Effect of dietary essential amino acid profiles on egg production performance of Japanese quails during 19 to 30 weeks of age

In order to reduce the dietary protein through maintaining essential amino acid profile (EAA), 312 laying quails were subjected to study the response of graded EAA profiles with reduced dietary protein from 19–30 weeks of age. Each of the six dietary treatments, with three levels of EAA (85, 100, 115% of NRC, 1994) and with 5% or without fishmeal in a 3 × 2 factorial design, was offered to 26 groups of two quails each. Hen-day and hen-housed egg production did not differ due to EAA, protein type or interaction. Egg weight and egg mass output improved linearly (P<0.01) with increased EAA levels. Quails fed 100 and 115% EAA had improved feed conversion (P<0.01) than 85% EAA. Protein utilization improved (P<0.01) linearly with decrease EAA, while (P<0.01) energy utilization was better in 100 or 115% EAA. Shell thickness improved (P<0.05) at 115% FM, 100% FM and 85% all vegetable diets. Dietary level of 100% EAA with 185 g kg⁻¹ CP and 2900 kcal ME per kg was optimum for laying quails during 19–30 weeks of age.