Improvement of the reproductive efficiency for the development of the Sardinian sheep breeding

Abstract

Reproductive activity of the sheep bred at temperate latitude is conditioned by photoperiodic trend. Melatonin haematic levels are considered the biological informer of photoperiodic trend. The action of melatonin on reproductive activity is carried on through receptors present at hypothalamic level. Polymorphism of receptor MT1 gene in several sheep breeds resulted involved in the regulation of reproductive seasonality. Then, the study of this gene even in the Sarda breed sheep can give the possibility of a better rationalization of the reproductive activity. With this purpose, blood samples from 1000 sheep from different farms were taken. Age, sex and lambing date of the animals were recorded during at least 3 years. The DNA obtained from each blood sample was used for the typication of the MT1 receptor gene. Finally, the obtained genetic and reproductive data were subjected to statistical analysis to show the probable link between them. The confirmation of a relationship between genetic variants and reproductive activity more or less connected to photoperiod can supply a new approach both to selection and management of Sarda breed sheep. In fact, the animals less bound to photoperiod could be used for the deseasoning of lambing and consequently of productions. On the contrary, animals with a reproductive activity deeply linked with photoperiod could be directed to obtain spring lambing. All that, undoubtedly, can produce a great development of the Sardinian ovine sector according to the trend of product demands of market, bound to the tourist vocation of the island.