Effect of genotype on production traits in broiler chickens


  • M. LALEV


broiler, European Poultry Efficiency Factor (EPEF), body weight, Cobb 500, Ross 308, slaughter analysis


The study was carried out on two broiler chicken genotypes Ross 308 and Cobb 500 in the nucleus poultry farm of the Institute of Agriculture – Stara Zagora between April and June 2012. For this purpose, 300 eggs of each genotype were set for incubation to compare the meat traits of two of the most popular broiler chicken hybrids: Cobb 500 and Ross 308 reared at the nucleus poultry farm of the Institute of Agriculture – Stara Zagora. The fertility rate, embryonic death rate, weight loss between incubation days 0 and 18, and the hatchability of set and fertilized eggs were determined. The number of chickens included in the study was 100 from each genotype (50 male and 50 female). Experimental birds were reared on wooden shavings bedded floor, with constant access to compound feed according to the age until 49 days of age. The live body weight was determined individually by weighing birds at 1, 14, 28, 42 and 49 days of age. By the end of the experiment, a slaughter analysis of three female and three male broilers with a live weight close to the group average was performed. For integral assessment of broiler combinations, the European Poultry efficiency factor (EPEF) was calculated. The results of the present experiments showed a number of differences in meat and slaughter traits between studied broiler chicken hybrids. The weight of hatchlings differed significantly according to the genotype (p<0.05). One-day-old Cobb 500 broilers were heavier than Ross 308 broilers. At the end of the experiment, Соbb 500 broilers attained a higher live weight, and were heavier than Ross 308 birds by 6.29 %. The feed intake per kg weight gain over the entire experimental period was 2.178 kg and 2.181 kg for Ross 308 and Cobb 500, respectively. Higher values of the European Poultry Efficiency Factor (EPEF) were established in Соbb 500 broilers, which were more economically efficient than Ross 308 by 14.87 points (6.18 %). The performed slaughter analysis showed higher values of slaughter traits in Cobb 500, which had higher growth potential: roasting weight 1810.67 g and grilling weight 1710.50 g; whereas the respective values in Ross 308 chickens were 1547.67 g for grilling and 1645 g for roasting. In male Cobb 500 broiler chickens, the roasting percentage was 74.02 %, which was 1.41 % more than that of Ross 308 males. The same trend was observed in female birds as well, i.e.