Reproductive performance of out of season mating in lactating Latxa dairy sheep

Abstract

In order to explore the induction of out of season lambing, to reduce the constraint on milk production, which results from the seasonality of estrus activity in ewes, synchronized estrus induction was carried. 47 Latxa dairy ewes, 2 and more years old, with 66 days of lactation and an average daily milk yield of 1265 grams were treated with progestagen and gonadotrophin during october 2001. Estrus detection was carried out with one raddled harnessed ram. Each ewe in heat was hand mated to one fertile ram, with two succesive mounts per ewe. 37/47 ewes showed estrus (78.7%), 26/37 conceived (70.2%), and 25/47 lambed (53.2%) between April 1st to 7 st. Thirty three lambs (132%) were born with an average birth weight of 4.5 Kg, and a perinatal mortality of 3%. April lambing in dairy sheep through synchronized estrus induction in lactating ewes and natural service with rams of the same breed in October, contributed to a more constant milk output during the year and and to a higher milk production per ewe present all year round in the flock.