Genetic and crossing effects in the crossing between sinai and white leghorn chickens for egg production traits

الملخص EN

The Sinai fowl (S), White Leghorn breeds (WL) and their reciprocal crossbreds (S x WL) and (WL x S) were used to evaluate the effects of crossing on egg production and estimates the heterocyst, additive, maternal, sex-linked and reciprocal effects during the first three months of production.

Egg number (EN), egg weight (EW), egg production (EP), age at first egg (AFE), body weight at sexual maturity (BWM) and egg quality traits were evaluated under desert conditions.

Significant differences (P < 0.05) were found between genetic groups for EN, EW, EP and BWM.

The Sinai females matured earlier but produced less egg than WL females.

White Leghorn showed higher EN and EP and reached later at sexual maturity when compared to Sinai and the crossbreds.

Significant differences between the crossbreds were found for all production traits.

Hybrid (WL x S) females commenced lay at an earlier age and produced more eggs than crossbred (S x WL) females.

The mean egg weight of Sinai was 51.8 g.

It was significantly (P < 0.05) higher than that of the WL (47.2 g) and of the crossbreds (52.3 and 48.5 g) in (WL x S) and (S x WL), respectively.

There were significant differences between genetic groups for all egg quality traits.

Sinai females had better egg quality traits than other genetic groups.

Additive genetic and sex-linked effects were highly significant (P < 0.001) for EN, EP and EW at 90 days of production.

Maternal and sex-linked had negative effects on EN and EP at 90 days of production.

The reciprocal effects for egg production did not show any significance.

No heterocyst was detected in EP at 90 days of production.

Significant heterocyst was observed in F1 crosses for increased egg weight (1.8 %) and percentage of egg production (1.54 %).

Most of egg quality traits had little or no heterocyst.

Sex-linked effects increased (P < 0.001) proportion of yolk but decreased albumen and shell percentages.

High genetic correlations were found between egg production traits (EN, EP and AFE).

Negative and significant (P < 0.05) genetic correlation between EN and EW was -0.22.

There was a moderate negative phenotypic correlation between EN and EW.

AFE showed negative and high correlation with EW.