bluuebunny/crossref_metadata_2025 huggingface dataset:
226 Evaluation of an active live yeast (Levucell SC, CNCM l-1077) on receiving and backgrounding phase growth performance in beef steers
Authors: Buckhaus Elizabeth M , Smith Zachary K , Karges Kip , Aguilar Angel
Published: November 2020

Low health risk, Continental × British steers (n = 199; off truck BW = 252 ± 32.1 kg) were received from two sources at the Ruminant Nutrition Center (RNC) in Brookings, SD in November 2019 and used in a 77 d feedlot receiving and backgrounding experiment. Steers were provided ad libitum access to long-stem hay and water at arrival. Steers were weighed, vaccinated for respiratory pathogens (source 2 only), clostridials, and administered moxidectin. Steers were allotted to pens (n = 20 pens; 10 pens/treatment; 8 to 9 steers/pen). Diets were based upon corn silage and dried distillers grains, treatments were 1) no direct fed microbial (DFM) fed (CON) and 2) DFM (Levucell SC, CNCM l-1077, at 10 g/hd/d providing 8 × 109 cfu, Lallemand Animal Nutrition, Milwaukee, WI; LC). Initial BW was the average of d -1 and d 1 BW (n = 176 steers; initial BW = 253 ± 27.6 kg). On d 21 steers received a 200 mg progesterone and 20 mg estradiol benzoate implant. Data were analyzed from d 1 to 47 (receiving period) and from d 1 to 77 (receiving and backgrounding period) as a RCBD; pen served as the experimental unit. On d 47 LC had greater BW (P = 0.01), ADG (P = 0.01) by 4.2%, and G:F tended (P = 0.10) to be 2.8% greater. Day 77 BW did not differ (P = 0.60), cumulative (d 1 to 77): ADG (P = 0.47), DMI (P = 0.66), and G:F (P = 0.56) were similar. In low–health-risk steers, LC improved performance during receiving; however, no influence to the addition of the DFM was detected from d 1 to 77. The confirmation of yeast counts showed the colonizing forming units to be above the expected level at start of trial but was found below expected level at end of trial. This may explain differences during the initial 47 d vs. 77 d results.
200 Effects of grain processing and undegradable fiber on rumen pH and fermentation of cattle fed high grain diets
Authors: Ran Tao , Saleem A M , Beauchemin Karen , Penner G , Yang Wenzhu
Published: November 2020

The objective of this study was to investigate the effects of processing index (PI, weight after processing/weight before processing × 100) of barley grain and dietary undegradable fiber (uNDF, 240 h of incubation in rumen) concentration on DM intake (DMI), ruminal pH and fermentation characteristics of finishing beef cattle. Six ruminally cannulated beef heifers (BW, 715 ± 29 kg) were used in a 6 × 6 Latin square design with 3 PI (65, 75 and 85%; fine, medium, coarse, respectively) × 2 uNDF concentrations (low and high; 4.6 vs. 5.6% of DM) factorial arrangement. Heifers were fed ad libitum a diet consisting of 10% barley silage (low uNDF), or 5% silage and 5% straw (high uNDF), 87% dry-rolled barley, and 3% vitamin and mineral supplements. An interaction of PI × uNDF was observed (P < 0.01) for DMI, but not for mean or duration of rumen pH < 5.8 or < 5.6 over a 24-h period. The DMI (kg/d) was greater (P < 0.05) for high (12.7) versus low (12.1) uNDF diets with 85% PI, with no difference in DMI (average, 12.1) between low and high uNDF diets with 65 or 75% PI. The duration of pH < 5.8 (14.6 versus 13.3 h) and pH < 5.6 (10.8 versus 8.6 h) reduced (P < 0.05) for high versus low uNDF diets. The PI did not affect total volatile fatty acid (tVFA) concentration or molar proportions of individual VFA, but the tVFA was less (172 and 162 mM; P < 0.01) and acetate proportion was greater (46.0 and 48.2%; P < 0.01) with high versus low uNDF. These results indicate that increasing dietary uNDF concentration is an effective strategy to improve ruminal pH status in finishing cattle, regardless of extent of grain processing, whereas minimizing the extent of grain processing did not reduce the risk of rumen acidosis.
394 Opportunities to enhance wean-to-finish pig survival
Authors: Tokach Mike D , Gebhardt Jordan T , Dritz Steve S , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D
Published: November 2020

Swine productivity as measured by total pigs born, growth rate, and efficiency has improved steadily over the last few decades. However, post-weaning mortality has not improved for several years. Estimates for post-weaning mortality are 3.6% for nursery, 4.1% for grow-finish, and 5.6% of pigs entering the wean-finish phase (USDA, 2015). The first step in improving wean-to-finish survival is to understand major causes. Post-weaning mortality can be categorized into non-infectious and infectious causes. Non-infectious factors can be classified into anatomic abnormalities, toxicity, animal factors, facility factors, nutritional inadequacies, season, and management factors. Important non-infectious mortality factors identified through literature review include birth weight, preweaning management, weaning age and weight, and season. Additionally, a low incidence but high consequence cause for individual pigs is abdominal organ torsion. Sodium ion or ionophore toxicosis or dietary imbalance due to feed formulation or manufacture error are infrequent, but can be high magnitude. Infectious factors can be categorized as respiratory disease caused by swine influenza virus, porcine reproductive and respiratory syndrome virus, Mycoplasma spp., Glasserella parasuis, and others; enteric disease caused by Lawsonia intracellularis, Brachyspira spp; or systemic disease caused by Erysipelothrix rhusiopathiae, Streptococcus suis, porcine circovirus, and others. Non-infectious and infectious mortality causes both need focus to improve wean-to-finish survival. Because of their importance in affecting survival rate, producers should focus on increasing birth and weaning weight, colostrum intake, and weaning age. Strategies to reduce abdominal organ torsions and gastric ulcers also are important for producers experiencing problems with these low frequency, high magnitude problems. Elevating biosecurity to prevent introduction of pathogens can reduce mortality due to infectious agents. For pathogens already present in the herd, producers must determine if the best management strategy is control (ex. vaccination), elimination (ex. mass exposure), or depopulation. Reducing post-weaning mortality remains an opportunity area in the swine industry.
254 Effect of presentation method on understanding of organic chemistry in an undergraduate animal nutrition course
Authors: Smith William B , Thompson Ashlie N , Hines Abbigail R
Published: November 2020

