bluuebunny/crossref_metadata_2025 huggingface dataset:
260 Genetic prediction for first-service conception rate in Angus heifers using a random regression model
Authors: Sánchez-Castro Miguel A , Thomas Milt , Enns Mark , Speidel Scott
Published: November 2020

First-service conception rate (FSCR) can be defined as the probability of a heifer conceiving in response to her first artificial insemination (AI). Given the binary nature of its phenotypes, FSCR has been typically evaluated using animal threshold models (ATM). However, susceptibility of these models to the extreme-category problem (ECP) limits their ability to use all available information to calculate Expected Progeny Differences (EPD). Random regression models (RRM) represent an alternative method to evaluate binary traits, and they are not affected by ECP. Nevertheless, RRM were originally developed to analyze longitudinal traits, so their usefulness to evaluate traits with singly observed phenotypes remains unclear. Therefore, objectives herein were to evaluate the feasibility of a RRM genetic prediction for heifer FSCR by comparing its resulting EPD and genetic parameters to those obtained with a traditional ATM. Breeding and ultrasound records of 4,334 Angus heifers (progeny of 354 sires and 1,626 dams) collected between 1992 to 2019 at the Colorado State University Beef Improvement Center were utilized. Observations for FSCR (1, successful; 0, unsuccessful) were defined by fetal age at pregnancy inspections performed approximately 130 d post-AI. Traditional FSCR evaluation was performed using a univariate BLUP threshold animal model, whereas an alternative evaluation was performed by regressing FSCR on age at AI using a linear RRM with Legendre Polynomials as the base function. Heritability estimates were 0.03 ± 0.02 for the ATM and 0.005 ± 0.001 for the average age at AI with the RRM, respectively. Pearson and rank correlations between EPD obtained with each method were 0.63 and 0.60, respectively. The regression coefficient of RRM predictions on those obtained with the ATM was 0.095. In conclusion, these results suggested that although a RRM genetic prediction for FSCR was feasible, a considerable degree of re-ranking occurred between the two methodologies.
423 WS Young Scholar Talk MS II: Heat stress-induced deficits in growth, metabolic efficiency, and cardiovascular function coincided with chronic systemic inflammation and hypercatecholaminemia in ractopamine-supplemented feedlot lambs
Authors: Swanson Rebecca M
Published: November 2020

Our 1st study evaluated the effects of □-adrenergic agonist (ractopamine) supplementation on growth, health, and wellbeing in heat-stressed feedlot wethers. Chronic heat stress impaired growth, metabolism, and wellbeing even when the impact of reduced feed intake was eliminated by pair-feeding. We observed systemic inflammation and hypercatecholaminemia that were likely mediators of these deficits. Moreover, ractopamine did not diminish any wellbeing indicators and improved muscle growth without worsening the effects of heat stress. Our 2nd study assessed the effects of pubertal cyclicity (weaning to 1st breeding) in cows on myoblast-mediated muscle growth, metabolism, and growth efficiency of their offspring. Maternal fertility and postnatal growth efficiency of offspring are imperative to successful beef cattle production. A maternal condition was previously identified in which cows exhibited irregular cyclicity patterns or were non-cyclic between weaning and 1st breeding. This condition is thought to be associated with high concentrations of androstenedione in their follicular fluid, which causes cows to be sub-fertile but also wean heavier calves when they do become pregnant. We hypothesized that calves from cows exhibiting irregular pubertal cyclicity would have enhanced growth efficiency compared to calves from cows with normal pubertal cyclicity. To test this hypothesis, we evaluated myoblast function, growth, and metabolism pre-weaning, as well as growth efficiency in the feedlot and carcass characteristics at harvest in calves from cows that were previously identified as having typical, start-stop, or non-cycling pubertal cyclicity patterns. Calves from irregular cycling cows had reductions in insulin sensitivity, plasma proteins and lipids paired with increased myoblast function and reduced myoblast glycolytic capacity. Data independently and combined suggest calves from cows with irregular cyclicity from weaning to 1st breeding have chronic inflammation. While the specific mechanism of inflammation is unknown, further research may allow mediators of abnormal cyclicity and offspring inflammation-induced dysfunction to be elucidated.
275 Phenotypic relationships between heart score and feed efficiency, carcass, and pulmonary arterial pressure traits
Authors: Heffernan Kathryn R , Speidel Scott , Thomas Milt , Enns Mark , Holt Tim
Published: November 2020

Pulmonary hypertension (PH) can lead to premature mortality in fed cattle and is often called Feedlot Heart Disease (FHD). To date, pulmonary arterial pressure (PAP) has been the only indicator trait of PH that has been evaluated. The objective of this study was to evaluate relationships between heart score (using heart score as a phenotype for PH) and PAP, carcass, and feed efficiency traits in fattening Angus steers. Our hypothesis was that feed efficiency and carcass traits, along with PAP, would demonstrate a strong relationship with heart score. Feed efficiency, carcass, PAP and heart score data from 89 Black Angus steers from Colorado State University Beef Improvement Center were collected and used for this study. Evaluations were performed using a multiple linear regression model, which included heart score as a categorical fixed effect and age as a continuous fixed effect. Least Square Means, pairwise comparisons, and ANOVA tables were constructed per trait. PAP (P < 0.001) showed an important relationship to heart score and average dry matter (P < 0.10) intake approached importance to heart score. In general, feed efficiency and carcass traits decreased as heart score increased, but PAP was the only trait with a strong relationship to heart score (P < 0.05). This led us to reject our hypothesis.
277 Phenotypic and genetic differences in Rambouillet lines divergently selected for reproductive rate over 50 years
Authors: Murphy Tom , Thomson Jennifer M , Berardinelli James , Roeder Brent
Published: November 2020

