EFFECT OF CROSSING AND SEASONS ON FITNESS TRAITS IN TURKEYS.

Crossing between the local Black Baladi (BB) and a commercial White Nicholas (WW) was carried out to estimate heterosis, direct additive and maternal effects for fitness traits, in addition to season effect. The breeding plan permitted the simultaneous production of the two pure varieties (BB and WW) and their reciprocal crosses (BWand WB) throughout two successive years from 2006 to 2007. Crossing and season had significant effect on most fitness traits studied (fertility, hatchability, late embryonic mortality, total egg loss, mortality rate, survival rate, and fitness index). The interactions between Genotypes and seasons were significant for all fitness traits studied. Eggs of BB hens and those produced from WW hens mated with BB toms had significantly the highest means for most fitness traits. The estimates of heterosis percentages for fitness traits indicated that the BW crosses had superior heterotic effect than the WB cross. The values of maternal additive and direct additive effects showed superiority of BB as sires which suggest that using of this variety as a terminal sire breed in crossbreeding programs including WW dams would be beneficial for improving the fitness traits. It could be concluded that crossing between BB variety and WW strain of turkey can improve fertility, hatchability and late embryonic mortality percentages, total egg loss, morality rate, survival rate and fitness index. [ABSTRACT FROM AUTHOR]