Voluntary food restriction by laying hens mediated through dietary self‐selection

Abstract

Individually caged Single Comb White Leghorn hens simultaneously received 2 diets which allowed selection of certain nutrients: these split-diets, essentially provided concentrated sources of either protein and energy (191 g crude protein [CP], 12.82 MJ ME [metabolizable energy] and 4.7 g Ca/kg diet) or Ca (107 g CP, 7.28 MJ ME and 131 g Ca/kg). During four, 28 day periods of lay, birds offered these split-diets consumed some 7% less food in total than did control birds receiving a conventional diet ad lib. Calculation of nutrient intakes showed that birds on the split-diets consumed significantly less protein, energy and Ca than the control birds. Giving split-diets also resulted in superior shell quality; treatment differences were also noted in the timing of oviposition. The voluntary reduction in food intake noted for birds offered split-diets is associated with an appetite for Ca.