Sire Groups Research Articles

PSIII-6 Multi-sire artificial insemination of beef heifers in the Nebraska Sandhills effect on pregnancy rate compared with single-sire insemination

Abstract The objective of this study was to compare pregnancy outcomes resulting from artificial insemination (AI) with multi-sire semen (MS) compared with single-sire semen (SS) in beef heifers. Another study observed pregnancy and paternity outcomes to sexed MS without a control treatment. In the first study, unrelated ABS Global Angus bulls (n = 3) were selected for AI to 441 (Yr 1) and 391 (Yr 2) Angus crossbred heifers. Heifers were synchronized with the melengestrol acetate – prostaglandin F2α timed-AI protocol. Conventional semen, from each bull, were labeled A, B, or C. Remaining semen was pooled in equal amounts to form conventional MS straws. Heifers were AI using alternating treatment of MS or SS: A, B, or C with one-half of inseminated heifers receiving either MS or SS. The GLIMMIX procedure in SAS 9.4 analyzed responses to treatments using the BIN distribution option and reported as LSMEANS. Contrasts and estimates analyzed responses between treatments. Ultrasound determined SS pregnancy rate averaged 60% (SS-A = 64%, SS-B = 58%, SS-C = 58%) and MS average 62% (P = 0.63). Paternity was determined in 57 MS calves and confirmed in 49 SS calves. In Yr 1, Bull A sired 7%, bull B sired 56%, and bull C sired 37%. Although bull A was much less successful than bull B or C, the values are not significantly different due to the small sample size (P = 0.11 and P = 0.24, respectively). Few conclusions can be made from the ongoing study, but it is hypothesized MS may improve consistency of pregnancy rate by equilibrating semen quality in herds subjected to timed AI. In the observational study, multiple 5-way cross bulls born from the ranch herd were selected for AI of 951 ± 41 heifers for 3 yr. Heifers were synchronized using the previously mentioned protocol with split-time AI. Unequal amounts of semen were collected, pooled, and sexed to favor heifer progeny at an expected ratio of 9:1. Semen from 2 to 4 random bulls were pooled making 3 to 4 MS groups each year. Heifers exhibiting estrus were administered sexed MS, but there was no control treatment. The observed ultrasound determined average pregnancy rate of heifers administered sexed MS was 65% (Yr 1), 75% (Yr 2), and 72% (Yr 3). Previous literature suggests average pregnancy rate to AI with sexed SS is 53%. Paternity testing in Yr 2 found semen contribution mirrored paternity ratios within some groups but the sire group with 2 bulls found one sired 15% and the other sired 85%. This study exemplified a viable method for AI that requires further research. Further research into semen quality of a single sire, and pooled semen could lead to optimization of fertilization among individuals within a herd.

228 Evaluation of sire vs. dam influences on age at first parturition in Brahman heifers

Abstract The objective of this study was to determine if sire or dam had a stronger impact on age at first parturition of Brahman heifers (n = 833) born between 2000-2021. Typically, in Bos taurus heifers, puberty occurs between 10 to 12 mo of age leading to parturition of the first calf occurring around 24 mo of age. However, in Bos indicus cattle, puberty is achieved between 15 to 17 mo of age leading to a first calf around 36 mo of age. The ability of heifers to achieve pubertal status earlier plays a vital role in reproductive success. For selection purposes, knowing if early pubertal attainment is influenced more by the sire or dam is important for herd management. For this study, to minimize any epigenetic and environmental changes, all heifers originated and were developed at the Texas A&M AgriLife Research Center at Overton. Sire groups (SG) and dam groups (DG) were established based on the number of offspring used in the study. Sire groups were comprised of SG-1 (1+ calves sired; n = 58 sires), SG-2 (5+ calves sired; n = 44 sires), SG-3 (10+ calves sired; n = 31 sires), SG-4 (15+ calves sired; n = 23 sires), SG-5 (20+ calves sired; n = 17 sires), and SG-6 (25+ calves sired; n = 12 sires). Dam groups consisted of DG-1 (1+ calves; n = 489 dams), DG-2 (2+ calves; n = 215 dams), DG-3 (3+ calves; n = 81 dams), DG-4 (4+ calves; n = 38 dams), and DG-5 (5+ calves; n = 9 dams). Statistical analysis (PROC GLM; SAS 9.4) included the fixed effect of sire group (dam group) and all dams (sires) utilized in that grouping. Significance for age at first calving was considered at P < 0.05. Mean separation for age was performed using LSmeans. Sire significantly impacted age at first calving in SG-1 (P = 0.0173) vs dam effect (P = 0.3993; n = 489 dams), SG-2 (P = 0.0159) vs dam effect (P = 0.5476; n = 481 dams), SG-3 (P = 0.0023) vs dam effect (P = 0.2532; n = 439 dams), SG-4 (P = 0.0022) vs dam effect (P = 0.3997; n = 400 dams), SG-5 (P = 0.0002) vs dam effect (P = 0.0602; n = 361 dams), and SG-6 (P = 0.0005) vs dam effect (P = 0.1058; n = 305 dams). The dam impact on age at first calving was never significant in the dam groupings but sires did impact age at first calving in two groups: DG-1 (P = 0.3993) vs sire effect (P = 0.0173; n = 58 sires), DG-2 (P = 0.4823) vs sire effect (P = 0.0173; n = 56 sires), DG-3 (P = 0.3011) vs sire effect (P = 0.3420; n = 49 sires), DG-4 (P = 0.3911) vs sire effect (P = 0.6278; n = 40 sires), and DG-5 (P = 0.3042) vs sire effect (P = 0.9159; n = 23 sires). In summary, evaluation of sire and dam influences on age at first parturition for female offspring demonstrates that the ability to calve at an earlier age is influenced by the sire but not the dam. Further studies into the mechanisms for the transmission of this trait are warranted.

