Analysis of quality and prediction of external and internal egg traits in Mexican native turkey hens

This study aimed to evaluate external and internal quality traits and determine prediction equations for some of these traits in eggs of Mexican native turkey hens. A total of 72 eggs from native turkey hens in the laying stage raised in rural municipality of Villaflores, Chiapas were measured. The external traits evaluated were: egg weight (EW), polar diameter (PD), equatorial diameter (ED), egg shape index (SI), shell weight (SW), shell percentage (SP), egg surface area (ESA) and shell weight per unit surface area (SSA). The internal traits were: albumen height (AH), yolk height (YH), albumen weight (AW), yolk weight (YW), Haugh units (HU), albumen percentage (AP), yolk percentage (YP) and yolk color (YC). The data were analyzed with descriptive statistics and Pearson correlation coefficients (r) and linear regression using the SAS program, ver. 9.4. The values obtained for the external egg quality traits showed greater variability. Pearson's correlation coefficients between external and internal traits were positive and moderately significant (P <0.05), as well as highly significant (P <0.0001), and ranged from r = 0.31 (EW vs PD) to r = 0.99 (ED vs ESA). All linear regression equations to predict EW, SW, AW and YW were found to be significant (<.0001). The best predictors of EW were PD, SI, SW and ESA (R-2 = 76%). SW and YW traits can be adequately predicted using the EW and SI values together (R-2 = 59% and R-2 = 74%, respectively), while the AW can be predicted from the EW (R-2 = 33%). Based on the results obtained, it is suggested to implement selection programs to improve the quality parameters of the native turkey hen egg in Mexico.