bluuebunny/crossref_metadata_2025 huggingface dataset:
297 Evaluation of Semen Characteristics During Pubescent Maturation After Prenatally Induced Stress of Brahman Bulls
Authors: Willis Caleta , Ketchum Jaclyn N , Epperson Kaitlin M , Quail Lacey K , Guy Chloey P , Love Charles , Kerns Karl , Long Charles R , Randel Ronald D , Welsh Thomas H , Perry George A
Published: November 2023

The objective of this study was to determine if prenatal stress impacted semen characteristics during pubescent maturation of Brahman bulls (n = 23). Prenatal stress was achieved by transporting Brahman dams for 2 h on d 60, 80, 100, 120, and 140 (± 5 d) of gestation. Semen from sexually maturing males born to transported (PNS; n = 11) or non-transported (CON; n = 12) dams was classified based on motility and concentration as prepubertal (< 10% and < 50 million), peripubertal (≥ 10% or ≥ 50 million), pubertal (≥ 10% and ≥ 50 million), or sexually mature (≥ 30% or ≥ 500 million). Sperm characteristics were determined by staining sperm with specific dyes [viability - Propidium Iodide and SYBR-14; Mitochondrial membrane potential (MMP) – JC-1; DNA damage – Aracidine orange; ROS –conversion of H2DCFDA to DCF and conversion of hydroethidine to ethidium] and analysis on an Amnis FlowSight flow cytometer. Treatment differences were tested by SAS procedures. Analysis of repeated measures (PROC MIXED) and chi-square (PROC FREQ) compared semen characteristics and percent pubertal versus mature, respectively. There was a weak tendency (P = 0.14) for more control bulls to reach puberty (100%) compared with PNS bulls (82%), but no difference (P = 1.0) in percentage reaching sexual maturity by 22 months of age (82% and 82%). Scrotal circumference (P < 0.01) and motility [at collection (P < 0.01) and post-thaw (P = 0.05)] increased as bulls matured but was not impacted by treatment (P > 0.86) or treatment by time (P > 0.60). Sperm viability (at collection, post-thawing, and post-stress test) was not impacted by treatment (P > 0.20), time (P > 0.53), or treatment by time (P > 0.50). Proportion of viable sperm with high MMP was not impacted by treatment (P = 0.70) or treatment by time (P = 0.49), but was increased (P = 0.03) in early peripubertal collections compared with pubertal or mature collections. Proportion of sperm with damaged DNA was decreased in PNS (1.6 ± 0.3%; P = 0.04) versus CON (2.4 ± 0.2%) but not impacted by time (P = 0.47) or treatment by time (P = 0.41). Percentage of sperm with elevated ROS (H2O2 and •O2) was not impacted by treatment (P > 0.33), time (P > 0.17), or treatment by time (P > 0.41). Prenatal stress tended to impact the proportion of bulls that reached puberty but had no impact on the percentage that reached sexual maturity by 22 months of age. Prenatal stress also impacted the proportion of sperm with DNA damage, but did not impact scrotal circumference, motility, MMP, or ROS. Stage of sexual maturity impacted scrotal circumference, motility, and MMP, but did not impact ROS. In summary, PNS may impact the ability to reach puberty, but did not impact sperm characteristics from prepuberty to sexual maturity.
294 KISS1 Knockout Boars Have Decreased Concentrations of Gonadotropins Leading to Smaller Testes and Reduced Skatole in Backfat
Authors: Ahern Daniel F , Florez Julio M , Martins Kyra , Huisman Abe , Sonstegard Tad S , White Brett R , Lents Clay A
Published: November 2023

In swine production, boars are castrated to prevent boar taint from testicular androgens and skatole accumulation in fat. Kisspeptin (KISS1) regulates secretion of gonadotropins and gonadal steroids. We used boars from our line of KISS1-/-pigs (10.3389/fgene.2022.1078991) to understand how loss of KISS1 function affects compounds causing boar taint. Boars were fed ad libitum during development. Body weights and testicular volume (TV) were collected at weaning, 40, 70, 100, 130, 160, and 190 d of age using TV = 4/3*π *a*b2*2 and subtracting scrotal skin thickness measured by a Harpenden skinfold caliper. Average daily gain (ADG) was calculated by subtracting the beginning from ending body weight at each age range and dividing by the number of days. At each age, a blood serum sample was collected by jugular venipuncture to quantify changes in hormones during development. Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone were quantified with radioimmunoassay and analyzed as repeated measures with genotype (KISS1+/+; KISS1+/-; KISS1-/-; n = 8 – 20 animals per genotype) and age as the fixed effects. Concentrations of androstenone and skatole in backfat (quantified using ELISA and HPLC, respectively) were log transformed and analyzed with ANOVA. Body weight did not differ among KISS1 genotypes but increased normally with age (P < 0.0001). During development, KISS1+/+ and KISS1+/- boars grew at similar rates. Although the ADG of KISS1-/-boars was similar to other genotypes up to 160 d of age, ADG was reduced at 190 d of age (age x genotype; P < 0.05). Mean concentrations of LH and FSH in KISS1+/+ and KISS1+/- boars were similar throughout development (LH, 1.16 ±0.11 and 1.34 ± 0.17 ng/mL; FSH, 0.88 ± 0.06 and 0.89 ± 0.05 ng/mL, respectively), and were greater than KISS1-/- boars (LH, 0.38 ± 0.23 ng/mL; FSH, 0.56 ± 0.07 ng/mL; P < 0.05). TV of KISS1+/+ and KISS1+/- boars did not differ during development and was greater than KISS1-/- boars (P < 0.05), for which testes could not be palpated after 100 d of age. Testosterone concentrations in KISS1+/+ and KISS1+/- increased 40-fold during development but were below detectable limits in KISS1-/- boars (age x genotype; P = 0.06). Androstenone and skatole in KISS1-/- boars (0.30 ± 1.24 µg/g and 12.6 ± 1.6 ng/g, respectively) at 190 d of age was less (P < 0.0001) than in KISS1+/+ and KISS1+/- boars (androstenone, 4.33 ± 1.16 µg/g; skatole, 69.2 ± 1.2 ng/g), which did not differ from one another. Thus, a single functional allele of KISS1 is sufficient to confer normal secretion of reproductive hormones, testicular growth, and skatole in boars. Moreover, knocking out the KISS1 gene will prevent boar taint, but might slightly reduce growth in later stages of development.
29 The Role of Leptin and Its Regulation in the Hypothalamus of Neonatal Calves
Authors: Long Nathan , McCarty Keelee J
Published: November 2023