Evaluation of the effect of calcium concentration in the wool of sires on se- men quality characteristics

Chemical elements, as structural components of the body, influence physiological processes and functions of the organism, growth, productive and reproductive traits, resistance and others. In this regard, the present study aimed to evaluate the effect of different calcium concentrations in the wool of Holstein sires on the semen quality characteristics. The studies were conducted in conditions of Leningrad and Vologda regions on Holstein sires, 3–5 years old (n = 40). Calcium concentration in wool was determined by atomic emission and mass spectrometry (AES–ICP and MS–ICP). According to the results of this analysis and comparison with previously developed reference intervals, we formed four groups of sires: I – level of Ca concentration less than 25th percentile, II and IV – within 25–75th percentile (physiological norm: 1597–2926 mg/kg) and III – more than 75th percentile. As a result of this distribution, the Ca concentration in the wool of animals of Group II was higher by 75.9 % compared to Group I; in turn, individuals of Group IV exceeded Group III – by 27.9 %. According to the results of semen quality characteristics evaluation, it was found that in the group of sires with Ca level within the previously developed reference intervals, the concentration of spermatozoa was higher by 15.3 % and their activity – by 0.17 points in fresh semen in comparison with the group with its reduced level (below the 25th percentile). High Ca content (above the 75th percentile) in wool contributed to a 9.0 % decrease in the concentration of spermatozoa compared to its average values. Thus, the calcium concentration, assessed by its level in the fur, affects the concentration and activity of sperm. It is necessary to evaluate it to improve the quality characteristics of sperm systematically.

Alternative Traits for Genetic Evaluation of Mastitis Based on Lifetime Merit.

Genetic selection has achieved little progress in reducing mastitis incidence. Mastitis traits are problematic due to the lack of sensitivity of the data and reliance on clinical diagnosis, often missing subclinical cases, and/or on monthly somatic cell count (SCC) measurements. The current measure for mastitis is the lactation average of the somatic cells score (LSCS). We studied two datasets: (1) 148 heifers divided into non-intramammary infected, sub-clinically infected and clinical mastitis groups; (2) data from 89,601 heifers from Israeli Holsteins through the same period divided into "udder healthy" (UH) and "non-healthy" (UNH) by a threshold of SCC 120,000 cells/mL in all nine monthly milk recordings. In study 1, non-infected heifers had significantly (p < 0.05) more partum, production days and overall lifetime milk production compared to clinical and sub-clinically infected. In study 2, UH heifers (20.3%) had significantly higher (p < 0.01) lifetime milk, production days, and lactations. Subdividing datasets by sires, the same analyses detected differences in percentages of UH daughters between the sire groups. Lifetime milk production correlated (r = +0.83, p < 0.001) with udder health status. SCC threshold of less than 120,000 cells/mL during all first lactation measurements indicated healthy udder, providing a valuable insight that this dichotomous trait is advantageous for calculating lifetime net-merit index (NM$) over LSCS.

