PERFORMANCE OF THREECROSS AND HEREFORD COWS. II. Characteristics related with body weight

Abstract

The performance of six groups of threecross and straightbred Hereford cows was studied during a period of six years. The crossbred cows were produced by F 1 1/2 Charolais (C) — Hereford (H), 1/2 Holstein (Ho) — H and 1/2 Sta. Gertrudis (SG) — Hereford (H) dams mated to Nelore (N) and Angus (A) bulis. The six groups of threecross and the straightbred Hereford cows were artificially inseminated with semen from Hereford bulis. The experiment was conducted at "Estação Experimental de Uruguaia- . na — RS". The average body weight at calving of the crossbred cows ranged from 419 kg (2/4 N 1/4 SG 1/4 H) to 369.9 kg (2/4 A 1/4 Ho 1/4 H) while for the H cows the average weight was 347.8 kg (P <0.05). At weaning, the average weight rangéd from 418.2 (2/4 N 1/4 C 1/4 H) to 354.3 kg (2/4 A 1/4 Ho 1/4 H) for the crossbred cows, while the H cows presented 349.6 kg (P < 0.05). The weight change from calving to weaning for the crossbred cows ranged from 12.6 kg (2/4 N 1/4 Ho 1/4 H) to — 15.6 kg (2/4 A 1/4 Ho 1/4 H), while the straightbred H cows showed only a small variation of 1.8 kg (P <0.05). The cows, daughters of Nelore sires, showed an average weight of 406.1 kg at calving, and 411.4 kg at weaning, which were higher (P <0.05) than those showed by the cows daughters of Angus sires (375.6 and 362.6 kg, respe,ctively). The breed of the cow's grandfather did not affect (P > 0.05) any of the traits studied.