Influence of some major genes on growth traits of local pullets in humid tropical environment

摘要

A total of 210 day-old local chickens generated from a main cross and reciprocal crossing of local chickens possessing some major genes (naked-neck (Na), frizzle (F) and normal feathered gene (na) were used to evaluate the growth characteristics of the pullets in a randomized complete block design. The genetic groups produced were homozygous naked neck, Naa and frizzle (F/Na), reciprocal naked neck (Na/F) and frizzle (F./Na) and normal feathered (naa) chickens. There was a significant difference (p<0.05) in mean daily feed intake at week 8, with the Na/F genotypes consuming more than other groups. Mean body weight gain and feed conversion ratio did not differ among all the genetic groups. Results indicate that the F/F genotype had significantly (p<0.05) highest mean day-old body weight (30.90±2.73g), highest mean body weigh at sixteen (442.50±6.61g) and twenty four weeks (114.00±32.99g) of age. The growth rate of frizzle genotypes in all combinations (F/F, F/Na, Fa) were significantly (p<0.05) higher than both naked neck homozygous and heterozygous (Na/Na, Naa) and normal (naa crosses when compared. The coefficient of determination (R2) of F genes (97.4, 84.40, 92.90) were high and compared favorably with other genetic groups indicating that F genes highly contributed to significant rates of growth of frizzle crosses. The naa individuals survived most and had significantly least mortality compared to other genetic groups. This result depicts the frizzle genotype as a fast growing indigenous chicken which may be involved in breeding for developing native foundation stock for production of meat type chicken in the humid tropics.