Reducing lamb mortality in hill sheep

Abstract

Lamb mortality is high in hill farming systems. This is not a new phenomenon. Orr and Fraser (1932) reported losses of lambs between birth and weaning of over 30% and indeed an annual ewe death rate of up to 24%.Poor nutrition, of both macro- and micro-nutrients, is a prime cause of this problem exaggerated by difficult environmental conditions at the time of birth. Improved nutrition during late pregnancy was believed to be the most important (Wallace, 1948) and nutrition during mid pregnancy received scant attention. However, applied experiments with mid-pregnancy feeding of hill ewes (Milne, 1984; Waterhouse and McClelland, 1987) showed very significant effects of better nutrition during this period. The present paper summarizes the implementation of improved mid-pregnancy nutrition in a monitored systems study, associated with changes in management in late pregnancy made possible by assessment of foetal numbers from ultrasound pregnancy scanning.