Estimativas da Produção de Leite de Vacas Cruzadas Angus x Nelore e Simental x Nelore.

Abstract

Milk production of 42 cows, 21 crossbred Angus x Nellore (AN) and 21 crossbred Simmental x Nellore (SN), with calves produced by artificial insemination with semen from Canchim, Bonsmara and Angus bulls, with 108 to 191 days of age, was estimated by the suckle-weight-suckle method. Milk production was estimated in two days, each day with a different group of 21 cows, homogeneous regarding to genetic group of cow and genetic group, sex and age of calves. Twenty-four hours milk production (MP, kg) was analyzed by the least squares method, with a model that included the effects of genetic group of cow (GGC), breed of sire of calf (BS), GGC x BS, sex of calf, day of control (D), and age of calf as a covariate (linear and quadratic effects). The results showed that sex of calf and day of control affected milk production. Male calves (6.44 kg) suckled more milk than females calves (4.82 kg), and milk production in first day (6.61 kg) was higher than production observed in the second day (4.64 kg). There was no difference between genetic groups of cows regarding to milk production (5.40 kg for the AN cows and 5.85 kg for the SN cows).