Heritability of the Body Weight of Crossbred Broiler Chicken : Selected in Five Generations

Abstract

Three hundred and nine crossbred broilers, in the first generation, which descended from the commercial broiler cockerel mated with Changhai-Rhode crossbred and Barred Phymouth Rook hens, were selected as parents for the next generation by using 6 weeks body weight as selection criterior. The average 6 weeks body weight of 745, 1,860, 1,470 and 1,235 progenies from the second, third, fourth and fifth generation were 871.7, 1,057.5, 1,021.8 and 1,205.1 grams comparing with 581.5 grams of the first generation. Except for the first generation, the feed conversion ratio (FCR) in the successive generations were 2.07, 2.06, 2.12 and 2.07, respectively. In five generation period of selection, the average 6 week body weight in the fifth generation was more than the first about 107.2% or 632.8 grams. The heritability value of 6 week body weights in five generation periods were ranged from medium to high as 0.22 to 0.48 the fifth generation had the lowest value (0.22). The genetic correlation (γ_G) computed from sire component in the first generation between 6 to 9 weeks was the highest value (0.97). From this experimental selection, it was shown that it is possible to establish our own broiler parent stocks by using 6 week body weight as selection criterior.