PSXII-17 The Influence of Sire on Gestation Length and Calf Performance

Abstract The objective of this study was to determine sire effects on calf gestation length (GL), birthweight (BW), weaning weight (WW), and intermediate feedlot weight (IFW) in beef cattle. In this study, five sires (four Braunvieh and one Simmental) were used to artificially inseminate (AI) commercial cows in Northwest Arkansas resulting in crossbred calves (n = 76) being born in the Fall 2021. Dates for AI were recorded at time of service in December 2020. At parturition, the calf date of birth (DOB) and a hoof-tape BW were recorded. Calf performance data collection included WW and IFW. Calves were categorized into sire groups (n = 5) and GL groups (n = 3). Sire groups included Braunvieh sire A through D and Simmental sire E. Gestation length groups included Short GL of 26 to 278 d (SGL), Average GL of 279 to -290 d (AGL) and Long GL of 291 to 305 d (LGL). Preliminary data were analyzed using Excel. Through ANOVA, GL groups were determined to be statistically significant (P &amp;lt; 0.05) with means of 276.3 ± 1.8 d for SGL (n = 24), 283.2 ± 2.5 d for AGL (n = 24), and 300.5 ± 10.3 d for LGL (n = 16). When comparing sire groups, no significant differences were found for GL (P = 0.39), BW (P = 0.71), WW (P = 0.64) or IFW (P = 0.84) between sires. Descriptive statistics for GL, BW, WW and IFW were 282.0 ± 7.2 d, 36.6 ± 6.4 kg, 262.3 ± 17.4 kg and 544.2 ± 43.0 kg for Sire A, 281.7 ± 9.3 d, 36.7 ± 15.8 kg, 247.8 ± 25.8 kg and 532.0 ± 26.4 kg for Sire B, 285.6±9.8d, 35.2±14.1kg, 259.8±26.1kg and 528.4±34.4kg for Sire C, 284.5±2.1 d, 40.4 ± 0.0 kg, 249.5 ± 32.1 kg and 532.1 ± 0.0kg for Sire D and 288.5 ± 14.4d, 35.4 ± 10.3 kg, 261.7 ± 34.2 kg and 542.9 ± 36.8 kg for Sire E. Gestation length was found to have no significant differences between bull and heifer calves (P = 0.37), with bull calves averaging a greater numerical value of 2.6 d when compared with heifer calves. A significant difference was found between bull and heifer BW (P &amp;lt; 0.05). Means BW for bull calves were 5.43 kg heavier than heifer calves. These data suggest that GL and BW trends follow previous publications when using GL as a breeding selection tool for commercial beef production.

140 Targhee Sire Benchmarking at the U.S. Sheep Experiment Station

Abstract The Targhee breed was developed at the U.S. Sheep Experiment Station (USSES) starting in 1926, and has become an established range breed used commercially in the Western U.S. Our objective was to benchmark the performance of industry-based (external) Targhee sires with those currently in use at USSES. Nineteen Targhee sires from 12 flocks were incorporated into the USSES breeding flock starting with the 2015 breeding season. Data were measured through 2022 for 3 production and 12 wool traits with a range of 180 to 1,967 records per trait. Externally sourced sires averaged 38.3 progeny (7 to 78), with 0 to 4 ram lambs (15 total) and 0 to 15 (106 total) ewe lambs retained per sire in the flock. They were ancestors of 984 grand-progeny. USSES sires averaged 25.0 progeny (5 to 52), with 0 to 1 ram lambs (2 total) and 0 to 8 (53 total) ewe lambs retained per sire. They had 275 grand-progeny. Pedigree data was used to compute the marginal genetic contributions for each sire to the current flock using ENDOG. External sires had a cumulative contribution of 31.9 percent (0.4 to 3.9) while the USSES sires contributed 1.4 percent (0.0 to 0.9). Using R, fixed effects examined were age of dam, lamb sex, lamb birth year, grazing group, and type of birth/rearing. Significant variation explained in a trait by main effects (P &amp;lt; 0.005), and their two-way interactions (P &amp;lt; 0.001), were included in the final linear mixed models fitted. Externally sourced and USSES sires were assigned to separate genetic groups to account for the anticipated differences in genetic base. Using WOMBAT, a univariate animal model was fitted to estimate variance components and predict estimated breeding values for each lamb trait. Selection of random effects was based on log-likelihood ratio tests. Final models fitted and estimated heritabilities are summarized in Table 1. Total litter weight at 120 days per ewe lambing (TW120) was evaluated using a repeated measures model with direct additive and permanent environmental random effects of the ewe. Genetic group solutions were not significantly different (P &amp;gt; 0.05) for any traits evaluated. Since both sire groups originated from the same population, this suggests significant selection divergence had not occurred between industry and USSES flocks. Incorporation of external Targhee sires increased the genetic diversity of the USSES flock. It also strengthened industry ties to the USSES flock, which will benefit the commercial genetic evaluation conducted by the National Sheep Improvement Program. USDA is an equal opportunity provider and employer.

Characteristics of the genealogical structure of the herd of Aberdeen-Angus breed by blood types and DNA marker CASTUOGC282G

Analysis of the research results showed that the antigen’s occurrence frequency by loci was distributed with high variability from 0 to 75%. At locus C, the concentration of R1 antigen was the highest in the groups of cows of Bismarck sires - 60% and Design - 75%. In the group of cows of the Bismarck bull, antigens W’ were not detected in the C locus and antigen V in the F-V locus, and antigens B’, 0’ in the B locus and H” in the S’ locus were not detected in the group of cows of the Design bull. Comparative characteristics of the main breeding traits of cows of two groups of locus B of the blood group did not reveal a significant difference in their productivity. At the same time, cows of the 2nd group with a live weight of 629.3±17.6 kg were superior to their peers of the 1st group by 7.4% (Р≤0.05), in terms of height in the sacrum (133.80±0.88 cm) - by 3.2% (Р≤0.01). The revealed difference in the indicators of breeding traits between groups of cows is associated with the genetic dominance of the sire Design bull and its prepotency. According to the results of genotyping of animals of two eco-groups according to the allelic composition of the CASTUOGC282G gene, the superiority of homozygous genotypes CC and GG relative to heterozygous CG in the Bismarck group by 0.12 and 0.24 units, in the Design group - by 0.25 and 0.17 units. The uterus of the Bismarck bull with the GG allelic set was significantly heavier than the females of the CC genotype - by 3.8% (P≤0.05), CC relative to CG - by 5.1 (P≤0.01) and GG close to CG - by 2.3% (P≤0.001). Similarly, female representatives of Design with genotypes GG had a significant advantage by 8.3% (P≤0.01) and CG by 10.7% (P≤0.001) compared with peers of the CC genotype. The cows of the sire group Design 1015 of three genotypes - GG, CC and CG were heavier than the cows of the Bismarck 5682 group by 11.6 (P≤0.001); 4.6 (P≤0.01) and 12.4% (P≤0.001). At the same time, the lowest indicator of the coefficient of variability was the height in the sacrum in both groups for all genotypes (3.66–2.19%), which indicates the genetic predisposition of animals to inherit this selection trait in offspring.

