Comparative analysis of turkey biometrics in Mexican, Spanish, and Italian populations

The present work aims to define the morphological variability of turkey populations from Italy (Brianzolo and Nero d'Italia), Spain (Andalusian), and Mexico (Guajolote from Hidalgo and Veracruz). To this end, a set of 21 body measurements, 8 body indices, and 16 qualitative traits were collected from 255 adult turkeys. A Pearson's correlation analysis was conducted separately in each sex to describe the association between the morphological variables. Furthermore, a discriminant canonical analysis was conducted for each sex to determine genotype differences. Therefore, a set of 17 and 20 discriminant items were identified for males and females, respectively. These variables included body measurements, biometric indices, and qualitative traits. The cross-validation test revealed a high accuracy of the discriminant model, which was slightly higher in males (97.6 %) than in females (96.2 %). Furthermore, the Euclidean distances between the observations indicated a close relationship between the Andalusian turkey and Mexican guajolote from Hidalgo. This work provides new insights into the biometric diversity of the domestic turkey, as most of the genotypes under study had not yet been characterized in an international context. Moreover, the morphological differences between indigenous turkeys were previously thought to be unnoticeable by most researchers. This would allow breeders' associations and public institutions to define measurement protocols, given the current lack of consistent guidelines worldwide. Furthermore, the findings of the present study seem to depict the historic expansion of the domestic turkey from Mexico to Europe through Andalusia.