The newborn lamb lacks circulating antibodies and relies on an early and adequate intake of colostrum for passive protection against disease and for energy (Black, Francis and Nicholls, 1985; Mellor, 1990). However, lambs may receive less colostrum than they require because of sibling competition, maternal undernutrition or udder disease. Colostrum insufficiency accounts for about 25% of perinatal lamb deaths world wide (Khalaf, Doxey and Baxter, 1979).

Powdered colostrum substitutes may be used to supplement ‘at risk’ lambs but, because the products are manufactured outside the United Kingdom (UK), mainly from bovine sources, their relevance to UK sheep enterprises is uncertain. Further, their available energy content is low because the main constituent, protein, is not catabolized by newborn lambs (Mellor and Cockburn, 1986). The present work measured the ability of one substitute derived from bovine whey (based on ProLAM, Fisons Animal Health Ltd), with or without supplementary glucose; to prevent disease and promote growth to 3 months in lambs reared in typical UK farm conditions.