Productivity of cows depending on the type of mating and genotype of sires

At breeding enterprises, the number of sires of Holstein breed homozygous for the genotype of the ЕАВ-locus is increasing, and there is a tendency for inbreeding coefficients to increase in populations of this breed. The dairy productivity of fi rst-calf heifers obtained from heterozygous and homozygous sires, as well as the change in indicators per generation with intra-line mating and line crosses were studied. It was found that in terms of the total yield of milk fat and protein for 305 days of lactation in the line Wes Back Ideal 1013415, the fi rst-calf heifers obtained from intra-line mating and line crossing exceeded the cows their mothers by 21,4 kg, and in the whole group of fi rst-calf heifers of homozygous sires this indicator was 51,0 kg higher against the average of fi rst-calf heifers of heterozygous sires. At the same time, for the cow-mothers of these groups, the corresponding diff erence was negative: –31,6 and –64,7 kg. Similar data were revealed for another main line Refl ection Sovereign 198998. When mating heterozygous sires according to the variants of line crosses, the milk yield was 227 kg higher (p &lt; 0,05), but the mass fat fraction in milk decreased by 0,06 – 0,08 abs.% (p &lt; 0,01). However, the levels of manifestation of traits among fi rst-calf heifers in comparison with cow-mothers with intra-line mating increased by groups of homozygous sires in milk yield by 32,5 %, mass fat fraction by 17,6 % and mass protein fraction by 25,0 %. The correlation coefficients «mother – daughter» for milk yield, mass fat fraction and mass protein fraction were relatively higher in the group of homozygous sires, whose heritability coeffi cient in one of the farms for milk yield was higher by 0,495, mass fat fraction by 0,305; mass protein fraction by –0,110, and in the other, respectively, by 0,026; 0,161; 0,121. The conclusion is made about a higher prepotency of heterozygous sires with improving mating.

57 Relationship between Proportion ofBos indicus Genetics of Dams and Calf Performance from a 31-Year Multibreed Herd Dataset

Abstract This is a 31-year retrospective cohort study aiming to evaluate the relationship between the proportion of B. indicus genetics of crossbred dams and the weaning weight of their calves. Our hypothesis was that crossbred dams with intermediate degree of B. indicus genetics wean heavier calves than those with low-to-high degree of B. indicus genetics at the subtropical condition. The cow-calf pairs (n = 4,901) were in six evenly distributed breed groups according to the proportion of Brahman: G0–19%, G21–34%, 38%, G41–59%; G63–78% and G81–100%. Dams reared contemporaneously were undergone to controlled breeding seasons where the six breed groups of dams and sires were reciprocally mated. Non-adjusted and 205d-adjusted weaning weight of calves were considered as dependent variables and analyzed using MIXED procedure of SAS 9.4. The following independent variables were included in the model as fixed effects: parity category order (primiparous, secundiparous and pluriparous), calving period (0-30d, 31-60d, 61-90d and 91-120d), gender of calf (male or female) and breed group. Year was included as a random effect. All possible interactions were tested and only those with P &amp;lt; 0.20 remained in the final model. Most of all, for the non-adjusted weaning weight, the breed group effect (P &amp;lt; 0.001) varied according to the calving period. Dams calving after 30d of calving season weaned the lightest calves. However, the magnitude of such losses was variable within breed groups. Calves from G0-19% and G81-100% of dams were the most and least impacted by calving period, respectively. The difference on weaning weight between calves born at 0-30d and 91-120d was 60kg for G0-19% of dams and 30kg for G81-100% of dams. For every other breed group, this difference ranged from 45kg to 55kg. In spite of such interaction effect, calves from G0-19% and G81-100% of dams were lighter (230.4 and 225.0 kg, respectively; SEM: 3.4) than any other breed group (238.3 to 242.5 kg). For the 205d-adjusted weaning weight, there was a breed group effect (P &amp;lt; 0.001), regardless of calving period. Lighter calves were still weaned from G0-19% and G81-100% of dams (214.9 and 206.5 kg, respectively, SEM: 2.8) compared with any other breed group (223.4 to 227.6 kg). Thus, crossbred dams with intermediate degree of B. indicus genetics weaned the heaviest calves, probably as result of outbreeding enhancement provided by the adaptability of B. indicus to the tropics and productivity of B. taurus.

