Ontogenesis of enzymatic activities in the gastrointestinal tract of young goats

Abstract The activity of 11 hydrolytic enzymes (lactase, maltase, invertase, amylase, cellulase, xylanase, pectinase, fructanase, urease, protease, lipase) was measured in the chymus of different parts of the digestive tract of goats between 9 and 112 days of age. Goats were weaned from milk in a stepwise manner at 7 weeks of age. High lactase activity was found in the duodenum, caecum and colon. The activity of lactase and protease declined in the postnatal period and activity of maltase and polysaccharide-degrading enzymes increased. Activity of enzymes degrading non-starch plant carbohydrates and activity of urease were higher in fermentative organs (rumen, caecum, colon) than in abomasum and small intestine. Activity of lipase was rather low in almost all samples examined. Age-related differences were more pronounced in the rumen than in other parts of the gastrointestinal tract. The results indicate that enzymatic activities found in weaned goats are adequate to deal with various plant matter components, except for a short period after weaning.