Feed Requirements for Egg Production

Abstract

Data for individual feed intake, liveweight, and egg production were recorded for five genetically different groups of 40 pullets each during 10 test periods of 28-days each. Average ambient temperature at cage level varied from 6.7 C during January to 21.1 C during June. A 2890 kcal/kg metabolizable energy (ME) diet with 16% crude protein (CP) was fed ad lib. Average egg production for the Small Leghorns (SL) was about 60%, for white-egg hybrids (WL) about 75%, for brown-egg hybrids (BL) about 72%, for female line broiler breeders (BB) about 48%, and for broiler-cross pullets (B) about 51%. Average grams liveweight and grams feed intake per hen day were: SL, 1426 and 83.7; WL, 1809 and 104.9; BL, 2610 and 122.9: BB, 4197 and 156.2; and B, 4158 and 167.7. Partition equations which describe the data for SL, WL, BL, and BB, assuming 70% efficiency of use of feed ME for maintenance, tissue formation, and egg formation were: F = (.534 − .004T)W .653 + 2.76ΔW + .80EM and F = (.259 −.00259T)W.75 + 2.76ΔW + .80EM. Similar equations for B, assuming 65% efficiency use of ME, are: F = (.589 − .0044T)W.653 + 2.9ΔW + .85EM and F = (.275 − .00275T)W.75 + 2.9ΔW + .85EM. The terms are: F = grams feed/hen day; T = ambient temperature in °C; W = grams liveweight; ΔW = grams daily change in liveweight; EM = grams egg mass per hen day. Equations which assume 70% efficiency of use of ME are shown to predict feed intake of a diet containing 2890 kcal of apparent ME per kilogram for white and brown-egg layers and broiler-breeder pullets varying in individual body weights from about 1 to 5 kg. Equations, assuming 65% energetic efficiency, describe feed intake for a group of broiler-cross pullets.