11 Impact of a Cache Valley Fever Outbreak on Lambing Performance in a Landrace Hair Sheep Flock: A Case Study

Abstract Cache Valley Fever (CVF) is a mosquito-born, viral disease endemic to North America. While generally not associated with clinical symptoms in ewes, it affects fetal development during the first trimester of pregnancy resulting in malformations and pregnancy loss. A suspected outbreak of CVF was recorded in a flock of Barbados Blackbelly and St. Croix hair sheep managed under an 8-mo, accelerated mating system with ewes bred in March, July and November. The outbreak was associated with a July breeding, in a summer with unusually high rainfall and standing water in pastures. There had been no previous occurrence of CVF or other abortion storms in the flock (20+ years). Lambing outcome associated with the suspected outbreak of CVF was compared with that of the three prior July matings (CON). Ewes (n = 32-35) were managed in a pasture-based system under rotational grazing. Ewes were mated in two single sire groups of 16 to 18 ewes to like-breed sires each breeding season. Pregnancy was determined by transrectal ultrasound at end and 21 d after the 25-day breeding season. Ewes lambed on pasture, and lambs were tagged, and birth weights recorded within 24 hours. Blood samples were collected from all ewes following the CVF lambing and submitted for CVF antibody testing. All ewes showed CVF antibody titers. Pregnancy rate for the CVF lambing was not different from CON (85.7 vs. 89.8%; P = 0.512), whereas lambing rate was less in CVF for both ewes exposed (74.3 vs. 88.8%; P = 0.039) and ewes lambing (86.7 vs. 98.9%; P = 0.004). Incidence of stillborn and neonatal death of lambs was greater in CVF than CON (37.0 vs.5.6%; P = 0.002), as was the number of malformed lambs (13.0 vs. 0%; P &amp;lt; 0.001). Malformed lambs were associated with breech presentations. Litter size was not different in the CVF lambing (1.77 vs 1.86; P = 0.471), but lamb birth weight tended to be less (2.80 vs. 3.04 kg; P = 0.055) while ewe postpartum weight was not different (45.3 vs. 47.0 kg; P = 0.384). The outbreak of CVF reduced the lambing rate and increased the incidence of neonatal death and malformations. The outbreak occurred during a summer with unusually high rainfall and may be associated with changing weather patterns linked to climate change. Delaying summer breeding may be considered a mitigation strategy if feasible.

Live and carcass production traits for progeny of purebred sires in comparison with the clone of a USDA prime yield grade one carcass.

Cloning is a technology by which an animal's tissue can be salvaged and replicated. Carcasses that grade USDA prime-yield grade 1 (P1) represent a rare and antagonistic outcome and are a goal for terminal sire selection in the United States. A terminal sire progeny test generated offspring for a crossbred bull (14% Zebu, 86% Angus; ALPHA), born in 2012 via somatic cell nuclear transfer (SCNT) from a carcass that graded P1. ALPHA progeny (steers and heifers) were compared against progeny of three purebred (Angus; Charolais; Simmental) reference sires. Live production traits included weaning weight, morbidity, mortality, and days on feed; carcass traits included abscessed liver frequency and lung lesion frequency, individual quality and yield grade (YG) parameters, and carcass value. Observed carcass traits for progeny from the Angus, Charolais, and Simmental sires were reflective of the carcass outcomes expected for each sire's respective breed. Calves sired by the Angus were the earliest maturing indicated by the youngest chronological age at harvest (P ≤ 0.02) concomitant with the most backfat (P < 0.01), and the greatest marbling scores (P < 0.01). Calves sired by the Charolais had the heaviest carcass weight (P = 0.04), greatest cutability as assessed by USDA calculated YG (P < 0.01) and were the heaviest muscled based on "longissimus" muscle area (P < 0.01). ALPHA-sired calves were the most similar in carcass outcomes to calves sired by the Simmental, combining advantageous quality and yield parameters to produce an intermediate for carcass quality and yield. The economic value of moderate carcass outcomes is reflected in the carcass value per century weight, in which ALPHA-sired steers tended (P = 0.07) to be of the greatest value compared to other sire groups. ALPHA progeny performed comparably to high-performing reference sires for terminal sire production traits and the P1 genetics in which ALPHA was cloned have economical and biological value in modern U.S. beef production.

Exploring associations among morphometric measurements, genetic group of sire, and performance of beef on dairy calves.

