SUMMARY The Guajolote is a native North American poultry, originally domesticated in Mexico, from where it was exported to Europe, and from there to the rest of the world, becoming the genetic base of the breeds and varieties of turkeys that are known in the present. However, the phenotypic and productive characteristics of Guajolotes have been poorly studied, which has limited its racial recognition. This review describes the current knowledge on the historical distribution, morphological, morphometric and phaneroptic characteristics of Guajolotes, as well as the productive performance and quality attributes of Guajolote meat and eggs. Due to the long process of evolution, Guajolotes have a good capacity for adaptation and high rusticity that allows it to reproduce under different environmental and management conditions. It has unique morphological peculiarities and great variability in terms of its morphometric and phaneroptic descriptors. This bird has a marked sexual dimorphism in favor of males. Females are excellent natural incubators, they start laying from between 6 and 8 months of age, laying an average of 16.7 ± 3.6 eggs per laying season. Males have a good capacity to convert food into meat and can reach a live weight of between 5499 ± 148 to 5835 ± 173 g at week 30 of age, having a carcass yield of 79%. The nutritional quality of meat and eggs of Guajolote is even higher than that of chicken. In conclusion, Guajolotes are poultry with characteristics of high biological and productive value; however, better management strategies are required to maximize its genetic potential for the benefit of the food security of small and mid-size producers that depend on this poultry genetic resource.

Meat is a complex food with a structured nutritional composition that makes it an essential component of the human diet. In particular, the meat of native guajolote that is traditionally raised in natural conditions is an important dietary source of proteins of high biological value for the rural population of Mexico. The study aimed to evaluate fatty acids (FAs) profile and nutritional indices of breast and leg meat of native guajolote subjected to two heat treatments. For the study, a total of sixty muscle samples (30 breast meat and 30 leg meat) from adult male native guajolotes were used. The FA profile and nutritional indices were evaluated in raw meat (control) and meat subjected to two heat treatments (boiled and baked). The heat treatments, independently of the type of muscle, increased (p ≤ 0.05) the concentration of saturated (SFA) and monounsaturated FA (MUFA); in contrast, polyunsaturated FA (PUFA) decreased. Likewise, the dietary FA index, which has a negative hypercholesterolemic effect, and the atherogenic index increased in guajolote meat from the effect of the heat treatments, while the essential and undesirable hypercholesterolemic FA indices decreased. In conclusion, heat treatments increase the content of SFA and MUFAs in breast and leg meat of native guajolote. Boiling or baking the meat deteriorates PUFAs but increases the nutritional indices. The present investigation would provide valuable information for the guajolote meat product processing.

Asociación Interprofesional para el Desarrollo Agrario AIDA. Información Técnica Económica Agraria ITEA.

Male turkeys are raised mainly for meat production due to their high carcass yields and good capacity to convert food into meat. However, their carcass characteristics remain poorly understood. The objective of the study was to describe the carcass traits of 45 male native Mexican turkeys raised in the municipality of Champoton, Mexico, using principal component analysis (PCA). Fourteen carcass traits, namely, slaughter weight (SW), hot carcass weight (HCW), cold carcass weight (CCW), dressing percentage (DP), neck weight (NEW), foot weight (FEW), breast weight (BRW), thigh weight (THW), drumstick weight (DRW), wing weight (WIW), back weight (BAW), gizzard weight (GIW), heart weight (HEW), and liver weight (LIW), were collected. Pearson’s correlation analysis revealed strong positive relationships among carcass variables, with the highest correlations observed between CCW and HCW (r = 0.99; p < 0.001), SW and HCW (r = 0.98; p < 0.001), and SW and CCW (r = 0.98; p < 0.001). Hierarchical clustering identified four main groups of variables with similar correlation patterns. Three principal components (PCs) with eigenvalues greater than 1.0 were extracted, explaining 85.48% of the total variance in carcass traits. The first principal component (PC1) contributed 72.81% of the total variation (eigenvalue = 10.19), with high loadings (>0.70) for CCW (0.98), HCW (0.98), SW (0.98), DRW (0.95), BRW (0.91), WIW (0.90), THW (0.89), HEW (0.87), BAW (0.81), and FEW (0.82), representing a general size factor. PC2 explained 6.86% of the variance (eigenvalue = 0.96), characterized by a negative loading for DP (−0.64) and positive loadings for GIW (0.35) and LIW (0.34). PC3 accounted for 5.81% of the variance (eigenvalue = 0.81), with a negative loading for LIW (−0.63) and positive loadings for NEW (0.51) and FEW (0.46). Communality values exceeded 0.85 for all variables, indicating adequate representation in the reduced dimensional space. It was concluded that PCA effectively reduced dimensionality while retaining 85.48% of original information and can be used for the improvement of the carcass traits of male native Mexican turkey breeding programs.

The study aimed to investigate the effects of slaughter age and gender on carcase characteristics and meat quality of native Mexican turkeys raised under an extensive production system. Forty-five native turkeys (36 males and 9 females) were used. They were sacrificed at 24, 32, and 40 weeks of age. Slaughter age significantly affected slaughter weight (SW), hot carcase weight (HCW) and cold carcase weight (CCW). Also, dressing percentages, non-carcase components, internal organs, abdominal fat, and most carcase parts and proportions were affected. Gender significantly affected SW, HCW and CCW, non-carcase components, internal organs, and carcase parts weights. Regarding the physical properties of breast and leg meat, pH values and colour parameters taken at 45 min and 24 h post-mortem, as well as the water-holding capacity (WHC), cooking (CL), and drip loss (DL), were significantly affected by slaughter age, except CL in leg meat. Meanwhile, gender influenced L*_45min, b*_24h, the pH_24h values, and CL in breast meat. Concerning the chemical composition of the meat, slaughter age had a significant effect on the ether extract (EE) content of breast meat and on dry matter (DM), crude protein (CP), EE, ash, and energy contents of leg meat. Gender significantly affected the DM, CP, and energy contents of breast meat and DM, EE, and energy contents of leg meat. These results indicate that the carcase weight and yield, and its components, as well as meat quality, were better in older male turkeys than in adult females.