Kordofan Animal Research Center, College of Agricultural Studies, Department of Animal Production, Sudan.

Sudan University of Science and Technology, College of Agricultural Studies, Department of Animal Production, Sudan.

Sudan University of Science and Technology, College of Agricultural Studies, Department of Animal Production, Sudan.

Sudan University of Science and Technology, College of Agricultural Studies, Department of Animal Production, Sudan.
Genotypes ,Gene ,Frizzle Chicken ,Heat Tolerance ,

Frizzled (Ff) and normally feathered (ff) genotypes were reciprocally mated to produce the first generation: frizzled (Ff-F and Ff-N) and normally feathered (ff-F and ff-N) genotypes. Later the second generation produced by internal mating within each genotype. The produced genotypes were: Frizzled (Ff-FF and Ff-FN), over frizzled (FF and normally feathered (ff-FF, ff-FN, ff-NF and ff-NN) genotypes. 192 and 288 chicks were used for the 1st and the 2nd generation. All chicken were kept on open sided houses and reared under the same environmental, managerial and hygienic condition. Feed and water were supplied ad libitum. In the first generation, the frizzled Ff-FF and normally feathered ff-FF genotypes has significant difference in body weight gain and the feed conversion ratio at 8-12 week than Ff-NN & ff-NN genotypes during. In the second generation no significant differences in body weight, body gain or feed intake were observed, although the normally feathered genotype showed significantly lower feed conversion ratio compared to the rest of the studied genotypes except for the frizzled Ff-FN genotype. The frizzled genotype Ff-FN was heavier than the Ff-F. Moreover, the frizzled hens were heavier than the normally feathered one at sexual maturity age. This could be attributed to the fact that, the values of the growth rate and the feed consumption and egg production measured during the winter and autumn seasons. However, the effect of the frizzle gene is only well pronounced at high constant temperature .This is attributed to its tolerance to heat stress and disease resistance. Therefore, introducing frizzle (F) genes in selection programs for its characteristics in heat tolerance and disease resistance must be taken into consideration.

6 , 7 , 2016