Effects of Dietary Protein Levels on Production and Characteristics of Japanese Quail Eggs

Abstract

Three different lines (normal, brown and crossbred) of Japanese quail were used in this study to examine the effects of dietary protein level on the production and quality of eggs. In all lines, poor egg production was evident throughout the experiment on a diet with 16% crude protein (CP). Egg production increased as the CP levels of diets increased. Until 32 weeks, normal (N) and brown (B) lines showed higher egg production at 24% CP, while the crossbred (BN) line showed higher egg production at 22% CP. The cumulative egg production at 24% CP was higher than or similar to that at 26% CP. A comparison of egg production among different lines showed that BN produced significantly (P<0.05) more eggs than N at the lower protein levels of 20% and 22% CP. Weight of eggs was lowest in all lines at 16% CP, and tended to increase with increasing protein level. No difference in egg weight was observed among lines. Egg weight and yolk color were significantly (P<0.05) affected by different levels of protein. It appears that 24% CP was optimal for higher egg production and egg weight for N and B lines and 22% CP for BN lines. Furthermore, our data indicate that heterosis was obtained in BN for egg production at the lower protein levels.