Sire selection for beef on dairy crosses plays an important role in livestock systems as it may affect future performance and carcass traits of growing and finishing crossbred cattle. The phenotypic variation found in beef on dairy crosses has raised concerns from meat packers due to animals with dairy-type carcass characteristics. The use of morphometric measurements may help to understand the phenotypic structures of sire progeny for selecting animals with greater performance. In addition, due to the relationship with growth, these measurements could be used to early predict the performance until the transition from dairy farms to sales. The objectives of this study were 1) to evaluate the effect of different beef sires and breeds on the morphometric measurements of crossbred calves including cannon bone (CB), forearm (FA), hip height (HH), face length (FL), face width (FW) and growth performance; and (2) to predict the weight gain from birth to transition from dairy farms to sale (WG) and the body weight at sale (BW) using such morphometric measurements obtained at first days of animals' life. CB, FA, HH, FL, FW, and weight at 7 ± 5 d (BW7) (Table 1) were measured on 206 calves, from four different sire breeds [Angus (AN), SimAngus (SA), Simmental (SI), and Limousin (LI)], from five farms. To evaluate the morphometric measurements at the transition from dairy farms to sale and animal performance 91 out of 206 calves sourced from four farms, and offspring of two different sires (AN and SA) were used. To predict the WG and BW, 97 calves, and offspring of three different sires (AN, SA, and LI) were used. The data were analyzed using a mixed model, considering farm and sire as random effects. To predict WG and BW, two linear models (including or not the morphometric measurements) were used, and a leave-one-out cross-validation strategy was used to evaluate their predictive quality. The HH and BW7 were 7.67% and 10.7% higher (P < 0.05) in SA crossbred calves compared to AN, respectively. However, the ADG and adjusted body weight to 120 d were 14.3% and 9.46% greater (P < 0.05) in AN compared to SA. The morphometric measurements improved the model's predictive performance for WG and BW. In conclusion, morphometric measurements at the first days of calves' life can be used to predict animals' performance in beef on dairy. Such a strategy could lead to optimized management decisions and greater profitability in dairy farms.

Effects of Imported Semen Based on Different Selection Indices on Some Production and Reproduction Traits in Iranian Holstein Cattle.

The aim of the present study was to evaluate the effects of imported semen of Holstein bulls from different countries on the economic traits of their daughters using the Lifetime Net Income (LNI) index in various climates of Iran. The data included the first lactation records of 274,057 Holstein cows collected during 1993 to 2017 by the Animal Breeding Center of Iran from 10 large dairy farms located in various provinces of Iran. The investigated traits included milk, fat and protein yields, calving age and calving interval. Breeding values of progenies were predicted by the Best Linear Unbiased Prediction (BLUP) method under the multi-trait animal model using DMU software. The genetic-economic merit of the progenies was estimated by the LNI index. There were significant differences between the estimated breeding values (EBVs) of sire groups (based on bull semen origin) for milk, fat and protein yields, calving age and calving interval in each climate (p &lt; 0.01). The obtained results showed that the highest least-square means of LNI index in semi-cold, moderate and warm climates belonged to the daughters of French sires; however, daughters of German sires were estimated to have the highest least-square means in the cold climate.

40 The Impact of Sire EBV for Growth and Feed Intake on Pig Activity Level Using Nuutrack

Abstract Feed cost accounts for two-thirds of the total cost in producing pork. The principle in reducing feed costs, without sacrificing pork output, is improving feed efficiency. To date, the two traits commonly associated with improving feed efficiency are growth and feed intake; however the impact they have on maintenance levels is unclear. Therefore, the objective of this study was to determine activity and behavior patterns of progeny using NUtrack from sires with different EBV combinations for growth and feed intake. A total of 175 pigs from four different sire groups (DNA Genetics Line 600; High Growth/High Feed Intake, HGHI; High Growth/Low Feed Intake, HGLI; Low Growth/High Feed Intake, LGHI; and Low Growth/Low Feed Intake, LGLI) were utilized at the UNL ENREC swine farm. Finisher pens were blocked by sire group and sex. Finisher exit weights were collected after 85 days, along with loin-eye area (LEA) and backfat (BF). NUtrack algorithms allowed for individual identification of pigs in a group housing setting to track daily activity behaviors including distance traveled (DIST) and time lying (LIE). Estimated marginal means were processed through RStudio. HIHG pigs traveled less DIST than those sired by LILG, HILG, and LIHG (P &amp;lt; 0.05; 929 vs. 1,066, 990, and 984m, respectively). The HIHG pigs had greater LIE time than LIHG and LILG pigs (P &amp;lt; 0.05; 1,119 vs. 1,188 and 1,175min, respectively). LILG pigs had greater LEA compared with HIHG, HILG, and LIHG sired pigs (P &amp;lt; 0.05; 52.85 vs. 49.39, 49.97, and 51.05cm2, respectively). The LILG pigs had less BF compared with HIHG, HILG, and LIHG sired pigs (P &amp;lt; 0.05; 1.42 vs. 1.48, 1.46, and 1.50cm, respectively). These results suggest that pigs from boars with high EBVs for growth travel less, spend more time lying and yield a fatter carcass.