An educator’s goal is to always explain classroom material to his or her students in the most efficient way possible. Chemistry is a fundamental foundation to the study of animal nutrition, but the concepts of organic chemistry are very difficult to relay to students of animal science, possibly due to the different types of student learners. It could be that mode of presentation may aid in relaying this information to the students. The sample for this experiment included students enrolled in an animal nutrition course at Tarleton State University. Students were presented with five methods of presentation of carbohydrate molecular structure in a laboratory session, each with an increasingly tactile approach: written description, printed 2-dimensional model, printed 3-dimensional model, ball-and-stick model, and self-constructing molecular model kit. Students were then asked to complete a survey to address effectiveness of presentation method. Data were analyzed using SAS v. 9.4. When addressing effectiveness of presentation method, the written description and the printed 2-dimensional model were rated as slightly-to-moderately effective (48.4 and 67.8%, respectively), the printed 3-dimensional model was rated as moderately effective (58.1%), the ball-and-stick model was rated as very effective (48.4%), and the self-constructing model was rated as very-to-extremely effective (80.6%). Cluster analysis revealed that students chose any of the presentation methods over the written description with preference for the self-constructing model. Results are interpreted to mean that presentation of organic chemistry concepts in animal nutrition are more effective when kinesthetic presentation methods are employed.
411 Sperm movement, storage, and release from the oviduct
Authors: Miller David J
Published: November 2020

After semen deposition, a fraction of sperm is transported through the female reproductive tract to the lower oviduct, the isthmus, where sperm are retained to form a reservoir. Some of these sperm are released to move to the upper oviduct, the site of fertilization. For sperm to make this journey, they must overcome challenges including possible phagocytosis, high fluid viscosity, and peristaltic contractions of the tract. The study of sperm transport is complex because so few sperm reach the site of fertilization. We have focused our studies on how sperm are retained in the reservoir, how storage prolongs sperm lifespan, and how sperm are released to fertilize oocytes. Sperm storage is particularly important in situations in which ovulation is not tightly synchronized with semen deposition. This occurs in domestic animals, but is especially notable in some species of bats, birds, and insects. Using porcine sperm and an array of 400 common glycans, we identified two specific glycan motifs found in all structures that bound sperm, a Lewis X trisaccharide and a branched 6-sialylated oligosaccharide. Tandem MS profiling indicated that both motifs were abundant in the asparagine-linked glycans of the oviduct epithelium and several larger oligosaccharides were identified that contained both motifs. When these motifs were immobilized, each could retain sperm, suppress Ca2+ influx and lengthen sperm lifespan. Secretions from the cumulus-oocyte complex (COC) and progesterone released sperm from immobilized oviduct glycans, suggesting that COCs can themselves signal sperm release. Progesterone-induced release required CatSper channels, sperm hyperactivation and was dependent on sperm protein degradation. These studies support a model in which sperm are retained in the isthmus by specific glycans on the epithelium, which extends sperm lifespan until COCs produce releasing factors that promote sperm liberation from the isthmus and movement to the ampulla to fertilize the COCs.
259 Effect of stair-step nutritional programming on ovarian development in replacement beef heifers
Authors: Rosasco Shelby L , Melchior Emily A , Cox Shad H , Dunlap Richard L , Gifford Jennifer A Hernandez , Scholljegerdes Eric J , Cushman Robert A , Summers Adam F
Published: November 2020

Based on recent research, it may be possible to influence the number of primordial follicles in the ovaries during the first year of life. Spring-born Angus crossbred heifers (n = 40) were utilized to determine the effect of a stair-step development system on growth and reproduction. Heifers (11 mo) were assigned to 1 of 4 treatments: 1) constant gain drylot (CG-d), 2) stair-step drylot (SS-d), 3) constant gain native range (CG-r), and 4) stair-step native range (SS-r). Heifers were fed individually with a constant gain target of 0.5 kg/d, while stair-step heifers were targeted to gain 0.25 kg/d the first 45 d (period 1) and 0.75 kg/d over the last 45 d (period 2). All heifers were ovariectomized on d 90. Heifer BW was similar on d 0 and d 45; however, native range heifers had an increased BW at d 90 (P < 0.01) compared to drylot heifers. Period 1 and overall ADG was greater in native range heifers (P < 0.01) compared to drylot heifers. During period 2 CG-r and SS-r heifers had an increased ADG compared to CG-d and SS-d heifers, with SS-d having an increased ADG (P = 0.03) compared to CG-d heifers. Reproductive tract score was similar (P = 0.19) between treatments. Ovarian weight and preovulatory follicle diameter were decreased (P < 0.02) in drylot compared to native range heifers. Primary follicles/section was increased (P = 0.05) in stair-s (P = 0.04) in SS-r and SS-d heifers compared to CG-d heifers, with CG-r similar to all other treatments. Differences in diets between drylot and native range positively influences mechanisms controlling primordial follicle activation. Developing heifers on a stair-step nutritional program resulted in a larger ovarian reserve, potentially resulting in an increase in reproductive longevity.
257 Beef cows with atypical estrous cyclicity at puberty produced calves with deficits in pre-weaning muscling, metabolic indicators, and myoblast function but not in feedlot performance
Authors: Swanson Rebecca M , Gibbs Rachel L , Cadaret Caitlin N , Erickson Galen E , Schmidt Ty B , Cupp Andrea S , Yates Dustin T
Published: November 2020