A long-term selection experiment was conducted in a Rambouillet flock from 1969 to 2017. The high (HL) and low lines (LL) were divergently selected based on a maternal reproductive index, and an unselected control line (CL) was also maintained. Adult ewe traits considered were NLB, greasy fleece weight (GFW), and body weight after fall weaning of their lambs (BW). Results indicated that NLB was greatest for HL (1.67 ± 0.01), intermediate for CL (1.48 ± 0.02), and least for LL (1.28 ± 0.01; P < 0.001). Ewe GFW was greatest for LL (3.9 ± 0.02 kg; P ≤ 0.01) but not different between HL (3.82 ± 0.02 kg) and CL (3.88 ± 0.02 kg; P = 0.08); whereas, BW was least for HL (61.7 ± 0.19 kg; P ≤ 0.01) and not different between LL (62.9 ± 0.21 kg) and CL (62.6 ± 0.25 kg; P = 0.58). Heritability was estimated to be low for NLB (0.13 ± 0.02) and moderate for GFW (0.55 ± 0.03) and BW (0.46 ± 0.04). Genetic correlations were estimated to be near zero between NLB and GFW (-0.07 ± 0.08) and NLB and BW (0.12 ± 0.08) and low between GFW and BW (0.29 ± 0.06). Trends for NLB predicted breeding value differed among all 3 lines (P < 0.01) and was positive for HL (0.012 ± 0.0002 lambs/birth year), negative for LL (-0.005 ± 0.0002), and small but positive for CL (0.002 ± 0.0002). Inbreeding rates were positive in all lines but greatest for HL (0.45 ± 0.005 %/birth year), intermediate in LL (0.37 ± 0.006), and lowest in CL (0.28 ± 0.006). Results indicated long-term phenotypic selection for reproductive rate was effective and not genetically antagonistic with wool production or mature BW.
282 The Influence of RFI classification and cow age on body weight and body condition change, supplement intake and grazing behavior of beef cattle winter grazing mixed-grass rangelands
Authors: Parsons Cory T , Dafoe Julia M , Wyffels Samuel , Van Emon Megan , DelCurto Timothy , Boss Darrin L
Published: November 2020

behavior of beef cattle winter grazing rangelands in North Central Montana. A herd of non-lactating commercial Angus cows, n = 205 (yr-1) and n = 203 (yr-2), ranging in age from 1 to 9 yr old, grazed rangeland pastures (586 ha) from mid-October to early January of 2018 and 2019. Cows were grouped into 6 age classes to evaluate the effects of RFI and age on average daily individual supplement intake, CV of supplement intake, and intake rate, as well as changes in body weight and body condition during an 84-day grazing period each year. Additionally, 30 cows were stratified by age and RFI and fitted with Lotek GPS collars each year to record distance traveled and time spent grazing. Change in cow weight differed by year where cows in yr-1 gained 26.3 ± 1.96 kg while cows in yr-2 lost 19.2 ± 1.96 kg during the 84-day grazing period (P < 0.01). Change in BCS exhibited an age × RFI interaction (P = 0.05); however, an analysis within age groups did not result in differences between RFI classifications (P ≥ 0.27). There was an interaction between RFI, age and year related to supplement intake expressed as g∙kg cow bw-1∙d-1 where in year 2, 4-yr-old high RFI cattle consumed less supplement than 4-yr-old low and average RFI cattle (P < 0.01). Supplement intake rate expressed as g∙min-1 also differed by year (P < 0.01), with cows in yr-1 consuming less supplement per minute than in yr-2 (29.9 ± 1.81 and 91.8 ± 1.87). There were no effects of RFI, cow age or year on time spent grazing (P ≥ 0.19) with cows averaging 6.1 ± 0.61 hrs per day grazing. In summary, cow age had an influence on supplement intake, change in weight and body condition, and grazing behavior, while RFI classification had minimal effects.
283 Heterosis and its potential influence on pulmonary arterial pressure in beef cattle
Authors: Gonzalez Murray Roderick A , Sánchez-Castro Miguel A , Thomas Milt , Speidel Scott , Enns Mark
Published: November 2020

High altitude disease (HAD) is a hypoxia-influenced pathologic condition experienced by cattle raised at high elevations (> 1,524 m). Pulmonary arterial pressure (PAP) is a common diagnostic tool used as an indicator of susceptibility to develop HAD. Given PAP is moderately heritable, possibilities to genetically reduce the incidence of HAD are feasible. However, an alternative strategy could be given by heterosis, since non-additive genetic effects have been related to survivability and environmental fitness. Therefore, objectives of this study were to determine heterosis and breed percentage effects on PAP measurements. A total of 1,083 cattle with varying percentages of Simmental, Angus, Hereford and Red Angus breeds were used for the study. Such animals’ available information included PAP records, PAP test date, PAP technician, sex, herd of origin and breed percentages of parents. A general linear model was utilized to estimate the effect of heterosis on PAP. Contemporary group (defined as a combination between herd, PAP date, PAP technician and sex) was included as a categorical fixed effect; whereas the age at PAP measurement and the degree of outcross were included as linear covariates. Similarly, breed effects were estimated by including breed percentages of Simmental, Angus, Hereford, Red Angus and “Other” breeds as linear covariates in the model. The general average for PAP measurements in the entire dataset was 41.29 ± 0.22, with range of 26 and 108 mmHg. The estimated regression coefficient for PAP on heterosis was -1.834 ± 1.676 mmHg/percent of outcross (P = 0.276), whereas, the range of breed effects on PAP was 15.08 mmHg. These results suggested that heterosis had no significant effects on PAP measurements. However, further research including other multibreed populations is required in order to better understand if increased levels of heterozygosity could potentially be related to lower PAP scores.
285 Supplement intake variation, weight, and body condition change in yearling heifers grazing late-summer dryland pastures with Rumax BoviBox versus Rumax BoviBox HM protein supplements
Authors: McClain Tyrell , Wyffels Samuel , Larsen Shay , Müller Luka , Davis Noah G , Carter Boone , Bowman Janice , Boss Darrin L , DelCurto Timothy
Published: November 2020

