Diallel Crossing Analysis for Body Weight and Egg Production Traits of Two Native Egyptian and Two Exotic Chicken Breeds

Crossbreeding is one of the tools for exploiting genetic variation. The main purpose of crossing in chicken is to produce superior crosses (i.e. make use of hybrid vigor), improve fitness and fertility traits. This study was carried out at South Sinai Research Station located at Ras Suder, Egypt. Two local breeds namely Fayoumi (F) and Sinai (S) and two exotic ones named Rhode Island Red (RIR) and White Leghorn (WL) were used in 4x4 diallel mating system. Breeds of RIR and WL are the best spread and adapted to the environmental conditions of Egypt, while F and S might be regarded as the principal well characterized local breeds of chicken. All possible purebreds (4 groups) and crossbreds (12 groups) were made among the four breeds. Body weights of 1149 chicks were recorded at 0, 1, 2, 3, 4 and 5 month of age. Also, egg production traits were determined. The present results showed that the RIR breed had heaviest body weight at 0, 2 and 3 month of age compared to remaining breeds. However, the Sinai breed had heaviest body weight at 1 and 4 month of age compared to other ones. With respect to crosses, it could be noticed that the FxS and SxWL crosses recorded heaviest body weight at all ages compared to other crosses. With respect to egg production parameters, the White Leghorn (WL) and Sinai (S) hens gave the heaviest egg weight 45.5g and 44.1g, respectively. Inversely, Fayoumi (F) hens were the lowest values of egg weight (42.2g). However, the Rhode Island Red (RIR) was intermediate (43.4g). Results of heterosis estimates indicated that crossing between Sinai (S) males and White Leghorn (WL) females as well as between Fayoumi (F) males and Sinai (S) females gave the highest heterotic effect for body weight. In accordance to egg production traits, the result indicated that FxS and SxRIR crosses and SxF and RIRxS reciprocal crosses recorded positive and high heterotic effects for egg weight. Crossing between RIR dams and either S or WL sires improved egg weight. With respect to the average of egg number in first 10 days laying, it could be noticed that FxS cross and SxF reciprocal cross achieved the highest H% for egg number (12.49 and 8.12%, respectively). However, crossing between WL dams and F, S or RIR sires resulted in high and positive heterosis percentage (H%) for egg number (4.71, 5.81 and 1.72%, respectively). General combining ability (GCA) was found to be the largest source of variation contributing to differences between crosses for body weights and egg production traits. The SxWL cross achieved the superior estimates of maternal effect (ME) f