Natural factors affecting puberty and reproductive performance in ewe lambs: A review

Abstract

In this paper information has been summarized on natural factors affecting sexual development in the ewe. Considerable differences exist both between and within breeds of sheep in the age and body weight at puberty. Genetic as well as environmental factors, and the interaction between these, clearly affect sexual development. Of the environmental factors, the plane of nutrition during rearing and the time of birth appear to be of the greatest importance. Generally, faster growth is associated with enhanced reproductive performance in ewe lambs, i.e. earlier attainment of puberty, more intense oestrous activity and higher conception and lambing rates when mated. However, compared with mature ewes, the young females normally express lower reproductive efficiency. The potential contribution of the ewe lamb should be considered in relation to methods of improving the lifetime productivity of the ewe.