Application of reproductive technologies for improving reproductive efficiency of sheep - A review

Sheep constitute an important livestock species in the rural agricultural economy of India. The country is endowed with vast diversity of sheep breeds. The low reproductive efficiency of indigenous sheep breeds has been a major concern into converting these immense bioresources into more remunerative wealth for millions of small, marginal and landless farmers. Application of reproductive technologies have opened up several possibilities of not only in bridging the gap that exists in enhancing production potential of native sheep but also in providing superior germplasm to farmers with improved reproductive efficiency and production. Substantial progress has been made during the last few decades on ovine assisted reproductive technologies, which include artificial insemination using fresh and frozen semen, estrus induction and synchronization, superovulation, in vitro fertilization, in vivo and in vitro embryo production and embryo cryopreservation. Recent advances made in physiological and genetic control of ovulation, identification of genes for prolificacy, gene transfer, sperm and embryo sexing, transplantation of male germ cells, somatic cell cloning and production of transgenic sheep have also been discussed in this review article.