Performance of Japanese Quails Fed Different Protein Levels and Supplemented with Betaine

Abstract

The objective of the experiment was to investigate the performance of Japanese quails (Coturnix coturnix japonica) fed different levels of protein and supplemented with betaine. The experiment used 300 quails with an average initial body weight of 43.21±2.68 g. The design used was completely randomized design of factorial 2 × 2. The rst factor was the 2 levels of crude protein (18.0 and 19.5%) and the second factor was the supplementation of betaine (0 and 0.12% betaine). Each treatment used 5 replications containing 15 quails each. During adaptation, quails were fed a grower diet until the age of 41 days and then replaced with a layer diet containing 18% protein. The treatments were given when egg production has reached 50%. The data were analyzed using analysis of variance followed by Duncan’s test. Feeding 19.5% increased feed intake (P<0.5). However, dietary protein did not affect egg production, egg weight, feed conversion and protein ef ciency ratio. Feeding 19.5% protein improved eggshell weight but resulted in a lower yolk index compared with 18% protein (P<0.05). Supplementation of 0.12% betaine increased feed intake, egg production, egg weight and protein ef ciency ratio and decreased feed conversion (P<0.05). Supplementation of 0.12% betaine did not affect albumen index and eggshell weight. Moreover betaine increased yolk weight but decreased yolk index (P<0.05). It can be concluded that increasing dietary protein levels from 18.0 to 19.5% had minor impacts on quails’ performance and egg quality. Supplementation of betaine improved the performance of quails but showed inconsistent effects on egg quailty.