Phenotypic diversity between Brazilian fighting cocks and naturalized roosters

Abstract

The present study was carried out to evaluate the phenotypic diversity between fighting cocks; roosters of the naturalized ecotypes Grauna Dourada, Brejeira, Teresina, and Nordestina; roosters of the Sertaneja genetic (synthetic) group; and family-farmed roosters via descriptive and multivariate analyses. The qualitative traits evaluated by descriptive analysis indicated a prevalence of single comb in the Grauna Dourada, Teresina, Nordestina, and Sertaneja ecotypes, whereas the Brejeira ecotype, fighting cocks, and family-farmed roosters have a pea-type comb, which can be viewed as a sign of introgression of the fighting cock in flocks of the region. Dark plumage prevailed across the groups. The quantitative traits subjected to multivariate analysis by clustering criteria placed the four ecotypes and the synthetic type in a single group, the family-farmed animals were allocated to another group, and, lastly, the fighting cocks were placed in a third group. These results were similar to those generated by principal component analysis, which indicated body length, wingspan, and body weight as the traits of greatest variability to discriminate the different groups. It is important to stress the risk of genetic erosion to which naturalized chicken populations are exposed as a consequence of the introgression of fighting cocks in naturalized-chicken rearing facilities.