Economic beef production requires efficient growth. In our herd, cows were identified that exhibited irregular (start-stop) or absent (non-cyclic) pubertal estrous cyclicity prior to their 1st breeding season. These cows were sub-fertile but weaned heavier calves. Here, we determined if these calves possessed enhanced muscling and metabolic efficiency. Early muscle growth and metabolic indicators, feedlot performance, and carcass traits were evaluated in steer calves from cows that had exhibited normal (typical), start-stop, or non-cyclic pubertal estrous patterns. Start-stop and non-cyclic cows calved later (P < 0.05) than typical cows, but calf birthweights did not differ among groups. Weaning weights tended to be decreased (P = 0.09) in calves from start-stop and non-cyclic cows, but 205-d adjusted weaning weights did not differ. At 3 mo, body composition estimated by bioelectrical impedance revealed a tendency for reduced (P = 0.10) muscle mass in calves from non-cyclic and start-stop compared to typical cows. Plasma cholesterol, high-density lipoprotein, and triglyceride concentrations were reduced (P < 0.05) and glucose/insulin tended to be increased (P = 0.09) in calves from non-cyclic cows. Plasma urea nitrogen did not differ among groups. Ex vivo proliferation was greater (P < 0.05) for myoblasts isolated from calves of start-stop and non-cyclic compared to typical cows. Total oxidative metabolism did not differ but glycolysis was decreased (P < 0.05) in myoblasts from calves of non-cyclic cows. Feedlot average daily gain and dry matter intake did not differ during growing or finishing. Feed efficiency tended to be increased (P = 0.09) in calves from non-cyclic cows but not when normalized to dressing percentage. Hot carcass weight, dressing percentage, ribeye area, fat thickness, and marbling did not differ among groups. These findings indicate that atypical maternal estrous cyclicity at puberty reduced early muscle growth and metabolism in offspring but not feedlot growth or carcass merit. We speculate that early growth deficits are influenced by inflammatory changes.
407 Nutrition and sexual development in bulls
Authors: Dalton Joseph
Published: November 2020

Bull management for reproduction begins at birth. The objectives of this invited review are to provide a brief summary of the impact of nutrition on sexual development and reproductive function in beef bulls, followed by a discussion of management before, during and after the breeding season. Increased calfhood nutrition results in greater testicular development at maturity. Conversely, poor calfhood nutrition results in delayed puberty and reduced testicular development at maturity. Unfortunately, it is not possible to compensate for the effects of poor calfhood nutrition by subsequently providing supplemental feed. Previous research investigating sexual development and reproductive function in bulls 6 to 16 months of age focused on associations of average daily gain (ADG) and body weight with age at puberty, scrotal circumference, sperm production and morphology. Researchers reported no significant correlations between cumulative ADG and any of the factors investigated, and concluded ADG of 1.0 to 1.6 kg per day did not result in excessive scrotal fat accumulation, increased scrotal temperature, or reduction in semen quality. A common recommendation is for yearling bulls to have a body condition score of 5.5 to 6.5 (on a 9-point scale) at the start of the breeding season. Spermatogenesis occurs over a 60-day period; therefore, nutritional effects of inappropriate nutrition (over- or under-feeding) on sperm will have a carryover effect. During the breeding season bulls are usually limited to the same nutritional plane as the cow herd; however, bulls losing an excessive amount of weight should be replaced. Nutritional management of bulls after the breeding season is influenced by age (potential for further growth) and weight loss during the breeding season. Managing nutrition of bulls through early life phases and the first breeding season provides the opportunity for desired sexual development and reproductive function.
278 Fleece and fiber characteristics of Rambouillet, Targhee, and their reciprocal-crosses at first shearing
Authors: Murphy Tom , Stewart Whit C , Notter Dave , Knuth Ryan , Feagler Trestin , Taylor Bret
Published: November 2020

Objectives were to evaluate breed, heterosis (HI), and maternal effects on wool production in Rambouillet (R x R), Targhee (T x T), and reciprocal-cross (R x T and T x R) 1-yr-old ewes. Greasy fleece weights (GFW) were obtained at shearing and mid-side, britch, and whole-fleece core wool samples were collected to quantify average (A-FD) and CV of fiber diameter (CV-FD). Laboratory scoured yield (LSY) was quantified on core samples and used to estimate clean fleece weight (CFW). Single-born ewes had greater GFW (3.48 kg), greater CFW (2.11 kg), and lower mid-side CV-FD (17.5%) than multiple-born ewes (3.18 kg, 1.95 kg, and 18.1%, respectively; P < 0.01). Rambouillet-sired ewes had greater LSY than T-sired ewes (60.6 vs. 60.0%; P < 0.01), but no breed effects were detected for GFW or CFW. A sire breed x dam breed interaction effect was detected for A-FD at all locations (P ≤ 0.05). Reciprocal-cross performance indicated unfavorable HI for A-FD within mid-side (+0.34 μm), britch (+0.97 μm), and core samples (+0.42 μm; P ≤ 0.05) compared to purebred average. Greater mid-side and britch A-FD in R x T (22.8 and 25.2 μm) than T x R ewes (21.2 and 23.5 μm; P < 0.01) implied a more favorable additive maternal effect for crossbred ewes gestated and reared by R compared to T dams. Future analyses will consider lifetime lamb and wool production of these breed types to evaluate the utility of finewool crossbred ewes in extensive production systems.
281 Techniques to estimate colostrum quality and the effects of cow age and pre-partum supplement intake levels on colostrum quality and serum IgG levels
Authors: Dafoe Julia M , Wyffels Samuel , Parsons Cory T , Carter Boone , DelCurto Timothy , Boss Darrin L
Published: November 2020

