Nutritional needs of sheep in the hills and uplands

Abstract

AbstractCurrent knowledge of the potential nutrient supply that can be derived from indigenous and sown pasture is described and related to classically derived nutrient requirements. From this information, nutrient deficits can be identified for specific times in the ewe's cycle of production. Whilst nutrient deficits have been clearly identified in late pregnancy and early lactation, responses to nutrients and nutrient supply from autumn pasture have not yet been adequately described for the ewe over the mating period.Nutrient deficits can be met by a combination of tissue catabolism and the provision of supplementary feeding. The dearth of knowledge of the factors influencing tissue catabolism and of the effects of supplementary feeding on herbage intake limits quantification of the amount and type of supplementary feeding to offer.The principles concerning supplementary feeding in late pregnancy in some circumstances still require elucidation because of the interactions between mid- and late-pregnancy nutrition and this will be illustrated with reference to sheep grazing a predominantly heather hill. However, the principles governing supplementary feeding in early lactation are relatively well understood in relation to sown pastures below 4 cm in sward surface height and these are outlined. Information on the relative importance of milk and herbage in the diet of the lamb to weaning is discussed. The dependence of one part of the annual cycle on the nutrition in other parts of the cycle is stressed.