Effect of Non Genetic Factors on Growth Traits in Short Term Selection for Different Ages in Japanese quail

Meat type Japanese quail were subjected to three different methods of individual phenotypic selection viz., high two week body weight, four week body weight and high four week body weight coupled with low relative body weight gain between 4-6 weeks of age for three generations. The lines, generations, sexes and hatches had significant (P < 0.01) effect on the body weight at hatch, 1,2,3,4,5, and 6 weeks of age, except the influence of sex on body weight at hatch which was not found to be significant. In base generation (S0), the least squares means of body weights at hatch,1,2,3,4,5 and six weeks of age were 8.31±0.04, 38.53±0.29, 82.72±0.60, 120.13±0.74, 148.34 ±0.85, 173.15±0.89 and 191.15±1.04 g, respectively. The corresponding means were 8.04±0.04, 38.84±0.30, 77.51±0.61, 110.71±0.75, 144.77±0.86, 170.27±0.90 and 190.81±1.06 g in first generation (S1); 8.93±0.04, 41.41±0.28, 78.81±0.58, 128.68±0.71, 165.83±0.82, 184.27±0.86 and 202.84 g in second generation (S2) and 8.42 ± 0.04, 39.73±0.26, 78.17±0.53, 123.86±0.65, 160.75±0.76, 183.53±0.79 and 202.59±0.93 g, in third generation (S3). The least squares means of body weights of males at hatch, 1, 2,3,4,5 and 6 weeks of age were 8.41±0.04, 39.32±0.26, 78.47±0.54, 118.72±0.66, 150.81±0.76, 169.87 ± 0.80 and 183.42±0.94 g, respectively and in females in the same were 8.44±0.04, 39.94±0.26, 80.14±0.52, 122.97±0.65, 159.04±0.75, 185.73±0.78 and 210.28±0.92 g, respectively.