Morphological and carcass traits of three chicken genotypes under free-range, semiintensive, and intensive housing systems

Abstract

The present study evaluated the effect of housing system on morphometric and carcass traits of 3 chicken genotypes. In total,180 cockerels and 180 pullets of 6 weeks old were studied. A randomized complete block design in factorial arrangement, with 18experimental units of 20 birds each, was applied. Treatments consisted of 3 genotypes consisting of purebred Naked Neck (NN) birdsand two crossbreeds (Rhode Island Red × Naked Neck = RNN, Black Australorp × Naked Neck = BNN) and 3 housing systems (freerange,semiintensive, and intensive). Regarding males, RNN chickens had the highest weight at slaughter (1491.12 ± 64.10 vs. 1390.30 ±49.15 and 1333.76 ± 37.54 g; P = 0.0009), dressed weight (870.12 ± 32.32 vs. 794.07 ± 24.75 and 724.51 ± 10.50 g; P < 0.0001), and breastweight (158.35 ± 8.03 vs. 128.26 ± 11.06 and 118.37 ± 8.18 g; P < 0.0001) as compared to BNN and NN. In terms of housing system,keel length (10.66 ± 0.15 and 10.42 ± 0.11 vs. 9.93 ± 0.15 cm; P < 0.0004), weight at slaughter (1482.78 ± 50.15 and 1498.02 ± 33.65 vs.1234.37 ± 19.95 g; P < 0.0001), and dressed weight (829.78 ± 37.63 and 829.05 ± 24.74 vs. 729.87 ± 15.49 g; P = 0.0007) were higher insemiintensive and intensive birds as compared to free-range birds. Regarding females, drumstick length (11.66 ± 0.25 vs. 10.47 ± 0.23and 10.36 ± 0.31 cm; P = 0.0007), drumstick weight (124.93 ± 13.70 vs. 93.41 ± 2.91 and 86.43 ± 2.51 g; P < 0.0001), and thigh weight(132.85 ± 13.23 vs. 107.68 ± 2.05 and 97.13 ± 3.42 g; P < 0.0001) were higher in intensive birds than free-range and semiintensive systems.In conclusion, RNN and BNN chickens of both sexes had better morphological and carcass traits during the growing stage as comparedto NN.