Response of Japanese quails to dietary protein quality during different phases of egg production

An experiment was conducted to elucidate the effect of dietary protein quality with age on egg production and egg quality of Japanese quails. 104, 5 wks old quails divided into 2 equal groups (26 replicates, each containing 2 birds) were offered either a diet containing soybean meal as sole protein source (D₁) or fish meal replacing 5% of soybean meal (D₂) upto 30 wks of age. Hen-day, hen-housed egg production, feed intake and feed utilization did not differ due to protein quality. Egg weight was significantly higher (P<0.01) in all-vegetable diet. Egg mass yield was also poorer in fishmeal-supple-mented diet (P<0.05). The egg quality parameters did not differ due to fishmeal supplementation. Feed cost per dozen egg was lower (P<0.05) in fishmeal supplemented diet than in all vegetable meal diet. Hen-day and hen-housed egg production (88% and 87%, respectively) was highest (P<0.01) during 10–14 wk, while reduced (82% and 78%, respectively) during 26–30 wk of age. Egg weight was lowest during 6–10 wk of age and thereafter increased (PO.01) sharply to highest weight in 14–18 wk with linear decrease thereafter. The feed intake per unit egg mass improved (P<0.01) in 26–30 wk. The gain in body weight continued upto 14^th week of age. The peak egg production and egg weight was achieved during 10 to 18 weeks of age. The interaction of age and protein type influenced the change in body weight (PO.01) and eggshell thickness. Shell thickness was higher during 6–10 wk and 10–14 wk of age that too in all vegetable diet than in fishmeal counterpart. It was concluded that fishmeal supplementation was not required if the diet of laying quails was adequately balanced with the critical amino acids calcium and available phosphorus.