Effects of Selection for Four Week Body Weight on Some Parameters in Japanese Quail (Coturnix coturnix japonica) 2. Production Traits and Genetic Gains [Japon Bildircinlarinda (Coturnix coturnix japonica) Canli Agirlik için Yapilan Seleksiyonun Bazi Parametrelere Etkisi 2. Verim Özellikleri ve Genetik Degişmeler (Kazançlar)]

This research was carried out to determine the genetic effects of divergent selection under two different selection under two different selection pressure for 4 week body weight over 3 generations on 4 week body weight and related characters such as slaughter weight, carcass weight, breast weight and leg weight in Japanese quail. Birds were weighted individuay. Individual selection for body weight was carried out at 4 weeks, separately for each sex. The proportion kept was 10% for males and 30% for females in H1 and H2 lines, and H4 lines were selected for low body weight, HS was a control line. Total gains obtained for 4 weeks body weight of 3rd generation H1, H2, H3, H4 lines males were 19.76 g, -47.92 g, 17.42g, -45.85g, respectively. Similar total gains for females were 26.49 g, -12.37 g, 19.18 g, -23.56 g, respectively. At the end of three generations, total genetic improvement obtained for 4 weeks body weight in H1, H2, H3 and H4 lines were 23.28 g, -8.52 g, 20.22 g, 14.12 g for males and 25.06 g, -12.83 g, 19.88 g, 14.79 g for females, respectively. Changes in 4 weeks body weight in H1, H2, H3, H4 lines were resulted with similar changes in slaughter weight, carcass weight, breast weight, leg weight, especially under high selection pressure in both direction. It was concluded that genetic improvement under high selection pressure for four week body weight will be more effective in both directions