EFFECT OF REPEATED BACKCROSSING FOR TWO GENERATIONS BETWEEN THE LOCAL BLACK BALADI AND WHITE NICHOLAS TURKEYS ON EGG PRODUCTION AND HATCH TRAITS 1- EGG PRODUCTION TRAITS

The present study was carried out at the Maryout Research Station, Desert Research Center; Ministry of Agriculture to study a backcrossing experiment between two strains of turkey summarized Black Baladi (BB) and commercial White Nicholas (WW) as well as their reciprocal crosses through three successive years. Results were as follows:
1- There was a highly significant difference between the different genotypes for both of body weight (BWSM) and age (ASM) at sexual maturity, egg number (EN), rate of laying (RL%), egg mass production (EM), egg weight (EW), feed intake (FI1) (Kg /hen /52weeks), feed intake (FI2) (g /egg) and feed conversation (Kg feed /Kg egg) (FC) through the three studied generations. No significant differences between BB varieties were found through the three studied generations in all former traits. Although the WW pullets were heavier than BB ones in the first generation, it was decreased from one generation to another so, there was no significant difference between WW and backcross of (7/8W x 1/8B) in the 3thgenerations.
2- As for strait-bred differences, the results showed that WW variety was superior to BB population in the three studied generations for BWSM, ASM, EW and FI1, but the superiority was decreased at the second and the third generations. The pure BB variety had the highest values for (EN), (RL), (EM), (FI2) and (FC) compared to the different studied genotypes through the 1st, 2nd and 3thgenerations.
3- After two repeated backcrossing pullets of BB laid significantly the highest number of eggs (93.3egg) compared to the WW pullets and those of the backcrosses of 7/8W x 1/8B and 7/8B x 1/8W (55.5, 45.5 and 76.5egg, respectively,), The estimates of rate of laying (RL %) had the same trend which observed in EN of the different generations studied.