Skip to main content
ARS Home » Research » Publications at this Location » Publication #68925
Title: ESTIMATES OF HERITABILITY AND REPEATABILITY OF WEANING WEIGHT OF NELLORE CATTLE IN BRAZIL

Author
item FIORETTI, M. - U. PERUGIA, ITALY
item ROSATI, A. - U. PERUGIA, ITALY
item PIERMATI, C. - U. PERUGIA, ITALY
item Van Vleck, Lloyd

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Data for animals born from 1970 to 1995 were used with inbreeding calculated using pedigrees from 1900. Five traits were analyzed: a) age first insemination; b) age first calving; c) 120-d weight; d) yearling weight males; e) yearling weight females. For traits a and b, 6,418 sires had 69,514 and 61,964 progeny; for traits c, d and e, 7,645 sires had 57,210, 18,832 and 35,996 progeny. Model 1 included fixed effects of herd-year (for a,b,d,e) or herd-year and sex (for c) and covariates for inbreeding of animal (for a,b), for age weighed, inbreeding of animal and dam (for c,d,e); random effects were for sires and for dams (for c,d,e). Model 2 did not include inbreeding coefficients. REML estimates of variance components were obtained for each trait from 10 samples. Average estimates were used with all data to predict breeding values. Heritability estimate was four times fraction of variance due to sires. For age first inseminated and first calved, 120-d weight and 360-d weights for males and females, heritability estimates were .19, .12, .16, .27, .26. For 120-d weight and 360-d weight for males and females, fractional estimates of dam variance were, .08, .13 and 08. Estimates of variances were similar for Models 1 and 2. Regression coefficients were; 62.3, 76.3 d, -23.5, -86.8, -34.8 kg for animal inbreeding. For dam inbreeding effects on 120-d weight and 360-d weight for males and females, regression coefficients were -3.8, -1.6 and -1.6 kg. Ranking for transmitting ability for sires changed little with the two models. The conclusions are that inbreeding might not need to be included in the model for prediction of breeding values or estimation of variances. Checking the relationship between sire and cow is needed.