The constant occurrence of increased feed intake in offspring exposed to intrauterine growth restriction has been noted across multiple species including ruminants. In ruminants, reduced circulating leptin concentrations from birth through the first week or two of life may influence the development of the appetite center of the hypothalamus. It should able be noted that increased circulating cortisol at birth has been associated with this decreased circulating leptin in the perinatal ruminants, yet information is limited as to any cause and effect relationship between the two hormones. The objectives of these studies were to test directly the effects of exogenous cortisol on leptin concentrations relative to development of the hypothalamus in perinatal calves and voluntary feed intake as yearling. In two experiments, Holstein bulls (n = 27) and calves (n = 32 males; n = 30 females) from commercial Angus cows were assigned to treatments at parturition (day 0). Calves were intravenously infused with either a low cortisol [LC; n = 9, 3.5 ug/kg of body weight (BW)], high cortisol (HC; n = 9, 7.0 ug/kg BW), or a control (CON; n = 9, saline). Calves were administered a half dose of their respective treatment 24h postpartum. Jugular vein blood samples were collected before infusion and daily until d 17 or necropsy. At 5 days of age Holstein bull calves were euthanized where cerebral-spinal fluid (CSF) and hypothalamic tissue were collected. Serum and CSF leptin concentrations were analyzed via RIA. Neuronal growth factors were analyzed in hypothalamus samples via qRT-PCR. In experiment 2, yearling calves entered a GROWSAFE System and daily feed intake (FI) measured. Animals were allowed a two-week adjustment period to a growing ration for heifers and a finishing ration for steers. Heifer body condition scores (BCS) were collected at the beginning and end of the trial. Heifers underwent the feeding trial for 70 days and steers until they obtained a back fat (BF) thickness of 1.15 cm. Blood samples were analyzed similar to experiment 1. All data were analyzed via repeated measures using appropriate models of SAS (SAS Institute Inc., Cary, NC). Perinatal dairy bull calves had decreased (P < 0.013) serum and CSF leptin concentrations of HC and LC calves compared with CON. Hypothalamic expression of BDNF, FGF1 and FGF2 were decreased (P < 0.006) in HC and LC compared with CON. During the feeding trial: BW gain, BCS change, and number of feed events were increased (P = 0.001) in LC compared with HC and CON heifers. However, LC observed greater daily FI (P = 0.047) and tended to have greater final BW (P = 0.080) compared with HC and CON steers. In summary, these data support that exogenous cortisol administered to perinatal calves affects leptin production and the appetite center of the hypothalamus when administered during the neonatal period.
310 Investigating the Relationship Between Wildfire Smoke and Performance Metrics on Beef Cattle Through Bayesian Additive Regression Trees
Authors: Franco Arturo Macias , Silva Aghata , Brody Tio , Fonseca Mozart A
Published: November 2023

Identifying causal relationships on a large-scale system is highly complicated, and when not careful, statistical theories may be violated, and biological spurious claims generated. The causality between livestock health/performance and wildfire smoke has not been investigated. To critically evaluate the effects of wildfire, air quality data was obtained and validated with sensors (1.6 km from feedlot) before analyses. Herein, we examine the influence of environmental quality parameters effects on dry matter intake (DMI), body weight (BW), water intake (WI), and average daily gain (ADG) over a period of three years in Reno, Nevada. The datasets comprised represented controlled no-smoke exposure instances and days with air quality indexes (AQI) as high as 453 (hazardous). The dataset consisted of over 10,000 observations with daily mapping of WI, DMI, ADG, and BW. To evaluate the potential relationship between air quality and animal performance, variable tree length Bayesian additive regression trees (BART) were utilized to investigate the relationships between AQI, particulate matter (PM) 2.5 um and 10 um, NO2, SO2, ozone, and CO levels in the air were utilized as covariates for BART. All statistical analyses were performed on R Statistical Software (R Core Team 2022), with use of the bartMachine package. The correlation values (), 95 % confidence intervals (CI), root mean squared error (RMSE), and coefficient of determination (r2) are reported. A significant correlation was detected between the environmental parameters and BW, (= 0.863, CI = [0.849, 0.877], P > 0.001, r2 = 0.75, RMSE = 51.27) with PM2.5 and PM10 being the most included parameters in the regression trees. For WI, correlation was also significant ( = 0.447, CI = [0.402, 0.490], P < 0.001, r2 = 0.20, RMSE = 14.57), the most included variables on the regression trees were the 10-um particulate matter followed by the CO. For DMI (= 0.727, CI = [0.700, 0.752], r2 = 0.53, RMSE = 2.58) PM10 and AQI were the most important inclusion proportion parameters. Similarly, for ADG (= 0.354, CI = [0.305, 0.401], r2 = 13, RMSE = 1.60) with ozone and PM10 being the most included parameters. In conclusion, our results more carefully examine relationships between smoke parameters and livestock performance. Uncertainty of relationship estimates, and variable importance highlights how performance parameters are differently affected by different environmental parameters highlighting the need for experiments with controlled exposure through time.
309 Dairy Cow Response to Heat Stress Modeled with a System Dynamics Approach
Authors: Cresci Roberta , Balkan Busra Atamer , Tedeschi Luis O , Cannas Antonello , Atzori Alberto S
Published: November 2023

