ENERGY UTILIZATION IN THE CHICK IN RELATION TO CERTAIN ENVIRONMENTAL STRESSES

Abstract

Reductions in weight gain, feed consumption and feed efficiency resulted under the stress of water restriction or high population density. The metabolizable energy (ME) content of the feed was unaffected by the severity of the stresses. Elevated and depressed environmental temperatures resulted in reductions in weight gain and feed efficiency, but there were no alterations in the ME content of the feeds. Water restriction decreased the sucrase activity, but not the maltase activity in the intestinal mucosa. Overcrowding had no effect on the level of these mucosal enzymes. At adverse temperatures mucosal sucrase and maltase activities were significantly higher for birds on a low energy than for those on a high energy diet. On the low energy, but not the high energy regime, the sucrase and maltase activities were increased at the elevated and depressed environmental temperatures.