The objectives of this study were to evaluate Rumax BoviBox versus Rumax BoviBox HM protein supplements on supplement intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during late summer. Fifty-nine yearling commercial Angus heifers (428 kg) were stratified by BW and randomly assigned to one of two supplementation treatments: 1) free-choice access to Rumax BoviBox protein block supplement (30% CP, 23% salt; n = 29); and 2) free-choice access to Rumax BoviBox HM high magnesium protein block supplement (28.7% CP, 23% salt; n = 30). Individual supplement intake, time spent at the feeder, and intake variation were measured throughout the study. On d 0, 42, and 84 heifers were weighed and assigned a BCS following a 16-h shrink. Additionally, forage was sampled every 14 d throughout the study. Supplement intake (kg ∙ d-1) displayed a treatment × period interaction (P < 0.01). However, within period, treatment differences were not observed with intakes averaging 0.15 and 0.34 kg ∙ day-1 for d 0 – 42 and 42 - 84, respectively. Heifers spent more time at the feeder in period 2 than in period 1 (P < 0.01), averaging 7.67 vs 4.00 min per day, respectively. Supplement intake rate (g ∙ min-1) also displayed a treatment effect (P < 0.01) indicating that heifers in the Rumax BoviBox treatment had lower intake rate compared to Rumax BoviBox HM supplemented heifers. In conclusion, there were only minor differences in intake behavior and animal performance with the Rumax BoviBox and Rumax BoviBox HM supplement treatments. However, supplement intake increased and variation in intake decreased with declining forage quality and quantity.
287 Effect of corn or barley in feedlot diets, on steer performance and feeding behavior
Authors: Wyffels Hannah DelCurto , Dafoe Julia M , Parsons Cory T , Boss Darrin L , DelCurto Timothy , Wyffels Samuel , Van Emon Megan , Bowman Janice
Published: November 2020

This study evaluated the effects of barley and corn finishing rations on feedlot performance and feed intake behavior of steer calves. For 2 consecutive years, Angus-based steer calves were fed and finished at the Northern Agricultural Research Center in Havre, MT. Steers averaged 427 kg (n = 48) in year 1 and 407 kg (n = 47) in year 2. Feedlot rations used in this study were comprised of 1) corn or 2) Hockett barley. Diets were balanced to be isonitrogenous (12% CP). Steers were fitted with an electronic identification ear tag and fed in a GrowSafe system to measure individual animal intake and behavior. Initial and final unshrunk weights were obtained on two consecutive days and averaged. Weight gain, ADG, and G:F were measured for each steer. Feeding behavior including: time spent eating (min∙day-1), visits per day, time per visit (min), eating rate (g∙min-1), intake (kg∙day-1), and intake per visit (g) were also measured for each individual. Average daily gain, final live weight, DM intake, hot carcass weight, marbling, and REA all had significant year effects (P < 0.05.). Corn-fed steers had heavier hot carcass weights (P = 0.01), and greater average daily gains (P = 0.04); however, corn-fed steers also had higher average daily DMI (P = 0.02) than barley-fed steers. Carcass weights were on average 15.89 kg heavier for steers fed corn compared to steers fed barley (P = 0.02) and corn-fed steers displayed higher numerical yield grade (P = 0.02). There were no treatment effects observed for final live weight, gain to feed, marbling, fat, REA, time spent eating, visits per day, time per visit, eating rate or intake per visit (P ≥ 0.05). In summary, barley-fed steers yielded comparable performance outcomes as corn-fed steers, thus, depending on cost and production year, barley could be a potential high-quality feed source in beef cattle finishing rations.
284 Influence of three times weekly alfalfa supplementation on the behavior of beef cows grazing dormant Montana rangeland
Authors: Davis Noah G , Wyffels Samuel , Sanford Carla , DelCurto Timothy
Published: November 2020

The objectives of this research were to determine how daily and hourly distance traveled, grazing time, and resting time of beef cows are influenced relative to the timing of supplementation. Over two winters, a herd of commercial Angus cows grazed in a 645-ha Montana foothill rangeland pasture for 56 days between December and February each year. At 1300 every Monday, Wednesday and Friday, all cows were gathered and taken to a central location in the pasture where 3.18 kg∙hd-1 of alfalfa pellets (17% CP) were immediately delivered. Each year, 18 cows were randomly assigned a global positioning system (GPS) collar. Using the GPS collar data, distance traveled, grazing time, and resting time were estimated for each hour and day for each cow. Activity was grouped into the 24-h period pre-supplementation and 24-h period post-supplementation. Cows traveled 1.7 km further and grazed for 0.7 h less per day post-supplementation (P < 0.01). Daily resting time was similar pre- and post-supplementation (P = 0.07). Post-supplementation, cows traveled further in the afternoon and morning and reduced grazing in the afternoon and at night (P < 0.05). Cows rested less in the morning pre-supplementation and in the afternoon post-supplementation (P < 0.03). Results indicate that three times weekly supplementation alters cow activity, though differences are mostly associated with the time surrounding when supplement is delivered.
PSV-12 Impact of grain processing and undegradable fiber on chewing behavior and feed sorting of finishing beef cattle
Authors: Ran Tao , Saleem A M , Beauchemin Karen , Penner G , Yang Wenzhu
Published: November 2020

