الفهرس 
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Abstract
This study was carried out at the Poultry Research Center, Poultry Production
Department, Faculty of Agriculture, Alexandria University, Egypt, during the breeding season
2017/2018. It aimed to contribute to the productivity improvement of the local chickens by
enhancing their growth and egg traits using crossbreeding program between Alexandria (local
strain) and Lohmann White (commercial strain).
The obtained results of this work could be summarized in the followings:
Significant differences between genotypes were observed for all growth and egg traits studied.
The local strain, Alexandria (AA) resulted significantly in a higher BW at 8 and 12 wks and
BWG during the growth period (0-12 wks) compared to the commercial strain, Lohman (LL)
and the other crossbred genotypes (AL & LA).
The estimates of direct additive effects for BW and BWG in these ages, were positive and
statistically significant
Significant positive heterosis were observed in BW at 4 and 8 wks of age with percentages of
13.45 and 8.41 %, respectively
Heterosis percentages were positive and significant for BWG during the growth periods, 0-4
and 4-8 wks (16.22 % and 9.72 %, respectively).
Reciprocal effects were significant for BW at 0 and 4 wks of age, as well as BWG during the
growth periods, 0-4, 4-8, 8-12 wks
LL-sired chickens laid eggs significantly earlier by 38.56 d, and heavier at sexual maturity by
74.10 g compared to AA- sired chickens.
The crossbred (LA) laid significantly earlier compared to the local strain (AA), (172.83 vs
182.78 d).
Age at sexual maturity of chickens mothered by the local strain (AA) was significantly
superior to those chickens mothered by the commercial strain (LL).
Significant negative heterosis (-8.15 %) for BSM was observed
As a result to the crossing between the local (AA) and commercial (LL) strains, both crosses
(AL and LA) significantly laid more eggs than the local strain (AA) (46.37 and 42.28 vs. 33.94
eggs), but they were consistently less than the commercial strain (LL) (59.00 eggs).
Crossing between the local (AA) and commercial (LL) strains resulted in both crosses (AL and
LA) significantly laid heavier eggs than the local strain (AA) (53.14 and 52.29 vs. 47.47 g),
but they were consistently less than the commercial strain (LL) (57.55 g). The same trend was
observed for egg mass. The crossbred (AL and LA) significantly laid egg mass (2452.69 and
2231.51 g) more than the local strain (1630.67 g), but they were consistently less than the
commercial strain (LL) (3394.82 g).
Reciprocal effects for EN, EN and EM were not significant i.e. both local (AA) and
commercial (LL) chickens strains could be used as line of dam, but they were mainly in favor
of the local strain (AA).