Our study was conducted to evaluate the influence of cow age and supplement intake level during gestation on the quality of colostrum at calving, serum IgG levels of the cow at parturition, and serum IgG levels of the calf 3 days post-partum using two on-farm refractometer methods. Forty-five non-lactating multiparous Angus cows were selected from a contemporary group of 300 cows winter grazing northern mixed grass prairie rangelands with free choice protein supplement. Specifically, 15 first service bred cows were selected for each of the following treatment groups: 1) low supplement intake (> -0.75 SD); 2) average supplement intake (± 0.50 SD); 3) high supplement intake (> +0.75 SD). Supplement intakes were measured using 8 feeding stations in a SmartFeed Pro self-feeder system (C-Lock Inc., Rapid City, SD) and measurements were obtained from d 164 to 215 of gestation. Cows were further divided by age comparing young (4, 5, and 6 yr) to old (7 and 8 yr). Cow age did not interact with supplement intake for any of the colostrum or blood serum measurements (P ≥ 0.29). In addition, cow age and supplement intake did not influence colostrum Brix %, calf serum total protein taken 3 d post-partum or cow serum total protein taken at birth (P ≥ 0.14). The optical refractometer was found to be a good alternative to the more expensive digital refractometer. When regressing values of the two techniques, they were observed to be correlated (P < 0.01; R = .96). In summary, cow age and supplement intake levels of mature cows during the mid to late stages of gestation did not influence colostrum quality at birth. The lack of colostrum quality differences was likely due to the moderate to good condition of the cows and adequate nutrition 90 d prior to parturition.
290 Impacts of dietary zinc concentrations on lamb feedlot performance
Authors: Knuth Ryan , Cunningham Hannah , Bangooura Berit , Julian Alexis , Page Chad M , Hummel Gwendolynn , Woodruff Kelly , Whaley Jaelyn , Bardsley Katherine , Lake Scott , Gifford Cody , Bisha Bledar , Stewart Whit C
Published: November 2020

The objectives of this study were to identify the impacts of Zn concentrations in lamb grower pellet on lamb feedlot performance and natural coccidia infection in terms of fecal Eimeria oocyst excretion. Rambouillet lambs (n = 33; 43.9 ± 1.0 kg) were used in a 63 d feeding trial to assess the effect of a diet fortified with a combination of ZnSO4 (80%) and Zn amino acid complex (20%; ZnAA; Zinpro Corp.; Eden Prairie, MN, USA) at three different dietary Zn concentrations (treatment, TRT) which met or exceeded current recommendations. These levels included 1×NRC requirements (450 mg/kg grower pellet; 1NRC), 2×NRC requirements (900 mg/kg grower pellet; 2NRC), and 3×NRC requirements (1350 mg/kg grower pellet; 3NRC). Lamb performance characteristics, including body weight (BW), average daily gain (ADG), average dry matter intake (DMI), feed efficiency (gain:feed, G:F), and residual feed intake (RFI), were quantified. Fecal samples were collected every 2 wk to assess coccidia infection status via fecal oocyst counts. Treatment × period (d 0–10, 11–42, 42–63) interactions were identified for DMI (P < 0.001). No main effect of TRT was identified for BW, ADG, G:F, or RFI (P > 0.36), but was for DMI (P = 0.02). Ten Eimeria species were detected and summed for total fecal oocyst count, but focus was on the most pathogenic species (E. ahsata, E. bakuensis, E. crandallis, and E. ovinoidalis). A statistical tendency for the interaction between TRT × day was detected for E. bakuensis and E. ovinoidalis (P ≤ 0.08). Transformed counts of E. bakuensis and E. crandallis were lower for 1NRC compared to 2NRC and 3NRC lambs (P < 0.05). Results indicate greater dietary Zn concentrations increased DMI and decreased Eimeria oocysts excreted.
PSV-5 Dairy worker perspectives on performing euthanasia as an essential component of their job
Authors: Simpson Hailey M , Cramer Catie , Edwards-Callaway Lily , Stallones Lorann , Thompson Sofia , Ennis Sari , Kim Elizabeth , Roman-Muniz I Noa
Published: November 2020

