Agricultural institute, Hybrid Centre of Poultry Breeding, BG - 6000 Stara Zagora, Bulgaria
OBLAKOVA, M., 2006. Phenotypic correlation between some morphological characteristics of eggs in basic turkey lines at the age of 32 weeks. Bulg. J. Agric. Sci., 12: 483-488
The study was performed in 2004 in the selection farm of the Hybrid Centre of Poultry Breeding at the Agricultural Institute, Stara Zagora. Eggs from turkeys from the following lines were investigated: Super Heavy (SH), Meat Heavy (MH), Layer heavy (LH), Layer Light (LL), North Caucasian Bronze (NCB) as well as the parental UK line BIG-6. The correlation coefficients and their statistical significance were determined for the relationships among the following traits: egg weight to yolk and shell weights, egg weight to shape, albumen and yolk indices; shell weight to yolk weight, shape, albumen and yolk indices; shape index to yolk weight, yolk index to albumen index; albumen index to yolk weight and yolk index; yolk weight to yolk index.
The observed correlations between the egg weight and yolk weight in hens from the LL, MH and SH lines were positive and statistically significant (r= 0.83, r=0.78 and r=0.68 respectively). The egg weight exhibited the same relationship to shell weight in LH (r=0.84), MH (r=0.83) and the LL (r=0.68) lines (P < 0.001). The augmentation of the shape index, the albumen index and yolk index did not result in increased egg weight. The observed correlation coefficients were negative and negligible (P < 0.05). The increased yolk weight would result in higher shell weight in hens from the MH (r=0.70), the LL (r=0.66) (P < 0.001) and the LH (r=0.47) lines (P < .01). There was not a correlation between yolk weight and the yolk index in turkeys at the age of 32 weeks that suggested the performance of independent selection for these traits.