Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Genetic study of Dandarawy chickens: I. Heritabilities and genetic correlations of body weight and weight gain | 81 Genet. Sei. Evol. 1989 21 81-92 Elsevier INRA Original article Genetic study of Dandarawy chickens I. Heritabilities and genetic correlations of body weight and weight gain . Abdellatif Faculty of Agriculture Animal Production Department Assiut University Assiut Egypt received 4-11-1987 accepted 5-5-1988 Summary Heritability values of body weight and weight gain at the ages of 1 d and 4 8 12 and 16 wk were estimated from 57 half-sib families of a strain of the Egyptian breed Dandarawy representing 57 sires 256 dams and 1 605 offspring. Estimates were obtained for both of the sexes separately as well as for the two combined. The estimates of heritability ranged from to for males and females from sire components of variance and to for males and females from dam components of variance. There were marked differences between heritability estimates from sire and dam components of variance and between males and females. The heritability estimates from sire components were generally higher than those from dam components which indicated the importance of the additive genetic effect and possible sex-linked effects. It was also noticed that the environment had an effect on both body weight and weight gain which is reflected in heritability estimates from one age to another. The results showed that there were highly significant correlations between body weights from 4 to 16 wk of age. There were no correlations between hatch weight and weights at the other ages. This indicates that it is possible to consider the hatch weight as a trait completely separate from the other traits in males females and the sexes combined. The highly significant genetic and environmental correlations showed that both genetic and environmental factors had the same influences on body weight from 4 to 16 wk of age. There were absent estimates of the genetic correlations especially with the dam components of variance in males and females. The correlations between weight gains .
