Sombra artificial e método de fornecimento de concentrado no comportamento e desempenho de bezerros desmamados

Abstract

It was evaluated the behavior, the physiological variables and the performance of Holstein calves and crossbred calves weaned using different shade screens and hours of concentrate supplying. There were used nine Holstein calves (H) and 15 crossbred Holstein calves (MH), housed on partially covered paddocks with a polypropylene screen (shade) with a loop of 70% of shadow (S70) and 40% (S40) receiving concentrate at three times: morning (M), afternoon (A) and alternate days (AD). The behaviors eating and ruminating lying were, respectively, more frequent on the environment S70 (34.29 and 11.40%) than on the environment S40 (30.18 and 6.76%), showing greater termical comfort for calves. The behaviors ruminating standing and standing were, respectively, more frequent on the environment S40 (6.42 and 40.25%) than the environment S70 (5.24 and 31.18%). The haircoat surface temperature presented higher values on the environment S40 for animals H (33.87°C) and MH (33.69°C), mainly on the hottest hours of the day, where the solar radiation was higher. The respiratory rate (RR) was higher for animals H just about on the environment S40 (55.66 mov. min -1) as much as on the environment S70 (60.98 mov. min. -1). The daily average weight gain did not vary according to the ration supplying, shade and genetic groups.