ARS | Publication request: PARAMETER ESTIMATES OBTAINED USING GIBBS SAMPLING FOR 4 TRAITS IN HEREFORD CATTLE SELECTED FOR YEARLING WEIGHT

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: February 23, 1996
Publication Date: N/A

Technical Abstract: Birth weight (BW), weaning gain (WG), post-weaning gain (PWG) and muscle score (MS) observations for 2,884 animals selected for increased yearling weight were analyzed with a multiple trait animal model including fixed sex-year effects, random direct and maternal genetic, maternal permanent environmental, and residual effects. The numbers of observations ranged from 2,031 to 2,597 for the 4 traits. Gibbs sampling estimates were calculated using the multiple trait Gibbs sampler for animal models (MTGSAM) programs. REML estimation of the (co)variance components was not possible with the MTDFREML programs because the simplex algorithm is extremely slow to converge due to the large number of parameters estimated (56 variance components). REML estimation using a canonical transformation was not possible due to missing observations. A total of 500,000 rounds of sampling were used, with the first 50,000 rounds discarded as burn-in. Direct heritability estimates were .44, .15, .64, and .58 for BW, WG, PWG, and MS, respectively. Maternal heritability estimates were .10, .24, .04, and .13. Estimates of phenotypic variance were 16.7 kg x kg, 527 kg x kg, 229 kg x kg, and 6.2. Additive (maternal) genetic correlation estimates for BW with WG, PWG, and MS were .09, .23, and .14 (.08, -.07, and .00), for WG with PWG and MS were .70 and -.40 (.68 and -.29), and for PWG with MS was -.45 (-.40). Estimates of correlations of direct and maternal genetic effects were .00, -.47, -.51, and -.54 for BW, WG, PWG, and MS.