Effects of feed intake and environmental temperature on chick growth and development

Abstract

SUMMARYBroiler chicks reared under three environmental temperatures (7·2, 23·9 and 35 °C) in the Southeastern United States of America in 1988/89 were precision-fed to levels which were c. 70, 90, 110 and 130% of the consumption observed in ad libitum-fed controls at 23·9°C, in order to examine the limitations imposed by feed intake upon growth rate, feed efficiency and survival. Ad libitum-fed birds that were housed at 7·2, 23·9 and 35 °C consumed feed at 12·1, 9·4 and 8·5% of body weight, respectively. Liveweight gain of birds consuming feed ad libitum was depressed by 26 and 46% in the 7·2 and 35 °C environments respectively. Increasing feed intake by precision feeding exceeded ad libitum consumption in the 23·9 and 35 °C environments, but not at 7·2 °C. Consumption of feed above thermoneutral ad libitum levels failed to increase (p <0·l) liveweight of carcass gain. Ration digestibility and dressing out percentage declined (P < 0·05) at the higher feed intake levels in the 7·2 °C environment.