The effect of colony size on the response of layers to moderate food energy restriction

1. Light hybrid layers were housed at 1, 3 or 5 birds per cage. From 32 to 60 weeks of age they received a diet containing 11.lb59 kj/kg ad libitum, at 95 or at 92% of ad libitum intake. Birds on these nine treatment combinations were fed from communal troughs. Two further treatments consisted of birds caged and fed individually with food offered either ad libitum or in slightly restricted amounts.

2. Restrictions of about 5% and 8% in food intake resulted in reductions in egg output of about 5% and 9% respectively.

3. As colony size increased the rate of lay decreased but colony size did not affect the response to restriction.

4. Among birds caged singly those fed individually laid more eggs than those fed communally despite the fact that the former consumed less energy. A similar degree of energy restriction resulted in a similar decrease in rate of lay at each colony size.

Notes

Present address: National Poultry Company, Baghdad, Iraq. 217