الفهرس 
Growth performanceOnly 14 pages are availabe for public view
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Abstract
Productivity level$ of native subtropical breeds of sheep are generally low. In many countries, attempts have been made to improve their sheep productivity through crossbreeding with exotic breeds. The success of crossbreeding prograrnms is influenced by the seasonality of reproduction in both the exotic temperate sheep raised under the subtropical environment and also in the crossbreds produced. Egyptian sheep breeds, similar to other subtropical breeds, are charactenized by an ability to bred at different seasons of the year. Early in the seventies, a crossbreeding programme with Finnish Landrace sheep was initiated in Egypt by the Ministry of Agriculture to improve prolificacy in two local valley breeds, Rahmani and Ossimi and to investigate the possibility of establishing a synthetic breed of higher fecundity suitable for the prevailing subtropical conditions. On the basis of the findings in the study of Aboul-Naga ( 1985 1 and Aboul-Naga et al. ( 1989 1, Finn. crosses seemed to perform substantially better than local breeds. The Finn. cross ewes showed a good ability to rebreed each eight months with higher conception rates than the locals.