Trypsin and Chymotrypsin Development in the Neonatal Lamb

Twenty-two neonatal lambs were sacrificed at various ages (0, 1, 7, 14, 21, 28, 35 and 42 days postpartum), and assays for trypsin and chymotrypsin activity were conducted on the duodenal section of the small intestine. No trypsin activity was found at birth, but gradual nonsignificant increases in activity were found through day 7 and over a fourfold increase (P less than .01) was observed between days 7 and 14, with no significant changes for the rest of the 42-day study. Chymotrypsin was present at similar levels from birth through day 7, with a twofold increase (P less than .05) in activity between day 7 and 14 and no significant change thereafter.