Topurko Z. Biotechnological methods of oestrus of induction and multiple births in sheep with use biologically active substances

. Object – stimulations of oestrus and multiple births in sheep of various genotypes. The purpose – improvement the ways of multiple births induction in ewes of local precos, and their hybrids with specialised meat breed (suffolk). Methods – experimental, laboratorial, laparoscopy, biochemical, statistical. Novelty – influence of gonadoliberine and pregnant mare serum gonaditropine with some biologically active compounds (BAC) on oestrus stimulations and multiple births in sheep was studied. It was experimentally proved the methods of oestrus stimulation during pairing and anoestrus periods, and ewes gave birth to twins of local precos and their hybrids with rams of meat breeds after application of BAC. Influence of the specified factors upon character of physiological and biochemical changes in the organism of animals were investigated. It is specified, that under the influence of an injection of analogue Gn-Rh and BAC during pairing period allows increasing multiple births in sheep of precos breed and their hybrids with suffolk breed. For the first time it was established the optimum doses of prostaglandine F2? for increasing fertilization rate in ewes of local precos and their hybrids with rams of meet breeds.