Sire-Son Relationships for Type in Holstein-Friesian Cattle

Abstract

Official classification scores of 336,253 registered Holstein cows recorded from 1 January 1967 through 30 September 1971 were utilized to develop daughter average progeny test information on bulls for final score, the four scorecard traits (general appearance, dairy character, body capacity, and mammary system), and 12 descriptive traits in the official Holstein classification program. Only the first available classification score on each cow was used. Age correction factors were derived for final score and for the scorecard traits, and all traits were adjusted to a 5-yr-old mature base. A total of 1,872 sire-son pairs was included. Regressions of son progeny test on sire progeny average were positive for all traits. Regressions generally were greater than .20 for final score, scorecard traits, and some descriptive traits including stature, back, rump, fore udder, rear udder, udder support, and teat placement. They were less than .20 for head, front end, hind legs, feet, and udder quality. Regressions of nonartificial insemination sons on artificial insemination sires were larger than regressions of artificial insemination sons on artificial insemination sires. Regressions of nonartificial insemination and artificial insemination sons on nonartificial insemination sires were erratic and were not consistent with overall regressions. For progeny averages from sires with varying numbers of sons, final score and scorecard traits along with stature, head, rump, hind legs, fore udder, and rear udder had received considerable emphasis in selection of sires of sons.