​Effect of Non-genetic Factors on Reproductive Parameters and Greasy Fleece Yield in Kashmir Merino Sheep

Background: A study was undertaken to estimate gestation length, birth weight, dam weight and greasy fleece yield in Kashmir Merino sheep and factors influencing these traits at Sheep Breeding Farm, Kralpathri in 2020-21. Methods: The traits considered in the study were overall all body weight of dams at tupping (DWT), average wool yield of dams (AWY), gestation period (GP) and birth weight (BW). The averages of 39.00±0.27 (kg), 2.38±0.02 (kg), 150.17±0.17 (days) and 3.87±0.04 (kg) for DWT, AWY, GP and BW with coefficient of variation 12.83%, 12.75,1.65 and 17.70, respectively were observed in the present study. The data was analyzed by Harvey, 1990. Result: Highest and lowest CV (%) was observed for BW and GP, respectively. Overall estimates of 37.43±0.41 (kg) and 2.21±0.02 (kg), 150.59±0.56 and 2.84±0.11 for DWT, AWY, GP and BW, respectively was observed in the present study. Effect of age of dam was significant (p less than 0.05) on DWT and AWY whereas effect of lamb weight at birth was significant on GP. The effect of genetic group of sire, dam weight, parity of dam, body weight of dam at tupping, sex and birth type of lamb had significant (p less than 0.05) effect on BW. Heaiver lambs were born to heavier dams. Therefore, increasing selection pressure at tupping for dam weight will result in improvement of birth weight and hence overall production performance of Kashmir Merino sheep.

Evaluation of terminal sire breeds for hair sheep production systems: Feedlot environment

Improving carcass merit while maintaining parasite resistance in Katahdin crossbred lambs has potential to improve profitability for U.S. sheep producers. To assess crossbred lamb parasite resistance, carcass merit and gain, purebred Katahdin ewes from the Southwest Virginia Agricultural Research and Extension Center (Glade Spring, VA) were mated to Katahdin (KT), Suffolk (SU) or Texel (TX) rams for three years. Lambs were born and raised in Virginia. Two weeks post-weaning, lambs were transported to the West Virginia University Animal Science Farm (Morgantown, WV). Lambs were dewormed and transitioned to a complete pellet (16% CP) and fed ad lib for the duration of the study. After transition, all lambs were infected with 10,000 Haemonchus contortus L3 larvae (HcL3) in suspension given orally. Weights, blood and fecal samples were collected weekly. After a 5 week primary infection, all lambs were treated with levamisole (8 mg/kg) and rested for 2–3 weeks, after which, lambs were challenge infected with 10,000 HcL3 and sampled weekly until slaughter endpoint in Years 1&2. Ultrasonic determination of REA and fat depth occurred 1 week prior to slaughter in Years 1&2. In Year 3 carcass evaluation did not occur and ultrasonic measurements were taken at termination of the trial. In Years 1&2, 5 lambs from each sire group (n = 15) were randomly selected for carcass analysis at the Virginia Tech Meats Laboratory. No significant sire effect differences were observed in FEC during primary infections across all 3 years. Fecal egg count of KT lambs peaked at week 6 during challenge infection but reduced FEC rapidly one week later. SU-sired lambs grew faster to a larger body weight than TX sired lambs (55.72 kg vs. 49.51 kg; 0.37 kg/d vs. 0.32 kg/d, P < 0.0001), with KT progeny having the least amount of weight gain (44.8 kg; 0.30 kg/d). Analysis of REA using ultrasound and live carcass measurements exhibited no difference between SU- (16.92 cm2) or TX-sired lambs (17.10 cm2) but both breeds were significantly higher than Katahdin lambs (13.67 cm2;P < 0.01). Leg score favored SU- (11.8) and TX-sired (12.0) lambs compared to KT-sired lambs (10.7;P < 0.01). Feed efficiency measured in RFI showed no significant difference between KT-, SU- or TX sired lambs (−0.08, 0.04, −0.04 kg/d respectively; P = 0.65). Taken together these data demonstrate that carcass merit of TX-sired lambs is equivalent to SU-sired lambs supporting the option of using an alternative terminal sire on Katahdin ewes without detrimental loss of parasite resistance in crossbred progeny.

Age of eruption of the first permanent incisors varies between Merino genotypes and is related to liveweight

The eruption of the first permanent incisors in sheep determines the classification of lamb and hogget and impacts the sale value of animals in Australia. This study tested the hypothesis that the age of incisor eruption would differ between progeny from different Merino sires and would occur earlier for progeny that were heavier at 12 months of age. The study utilised wether progeny at a site in Western Australia from 29 sires born in 2016 (n = 347) or 2017 (n = 553), and ewe and wether (castrated male) progeny at a second site in New South Wales from 29 sires born in 2017 (n = 713 ewes and 343 wethers) or 2018 (n = 638 ewes and 457 wethers). Classing of incisor eruption commenced at 10–11 months of age and was recorded monthly until 19 or 20 months of age at the two sites. The average age of incisor eruption varied by up to 2.5 months between sire groups (P < 0.001) and incisor eruption was completed for all progeny within a sire group over three months for some sires but over 6 months for other sires. Incisor eruption occurred earlier for animals that were heavier at 12 months of age (P < 0.001). The period when animals gained weight up to 12 months also influenced incisor eruption, as differences in liveweight at weaning had twice the effect on age of incisor eruption compared with differences in liveweight gain post-weaning at both sites. Estimated stage of maturity at 12 months of age had minimal effects on subsequent age of incisor eruption, and regardless, the large variation in age of incisor eruption between sires were not accounted for by liveweight or stage of maturity at 12 months. In addition to selecting Merino sires that produce progeny that can be sold as lamb at an older age, farmers may also benefit from understanding the pattern of the first permanent incisors eruption specific to their genotype and monitoring liveweights and liveweight change to optimise the time and value of animals at sale.