The objective 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 chewing behavior (3 days, video recording) and feed sorting of finishing beef cattle. Six ruminally cannulated beef heifers (BW=715 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 TMR consisting of 10% barley silage (low uNDF) or 5% silage and 5% chopped straw (high uNDF), 87% dry-rolled barley grain, and 3% vitamin and mineral supplement. An interaction of PI with uNDF occurred (P < 0.01) for DM intake, ruminating and total chewing time. Intake of DM (kg/d) did not differ (12.1) between low and high uNDF diets with 65 or 75% PI, whereas it was greater (P < 0.05) for high (12.7) than low (12.1) uNDF diets with 85% PI. Eating time (min/d) was not affected by PI but eating time (106 vs. 95 min/d; P = 0.03) and eating index (9.3 vs. 8.0 min/kg DM; P = 0.02) were greater with high than low uNDF diets. Ruminating (305 vs. 258 min/d) and total chewing (406 vs. 357 min/d) times were greater (P < 0.05) with high than low uNDF at 65% PI, with no effect of uNDF at 75 and 85% PI. Moreover, no interaction between PI and uNDF and no effect of PI on sorting index was observed. Heifers fed high vs. low uNDF diets sorted (P < 0.01) against long particles (>19 mm). These results suggest that when cattle are fed finely processed barley, increasing uNDF concentration of the diet may promote chewing and benefit rumen health.
PSV-19 Preliminary exploration of caretaker and manager perspectives of on-farm euthanasia on swine operations
Authors: Simpson Hailey M , Edwards-Callaway Lily , Cramer Catie , Roman-Muniz I Noa , Calaba Elaine N , Stallones Lorann , Thompson Sofia , Ennis Sari , Kim Elizabeth , Pairis-Garcia Monique
Published: November 2020

Employees on swine operations have the critical role of ensuring animal health and well-being, which sometimes involves performing euthanasia. This study aimed to understand caretaker and manager involvement and perspectives on performing euthanasia on swine farms. Individuals were recruited through online (newsletters and emails to companies) and in-person (e.g. Pig Welfare Symposium, MN) methods in the fall of 2019. The survey consisted of 61 questions on topics related to training, methods of euthanasia, perspectives about euthanasia and knowledge of available mental health resources. Thirty-nine individuals participated in the survey (18 caretakers, 21 managers). Half of respondents (50%, n = 20) indicated that they were involved with making euthanasia decisions. The vast majority of respondents “believe that euthanasia is a humane way to end animal suffering” (95%; n = 36) and that “the euthanasia process on-farm is necessary” (97%; n = 34). A quarter of individuals (25%, n = 9) “feel emotionally upset after euthanizing a pig” and 84% (n = 26) indicated it is “easier to euthanize a pig the more they do it.” Additionally, 92% (n = 35) of respondents agreed that they have “enough experience and knowledge to know when to euthanize a pig.” Most of survey respondents (n = 34) agreed that they “feel as though I can communicate with my supervisors if I feel uncomfortable performing euthanasia” and that their “supervisors aim to promote a safe and encouraging work environment” (n = 38). Despite this, a small number of respondents (n = 6) did not feel “as though my supervisors acknowledge concerns that they may have” and did not feel that their supervisors take “an interest in my professional development and/or job performance.” Overall, data suggest that caretakers and managers understand the importance of euthanasia regarding animal well-being and generally feel they can communicate their concerns.
PSV-9 Exploring the use of sodium nitrite as a humane method for mass euthanasia of poultry
Authors: Lay Donald C , Enneking Stacey A
Published: November 2020

When disease outbreaks that threaten the poultry industry require mass euthanasia, it is imperative to ensure humane methods of euthanasia. Current methods are not practical on a large scale. Sodium nitrite ingested at high concentrations prevents the transport of oxygen in the blood and thereby renders the animal unconscious and then dead. Laying hens (n=8 per treatment, 18 wk of age) were subjected to 1 of 4 treatments: A, 75 mg/kg BW; B, 150 mg/kg BW; C, 300 mg/kg BW; or D, 600 mg/kg BW of sodium nitrite in feed. Behavior was recorded via direct observation and video recording. The D hens spent more time lying/sitting, less time standing, and more time inactive alert then C hens (P < 0.03), but not A and B hens. However, A, B, and C hens spent more time standing compared to lying/sitting (P < 0.01), whereas D hens spent equal time in both behaviors. The D hens spent less time eating and drinking, and had fewer drinking events compared to the A, B, and C hens (P < 0.04). Only 1 hen, a D hen, died. She stopped eating 1 min after eating, was lying on her side by 2 min, had total loss of posture and feather erection at 2.5 min, and tremors and wing flapping 5 s later, with subsequent (1 s later) lack of palpebral reflex. The greatest dose of sodium nitrite caused hens to be lethargic and eat and drink less. This could be due to sedation and aversion to the taste of sodium nitrite. The hen that died did so in an apparently humane manner; however, with only 1 hen dying it is not possible to say if sodium nitrite is a humane method of euthanasia and future research should investigate feeding in an encapsulated form.
PSV-1 A prospective longitudinal study of the incidence and risk factors associated with footrot in feedlot lambs in Southern Alberta
Authors: Schwartzkopf-Genswein Karen S , Nordi Wiolene M , Gellatly Désirée , Meléndez Daniela M , Schwinghamer Timothy D , Marti Sonia , Anklam Kelly S , Dopfer Dorte , Van Donkersgoed Joyce
Published: November 2020

