Introduction
In Egypt, as in most countries, poultry production plays an important role in providing customers with animal protein. Egyptian poultry industry depends mainly on importing commercial parent stocks for both meat and egg production. However, local chicken breeds are greatly participating in poultry market. Although, local breeds have lower rate of growth, produce fewer eggs and less feed efficient compared to commercial strain, small holders prefer to raise local breeds for the following reasons:
1) They are adapted to tough environments and hygiene. 2) They consume less amount of feed. 3) Their nutrition and housing requirements are comparatively cheap. 4) They are relatively more resistant to diseases. 5) They are preferred by consumers because of their palatability. Thus consumers are ready to pay premium prices for their products.
Therefore, researchers pay much attention to improve the local breeds performance by selection and crossing with exotic breeds. Most of crossing studies between local breeds were based on two-way crosses. However, a few studies were performed using three and four-way crosses. Females from two-way crosses previously produced by diallel matting of three native and two exotic breeds of chickens were crossed with males from a third breed to produce the three-way crosses chicks in Animal Production Department, Faculty of Agriculture, Suez Canal University. Then on the second year three-way cross females were mated with males from a fourth breed to produce the four-way crosses chicks. The five pure breeds were three native (Fayoumi, Sinai, and Dandarawi) and two exotic (Rhode Island Red and Single Comb White Leghorn). The aim of this study was to evaluate the productivity of some three and four-way crosses for both meat and egg production. Male and female chicks were reared to 21 wk of age then females were kept to sexual maturity until the end of the first 120 days of lay to evaluate the productive characters during rearing and production periods. The studied traits were body weight, growth rate, age and body weight at sexual maturity, phenotypic body measurement at sexual maturity, egg production, egg weight and, egg mass during the first 90 and 120 days of lay.
Collected data were statistically analyzed employing the computer program with the appropriate models to calculate Least Square Means, genetic and phenotypic correlation, and heritability of different traits. The differences among genotypes were also examined.