As a result of the conducted comparative studies, it was found that in the process of fattening, the broiler chickens of the Cobb-500 and Ross-308 crosses met the standards of meat productivity grown in the conditions of feedlots on the territory of the Voronezh region. The results of fattening showed that Cobb-500 and Ross-308 cross broiler chickens had different indicators of live weight and, accordingly, the mass and yield of carcasses after primary processing as a result of slaughter. The live weight index of broiler chickens of the Ross-308 cross was 154.5 grams lower than that of the Cobb-500 cross, respectively, the mass of the unemboweled carcass after transportation by 208.5 grams, the mass of the gutted carcass by 178.7 grams. The slaughter yield of the unemboweled carcass was also 0.5% lower, and the gutted one by 1%. Individual anatomical parts of the carcasses of broiler chickens of the Cobb-500 cross exceeded the mass of individual anatomical parts obtained after cutting the Ross-308 cross. It was determined that broiler chickens of the Cobb-500 cross as a result of a more intensive increase in muscle mass under equal conditions compared with the Ross-308 cross with intensive metabolic processes in the body had lower safety indicators for the herd. It is determined that the Cobb-500 cross is more susceptible to the stressful effects of technological factors, for example, due to the increased temperature and humidity conditions of the room, noise, etc. Based on this, the bird at the final stage of fattening has more contact with the aggressive environment of the bedding material, i.e. spends more time sitting as a result of a heavy load of body weight on the joints of the legs. As a result, the case increases, the weight gain on the herd decreases, and the number of pathological processes of paws increases and, accordingly, their culling. As a result, it can be noted that broiler chickens of the Ross-308 cross are less susceptible to stressful production factors, and also have higher rates of preservation and slaughter yield of bird paws as a by-product, based on the fact that the number of defective products decreases
