Relações entre o comportamento e crescimento em bezerras leiteiras na fase de aleitamento mantidas em baias individuais

Abstract

With the growing demand for animal production systems, especially dairy cattle, there is a need to increase the efficiency of these systems. The work aimed to analyze the relationship between behavior and growth in crossbred zebu calves housed in individual stalls, during a lactation phase. Behavioral observations were carried out in the periods of 20 22, 20 42 and 60 and 62 days of life of 60 calves, using the Scan method, with 10 min intervals. The following categories were recorded: standing, lying, moving, standing still, sleeping, positive (playing, leaping /jumping), concentrated eating, ruminating, non nutritional oral behaviors (licking the stall facilities, smelling the facilities), grooming (whether licking, scratching), social (interacting with the calf in the bay next door). As a growth indicator, weekly measurements of body mass were used until the 63rd day of life, generating three measures of average daily weight gain (GMT1 (1 28), GDM2 (28 63) and GMDT (1 63)). For data analysis, Spearman's principal component and clarifying analysis were used. The results showed that motor behaviors such as moving and jumping had a positive effect on weight gain, while standing behavior was negatively related, with animals that spent more time standing gaining less weight than animals that spent more time standing. more time standing still and moving around, grooming behaviors and lying down were also a positive view with weight gain. It was concluded that the more active calves had greater average daily weight gain during the lactation phase, contradicting our initial hypotheses that the more active calves would expend more energy and gain less weight during the experimental period. Future studies will enable a better understanding of behaviors during the breastfeeding phases with weight gain and performance of dairy calves.