Structure of the holstein dairy cattle subpopulation in Russia by locus CSN2 and CSN3

Purpose: to determine the potential of the Russian subpopulation of the Holstein breed in relation to selection by loci of beta-and kappa-casein.Materials and methods. For loci CSN2 and CSN3, 1,539 Holstein cattle were genotyped, including 1,242 cows and heifers and 297 sires, and information on CSN2 and CSN3 genotypes of 297 US bulls was analyzed (World Wide Sires, Ltd).Results. It has been established that in the last two years there has been an increase in the percentage of sires in WWS with CSN2 genotypes A2A2 and CSN3 genotypes BB. Thus, sires allele frequency in the 2019 catalog was 0.51 and 0.29, respectively; and in the 2021 catalog was 0.68 and 0.31, respectively.Genotyped sires of domestic breeding organizations, which are mostly foreign origin, were characterized by predominance of the A2 allele CSN2; in this group the frequency of the allele was 0.63. However, the CSN3 B allele in the group of sires belonging to domestic organizations was found with a frequency of 0.34, which is 1.6 times lower than that of sires of American origin.In the genotyped group of Holstein cows and heifers (n = 1242) belonging to 3 large farms in the Krasnodar Krai, the gene frequency CSN2 allele A2 was minimal (0.57), and the CSN3 allele B (0.40) was higher than the allele frequency in the sires group of domestic breeding enterprises.Conclusion. At present, Russian breeding enterprises and farms are lagging behind in these indicators, however, by conducting targeted selection in accordance with the indicated trend, by selecting the appropriate breeding bulls, it is possible in the next generation to increase the proportion of animals carrying valuable genotypes.

Genetic parameter estimation for growth traits in males of Karan fries cattle

The significance of sire selection in the herd is reflected by the total genetic gain through sire-to-sire and sireto- dam pathways contributing greater than 50% contribution. The present investigation was carried out to estimate genetic parameters of males of Tharparkar (TP) and Karan-Fries (KF) cattle. Data on body weights of Tharparkar and Karan Fries males born during the period 199-2012 at ICAR-National Dairy Research Institute (ICAR-NDRI), Karnal, India were utilized in the present study. The genetic and phenotypic correlations among different body weights were estimated from the analysis of variance and covariance among sire groups. Paternal half-sib correlation method was used to estimate heritability of growth traits. Heritability estimates in KF were found to be of moderate to high magnitude, as 0.23±0.06, 0.43±0.10, 0.28±0.10, 0.36±0.11, 0.39±0.12, 0.38±0.14, 0.27±0.19 for weight at birth and weight at monthly interval up to six months, respectively. Genetic and phenotypic correlations were found to vary from moderate to high among the traits. Our study revealed that the magnitude of heritability indicates a high scope of further improvement in Karan Fries. Selective breeding and positive genetic correlations should be considered while designing selection programs.

Identification of Genomic Regions for Carcass Quality Traits within the American Simmental Association Carcass Merit Program.

Simple SummaryThe American Simmental Association has an ongoing project assessing carcass composition and quality. Typically, when animals for mating are selected on maternal traits, there is a concomitant reduction in carcass value as many maternal traits are antagonistic to carcass traits. Analysis of the current data showed the correlation between hot carcass weight and calving ease direct to be lower than previously reported. This shows that multi-trait selection reduced the problem that arose when selecting for carcass traits or maternal traits individually.USDA quality and yield grade are primary driving forces for carcass value in the United States. Carcass improvements can be achieved by making selection decisions based on the results of genetic evaluations in the form of expected progeny differences (EPD), real-time ultrasound imaging, and physical evaluation of candidate breeding animals. In an effort to advance their ability to accurately predict the breeding value of potential sires for carcass traits, the American Simmental Association launched the Carcass Merit Program as a means to collect progeny sire group carcass information. All records were extracted from the American Simmental Association database. Progeny data were organized by sire family and progeny performance phenotypes were constructed. Sire genotypes were filtered, and a multi-locus mixed linear model was used to perform an association analysis on the genotype data, while correcting for cryptic relatedness and pedigree structure. Three chromosomes were found to have genome-wide significance and this conservative approach identified putative QTL in those regions. Three hundred ninety-three novel regions were identified across all traits, as well as 290 novel positional candidate genes. Correlations between carcass characteristics and maternal traits were less unfavorable than those previously reported.