Modeling the individual animal response to heat stress (HS) conditions is challenging because of the complex interactions that characterize the system behavior. In explaining the resulting animal behavior, the dynamicity, nonlinearity, and delays in the HS response are often unaccounted for or misinterpreted. The system dynamics (SD) methodology, a mathematical modeling approach based on feedback loop structures, allows for modeling and understanding the behavior of complex systems over time. By applying SD methodology, this study developed a preliminary conceptual model to capture the cow response and observed milk yield (MY) under HS. The data on the temperature-humidity index (THI) and MY used for model development were collected from a dairy cattle farm in August 2021. The parameters related to the HS response of 20 selected cows were used for calibration and parameterization of the model. To minimize the effect of the lactation stage on milk production and model results, 20 cows were selected for days in milk (DIM) to be between 70 and 220 d. After the parameter calibration using MY data, it was found that the historical data pattern of 13 out of 20 cows followed the expected behavioral pattern generated by the model. In contrast, the behavior of the remaining seven cows did not align with that generated by the model. Therefore, based on their patterns, the cows were identified as fitting or non-fitting the model’s structure. The structure of the model captured the effect of HS on fitting cows with high accuracy (mean absolute percentage error, MAPE < 5%; R2 > 0.6; concordance correlation coefficient, CCC > 0.6). At the same time, the behavior of the non-fitting cows could not be explained by the defined parameter space. We believe they either had heat-resistant behavior or experienced different biological delays than average. Based on the obtained results, the evaluation of parameter values should be done only for the fitting cows, as the work aimed to develop a model to understand the HS response. The behaviors generated by the model can help farmers and decision-makers distinguish heat-sensitive from heat-tolerant cows and quantify the animal response in terms of MY so that mitigation strategies can be implemented.
306 Shinyanimalcv: Interactive Web Application for Object Detection and Three-Dimensional Visualization of Animals Using Computer Vision
Authors: Wang Jin , Xiang Lirong , Morota Gota , Wickens Carissa , Cushon Emily , Brooks Samantha , Yu Haipeng
Published: November 2023

Precision livestock farming applies integrated sensors and information technology to provide individualized animal care in a timely manner. A computer vision system, a non-intrusive and cost-efficient sensor technology, may be useful for monitoring animals to support farm management decisions. While the advancement in camera sensors provides a great opportunity for producers to improve animal health and welfare sustainably, the limited availability of user-friendly image data processing software tools substantially hinders the implementation of computer vision in livestock production systems. The objective of this study was to develop ShinyAnimalCV, which is a Shiny-based interactive animal computer vision web application. This software tool offers a user-friendly graphical user interface for object detection and three-dimensional visualization. The object detection module employs the Mask-RCNN to precisely segment the masks (regions) of the focal animals from two-dimensional images. A Python-based computer vision library OpenCV was used to draw minimum bounding boxes covering the segmented masks for object detection. The three-dimensional visualization module takes the depth map file captured from a top-view three-dimensional camera as an input, which contains the numerical distances between the camera and the objects (animals and background). The depth map file was first converted to a heatmap image, followed by identifying and segmenting the animal from the background using the Mask-RCNN model. The object detection module returns detection results, including the detected animal’s location, class/type, and morphological traits (e.g., body length and width). The visualization module generates a segmented mask to extract the height of the animal from the depth map file, which can be used to interactively visualize the three-dimensional surface of the animal and estimate its morphological traits, including length, width, height, and volume. By integrating these two modules into R Shiny, we deployed ShinyAnimalCV on a cloud server with pre-trained Mask-RCNN models using pig and cattle data to allow users to upload custom data and perform object detection and three-dimensional surface visualization. The features extracted by ShinyAnimalCV are expected to be useful for performing animal identification, feed intake monitoring, body weight predictions, and body condition score estimations. We conclude that the newly developed ShinyAnimalCV could facilitate the application of computer vision in the animal science community.
300 Primeone Sire Comparison on Jersey Dairy Cows
Authors: Belt Kara , Lawrence Ty E , Tennant Travis C , Lucherk Loni W , Lust David G , Richardson Katylyn J , Perkins Tommy L
Published: November 2023

Objective

The objective of this study was to compare carcass grading outcomes of progeny from a sire derived via carcass cloning to progeny from a competitive traditional purebred Angus sire. Semen was artificially inseminated into Jersey cows from an F1 sire (AxG1) derived from Prime-yield grade 1 carcass clones and a high-performance purebred Angus sire (Foundation). Calves were born at the dairy, raised in hutches on the dairy, and grown in a separate facility, all in the Texas panhandle. Cattle were later transported to Nebraska for finishing. Both steers and heifers were harvested at a commercial beef processor in Colorado and camera data were collected to assess carcass quality and yield outcomes. Data were analyzed using mixed models; treatment comparisons were tested for significance with α = 0.05.