Lameness in sheep caused by footrot (FR) is a significant health, welfare, and economic concern worldwide. To date, no studies have documented the incidence of FR or associated risk factors in feedlot lambs in Alberta. The objectives of this study were to determine 1) FR incidence and 2) animal, managerial and environmental risk factors associated with FR in one Southern Alberta, lamb feedlot. Assessments were conducted biweekly (average of 10 pens per visit) by 2 experienced observers. A total of 73,150 lambs were assessed between October 2017 and March 2019. All lame lambs were scored according to a 3-point mobility scale (1 = mild, 2 = moderate, and 3 = severe lameness) and physically examined to diagnose the cause of lameness. Risk factors associated with FR were documented and included gender, days on feed (DOF), diet composition, and season. Multivariable regression models (SAS PROC GLIMMIX) were used to determine significant risk factors. A total of 473 lambs were identified as lame, 107 of which were diagnosed with FR (incidence of 22.6%). Footrot affected lambs had greater mobility scores (≥ 2; P < 0.0001) than all other lame diagnoses. Footrot was 4.40 and 0.10 times more likely (P < 0.0001) in female and wether than ram lambs, and 0.60 and 0.23 times more likely (P < 0.0001) in fall and summer than winter and spring seasons. The odds of being diagnosed with FR increased for each additional DOF and each unit increase of barley in the diet (P = 0.0268), while the odds decreased (P = 0.0016) for each additional unit of supplement in the diet. Based on our findings, footrot is an issue to lambs in Alberta, and further studies are still necessary to understand the risk factors associated with potential strategy for mitigating FR in feedlot lambs.
PSV-40 Effects of regrouping and administrations of meloxicam and chromium on plasma cortisol concentrations and behaviors in dairy calves
Authors: Jung Da Jin Sol , Lee Jae Sung , Kim Do Hyun , Seok-Hyeon Beak , Hong Soo Jong , Jeong In Hyuk , Yoo Seon Pil , Lee Jin Oh , Cho In Gu , Fassah Dilla Mareistia , Kim Hyun Jin , Baik Myunggi
Published: November 2020

This study investigated effects of regrouping and oral meloxicam and chromium administration on growth performance, blood cortisol concentrations, and behaviors in dairy calves. Fifty Holstein calves (average age 196 ± 24.7 days, average body weight 198kg ± 32.7 kg) were equally divided into five groups: no regrouping with lactose monohydrate administration (NL), regrouping with lactose monohydrate administration (GL), regrouping with Cr administration (GC), regrouping with meloxicam administration (GM), and regrouping with both meloxicam and Cr administration (GMC). Blood was collected before regrouping and at 3h, 9h, 24h, 1w, and 2w after regrouping. Behaviors have been monitored from d1 to d7. Regrouping did not affect average daily gain (ADG), and the administrations of both meloxicam and chromium increased (P < 0.02) ADG compared to NL group during 2 weeks. Regrouping increased (P < 0.05) plasma cortisol concentrations in GL group, and both meloxicam and chromium and its combination treatments decreased cortisol concentrations compared to GL group at 24h, but not at other times. Regrouping increased (P < 0.05) fight, duration of eating time, head bunt, drinking time, and standing time behaviors in GL group at d1, d2, d2, d3, and d4 respectively. Regrouping also increased (P < 0.05) displacement at eating place in GL group from d3 to d6, but this effect was not significant (P < 0.05) at d7. In conclusion, regrouping caused elevation of plasma cortisol concentrations and abnormal behaviors. Meloxicam, chromium, and/or its combined administrations improved growth performance and reduced circulating cortisol concentrations in regrouped dairy calves, suggesting a feasible strategy to alleviate regrouping stress.
PSIII-12 Genetic analysis of heat tolerance in Holsteins using test-day production records and satellite-based meteorological data
Authors: Rockett Paige L , Schenkel Flavio , Baes Christine F , Miglior Filippo , Tulpan Dan
Published: November 2020

Heat stress in dairy cattle is an existing issue in temperate regions that can cause reduced milk production, impaired fertility, and mortality. Genetic selection for heat tolerance using test-day production records and weather station data is a potential mitigation strategy. However, weather stations can have temporal data gaps and a low spatial resolution, which reduces the number of herds that can be incorporated into an analysis. The objectives for this study include: (1) compare satellite-based meteorological data from the NASA POWER database to weather station records in Ontario and Quebec, (2) evaluate the effects of heat stress on Canadian Holsteins, and (3) assess breeding value estimates for heat tolerance in the same population. Daily estimates of ambient temperature, dewpoint temperature, relative humidity, and wind speed from 481 weather stations in Ontario and Quebec were compared to the parameters estimated by the NASA POWER project using an ordinary least squares regression. The coordinates of herds in Ontario and Quebec were estimated using their addresses and Google Maps Geocoding. The best weather data for each herd location will be incorporated into two random regression animal models to analyze three test-day production traits: milk, fat, and protein yield. The first model will be used to estimate general and specific additive genetic merits over the thermal gradient. The second model will estimate the traditional additive genetic merit. In conclusion, this study explores the use of satellite estimated meteorological parameters in addition to or alternatively to weather station data in heat tolerance studies, quantifies the sensitivity of Canadian dairy cattle to heat stress, and evaluates if genetic selection for increased heat tolerance in Canadian dairy herds is possible.
PSIII-7 Determining the requirement of puberty induction to the reproductive performance of Bos indicus-influenced heifers submitted to AI
Authors: Martins Thiago , da Silva Felipe A C C , Sponchiado Mariana , Soriano Gabriela A , Pinto Leonardo M F , Rocha Cecilia C , Podversich Federico , Tarnosky Federico , Lenin Yasser , Driver Joseph D , David Thomas , Rae Owen , Gonella-Diaza Angela M , DiLorenzo Nicolas , Binelli Mario
Published: November 2020

