Quantitative and qualitative feed restriction on growth characteristics of male broiler chickens.

Four experiments were conducted to evaluate the quantitative and qualitative feed restriction on the performance of male broiler chickens. In the first experiment, broilers fed identical pelleted diets were feed-restricted from 5 to 42 d by giving 95, 90, or 85% of the feed consumed ad libitum by control birds the previous day. In a second experiment, broilers were fed pellet or mash diets from 1 to 7 wk. In Experiments 3 and 4, broilers were feed-restricted to 90% of the ad libitum intake of a control group during different intervals. Results from Experiment 1 indicated that live body weight at 42 d was significantly different between unrestricted and restricted broilers (P < 0.01). A reduction in mortality was noted when feed intake was reduced (P < 0.05). In the second experiment, broilers fed mash had lower body weights and breast meat yields at 42 and 49 d (P < 0.05). Cumulative mortality at 42 and 49 d was reduced in broilers fed mash (P < 0.05). Results from Experiment 3 indicated that body weight and mortality were not significantly different (P > 0.05) at 42 d across treatments. There was a significant (P < 0.01) linear improvement on feed conversion at 42 d due to duration of feed restriction. Breast meat yield at 42 d was less in broilers subjected to mild feed restriction (P > 0.05) (Experiments 3 and 4). Broilers appeared able to recover from mild feed restriction, and there was always an associated reduction in mortality.