Results

In live growth, calves sired by Foundation were heavier (P < 0.01) both when they entered (396.1 vs 383.0 kg) and exited (590.1 vs 568.8 kg) the feedyard. Similarly, calves sired by Foundation had heavier (P < 0.01) hot carcass weights than AxG1 (374.9 vs 361.4 kg). No difference (P ≥ 0.27) was detected between sires for longissimus muscle area (96.6 vs 95.7 cm2) or marbling score (Moderate26 vs Moderate20). AxG1 sired calves had greater (P < 0.01) muscle area per unit of carcass weight (26.7 vs 25.9 cm2/100kg). Calves sired by AxG1 were leaner (P < 0.01) than those sired by Foundation as evidenced by less 12th rib s.c. fat (1.11 vs 1.26 cm) coupled with decreased calculated yield grades (2.34 vs 2.59). Moreover, calculated Empty Body Fat was greater (P < 0.01) for Foundation sired carcasses than those sired by AxG1 (30.0 vs 28.9 %). Foundation sired calves were represented by a greater (P < 0.05) percentage of USDA Prime carcasses (26.32 vs 17.79 %) whereas AxG1 sired calves had a greater (P < 0.05) percentage of USDA Choice carcasses (77.74 vs 69.48 %). AxG1 sired calves were represented by a greater (P = 0.04) percentage of Yield Grade 1 carcasses (27.48 vs 19.25 %). No difference in frequency of Yield Grade 2 (55.40 vs 58.00 %) or 4 (1.41 vs 1.0 %) carcasses was observed between sires. Frequency of Yield Grade 3 carcasses was greater (P < 0.01) for Foundation compared with AxG1 (23.94 vs 13.58 %). Carcass outcomes suggest that progeny sired by Foundation were of slightly higher quality whereas progeny sired by AxG1 were of slightly higher yield.
355 Effects of Processing Method of Hybrid Rye for Cattle Backgrounding Diets
Authors: Tobin Colin T , Carlson Zachary E , Swanson Kendall C , Hoppe Karl , Rusche Warren C , Smith Zachary K
Published: November 2023

Cereal rye is used to diversify crop rotations in the Northern Great Plains and can be harvested through grazing, processed as forage (hay or silage), or allowed to reach maturity for grain and straw. Although rye has not traditionally been used in growing and finishing cattle diets due to the occurrence of ergot. Recent hybrid germplasms have shown promise with increased yields and decreased ergot incidence. This study aimed to determine the effects of substituting dry-rolled or ground hybrid rye for dry rolled corn (DRC) on dry matter intake (DMI), growth performance and gain:feed (G:F) of growing beef steers. One-hundred-fifty crossbred steers [260 ± 22.3 kg, initial body weight (BW)] were transported to the Carrington Research Extension Center near Carrington, North Dakota, stratified by BW, and assigned to one of fifteen pens (n = 10 steers/pen) and three dietary treatments in a randomized block design. Hybrid rye was substituted on a dry matter basis for DRC as follows: a basal diet formulated 33.8% corn silage, 23.6% forage barley hay, 17.5% modified distillers grains and solubles (MDGS), and 3% supplement and limestone with either 22.1% DRC (CON), 22.1% dry rolled hybrid rye (RRYE), and 22.1% ground hybrid rye (GRYE) on a dry matter basis. Due to extreme cold windchill temperatures, steers were fed for a total of 64 days beginning October 24, 2022. Body weights were taken before feeding on Day 1, 2, 28, 63, and 64 with a 4% pencil shrink applied to the initial and final BW. Performance data including animal BW, average daily gain (ADG), DMI and G:F ratio were calculated. The monthly average of growth performance were analyzed using the repeated measures procedure of PROC MIXED in SAS 9.4 with pen serving as the experimental unit. Pre-planned contrasts (control vs rye; rolled rye vs ground rye, rolled rye vs control, and ground rye vs control) were analyzed. No differences in BW (P = 0.35), ADG (P = 0.19), DMI (P = 0.83), or G:F (P = 0.21) were detected due to the replacement of DRC with hybrid rye throughout the study (Table 1). Steers assigned to GRYE had increased G:F (P = 0.04) and tended (P = 0.05) to have greater ADG compared with RRYE throughout the study. Steers fed hybrid rye tended to have lesser BW (P = 0.06) than those fed DRC after the first 28-day weigh period. During the final 36 days, steer assigned to GRYE had increased ADG (P = 0.03) compared with RRYE and tended (P = 0.05) to have greater ADG than those assigned to CON. Results from the study suggest that steers fed processed hybrid rye grain in a high forage backgrounding diet performed similarly to calves fed DRC.
349 Effects of Adding a Yeast Blend to Diets with High Levels of Dried Distillers Grains on Feeding Behavior, Intake, and Performance of Beef Cattle Fattened in Feedlot
Authors: Martins Leandro , Bonato Melina A , Reis William
Published: November 2023

