Comparing slow-growing chickens produced by two- and three-way crossings with commercial genotypes. 2. Carcass quality and blood parameters

Abstract

This study examined live weight, carcass traits, meat quality and blood parameters of slow-and medium-growing chickens at 84 days of age and compared them with those of commercial slow-and fast-growing genotypes. A total of 2,240 chicks were used in the study. Day-old chicks were wing-banded, and 280 mixed male and female chicks from each genotype were randomly allocated to one of four 1.7 x 3 m compartments. At 84 days of age, 10 males and 10 females per genotype from each compartment were slaughtered, and the following characteristics were evaluated: slaughter weight and carcass traits; meat pH, color values (L* a* b*), water-holding capacity (WHC), chemical composition and texture, blood-serum parameters. Similarities of traits were observed between two-way crossing and commercial slow-growing genotypes and between S3 and S4 three-way crossing and fast-growing genotypes. S5 and S6 three-way crossing genotypes had the slowest growth rates. Genotype was found to have a significant effect on thigh and breast dry-matter and protein levels, with the highest levels found in the two-way crossings. Genotype was found to have a significant effect on blood parameters. Significant differences were found between the sexes in thigh and breast ratios, abdominal fat levels, pH and some color values (P < 0.05). Female chickens also had significantly higher albumin, triglyceride and thigh-meat protein levels than males (P < 0.05). Differences in meat chemical composition did not vary significantly by sex. Sex x genotype interaction was found to have an insignificant effect on all parameters with the exception of texture (breast-meat hardness).