Effects of selection for high body weight and age of hen on egg characteristics in Japanese quail (coturnix coturnix japonica) [Japon bildircinlarinda (coturnix coturnix japonica) canli agirlik yönünde yapilan seleksiyonun ve yaşin yumurta özelliklerine etkileri]

The present study was conductud on quails (Coturnix coturnix japonica) to evaluate the effects of line and age of bird on egg characteristics. Total ninety Japanese quail from unselected (C) and selected (S) for high 4-week body weight for five generations were used. All birds were weighed individually at 10, 14 and 18-week of age and egg characteristics were obtained on all eggs collected during these weeks. The results showed that egg weight was increased by selection for high 4-week body weight and egg weight differences between the lines was due to increases in yolk and albumen weight of egg. However there were no difference in percentages of albumen, yolk and egg shell between S and C lines. Egg productions of two lines were similar. While increasing flock age. egg weight was increased, egg shell thickness was decreased, haugh unit and shape index were not changed. Consequently, composition of egg was changed by age of bird. In early stage of egg production yolk percentage was lower, albumen percentage was high in S line than C line, but later stage of production these differences between the lines were disappeared