Feeding ruminants with a blend of autolyzed yeast grown on sugarcane molasses and live yeast allows nutritionists to explore synergistic effects on digestion and performance (Angulo et al.,2021; Zapata et al., 2021). However, the feeding behavior and the challenges faced in large pen feedlot operations differ from the behavior and challenges faced by animals studied in small groups or metabolic cages. Therefore, we aimed to study the feeding behavior and performance of beef cattle fed in groups in large pens, mimicking the feedlot operations of leading producers and exports of meat in the world. The trial lasted 112 days and was conducted in Nutripura’s research center in the midwest of Brazil. Six hundred five non-castrated males (Nelore and F1 Nelore-Angus), 405 kg (± 35), distributed in 20 pens, were divided into two treatments: 1) Control, a diet with no yeast additives; 2) Yeast Blend (YB), a diet with a blend of autolyzed yeast and live yeast, SymbioYeast, 7g/anima/day (ICC, São Paulo, Brazil). Both diets contained monesin (28 mg/kg DM). The data were analyzed in the software SAS following the model Yijk= μ+Ti + Fj + Bk +еijk (μ = general mean; T = treatment effect; F = Breed effect; B = backgrounding phase effect; e = error). Initial body weight was used as a covariable to analyze final body weight and average daily gain (ADG). Dry matter intake increased (P < 0,05) when animals were supplemented with YB (10,99kg vs. 11,12kg). Final body weight and hot carcass weight tended (0.1 > P ≥ 0.05) to increase when YB was added to the diet. (598 kg vs. 602 kg, 343 kg vs. 345 kg). The ADG was unaffected (P = 0.1069, control 1.735 kg, and YB 1.768 kg). Increasing DMI is a well now property of some yeast derivatives (Torres et al., 2022). This may be related to changes in digestion (Torres et al., 2022) and the diet’s palatability. The palatability of yeast products is claimed on organoleptic and flavor characteristics (Tao et al., 2023). Drone photos taken every 15 minutes suggested that YB altered how animals interact with feed. Feed was delivered between 0700 h and -0930 h and 1300 h and 1530 h. After delivery, a greater percentage of the visit of the animals to the feed bunkers in YB groups. This behavior was even more evident in the morning feed delivery (Figure 1). In summary, YB increased intake and performance. It also changed the interest of animals in visiting feed bunk.
339 An Evaluation of the Effects of Feeding an Exogenous Fibrolytic Enzyme Product on the Growth Performance and Apparent Nutrient Digestibility of Growing Bison Calves Fed in a Commercial Feed Yard
Authors: Winders Tommy , Boyd Bradley , Parrott Terry , Li Wenting
Published: November 2023

While exogenous enzyme supplementation has been tested in ruminants as early as the 1960’s, industry adoption of such technologies has been slow. With high feed costs, technologies such as feed enzyme could potentially help producers to lower the production cost by improving feed efficiency. A 69-day growing experiment was conducted at a commercial feed yard in Western NE using bison calves [n = 228; initial body weight (BW) = 269 kg, SD = 41 kg] to determine the effects of supplementation of an exogenous fibrolytic enzyme from T. reesei on calf dry matter intake (DMI), growth performance and nutrient apparent digestibility. A completely randomized design was utilized with two treatments, control (CON) or enzyme (CX), and four pens, with calves assigned randomly to pen and pen assigned to TRT (48 to 66 calves per pen). Individual calf BW were obtained on day 0, day 35, and day 69. The DMI was measured daily by pen, with feed offered adjusted daily and fecal samples were composited and analyzed on pen-basis. Data were analyzed using JMP statistical software, with initial BW included as a covariate in the analyses. Average daily gain and DMI in calves fed the CX treatment was 7% greater (0.895 vs. 0.830 kg/d; P = 0.02), and 11% less (7.83 vs. 8.75 kg/d; P = 0.02) than in calves fed the CON treatment, respectively, resulting a 18% numeric improvement in feed efficiency for calves fed the CX treatment compared with calves fed the CON treatment. Apparent starch digestibility tended to improve (P = 0.07) by 15% in calves fed the CX treatment compared with calves fed the CON treatment, while apparent neutral detergent fiber (NDF) digestibility (as a percent of NDF) was numerically improved by 9% in calves fed the CX treatment compared with calves fed the CON treatment. Although the mode of action warrants further investigation, these data suggest that feeding an exogenous fibrolytic enzyme product may be beneficial for growing bison calves, likely in part because of greater apparent nutrient digestibility.
334 Use of Feed Additives in Unweaned Calves with Compromised Gut Integrity After Transportation
Authors: Marti Sonia , Blanch Marta , Devant Maria
Published: November 2023