Induction of puberty by treating heifers with progesterone (P4) inserts may favor pregnancy/AI (P/AI) to a subsequent estrus synchronization program. However, it remains to be elucidated whether induction is required when the synchronization program contains P4 supplementation. To address this question, yearling, Brahman-influenced heifers (mostly 3/8 Brahman) classified as pubertal (PUB; n = 363) or prepubertal (PRE; n = 214) based on the presence of a CL, were assigned to receive no P4 supplementation (NoCIDR) or a CIDR for 10 days, starting on D-23. On D-13, all heifers received a dose of prostaglandin analogue and CIDRs were removed. On D-9, all heifers were enrolled in a 6-day CIDR & TAI protocol. Heifers were serviced based on heat between D-2 and D0 or were TAI on D0. Reproductive tract scores (RTS, 1 to 5 scale) were evaluated on D-23 and D-3. Induction increased the proportion of PRE heifers bearing a CL on D-3 (PRE|CIDR: 60.3% vs. PRE|NoCIDR: 42.7%). Among heifers with CL on D-3, P/AI of PRE heifers (42.5%) was similar to that PUB (47.7%). Conversely, for heifers without CL on D-3, P/AI of PRE (14.7%) was lower than PUB (37.3%). RTS increased between D-23 and D-3 from 2.3 to 4.0 (CIDR) and 2.3 to 3.6 (NoCIDR). For every 1-point increase in RTS, P/AI was 6–9% greater. Despite hastened puberty, P/AI of PRE heifers were less (PRE|NoCIDR: 29.2% and PRE|CIDR: 30.4%) than that of PUB (PUB|NoCIDR: 50.7% and PUB|CIDR: 42.2%). Less PRE (42.5%) than PUB animals (69.7%) were AI at estrus, and heifers showing estrus had a higher P/AI (52.8% vs. 18.7%). In conclusion, induction is not required when the subsequent synchronization protocol for AI contains progesterone. Induction hastened puberty attainment but failed to improve estrus response and fertility to the synchronization protocol.
PSIII-9 Differences in Conception Rate across Breeding Protocols in Dairy Cattle
Authors: Lynch Colin , Oliveira Gerson , Schenkel Flavio , Baes Christine F
Published: November 2020

Fertility performance success on dairy farms starts with estrus detection, especially for artificial insemination programs. Detection of estrus has become more difficult over the years due to a decrease in estrus expression in high-producing dairy cows, with up to 60% of ovulations accompanied by no standing mount. In order to alleviate the pressure of estrus detection, management technologies have been developed, including automated detectors of standing heat, activity monitors, automated in-line systems measuring milk progesterone, and hormonal synchronization protocols (FTAI). To gauge the effectiveness of such technologies, records from 647,940 cows across 1,166 herds over the past ten years (total of 3,466,593 breeding records) from herd management software were analyzed. Across all herds, there were 5,804 breeding protocols, of which 2,046 were unique. Due to the wide range of breeding protocols, records were classified as HORMONES, FTAI, HEAT DETECTION and OTHERS. Breeding protocols were classified as HORMONES if they included any hormone treatment. FTAI was a stricter subset of HORMONES, which included only clear FTAI protocols. Protocols were classified as HEAT DETECTION if they were a clear heat detection protocol, with all remaining protocols classified as OTHERS. These classifications resulted in 3,258 protocols classified as HORMONES, of which 2,002 were FTAI, while a further 1,840 were classified as HEAT DETECTION. The remaining 706 codes were classified as OTHER and removed from this study. These classifications provided an initial overview of breeding methods conception rates, with results indicating significant differences (P < 0.05) between all protocol groups, as outlined in Table 1. Further analysis will be completed to indicate conception rates from the most commonly used breeding protocols across each of the protocol groups within the 1,192 herds. This work will help provide a better understanding of the expected conception rate of various management technologies on commercial farms.
PSIII-1 Activity of nucleolar organizers depending on genotype
Authors: Klenovitskiy Pavel , Iolchiev Baylar S , Vetokh Anastasia N
Published: November 2020

The level of protein proliferation and biosynthesis in various physiological and pathological processes depends on the functional activity in the nucleolar apparatus of cell. The activity degree of the nucleolar organizers varies depending on the level of functional load on the cells. It is associated with the exogenous and endogenous factors and the manifestation of polygenic traits, such as the synthesis intensity of subunits rRNA (18S and 28S) that enter the ribosome. The aim of this research was to study the relationship between the activity of nucleolar organizers and the animal genotype. The objects of study were goats with different genotypes divided by 3 groups of goats hybrids were used: group_I was 5 individuals of Karachay × F1(C.sibirica×C.hircus); group_II - 4 individuals of Boer × F1; group_III - 3 individuals of F2(C.sibirica×C.hircus) × F1. The material for the study was venous blood. Blood smears were fixed with Lillie’s solution and were stained using the Havel and Blake technique. Microscopic studies were performed using a Nikon Eclipse Ni equipped with Nikon DS-Qi2 camera (4908×3264). For statistical analysis of the obtained data, the SPSSv.23 was used. We used the average optical density AgNOR (DNOR) as an indicator reflecting the total amount of Ag bound to the argyrophilic proteins of the nucleolar organizer, It was found that in goats of the second group this indicator was 158.58±10.18, which was significantly inferior in terms of AgNOR to animals in group_I (211.10±3.62) and in group_III (206.77±4.43). No significant differences between the goats of groups I and III were found. Thus, the AgNOR criterion depends on the goat genotype to a certain extent and is of interest for assessing the activity of the nucleolar organizers in goats. Supported by RFBR project №20-016-00116А and the Ministry of Science and Higher Education of Russia (№АААА-А18-118021590132-9).
PSIII-14 Genetic Diversity and Haplogroup Distribution of Asian Chicken Populations using Mitochondrial DNA sequence
Authors: Roh Hee-Jong , Cho Chang-Yeon , Kim Seung-Chang , Kim Dong-Kyo , Lee Jinwook , Kim Kwan-Woo , Lee Jaeyeong
Published: November 2020

