قابلية التآلف و فعل الجين لسلالات مختلفة من آباء و أمهات فروج للحم 1. وزن الجسم

Abstract EN

An experiment was carried out to estimate the general (GCA) and specific (SCA) combining ability and reciprocal effects, as well as degree of dominance.

Four broiler breeder strains (Fawbro, FB; IPA 2000, IP; Lohmann, LH; Hybro, HB) with 160 dams and 46 sires from each strain were selected to be parents.

They were mated a full 4 x4 diallel) cross, which resulted in a number of genetic groups (16 genetic groups).

The comparisons among genetic groups were made after obtaining hatching eggs (100 eggs/ combination) from parent dams at 50 wk of aee.

These hatching eggs were incubated to obtain the genetic groups that used in this study.

A tota3 of 50 broiler chicks per strain crosses (800 chicks for all genetic combinations) were reared in floor house with 32 pens.

They were assigned after wing-banded on the experimental replications with two replicates per combination (25-chicks/ replicate).

Significant differences tP<0.05) were found among genetic groups for body weight (BW) at 1, 28 and 49 day of age.

The hybrids LHxHB and hybrids reciprocal HBxLH significantly dominated all parents of FB and IP exhibited negative significant GCA on BW.

The hybrids reciprocal hybrids LHxFB, LHxIP and HBxFB had highest specific combiuine ability( SCA) and reciprocal effect (RCA) on BW at 49 days of age.

The degree of dominance of hybrids and reciprocals were greater than 1.0 at day old and less than 1.0 at days 28 and 49 of age.

This result refers to both additive and non-additive genes action had an effect on BW.

In spite of the effect of SCA on BW, It can be concluded that the GCA is the most important factor in inheritance of BW rather than SCA.

This mean that the effect of additive genes had play an important role on growth performance.