Abstract

QUINTEROS POZO, Orlando Roberto; DI MASSO, Ricardo José  and  MARINI, Pablo Roberto. Growth pattern during the first gestation of heifers crosses with Brahman father and different maternal genotype. La Granja [online]. 2019, vol.30, n.2, pp.40-47. ISSN 1390-8596.  https://doi.org/10.17163/lgr.n30.2019.04.

The objective of the present work was to evaluate the growth pattern during the first gestation of heifers crossed withBrahman father and different maternal genotype in the Ecuadorian Amazon. Retrospective data of 2304 individualweights of 48 dairy cows were used. The dynamic behavior of the body weight of four genotypes was evaluated:Brahman x Gyr (Gyr) (n=12), Brahman x Brown Swiss (BS) (n=12), Brahman x Jersey (J) (n=12) and Brahman x Sahiwal(S) (n=12) belonging to the dairy herd of the Research Center, Postgraduate studies and Preservation of the AmazoniaBiodiversity (CIPCA) – Ecuador. The differences between genotypes in body weight at pregnancy and at first birthwere not statistically significant. Differences in age at the first pregnancy were observed, with the highest precocity atcrossing with Brown Swiss mother and the lower precocity at crosses with Gyr and Sahiwal. The females producedby crossing with Jersey showed intermediate behavior. It was observed that, during their first gestation, F1 heiferswith Brahman father and different maternal genotype have a similar growth pattern under the conditions of theEcuadorian Amazon, response in terms of negative genotype-environment interaction.

Keywords : age at first calving; weight gain; crosses; genotype-environment interaction; Amazonia.

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