Abstract
1. A total of twenty-one Merino lambs varying in age from 2 to 11 weeks were slaughtered.2. The enzymic activity of their rumen contents was measured on a variety of carbohydrates and on protein.3. Enzymic activity was expressed as mg. carbohydrate hydrolysed/mg. protein nitrogen/hour.4. When compared with the rumen contents of adult sheep, lactase and proteolytic activity decreased with age; maltase, sucrase and fructanase activity increased; amylase activity decreased from 2 to 11 weeks though adult values were similar to those of the 2-week-old lamb.5. The rumen contents of the lamb were as efficient as those of the adult sheep in their ability to hydrolyse a wide variety of carbohydrates and protein.