Resumen

RODRIGUEZ, Yhoangel; MARTINEZ G, Gonzalo  y  GALINDEZ G, Rafael. Non-genetic factors affecting weaning weight in registered Brahman cattle.. Zootecnia Trop. [online]. 2009, vol.27, n.4, pp.383-391. ISSN 0798-7269.

To determine the influence of some non-genetic factors on weaning weight adjusted at 205d (P205) of Brahman registered cattle, 3221 weights were analyzed. All the animals were grazing and under sanitary managing adapted to the conditions of every herd. The data was analyzed using an analysis of variance under restricted maximum likelihood methodology and the statistical model included: herd (H; 1-4), year of birth (AN; 1996-2004), season of birth (EN; Dry and Rainy), age of the mother at calving (EM; 3-10 ó more years) and sex (S; Males and Females) and the interactions HxAN, HxEN, HxS, ANxEN and ANxEM. All effects and the interactions affected P205 (P<0,01), with the exception of EN (P<0,05). The average P205 was 190,94 kg (standard error = 1,78 kg). Important differences existed among herds, being 34,13 kg for extreme herds. The differences between the best years (2002) and worse year (2003) was of 24,74 kg. Cows of 3,..., 10 ó more years had in average calves 10 kg less heavy than cows from 4 to 9 years of age. Males calves weighed 14,20 kg more than females. The interactions that involved H indicate that the direction and magnitude of the effects are not constant within every herd. The P205 is affected by all the environmental factors studied, but it was not affected by EN, although, it existed differences between EN inside H and AN, due to the interaction between EN and those factors

Palabras clave : beef cattle; environmental factors; preweaning growth.

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