by DHIA and immunoglobulin content (IgA, IgG, IgG1, IgM) via ELISA. Data were analyzed with the PROC MIXED procedure of SAS 9.4 with fixed effects of breed and photoperiod treatment. Replicate, animal age, number of days of treatment, season of calving, inbreeding percentage and previous lactation production were included as random effects. Only the percentage of IgG made up by IgG1 differed by treatment, being greater for SDPP cows (79.6% ± 4.6%) than LDPP cows (68.0% ± 3.1%; P < 0.05). Jerseys had greater Brix score (27.8% ± 0.7% vs. 23.4% ± 0.7%), colostral protein (9.3% ± 0.3% vs. 7.6% ± 0.3%) and IgA (5.7 ± 0.7 vs. 3.2 ± 0.5 g/L; P < 0.01), and a tendency for fat and IgM to be greater as well (P < 0.10). These data indicate that measures of colostrum quantity and quality differ by breed but are largely unaffected by photoperiod treatment.