Euthanasia is a critical component of dairy management as it provides a way to alleviate animal suffering. Limited research explores dairy worker perspectives regarding their role in performing euthanasia or the impact of this practice on worker wellbeing. Additionally, training offered to caretakers is inconsistent in content and frequency and lacks cultural congruence. This project aimed to identify how euthanasia methods, procedures, and training affect caretaker attitudes towards performing on-farm euthanasia, job satisfaction and sense of well-being of dairy workers and managers. Focus groups, facilitated by Colorado State University researchers, were conducted at five large Colorado dairies. Thirty-eight animal caretakers (workers, n = 29; managers, n = 8; and veterinarians, n = 1) participated in focus groups according to their job description and language of choice (English or Spanish). Focus groups were recorded for subsequent transcription and translation. Thematic analysis was performed to identify recurring themes in the transcripts. Themes that emerged from the focus groups included: stressors related to physical, work, and social environments; euthanasia techniques, frequency, process, decision making, and who performs this task; the language used when referring to euthanasia; animal welfare; and the effect of the human-animal bond on euthanasia decision-making and performing euthanasia. Preliminary analysis of themes indicated that multiple factors influence how euthanasia is performed and the euthanasia decision-making process. Additionally, euthanasia and job-related tasks were identified as sources of stress for dairy workers. Strength of the human-animal bond and worker compassion towards the animals they care for were evident for all participants. Initial analysis showed a lack of caretaker awareness regarding mental health services available in their community. Training programs on dairy farms should incorporate worker health and safety, particularly as it pertains to performing euthanasia, and address the mental wellbeing of dairy workers. Information regarding mental health services in the community should also be accessible to caretakers.
PSV-20 Preliminary exploration of swine veterinarian perspectives on euthanasia on-farm
Authors: Calaba Elaine N , Edwards-Callaway Lily , Cramer Catie , Roman-Muniz I Noa , Stallones Lorann , Ennis Sari , Kim Elaine , Simpson Hailey M , Pairis-Garcia Monique , Thompson Sofia
Published: November 2020

Euthanasia is a critical component of swine production. Veterinarians should play a key role in development of euthanasia protocols and training to ensure humane euthanasia. This study aimed to understand veterinarian involvement and perspectives on euthanasia training on swine farms. An online survey was disseminated through the American Association of Swine Veterinarians newsletter in February 2020. The survey consisted of 56 questions. Twenty-six veterinarians responded to the survey. The majority (88%, n = 23) of respondents indicated that most of the facilities with which they work have a written euthanasia protocol, and 69% of respondents indicated that they participated in the protocol design. The majority of respondents (88%; n = 23) indicated that caretakers are responsible for performing euthanasia of the pigs. When presented with the statement: “All employees performing euthanasia have been trained adequately,” 52% of respondents agreed while 42% disagreed. Additionally, 81% (n = 21) of the respondents indicated a desire to facilitate additional euthanasia training. All respondents (100%; n = 26) “believe that euthanasia is a humane way to end animal suffering” and that “the euthanasia process on-farm is necessary.” Over half of respondents (62%; n = 16) reported feeling emotionally upset after euthanizing an animal. Approximately half (54%; n = 14) of respondents believe their workplace values the mental health of employees, yet 50% (n = 13) indicated there were no programs to promote worker mental health and 96% (n = 25) indicated there were no mental health evaluations. Fifty four percent of respondents (n = 14) reported there were no employee check-ins with supervisors. Preliminary data supports the need for further euthanasia training on-farm developed with veterinarians and suggests veterinarians want to deliver more training. Although some facilities are considering employee mental well-being, further development of euthanasia training and wellness programs could benefit caretakers.
PSV-10 Free-choice diet selection by sheep during peripartum
Authors: Burgos-González Carlos , Villalba Juan J , Vázquez Reyes , Pedernera Mariana
Published: November 2020

Our objective was to explore diet selection and productive performance by sheep during peripartum. Pregnant Saint-Croix and Katahdin ewes were housed in individual pens from 100 days of gestation to 60 days of lactation and assigned to two groups: Free-choice-FC and Mixed-ration-MR (n = 12/group). Sheep in FC received ad-libitum amounts of soybean meal, sorghum grain, alfalfa and oat hays, presented in individual troughs. Animals in MR received a total-mixed-ration with these feeds, balanced for gestation or lactation according to NRC. Dry matter (and nutrient) intake/kg BW was measured daily, whereas BW and BCS were measured every 7 and 14 d, respectively. Data was analyzed as a Linear Mixed Model with repeated measures; group, breed, litter size (single, twins) and parity (primiparous, multiparous) were the fixed factors and sheep (random factor) was nested within group. Overall dry matter and ME intake did not differ between groups (P > 0.05), without breed, litter size or parity effects (P > 0.05), but protein intake was greater and NDF and ADF intakes were lower in FC than in MR (P < 0.001). During gestation, FC sheep consumed soy=alfalfa >sorghum >oats, and during lactation they increased (2X) soy intake (P < 0.001). Body weight was similar between groups (73.3±1.3, and 70.6±1.3 kg, for FC and MR, respectively; P=0.148), whereas BCS was greater for FC than for MR (3.9±0.2 vs. 3.3 ±0.1; P = 0.01). During lactation, ewe BW (67.3±1.3 vs. 61.92±1.3 kg; P = 0.01) and BCS (3.83±0.1 vs. 3.03±0.1; P < 0.001) were greater for FC than for MR. Offspring BW was similar between groups (11.5±0.6, and 11.4±0.5 kg, for FC and MR, respectively; P = 0.804). In conclusion, the free-choice treatment enhanced ewe nutrition, reducing BW and BCS losses during lactation without influencing offspring growth. Free-choice may enable ewes to meet their individual nutrient needs, with benefits to their welfare and postpartum ovarian activity.
PSV-23 The influence of prior experience on dietary diversity in sheep
Authors: Pedernera Mariana , Vulliez Alejandra , Villalba Juan J
Published: November 2020