Estimating the genetic diversity and origins is critical for the identification and conservation of valuable animal genetic resources. Mitochondrial DNA (mtDNA) polymorphisms have played a significant role in tracing the origin of specific breeds and the genetic diversity of domestic chicken and other livestock species due to their maternal inheritance, greater rate of substitution relative to unclear genes, and much lower rate of recombination. In this study, we analyzed the mtDNA D-loop region of 457 genomic DNA samples from 28 Asian chicken populations (Korea: 6, Laos: 4, Bangladesh: 3, Cambodia: 3, Indonesia: 3, Vietnam: 2, Kyrgyzstan: 1, Mongolia: 1, Nepal: 1, Sri Lanka: 1 and White Leghorn, Cornish, Rhode Island Red) from ten Asian countries to clarify their genetic diversity and phylogenetic relationships. In addition, 49 reference data (43: Oka et al data, 6: red jungle fowl) were used. We found 82 haplotypes defined by 81 variable sites. Overall haplotype and nucleotide diversity were 0.978±0.01 and 0.0018, respectively. Phylogenetic analyses revealed seven haplogroups (Type A-G). The most of Asian chickens were included in haplogroup A(44.9%), B(22.8%), C(19.3%). Haplogroup F did not belong to any Asian chicken populations (include only 2 reference data). Mongolia chickens were only clustered in haplogroup A and Indonesian chickens did only haplogroup C. About half of Kyrgyzstani chicken populations (43.4%) were clustered in haplogroup E. Vietnamese chicken populations belong to all haplogroup except F. In case of red jungle fowl, G.g.gallus and G.g.bankiva were clustered in haplogroup C. G.g.spadiceus was clusterd in haplogroup E or A. As a result, it was possible to identify the mtDNA diversity and origin of Asian chicken populations. In future studies, it is necessary to understand the origin of each haplogroup by adding more reference data and red jungle fowl sequence data.
PSIII-4 Asthenozoospermia in geomagnetic activity
Authors: Iolchiev Baylar S , Klenovitskiy Pavel , Iolchiev Rustam , Tadzhieva Anna
Published: November 2020

Reproductive qualities depend on a complex of biotic and abiotic factors. The ejaculate of bulls is characterized by morphological heterogeneity. Pathologies in the structure of each segment or several segments simultaneously may occur under the influence of biotic and abiotic factors. The aim of the study was to study the influence of geomagnetic storm on the occurrence of asthenozoospermia in freshly collected bull sperm. Monitoring of geomagnetic activity in the region of the study was carried out according to the Institute of terrestrial magnetism, ionosphere and radio wave propagation. N. V. Pushkova of the Russian Academy of Sciences.Sperm quality assessment was carried out using the software “Argus-CASA.” A Mackler’s camera was used to assess mobility and concentration. Statistical analysis of the results of the study was carried out using IBM SPSS Statistics 23.0. The slides were visualized using a Nikon Eclipse Ni-U microscope and a Nikon DS-Qi2 camera. A geomagnetic storm with a K-index ≥ 5.0 was recorded four times in the monitoring region during the study period. During the period when the geomagnetic situation was normal (K = 1,0 1.0), the content of sperm with progressive movement (PR – progressive-mobile) was 87±2.3%, it varied from 82% to 91%. The content of sperm with flagella pathology was 5.74±0.12%. With an increase in geomagnetic activity to K-index ≥ 5.0, the content of sperm with non – progressive movement (NP-non-progressive-motile) increased to 14.2% and motionless sperm to 27.8% (IM-motionless). The content of motionless sperm at some individuals was 38%. Cells with multiple morphological anomalies accounted for 34% at some bulls. Asthenozoospermia in the period of geomagnetic activity is accompanied by an increase in the number of cells with flagella pathology, including multiple morphological anomalies. The study was supported by RFBR, project №. 18-016-00128 А
PSIII-13 Genetic assessment of isolated reindeer (Rangifer Tarandus) population from Tuva, Russia
Authors: Dotsev Arsen V , Kharzinova Veronika R , Shimit Larisa D , Sergeeva Olga K , Goncharov Vasily V , Layshev Kasim A , Romanenko Tatiana M , Fedorov Valeriy I , Senchik Alexander V , Okhlopkov Innokentiy M , Medvedev Dmitry G , Reyer Henry , Wimmers Klaus , Brem Gottfried , Zinovieva Natalia A
Published: November 2020

