A crossbreeding experiment was executed between three breeds were selected three generation for heavy body weight under high temperature condition Sinai (SI) and Rhode Island Red (RI) and Fayoumi breeds. 900 crossing meals from each genotype were recorded singular body weight and body weight gain at hatch, 4, 8 and 12 weeks of age. crosses SI XRI and reciprocal RI x Si significant heaver body weight and body weight gain compared than other crosses and pure breed. On the other hand body weight and body weight gain were significant heaver for pure line Sinai or Rod iland read and crosses SI x F, F x RI, Fx SI and RI xF compared to Fayoumi pure line. Heterosis was positive significant on body weight at hatch, 4,8 and 12 weeks of ages. As the same trend results of body weight gain but, negative significant at the intervals from 4wks to 8wks only. It could be observed that the hybrid vigor of body weight was significant positive effect for crosses SI X RI and reciprocal crosses RI XSI and RI XF ones.
While, the hybrid vigor of body weight gain was significant positive effect for all diallel crossing except F X RI crosses. the direct additive effects were negative for line Fayoumi both body weight and weight gain taits at diferent age of these study. But these reciprocal effect were significant positive for Sinai and Rodiland red lines both body weight and body weight gain. These resuls shown that the croses RI XSI beter than SI X RI for both body weight and body weight gain. Maternal effect of body weight and body weight gain were significant positive effect at hatcher , for FF and SI SI. While, it was significant negative effect for RIRI. On the other hand, were significant positive for body weight at hatcher and 4 weeks of age only. While, maternal effect was significan positive at the intervals 0-4weeks only. The last shown that the maternal effect had a play essential role on body weght and body weight gain.
Recommended used crosses Sinai and rod Iland red to produce commercial meat strains in hot climated countery.