Effects of protein levels and methionine supplementation of the diets of layers on egg production rate, fertility and hatchability of eggs in the tropics

A trial was run with 540 laying hens of the White Rock x White Leghorn crosses to determine the effects of varying protein levels and the supplementation of the diets with DL‐methionine on the laying performances, egg grades, their fertility and hatchability, of the birds reared in a tropical environment. The protein levels used were 14, 16 and 18%, and the levels of methionine supplemented were 0, 100 and 110% the recommended minimum requirements for layers by the NRC (1971). Hen‐day production increased as the percentages of crude protein and levels of methionine supplementation increased. There were also larger percentages of large‐sized eggs as the protein levels and level of methionine supplementation increased and the feed/dozen eggs improved with increases in protein levels and with increases in level of methionine supplementation. Finally, both the levels of fertility and hatchability of the eggs were increased with increases in protein and levels of methionine supplementation.