Reindeer herding is traditional in Tuva, Russia. This region is located in the southern part of the country, on the border with Mongolia and isolated from the other reindeer herding areas of Russia. During the last three decades, the census population size of Tuva reindeer has decreased drastically, from 15,000 to 1,500 heads. The aim of our study was to assess genetic characteristics of Tuva population of reindeer. Samples of Tuva reindeer (n = 12) were genotyped using Illumina BovineHD BeadChip. To perform the comparison with other ecotypes of domestic reindeer we added samples of all the breeds, which are officially recognized in Russia: the Chukotka (n = 12), the Nenets (n = 31), the Even (n = 12) and the Evenk from Yakutia (n = 12) and Krasnoyarsk region (n = 19). Reindeer from Mongolia (n = 11) as well as the wild reindeer from Yakutian and Taimyr tundra (n = 20), and Baikal and Amur taiga (n = 9) were added to our dataset. After quality control, 7,202 SNPs were selected for subsequent analyses. On PCA plot Tuva reindeer were clustered together with Mongolian reindeer. The FST genetic distance was lowest between these two groups – 0.039 comparing to FST values between Tuva and other groups of domestic reindeer, which ranged from 0.092 (the Evenk from Yakutia) to 0.137 (the Chukotka) and were highest between Tuva and wild reindeer populations (0.146). Allelic richness was lowest in Mongolia (1.288±0.004) and Tuva reindeer (1.301±0.004). In other breeds this parameter ranged from 1.323±0.004 (the Chukotka) to 1.356±0.004 (the Evenk from Yakutia). In our study, it was shown that reindeer from Tuva do not belong to any official breed of Russia and genetically are very close to Mongolian ecotype. Our results should be considered at developing programs for restoration of Tuva reindeer. This work was supported by Russian Science Foundation grant 16-16-10068-P
PSXII-32 Testing of low-density SNP panel in wild and domestic reindeer populations (Rangifer tarandus)
Authors: Deniskova Tatiana Evgenievna , Kharzinova Veronika R , Dotsev Arsen V , Solovieva Anastasiya D , Layshev Kasim A , Yuzhakov Alexander A , Romanenko Tatiana M , Fedorov Valeriy I , Reyer Henry , Wimmers Klaus , Brem Gottfried , Zinovieva Natalia A
Published: November 2020

A territory of northern Russia covering more than 4,194 square kilometers is the world’s largest dwelling and breeding area of wild and domestic reindeer. Unlocking its complete genome sequences should have promoted design and development of species-specific genotyping arrays, but this process is still in progress. However, evaluation of state of gene pool of reindeer populations cannot be paused to prevent dramatic losses in genetic diversity. Thus, we aimed to select SNPs to create low-density panel to perform genetic assessments without losing biological content. Our study was based on SNP genotypes of wild reindeer (n = 83), and domestic reindeer from the Nenets District (Nenets breed, n = 100), Murmansk Region (Nenets breed, n = 19), Republic of Sakha (Yakutia) (Evenk breed, n = 19) obtained using Illumina BovineHD BeadChip. The data processing performed in PLINK 1.9 revealed 4456 polymorphic SNPs. Using Delta method implemented in the TRES software, 368 informative SNPs were selected from the whole set of polymorphic SNPs for further analysis. To compare the resolution power of low-density SNP panel with a whole set of polymorphic SNPs, we estimated minor allele frequencies (MAF) and performed PCA analysis and Admixture clustering. In case of low-density panel, we observed obvious bias to higher MAF (≥ 0.30), and 4% of SNPs had MAF around 0,1. Among the whole set of polymorphic SNPs, 70% SNPs had MAF ≤ 0.2. PCA obtained with low-density panel and the whole SNP set provided similar pattern of genetic differentiation between studied groups. Wild animals were clearly separated by PC1 from their domestic relatives. Besides Evenk reindeer was distant from two Nenets groups. The Admixture clustering demonstrated the identical patterns for both SNPs sets. The next step of our study will be developing custom DNA array based on 368 selected informative SNPs. The research was funded by RSF № 16-16-10068-P.
PSXII-37 Validation of single-step GBLUP genomic predictions from threshold models using the linear regression method: an application in chicken mortality
Authors: Bermann Matias , Legarra Andres , Hollifield Mary Kate , Masuda Yutaka , Lourenco Daniela , Misztal Ignacy
Published: November 2020

The objective of this study was to determine whether the linear regression (LR) method could be used to validate genomic threshold models used for analysis of categorical data. Statistics for the LR method were computed from estimated breeding values (EBVs) using the whole and truncated datasets. The method was tested using simulated and real chicken datasets. The simulated dataset included ten generations of 4,500 birds each; genotypes were available for the last three generations. Each animal was assigned a continuous trait, which was converted to a binary score assuming an incidence of failure of 7%. The real dataset included the survival status of 186,596 broilers (mortality rate equal to 7.2%) and genotypes of 18,047 birds. Both datasets were analyzed using Best Linear Unbiased Predictor (BLUP) or single-step GBLUP (ssGBLUP). The whole dataset included all phenotypes available, whereas in the partial dataset, phenotypes of the most recent generation were removed. In the simulated dataset, the accuracies based on the LR formulas were 0.45 for BLUP and 0.76 for ssGBLUP, whereas the correlations between true breeding values and EBVs were 0.37 and 0.65, respectively. The gain in accuracy by adding genomic information was overestimated by 0.09 when using the LR method compared to the true increase in accuracy. However, when the estimated ratio between the additive variance computed based on pedigree only and on pedigree and genomic information was considered, the difference between true and estimated gain was less than 0.02. Accuracies of BLUP and ssGBLUP with the real dataset were 0.41 and 0.47, respectively. Smaller improvements in accuracy when using ssGBLUP with the real dataset were due to population structure and lower heritability. The LR method is a useful tool for estimating improvements in accuracy of EBVs due to the inclusion of genomic information when traditional validation methods are not applicable.