Effects of supplementation and calving season on preweaning growth of female crossbred calves

In a farm with semi-intensive production system under a tropical sub-humid forest, located in Venezuela, thirty female crossbred carves, Holstein (H), Brown Swiss (BS) and Mosaicos (M) were studied to evaluate the supplementation effects (1: corn meal and 2: commercial concentrate) on preweaning growth. Least-square analysis of variance-covariance included effects of breed, supplementation and calving season (humid and dry). The average daily gain (ADG), thorax perimeter (IDTP), hip height (IDWH), croup height (IDCH) and body lenght (IDBL) were affected by supplementation levels (P<.05). The basal diet had the best response. Excepting IDBL all this variables were affected by calving season and the humid season had got the best response. The ADG was greater in H (418.16) and M (424.88) than BS (392.39 g/day) female calves. IDTP and IDWH were greater in H (2.04 and 1.21) than BS (1.93 and 1.17) and M (1.93 and 1.16 mm/day). Between H (1.27), BS (1.36) and M (1.20 mm/day) there were significant differences (P<.01) for IDCH, IDBL was greater in H (2.2) and PS (2.2) than M (2.0 mm/day). The interactions revealed advantageos for the M female calves supplemented with basal diet and born in the humid season.