Abstract
The study was planned to evaluate the effect of different naked-neck (NN) chicken genotypes and breeder ages on the growth performance of their progenies. A total of 126 chicks, from two breeder ages and three NN varieties, were reared up to 20 weeks of age. A randomized complete block design in factorial arrangement, with six treatments of seven replicates of two females and one male each, was applied. Treatments consisted of three NN varieties (light brown, black, and dark brown) and two breeder age groups (45 and 55 weeks old). Growth performance (body weight gain, feed intake and feed conversion ratio) were evaluated. Higher feed intake was observed in both the male and female progenies of 55-week-old compared with 45-week-old breeders. Light brown males had higher weight gain than dark brown males, whereas in the female progeny, higher weight gain was obtained in the black variety than that in the light brown and dark brown varieties. Regarding breeder age groups, both male and female progenies of 55-week-oldbreeders exhibited higher weight gain than those of 45-week-old breeders. The male progeny of 55-week-old black breeders showed the highest body weight gain among all treatments. Regarding female progeny, higher weight gain was observed in the black variety compared with the light brown and dark brown variety, and in the progeny of 55-week-old breeders than in the progeny of 45-week-old breeders. The interaction between factors showed that females from 55-week-old black breeder has the highest weight gain, whereas the lowest weight gain was found in the progeny of 45-week-old light brown breeders. The male progeny of light brown breeders showed better FCR than those of black and dark brown breeders and of 55-week-old breeders compared with that of 45-week-old breeders. The best FCR was obtained in the progeny of 55-week-old light brown breeders. In females, while no influence of breeder age was detected, better FCR was determined in black than in dark brown and light brown varieties; however, the interaction between factors was significant, with the best FCR obtained in the female progeny of 55-week-old black breeders, and worst in the progeny of 45-week-old light brown breeders. In conclusion, the light brown and black varieties of naked-neck chickens and the progeny of 55-week-old breeders presented better growth performance.