The gastrointestinal tract of unweaned calves is compromised after the stress and feed restriction due to marketing and transportation. The use of feed additives to enhance intake and gut immunity at farm arrival could be a strategy to minimize those negative effects. A total of 70 dairy beef calves (50.9 ± 1.66 kg) coming from auction market and with a compromised gut integrity at arrival were used to evaluate the effect of various feed additives [FA; comprising palatability enhancers (PE), standardized olive pomace extract (OE), and tributyrin (TB)] on performance until 2 weeks after weaning. Calves were distributed in 5 treatments: calves fed milk replacer (MR) and concentrate without FA (CTR; n = 14); calves fed MR and concentrate with PE (PE; n = 14); calves fed MR with OE + PE and concentrate with PE (OEPE; n = 14), calves fed MR with TB + PE and concentrate with PE (TBPE; n = 14); and calves fed MR with OE + TB + PE and concentrate with PE (complete - COM; n = 14). At arrival animals received 2.5 L of MR twice daily at 12.5% and ad libitum concentrate feed. On day 35 of the study, animals were submitted to a social stress challenge, calves within one treatment were mixed for 24 h, and on day 36, calves returned to their home pens and the afternoon milk was removed. On day 42, all calves were weaned, and they were followed until day 56. Data were analyzed with a mixed-effects model. After transportation calves had an average of 1.6 ± 0.09 mg/L of serum Cr-EDTA the first week after arrival indicating that those calves had increased gastrointestinal permeability and a compromised gut barrier for a full week; consequently, concentrate intake during that week was decreased for all treatments (P = 0.56) with an average of 27 g·calf-1·d-1. An interaction between treatment and time (P < 0.01) was observed on concentrate intake the last two weeks of the study when calves were already weaned; on week 7, from day 42 to d 49, COM and TBPE calves had greater concentrate intake than CTR calves, and PE and OEPE did not differ among others; and on week 8, between day 42 and day 49, COM calves had the greater concentrate intake than CTR, while other treatments were in between. Although only numerical differences were observed in final BW, COM calves were heavier than the rest of the treatments at the end of the study. In calves with severe problems of gastrointestinal permeability at arrival, the mixture of palatability enhancers, standardized olive pomace extract, and tributyrin increases concentrate intake and potentially improve the recovery of the animals.
333 Using Specific Bacillus Strains to Improve Digestibility and Performance of Growing Steers
Authors: Pan Liyi , Eyre Karen , Harper Karen , Silva Luis Prada e
Published: November 2023

Low fiber digestibility is an important factor restricting the growth performance of cattle in the dry tropics, both during the initial growth phase in grazing systems and later during finishing in high-starch diets. Due to concerns relating to the non-therapeutic use of antibiotics, including ionophores, there is interest in replacing these with probiotics. The objective was to evaluate the effects of specific strains of Bacillus spp. (Bovacillus, Chr. Hansen, Denmark) on intake and total tract nutrient digestibility of two diets. The first diet was forage based [100% Rhodes grass hay with 69% neutral detergent fiber (NDF)], the second was a high-energy diet (20% Rhodes grass hay, 40% finisher pellet, 30% peanut hull fiber pellet, 10% ground barley, 47% NDF, 18% starch). Twelve Bos indicus steers (267 ± 7.5 kg) were blocked by initial body weight and randomly assigned to receive the diets either without probiotic supplementation (n = 6, Control) or the diets plus 3 g per head of a probiotic containing a mixture of Bacillus licheniformis and Bacillus subtilis (3.2 x 109 CFU/g) for the duration of the trial. Each diet was fed for a 34-d period in individual pens followed by a 7-d sampling period during which the steers were housed in metabolism crates for total collection of urine and feces. On the high-fiber diet, supplementing with the probiotic increased organic matter digestibility by 7.8% (49.9 vs. 53.8%) and NDF digestibility by 8.4% (49.7 vs. 53.9%) resulting in greater (P < 0.05) digestible fiber intake (1.62 vs. 1.72 kg/d). There was no effect of probiotic supplementation on intake or digestibility in the high starch diet, and Bacillus supplements did not change rumen microbial protein synthesis in both diets. In conclusion, supplementing steers with a Bacillus-based probiotic has the potential to improve the nutrient digestibility and performance of beef steers, especially in tropical grazing systems.
365 Effects of Supplementing Carinata Meal Compared with Cottonseed Meal on Performance, Carcass Characteristics, and Sensory Attributes in Beef Steers Consuming a Finish Diet
Authors: Schulmeister Tessa M , Tarnonsky Federico , Podversich Federico , Maderal Araceli B , Cuervo Wilmer , Marenchino Ignacio Fernandez , Vargas Juan , Ramirez-Sepulveda Vanesa , Gomez-Salmoral Macarena , Novo Sabina , Gonella Angela M , Dubeux Jose C B , DiLorenzo Nicolas
Published: November 2023