The objective of this study was to explore the influence of prior dietary experiences on intake and selection of novel feeds by lambs. Twenty lambs housed in individual pens were assigned to two groups (10lambs/group): Negative (NE) and Positive (PE) Experiences, in a split-plot design. Lambs were offered a nutritive novel feed followed by intra-ruminal infusions of lithium chloride-LiCl (150 mg/kg BW), a toxicant that causes food aversions (NE), or vehicle (water; PE). The feed was offered daily and infusions were delivered only when intake was ≥50g, when the protocol was repeated with another novel feed until 4 feeds (oats, wheat bran, corn, beep pulp) were offered. After exposure, all lambs were tested for their acceptance of single novel feeds, each offered during 2 consecutive days: sorghum grain, rice bran, Calfmanna® pellets and soybean meal. Subsequently, all lambs were offered a 5-way choice among these feeds and alfalfa (familiar feed). Intake data, preference and Shannon’s diversity index (5-way choices) were analyzed with a Mann-Whiney U test. During exposure, the NE group ate less of the 4 feeds than the PE group (P < 0.05). Moreover, as exposure progressed, it took more days for NE lambs to reach the 50 g intake threshold, suggesting that neophobia in this group increased with negative experiences. During testing, NE lambs ate less (P < 0.05) of the novel feeds, except soybean meal, than the PE lambs. During the 5-way-choice test, preference for alfalfa was 63.6±3.5% for NE and 45.2±2.6% for PE (P < 0.001). The Shannon’s index was 0.85±0.05 for NE and 1.24±0.03 for PE (P < 0.001), suggesting that lambs in NE selected a less diverse diet. Thus, prior experience influenced neophobia and dietary diversity, an outcome that could impact the nutrition and welfare of grazing animals introduced to novel environments and the diversity of plant communities.
PSV-14 Influence of monsoon rainfall events on movement patterns of Angus crossbred vs. Raramuri Criollo cattle on desert rangeland
Authors: Nyamuryekung’e Shelemia , Cibils Andres , Estell Rick , Gonzalez Alfredo , McIntosh Matthew , Spiegal Sheri , Duni Danielle
Published: November 2020

The Chihuahuan Desert averages 247 mm of precipitation annually, 53% of which occurs between July and September. Our objective was to examine movement, activity, pasture use, and watering patterns of Angus x Hereford (AH) and Raramuri Criollo (RC) cows on days with precipitation events (PE, ≥ 1.3 mm rain recorded) vs. days with no precipitation (NP) at the Jornada Experimental Range in southern New Mexico during the summers of 2015, 2016, and 2017. Breeds grazed two adjacent pastures (12A = 1190 ha; 12C = 1165 ha) separately in a crossover design for 4 weeks each year. Seven to nine randomly selected cows per breed were collared with Lotek 3300-LR GPS set to log position every 10 min. An average of 7.6 PE occurred during the 4-week trials each year. On PE days, cows traveled farther (PE = 6.95 vs. NP = 6.43 km, P < 0.01), spent more time grazing (PE = 9.07 vs. NP = 8.76 h/day, P = 0.07) and less time resting (PE = 13.90 vs. NP = 14.38 h/day, P = 0.01), and traveled similar distances from watering points (PE = 0.84 vs. NP = 0.80 km, P = 0.41) compared to NP days. On PE days, cows spent less time within 200 m (PE = 1.32 vs. NP = 2.95 h, P < 0.01) and 100 m (PE = 0.79 vs. NP = 1.90 h, P < 0.01) of drinkers regardless of breed. We detected no rainfall x breed interaction (P > 0.05). Overall, RC cows traveled farther, at higher velocities, spent more time grazing, less time resting, and explored areas with greater radius than AH counterparts (P < 0.05). Precipitation appeared to relax environmental constraints on activity of both breeds, likely due to availability of ephemeral watering sources and a transient drop in temperature.
PSV-21 The behavior, physiology and immunity of pregnant sows housed in individual crate with different frequency of sham-chewing
Authors: Yi Ran , Zhang Runxiang , Liu Honggui , Li Xiang , Bao Jun
Published: November 2020

The sham-chewing behavior indicates the poor welfare of sows and quite frequently occurs in confined environment. To evaluate the behavior, physiology and immunity of pregnant sows with different frequency of sham-chewing, 63 sows (Large White × Landrace) housed in individual gestation crate were divided into the high (H), middle (M) and low (L) frequency groups based on the sham-chewing frequency analyzed by Hierarchical cluster using SPSS 20.0 systems. The behavioral data, including sham-chewing, standing, sitting, ventral lying, lateral lying, bar-biting and rooting, was observed in early, middle and late pregnancy (days 26–27, 61–62 and 91–92) of the sows. Serum CRP, IL-10 and IFN-γ contents were detected by enzyme-linked immunosorbent assay (ELISA). The results showed that the frequency of sham-chewing significantly reduced with the increase of the pregnancy period (P < 0.001) and the difference among three groups was significant in early and middle pregnancy (P < 0.001). Standing behavior in Group H and M decreased significantly (P = 0.004; P = 0.020). Sitting, ventral lying and lateral lying behaviors were significantly lower in early pregnancy than those in late pregnancy (P < 0.05). In late pregnancy, bar-biting of Group H was significantly increased (P = 0.018), while rooting was decreased (P = 0.033). The CRP level was significantly higher in Group H than L in middle pregnancy (P = 0.031). The IFN-γ level was significantly lower in Group H (P < 0.05). In late pregnancy, IL-10 level was significantly higher in group H and M than L (P < 0.05). Therefore, the pregnant sows with different frequency of sham-chewing showed differences in standing and lateral lying behaviors. The expression of sham-chewing reflects the higher level of stress and lower level of immunity and may indicate the maladaptation of pregnancy sows to the confined environment.
PSV-17 Measuring motivation for forage of finishing cattle fed high-concentrate diets using a short-term thwarting test
Authors: Coon Rachael E , Peterson Allisen , Tucker Cassandra
Published: November 2020

