Abstract:
The present study was conducted to estimate correlations among performance and egg
quality traits in Iranian native fowl. Data were collected from 21,679 birds at the Isfahan
Native Fowl Breeding Center to derive genetic parameters for performance traits and egg
quality traits were measured on eggs of 1,020 birds. Genetic correlations of performance
and egg quality traits were estimated with a bivariate animal model using ASREML
software. Body weight at hatch, 8, and 12 weeks of age (BW0
, BW8
and BW12,
respectively) positively (0.05 to 0.82) correlated with egg weight (EW), shell weight (SW),
specific gravity (SG), yolk height (YH) and albumen weight (AW). BW0
and BW12
negatively (-0.10 to -0.26) correlated with shell strength (SS) and shell thickness (ST).
Genetic correlations of BW8
and BW12 with albumen height (AH) and Haugh unit (HU)
were highly negative (-0.45 to -0.55), whereas BW12 showed positive correlation with
shape index (SI) (0.22). Shell weight showed high positive genetic correlation with age at
sexual maturity (ASM) (0.75), while its genetic correlation with egg number (EN) was
highly negative (-0.71). EN also showed high negative correlation with yolk and albumen
weight (-0.91 and -0.75, respectively). Based on the present results, selection for higher
BW will lead to production of eggs with higher internal quality. In contrast, this kind of
selection will reduce the shell strength and shell thickness. Therefore, selection should be
based on an index including performance and egg quality traits. This will help to develop
indigenous strain of meat-cum-egg type chicken.
Keywords: Age at sexual maturity, Haugh unit, Specific gravity