The value of carinata, a non-food oilseed crop, has been demonstrated as a high-quality jet fuel alternative and successful cover crop in the southeastern U.S.; however, research is limited regarding carinata as an alternative for commonly used protein sources in livestock. Thirty-two Angus crossbred steers were used in a generalized randomized block design to evaluate the effects of supplementing carinata meal compared with cottonseed meal on performance, carcass characteristics, and meat sensory attributes in a finishing diet. Treatments included: either 90% basal diet + 10% inclusion of Brassica carinata meal (BCM) or 90% basal diet + 10% inclusion of cottonseed meal (CSM), on a dry matter (DM) basis. The basal diet consisted of 40% cracked corn, 35% soyhull pellets, 5% gin trash, 5% bermudagrass hay, and 5% vitamin-mineral supplement. Treatments were premixed before delivery and provided ad libitum, with individual intake measured using the GrowSafe system. Data were analyzed using Proc Glimmix of SAS. Protein source did not affect (P > 0.05) final body weight, dry matter intake, average daily gain, gain to feed ratio, or residual feed intake. Protein supplementation did not affect (P > 0.05) initial or final evaluations of longissimus muscle area (LMA), rib fat thickness (RF), and intramuscular fat performed via ultrasound during the performance portion of the experiment. Hot carcass weight (P = 0.10) dressing percentage (P = 0.61), LMA (P = 0.33), RF (P = 0.42), yield grade (P = 0.47), and marbling score (P = 0.89) were not affected by protein source. No effect of protein source was observed (P > 0.05) on slice shear force, juiciness, beef flavor, tenderness, connective tissue, off-flavor, crude fat, thaw loss, cook loss, lightness, redness, or yellowness. The frequency of Prime (P = 0.76), upper 2/3 Choice (P = 0.71), low Choice (P = 0.46), and Select (P = 0.34) USDA quality grades did not differ with protein source. carinata meal inclusion at 10% of the diet DM performed similarly to cottonseed meal in steers fed a finishing diet, thereby enhancing its value in the southeastern U.S.
36 Beyond Environmentally Adapted, Towards Ecologically Purposed: Sheep Production in the Us West
Authors: Bret J , Taylor B
Published: November 2023

Consumer demand for sheep products is robust, the annual consumption of U.S. lamb is steadily rising, and the number of U.S. sheep farms is increasing. Nevertheless, the U.S. sheep industry continues to lose market share to foreign competitors and the breeding ewe inventory has declined 30% since 2002. This decline has been more drastic in the upper U.S. Mountain West states, where ewe inventories have declined 37% compared with the national average decline of 26%. This is problematic given the Mountain West generates one-third and one-half of the total U.S. lamb crop and wool revenue, respectively. This depopulation trend indicates obstacles unique to the Mountain West, which are not experienced elsewhere in the nation. Mountain West sheep production systems depend on both private and public rangelands for grazing, which must co-exist with many other goals for public lands, including species conservation and critical wildlife habitat. Extensive conversion of native rangeland to croplands, rural housing, and degraded grasslands has simultaneously resulted in a substantial loss of wildlife habitat, thus creating competing ideologies for how remaining rangelands should be managed. Accordingly, public land management agencies are constantly pressured to change land management plans to accommodate public agendas aimed at restricting or halting livestock grazing on public lands with the assumption wildlife habitat will automatically improve. Such exclusion of grazing from public lands has negatively impacted operational capacity of sheep ranches, thus posing serious threats to the U.S. sheep industry and its contributions towards national food security, rural communities, and rangeland conservation. Therefore, to maintain grazing access to public lands, sheep producers and land managers urgently need tools (e.g., management, genetic) to optimize both conservation and production outcomes synergistically. However, ecological and sheep genetic outcomes have thus far been considered separate rather than integrated goals. Traditional genetic improvements in sheep production are focused strictly on the sheep without regard to the ecological outcome. In other words, the “ecosystem” is only considered to achieve profitable production within that environment. With this in mind, can sheep research move beyond the traditional focus of “environmentally adapted” flocks to “ecologically purposed” flocks? We propose that heritable ecologically focused traits can be identified and used to complement the overall sheep genetic improvement goals of the industry while creating precision-based solutions for sustainable habitat management, such as mitigating catastrophic wildfire risk, halting noxious weed invasion, and shaping vegetative structure of native plant communities towards desirable rangeland and conservation goals. We believe such outcomes extend beyond shaping public opinion about sheep grazing but also towards introducing novel value-based marketable products from the sheep industry.
381 Evaluating Indirect Measures of Milk Production in Heat-Stressed Lactating Sows Genomically Selected for Improved Thermotolerance
Authors: Byrd MaryKate , Brito Luiz F F , Wen Hui , Freitas Pedro H F , Hartman Sharlene , Maskal Jacob M , Huang Yijian , Tiezzi Francesco , Maltecca Christian , Schinckel Allan P , Johnson Jay S
Published: November 2023

Lactating sows are among the most heat stress sensitive population in the swine herd. Exposure to high ambient temperatures causes a marked decrease in production measures and welfare in lactating sows and may have a negative downstream impact on piglet growth due to impaired sow lactogenesis. Genomic selection for improved heat stress (HS) tolerance may be a viable method to reduce the negative impacts of HS on lactating sows and their offspring. However, selection for HS tolerance is generally associated with decreased productivity. Therefore, the study objective was to evaluate the impact of genomic selection for thermotolerance on indirect measures of sow milk production under HS conditions. We hypothesized that heat tolerant sows would have a decrease in indirect measures of milk production when compared with heat sensitive sows. A total of 20 multiparous lactating sows (Large White x Landrace; parity = 4.85 ± 0.75) divergently genomically selected for heat tolerance (TOL; n = 11) or heat sensitivity (SEN; n = 9) were subjected to cyclic HS temperatures (28 to 32° C) from day 2.5 ± 1.0 post-farrowing until weaning (d 21.3 ± 1.1). On d 4, 8, 14, and 18 of lactation, indirect calorimetry was used to estimate total heat production (THP) on an individual sow basis following previously published methods by our group. In addition, sow respiration rate (RR) was measured daily at 0800, 1200, 1600, and 2000 h. All data were analyzed using PROC GLIMMIX in SAS 9.4 with individual sow included as the experimental unit. It was determined that TOL sows had an overall increase (P = 0.04; 5.68 ± 0.24 kcal·sow· kg BW0.75(-1)) in THP when compared with SEN sows (4.74 ± 0.18 kcal·sow· kg BW0.75(-1)). A treatment by day effect was observed where THP was greater (P < 0.01; 88%) for TOL sows on d 4 of lactation when compared with SEN sows. Preliminary evidence suggests that TOL sows had an overall increase (P = 0.01) in RR (78 ± 5 bpm) when compared with SEN sows (73 ± 5 bpm). Taken together, these data suggest that genomic selection methods used to increase lactating sow thermotolerance may have had a positive impact on indirect measures of lactogenesis under HS conditions.
409 Awardee Talk: Philosophy and Examples from a Career in Animal Science Education
Authors: Huntington Carolyn E
Published: November 2023