Beef cattle are commonly fed a high-concentrate, grain-based diet in the finishing period. Longer forage particles stimulate chewing and rumination, which may increase saliva production to buffer the rumen, mitigating a harmful drop in pH that can result from a high grain diet. Our objective was to quantify motivation of finishing cattle to access forage with a short-term thwarting test. We predicted cattle would show more interest in forage, versus an additional offering of their primary diet, during initial exposure and when access to this resource was thwarted. Sixteen finishing cattle were fed a high-concentrate primary diet (16% forage) ad-libitum. Twice per day for 4 days, cattle were exposed to 1 of 2 treatments for a maximum of 1 hr/exposure: 1) 100 g of beardless wheat hay (WH; n=7) or 2) 100 g of the primary diet (TMR; n=9). On the 5th day, the bins containing the dietary treatments were covered with a metal mesh that thwarted access to the contents while still allowing visual and olfactory contact. Interaction with and time spent in proximity to the bins were video recorded and feed intake recorded during days 1–4. T-tests did not detect treatment differences during the thwarting test in any behavioral response (p≥0.292). However, repeated measures analysis indicated that intake of the dietary treatments and interactions with the bin decreased over days 1–4 for WH cattle, while these same measures increased for TMR cattle (day*treatment, p≤0.001). These results suggest that animals were more interested in eating and interacting with additional high-concentrate diet than with a small amount of forage. Our findings may be explained by several factors, including that the TMR was highly palatable or that the inclusion rate of forage in the primary diet may have been sufficient, thus cattle showed little motivation for forage during the thwarting test.
PSIII-3 Association of heat shock factor protein 1 and prolactin receptor variants with molecular breeding values in Senepol cattle
Authors: Ortiz-Uriarte Bianca P , Moreno Edgar J Soto , López-Nieves Lourdes E , Negrón-Pérez Verónica M , Casas Americo , Pagán-Morales Melvin
Published: November 2020

Thermal stress has been associated with lower food intake and growth rate in beef cattle. The purpose of this study was to assess the segregation of the p.Leu462* nonsense mutation in the prolactin receptor gene (PRLR) responsible for slick hair (SH) phenotype in Senepol and a T >C missense variant (V344A) located in the heat shock transcription factor protein 1 gene (HSF1). We compared the potential association of these polymorphisms with molecular breeding values (MBV) that were estimated using a panel of commercial genetic markers (Igenity, Neogen Corp). For this, 29 females and 21 males were genotyped by PCR and sequencing. Three genotypes were observed for the p.Leu462* with frequencies of 0.02 C/C, 0.16 C/- and 0.82 -/-. For V344A only two genotypes were observed with frequencies of 0.86/TT and 0.14/TC. This polymorphism was in linkage disequilibrium with a C >T synonymous variant; therefore, for the statistical analyses, the HSF1 genotypes were combined as TT/CC and TC/CT. The GLIMMIX procedure and Tukey test of SAS were used (effect of sex, HSF1 and SH genotype and interactions). MBV for production traits such as average daily gain, tenderness, yearling weight (YW), marbling, fat thickness (FT), percent choice (PC), ribeye area (RA) and carcass weight. Effect of sex (P < .05) were found for YW (males: 6.93lbs ± 0.53, female: 5.74lbs ± 0.57) and for PC (female: 16.17±0.75, male: 15.02±0.55). Differences between HSF1 genotype combinations were significant for the MBV of RA (TC/CT: 0.96in2±0.10; TT/CC: 0.781in2±0.07 and for FT (TC/CT: 0.16in±0.02; TTCC: 0.12in±0.01). The similarity in segregation of SH responsible genotypes (C/- and -/-) and HSF1 (TC/CT and TT/CC) in Senepol could indicate a potential role of HSF1 in adaptation to heat stress in cattle with an additional effect in muscling and fat deposition.
PSIII-5 Comparison of Bivariate Machine Learning and Linear Model for Genomic Prediction with Different Heritability, QTL and SNP Panel Scenarios
Authors: Peters Sunday O , Sinecan Mahmut , Kizilkaya Kadir , Thomas Milt
Published: November 2020

This simulation study used actual SNP genotypes on the first chromosome of Brangus beef cattle to simulate 0.50 genetically correlated two traits with heritabilities of 0.25 and 0.50 determined either by 50, 100, 250 or 500 QTL and then aimed to compare the accuracies of genomic prediction from bivariate linear and artificial neural network with 1 to 10 neurons models based on G genomic relationship matrix. QTL effects of 50, 100, 250 and 500 SNPs from the 3361 SNPs of 719 animals were sampled from a bivariate normal distribution. In each QTL scenario, the breeding values (Σgijβj) of animal i for two traits were generated by using genotype (gij) of animal i at QTL j and the effects (βj) of QTL j from a bivariate normal distribution. Phenotypic values of animal i for traits were generated by adding residuals from a bivariate normal distribution to the breeding values of animal i. Genomic predictions for traits were carried out by bivariate Feed Forward MultiLayer Perceptron ANN-1–10 neurons and linear (GBLUP) models. Three sets of SNP panels were used for genomic prediction: only QTL genotypes (Panel1), all SNP markers, including the QTL (Panel2), and all SNP markers, excluding the QTL (Panel3). Correlations from 10-fold cross validation for traits were used to assess predictive ability of bivariate linear (GBLUP) and artificial neural network models based on 4 QTL scenarios with 3 Panels of SNP panels. Table 1 shows that the trait with high heritability (0.50) resulted in higher correlation than the trait with low heritability (0.25) in bivariate linear (GBLUP) and artificial neural network models. However, bivariate linear (GBLUP) model produced higher correlation than bivariate neural network. Panel1 performed the best correlations for all QTL scenarios, then Panel2 including QTL and SNP markers resulted in better prediction than Panel3.
PSIII-16 Genome-wide association mapping and functional analysis of body weight, feed intake and walking ability in turkeys
Authors: Abdalla Emhimad , Makanjuola Bayode , Wood Benjamin , Baes Christine F , Vanderhout Ryley J
Published: November 2020

