scholarly journals Genetic parameter estimates of conformation and performance traits in station-tested Limousin bulls

1994 ◽  
Vol 74 (2) ◽  
pp. 379-381 ◽  
Author(s):  
Filippo Miglior ◽  
E. B. Burnside ◽  
R. A. Kemp
Keyword(s):  
Genetic Parameter ◽  
Average Daily Gain ◽  
Parameter Estimates ◽  
Multiple Trait ◽  
Muscular Development ◽  
Scrotal Circumference ◽  
Performance Traits ◽  
Type Traits ◽  
And Performance ◽  
Highly Correlated

Genetic and residual parameters were computed for conformation and performance traits of Limousin bulls in Ontario central test stations. Following editing, data were available on 456 bulls tested in 1990. Genetic parameters for performance traits were similar to those reported in the literature. Heritability of bone score (1 — light to 9 — heavy) was 0.22 ± 0.23. Heritability of a composite muscular development score was 0.51 ± 0.14. Muscular development was positively correlated genetically with all traits studied, including average daily gain (140 d), height, scrotal circumference and bone, and very highly correlated genetically with backfat thickness and weight at end of test. Selection for muscular development using a linear scoring system is feasible, but consideration should be given to correlated responses in other economically important traits. Key words: Multiple-trait analysis, growth and type traits correlations, station-tested beef bulls

PSIII-8 Genetic Parameter Estimates for Bull Prolificacy and Its Relationship with Scrotal Circumference in a Commercial Beef Cattle Population

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 158-159
Author(s):  
Chad A Russell ◽  
E J Pollak ◽  
Matthew L Spangler
Keyword(s):  
Beef Cattle ◽  
Breeding Season ◽  
Random Effects ◽  
Fixed Effects ◽  
Genetic Parameter ◽  
Additive Genetic Effect ◽  
Parameter Estimates ◽  
Contemporary Group ◽  
Scrotal Circumference ◽  
Heritability Estimates

Abstract The commercial beef cattle industry relies heavily on the use of natural service sires. Either due to the size of breeding herds or to safe-guard against injury during the breeding season, multiple-sire breeding pastures are utilized. Although each bull might be given an equal opportunity to produce offspring, evidence suggest that there is substantial variation in the number of calves sired by each bull in a breeding pasture. DNA-based paternity assignment enables correct assignment of calves to their respective sires in multi-sire pastures and presents an opportunity to investigate the degree to which this trait complex is under genetic control. Field data from a large commercial ranch were used to estimate genetic parameters for calf count (CC; n=623) and yearling scrotal circumference (SC; n=1962) using univariate and bivariate animal models. Average CC and SC were 12.1±11.1 calves and 35.4±2.30 cm, respectively. Average number breeding seasons per bull and bulls per contemporary group were 1.40 and 24.9, respectively. The model for CC included fixed effects of age during the breeding season (in years) and contemporary group (concatenation of breeding pasture and year). Random effects included additive genetic and permanent environmental effects, and a residual. The model for SC included fixed effects of age (in days) and contemporary group (concatenation of month and year of measurement). Random effects included an additive genetic effect and a residual. Univariate model heritability estimates for CC and SC were 0.237±0.156 and 0.456±0.072, respectively. Similarly, the bivariate model resulted in heritability estimates for CC and SC of 0.240±0.155 and 0.461±0.072, respectively. Repeatability estimates for CC from univariate and bivariate models were 0.517±0.054 and 0.518±0.053, respectively. The estimate of genetic correlation between CC and SC was 0.270±0.220. Parameter estimates suggest that both CC and SC would respond favorably to selection and that CC is moderately repeatable.

Genetic parameter estimates for scrotal circumference and semen characteristics of Line 1 Hereford bulls1

2006 ◽  
Vol 84 (2) ◽  
pp. 283-290 ◽  
Author(s):  
C. G. Kealey ◽  
M. D. MacNeil ◽  
M. W. Tess ◽  
T. W. Geary ◽  
R. A. Bellows
Keyword(s):  
Genetic Parameter ◽  
Parameter Estimates ◽  
Scrotal Circumference ◽  
Semen Characteristics

Genetic parameter estimates for early growth traits in Naeini goat

2012 ◽  
Vol 52 (11) ◽  
pp. 1046 ◽  
Author(s):  
Hasan Baneh ◽  
Mojtaba Najafi ◽  
Ghodrat Rahimi
Keyword(s):  
Environmental Effects ◽  
Variance Components ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Parameter ◽  
Average Daily Gain ◽  
Parameter Estimates ◽  
Estimate Variance ◽  
Daily Gain ◽  
Birth Type

The present study was carried out to estimate variance components for growth traits in Naeini goats. Bodyweight records were collected for two flocks under supervision of the Agriculture Organisation of the Esfahan province between 2000 and 2007. Investigated traits were birthweight (BW; n = 2483), weaning weight (WW; n = 1211) and average daily gain from birth to weaning (ADG; n = 1211). Environmental effects were investigated using fixed-effect models, while (co)variance components and genetic parameters were estimated with single- and three-trait analyses using REML methods and WOMBAT software. Six different animal models were fitted to the traits, with the best model for each trait determined by log-likelihood ratio tests (LRT). All traits were significantly influenced by herd, birth year, sex of the kid, birth type and dam age (P < 0.01). On the basis of LRT, maternal permanent environmental effects (c2) were significant for WW and ADG, while BW was affected only by direct genetic effects. Direct heritability estimates for BW, WW and ADG were 0.25 ± 0.05, 0.07 ± 0.06 and 0.21 ± 0.11, respectively. The estimate of c2 was 0.16 ± 0.06 for both WW and ADG. Estimates of genetic correlation for BW–ADG, BW–WW and ADG–WW were 0.49, 0.61 and 0.94, respectively. The estimated phenotypic correlations were positive and were between 0.03 (BW–ADG) and 0.95 (ADG–WW). These results indicate that selection can be used to improve growth traits in this goat breed.

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