Training competent and successful students for career readiness is an ever-changing puzzle. These puzzle pieces include an understanding of the student demographics, consideration of the vision and mission of the department, engagement with alumni, and awareness of opportunities for employment and industry needs. These pieces require the development of a curriculum model that can evolve and respond to these components in a timely way. My career at two universities in roles including Undergraduate Coordinator and Director of Undergraduate Advising has given me the privilege to teach and work with nearly 5,000 students while addressing these puzzle pieces. Students enter with a limited understanding of career opportunities within Animal Sciences but are eager to learn more and are seeking opportunities to do so. As faculty, we can provide meaningful high impact experiences for our students, both inside and outside of the classroom, that also directly align with our appointments and expertise in research, teaching, and Extension. Success requires creating a departmental culture that fosters creativity and a willingness to experiment with new ideas and practices. These high impact experiences provide our students with greater awareness and appreciation for career possibilities that they had not considered before. As the Undergraduate Coordinator, I lead strategic conversations and planning with our faculty to discuss how our departmental core courses and supporting coursework prepare our students professionally. This includes discussion of our annual program assessment, identifying areas of strengths, where our resources may be limited, and how we are teaching to inspire, challenge, and meet the needs of our students. As we all strive to continually improve academic excellence within each of our programs, we must remain nimble and arrange the puzzle pieces to best serve our students.
73 Creating Context and Vision in Animal Science Graduates
Authors: Wickersham Tryon A
Published: November 2023

Increasingly undergraduate and graduate students enter animal science programs with relatively little experience in production agriculture. Often, students arrive with the expectation or hope of admission to vet school only to have that dream smacked against the realities of organic chemistry and biochemistry or changing aspirations. These two factors: 1) limited background, and 2) unrealized goals coupled with others lead to frustration, confusion, and anxiety. Furthermore, a lack of background makes it difficult for them to contextualize information presented in lectures, laboratories, reading, and research. This makes it challenging for students to determine what’s next, what route they should pursue for a career. It creates uncertainty as they seek internships, consider graduate school, and begin to ponder life after graduation. Connecting students to industry professionals and experiences can go a long way towards helping students create context and begin the process of mentally exploring careers. In the university setting having a faculty with an extensive network of industry professionals and a willingness to share those contacts and work with students is essential. As a faculty member, I have focused on addressing this need in four ways: 1) being present, 2) taking them on a trip, 3) providing safe experiences, and 4) giving them a tribe. Additionally, whenever possible, I try and give them an industry role model with a similar background. To accomplish these things, I must step outside of the university and my comfort zone to engage industry stakeholders in a variety of ways. During the course of my presentation, I will discuss the four ways I help students create context for learning and a vision for themselves while also covering the methods I use to engage with industry. Ultimately, a faculty that creates and maintains connections with industry is essential for developing course content, curriculum, research questions, and, most importantly, well-rounded animal science graduates.
9 Practical Considerations for Adaptive Strategies By United States Grazing Land Managers with a Changing Climate
Authors: Derner Justin D , Wilmer Hailey , Stackhouse-Lawson Kim R , Place Sara E , Boggess Mark V
Published: November 2023

We outline practical considerations for grazing land adaptations with a changing climate, with an emphasis on the ranch operation scale and specific attention to directional climate changes and increased climate variability. These adaptive strategies fall into two themes: flexibility and learning under uncertainty. Ranches and livestock operations with greater land, social, or other capital resources may have more flexibility. Risk can be reduced for managers (ranchers, farmers, operators, and livestock managers) through participation in conservation or farm policy programs and/or market-based approaches. Bolstering adaptive capacity across landscapes and time can originate from social capital of operators and strategic collaborations among managers and scientists. As climate diverges from historical baselines and the realm of managers’ experiential knowledge, new conceptual frameworks are needed to structure conversations, influence research relevancy and impact, and drive imaginative solutions among researchers, managers, and local communities for socio-ecological systems. We provide simplified frameworks to help guide conversation, future research, and new imaginative solutions for systems-scale knowledge needs and adaptation to address increasingly uncertain and complex change at multiple scales. Practical considerations for adaptive strategies by grazing land managers with a changing climate will be accelerated through 1) collaborative efforts among managers and explicitly with science-management partnerships becoming more mainstream, 2) co-produced research with managers and researchers at ranch-scales, 3) development of communities of practice and associated learning opportunities, and 4) continued co-development and advancement of technologies and tools that result in high uptake adoption by ranch managers.