Growing and laying performances of two varieties of Noi chickens raised in an intensive farming system

This study was conducted to compare the black and dark brown varieties of Noi purebred chickens raised in an intensive farming system. A total of 600 black and 600 dark brown Noi chickens were observed starting from 1 day after hatching. At 20 weeks of age, 30 black Noi cocks and 300 black Noi hens, as well as 30 dark brown Noi cocks and 300 dark brown Noi hens, were studied until the beginning of reproduction. All roosters and hens were kept in individual cages and mating was accomplished artificially. At 24 weeks of age, the black and dark brown Noi cocks had average weights of 2555 and 2600 g, respectively, and 1796 and 1830 g for hens, respectively. There was no difference in body weight between the two varieties. The first egg-laying ages of both varieties were relatively late. From the age of 25 weeks up to 50 weeks, the egg yields of the black and dark brown Noi hens were 74.33 and 77.98 eggs/hen, respectively, with average egg weights of 48.3 and 49.7 g, respectively. Embryonic egg rates were low at 80.3 and 81.9% for the black and dark brown varieties, respectively, and the rate of chick/incubated eggs was 73.4 and 77.0%, respectively. The Noi chickens, especially the dark brown variety, reached a relatively high egg yield in an intensive farming system, which creates great potential for the exploitation and development of this genetic source.