The underlying genetic mechanisms affecting turkey growth traits have not been widely investigated. Over the last few years, genome-wide association studies (GWAS) became the de facto approach to identify candidate regions associated with complex phenotypes and diseases in livestock. In the present study, we performed GWAS to identify regions associated with growth traits, feed intake and walking ability in a breeding turkey line. This was followed by studying the functional evidence that may support the impact of those regions on the economic traits in turkeys. A total of 31,950 phenotypic records for body weight, feed intake and walking ability with genomic (56,393 SNP) data were provided by Hybrid Turkeys, Kitchener, Canada. The analysis was carried out using a mixed linear model with hatch-week-year and sex fitted as fixed effects and the accumulated effect of all markers captured by the genomic relationship matrix fitted as random polygenic effects. Significant markers were observed on several chromosomes across the turkey genome. For example, COL8A1 and RBPMS2 genes were identified on chromosome 1 and 12, respectively, and associated with body weight. Furthermore, a gene-set enrichment analysis was performed for each trait. These functional and positional analyses uncovered a number of gene ontology functional terms, Reactome pathways and Medical Subject Headings that showed significant enrichment of genes associated with the studied traits. Many of the observed gene ontology functional terms (e.g., skeletal muscle tissue growth, regulation of digestive system process, and adult walking behavior) are known to be related to body growth, feed intake and walking ability. The results of this study revealed novel candidate genomic regions and candidate genes that could be managed within a turkey breeding program.
PSXII-35 The Periovulatory Endocrine Milieu Affects the Composition of the Oviductal Fluid in Beef Cows
Authors: Gonella-Diaza Angela M , Sponchiado Mariana , Pugliesi Guilherme , Turco Edson G Lo , Binelli Mario
Published: November 2020

Our main objective was to compare the composition of the oviductal fluid (OFL) between cows of high and low receptivity to the embryo. A model for receptivity based on the manipulation of the size of the preovulatory follicle (POF) was used to compare the composition of the OFL. Using this model, it has been proved that the oviduct of high receptivity cows has differences in morphology, gene expression, and extracellular matrix remodeling when compared to low receptivity cows. Cycling, non-lactating, multiparous Nelore cows (n = 14) were presynchronized before receiving cloprostenol (large follicle [LF] group) or not (small follicle [SF] group), along with a progesterone (P4) device on Day (D) ─10. Devices were withdrawn, and cloprostenol administered 42–60 h (LF) or 30–36 h (SF) before GnRH agonist treatment (D0). As a result, higher estrogen concentrations, corpora lutea, and progesterone concentrations were also observed in the LF group in comparison to the SF group. Four days after GnRH-induced ovulation, OFL was collected. Quantitative mass spectrometry was used to determine the concentration of 21 amino acids, 21 biogenic amines, 40 acylcarnitines, 76 phosphatidylcholines, 14 lysophosphatidylcholines, 15 sphingomyelins, 29 hexoses, and 17 prostaglandins and related compounds in the OF. MetaboAnalyst 3.0 was used to identify which metabolites better explained the separation of experimental groups and which could potentially be used as markers of receptivity. After multivariate and PLS analysis, samples of the LF and SF were divided clearly into two non-overlapping clusters. The most influential variables to separate the two groups included: Glutamate, Leucine, four phosphatidylcholines, three lysophosphatidylcholines, and arachidonic acid. Univariate analyses further confirmed these results. There were statistical differences in the concentration of 31 metabolites (P ≤ 0.05) between groups. We concluded that the composition of the OFL is different between cows with contrasting receptivity and fertility status.
PSXII-23 Identification and evaluation of novel fertility traits using automated activity monitor data from commercial dairy herds
Authors: Rosenberg Camila A , Cardoso Diercles F , Malchiodi Francesca , Schenkel Flavio , Baes Christine F
Published: November 2020

The reproductive performance of dairy herds is a determinant factor in their production efficiency and long-term profitability. While the genetic improvement of fertility in cows has been a top breeding objective, its success has been constrained by the low heritability of current traits and the negative impact of management practices on trait measurement accuracy. The recent development and adoption of automated sensor technologies, such as activity monitors, within dairy production systems have provided new opportunities to identify relevant and cost-effective phenotypes of fertility. To date, several activity-based measurements of estrus expression have been associated with fertility outcomes and may, therefore, be suitable predictors of female fertility. The objective of this study was to identify and evaluate novel estrus-related fertility traits using automated activity monitor (AAM) data from commercial dairy herds. A total of 8,730,987 records consisting of 10,529 estrus events were collected between January 2019 and March 2020 from 2,434 cows and 689 heifers of two U.S. commercial herds, where cows were fitted with collar-mounted accelerometers (Heatime, SCR Engineers Ltd., Netanya, Israel). The AAM dataset contained individual bi-hourly activity and rumination patterns, as well as computed fertility index scores, which were used to derive fertility traits related to estrus duration and intensity. The mean number of estrus events per cow and heifer was 4.06 ± 0.04 and 2.63 ± 0.07, respectively, with 1,408 of estruses resulting in pregnancy. Traditional fertility traits were calculated from the breeding record information of 3,255 animals. An estimation of the heritabilities along with genetic and phenotypic correlations between the novel estrus-related fertility traits and traditional fertility traits was undertaken using the program AIREML. Outputs from this project are expected to provide further insight on how to best use AAM measurements to improve selection for reproductive performance in commercial dairy herds.