A review on crossbreeding in Iranian sheep

Crossbreeding is used in order to take advantage of the different and complementary strong points of two or more breeds and to utilize hybrid vigor. In this study the results of sheep crossbreeding have been reviewed from published over the last years in Iran. The results showed that much of the crossbreeding in the sheep industry in Iran due to incorrect selection of breeds was not suitable. The main disadvantages points of Iranian sheep are low reproduction performance, low longevity, insufficient growth rate, unsuitable carcasses composition and feed efficiency, respectively. While, in the most crossbreeding schemes have been done between Iranian breeds of sheep, focused on improve growth traits and reduced fat-tail weight, which created low and no significant changes in crossbreds for these traits, leading to reducing economical efficiency and unsustainable of rearing sheep in semi-intensive or village system over last years. Sustainability could been achieved by combining desirable characteristics from the indigenous breeds to keep fitness and marketability with those of specialist exotic breeds that had already demonstrated genetic potential for traits of economical importance for commercial production. However, research findings suggested that in well-planned efforts to create composite breeds (with minimum 50% native) using the prolific breeds (such as Romanov), with high mothering ability, low maturity age, suitable carcass composition and medium ewe body weight could increased productivity of sheep in village system in Iran.