Pre-weaning growth of Argentine Criollo calves

Abstract

The weaning weight of calves depends mainly on the pre-weaning growth rate, and it is associated with the dairy ability of the cow. Milk is the main food available during the first two months of life of the calf and it is from the third month when the consumption of forage begins to take relevance, being of importance its quality. In the Northwest of Argentina, bovine breeding is based on the use of C4 perennial grasses with summer growth, high levels of fiber, and moderate digestibility. The objective of this work was to evaluate the weight gain of Creole calves in two stages prior to weaning: from birth to 130 days of life and from 131 days to weaning at 205 days. We worked with the offspring born in 2014, 2015, and 2016. For the analysis, we used proc GLM from the statistical package SAS. The model included as fixed effects the mother's age at birth, the sex of the calf, and the year of delivery. The results indicate significant effects for the three variables analyzed (P <0.05). The average weight gain from birth to 130 days of life was 648.0 g/d, being 422.8 g/d higher than in the second period. Male calves presented higher weight gains than females and adult cow calves, 7 to 10 years old at parturition, had the highest values ​​of weight gains in both stages. The daily weight gain, in the second period, represented 68% of the weight gain of the first stage, which reflects a decrease in the milk production of the cow that does not becomes compensated by the available forage.