Poultry Feed Restriction
Poultry feed restriction in broilers and their parent stock have the potential for rapid early growth and eat at or near the capacity of their gastrointestinal tract when fed ad libitum. Thus, unless the feed intake of broiler breeders is limited, the resulting obesity will have negative effects on reproduction, vigor, and viability. Under current commercial feed restriction programs, breeders are fed an amount of feed either daily or on alternate days that is calculated to achieve and maintain preferred body weights.
Feed restriction of this type has been shown to be a stressor in broiler breeders, resulting in increases in activity, aggression, stress hormone levels, and the performance of stereotyped behaviors. Although the health benefits of commercial feed restriction programs to the bird outweigh these negative aspects, alternative methods for controlling body weight in breeders require investigation.
Special Note: 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.