Effect of Broiler Strain, Sex, and Age on the Live Body Weight and Relative Weights of the Visceral Organs in Broiler Chickens

Abstract

The study examined the effect of age, strain, and gender on chickens' body weight, carcass yield, and relative weight of some visceral organs. A total of 224-day-old chickens from two broiler strains (Arian and Ross 308) were randomly allocated into 56 wire cages. Each cage contained 4 broilers (two males and two females), resulting in 28 replicate cages for each strain. On four specific days of the rearing period (days 10, 24, 32, and 42), 12±2 male and 12±2 female chickens from each broiler strain were randomly selected, weighed, and slaughtered. The carcass yield, visceral organ weights, and the weight of different segments of the alimentary tract were determined on each slaughter day after evisceration. The findings indicated that Ross 308 broilers were significantly heavier than Arian chickens at the ages of 32 and 42 days. The gizzard and jejunum relative weights in the Arian strain were significantly higher than in Ross 308 (P<0.05). Females in both strains had a higher relative liver weight compared with males. The bursa in the Ross 308 was found to be significantly heavier compared to Arian only in 32-day-old broiler chickens. Additionally, in 24-day-old chickens of the Ross strain, the weight of the bursa was heavier than that in 10-day-old chickens from the same strain (P<0.05). Therefore, due to enhanced bursa growth (10–24 days) and higher relative bursa weight in Ross 308 compared with Arian, it is postulated that the Ross 308 strain underwent more intensive breeding programs for improved immune competence.