[Investigations of the activity of disaccharidases in growing sheep. 1. Suckling lambs from birth to an age of 4 weeks]

Disaccharidase activity in intestine epithelium microvilli membranes of lambs during the first month after birth

Disaccharidase activity was studied in microvilli membranes of enterocytes isolated from duodenum, jejunum and ileum of lambs at an age of 1, 7 and 23 days. A maximum of lactase activity was observed on the 7th day compared to activity on 1st and 23rd day after parturition and a decrease in enzyme activity on the 23rd day compared to activity on the 7th day. Differences, however, were significant only in respect to activity in ileum. A significant increase of maltase activity in ileum and jejunum was established on the 7th and 23rd day compared to activity on the 1st day after parturition. Trehalase activity attained a maximum in all the three intestine divisions, consequently it subsided with no statistically significant differences. Lactase activity in ileum was significantly lower compared to activity in jejunum of lambs at an age of 1 and 23 days. A marked decrease of maltase activity in distal direction was found only on 1 day-old lambs. No significant alterations were observed in trehalase activity along the small intestine of lambs of the three age groups.

[Activity of disaccharidases in growing sheep. 3. Fattening lambs 5 to 18 weeks of age]

Lambs at an age between 4 and 18 weeks were kept on perforated floor and received pelleted fattening feed for lambs as sole feed ad libitum. After the maltase activity in the duodenal mucosa resp. the contents of the duodenum at an age of 5 weeks was low, it amounted to 6.98 resp. 5.31 units per 0.1 g fresh weight at the end of the eighth week and in the duodenal mucosa it remained on this level to the age of 18 weeks. In the contents of the duodenum it decreased to 3.25 units in this period. The lactase activity in the duodenal mucosa resp. the contents of the duodenum decreased continuously from 30.5 resp. 25.7 to 13.6 resp. 14.8 units in the period investigated. The maltase activity in the pancreas remained constant in the period investigated (4 units per 0.1 g fresh weight). Saccharase activity could not be detected in both duodenal mucosa and contents of the duodenum.

[Studies of the activity of disaccharides in growing sheep. 2. The influence of the feeding regime on the activity of disaccharidases in lambs up to the age of 4 weeks under various rearing conditions]

In two groups of 16 animals each lambs were fed restrictively resp. ad libitum withour ewes with a milk replacer up to the age of four weeks. Maltase activity in the contents of the duodenum and the pancreas homogenate increased with the increasing age of the lambs. The maltase activity of the restrictively fed lambs was higher. The maltase activity in the duodenal mucosa was not influenced by the age. Lactase activity in the duodenal mucosa showed a decreasing tendency up to the end of the four week of life; an increase of lactase activity in the contents of the duodenum could be ascertained up to the fourth week. In comparison with the suckling lambs reared by ewes (cf. 1.) the maltase activity in the duodenal mucosa of the lambs reared without ewes was lower and that in the contents of the duodenum was higher. Concerning lactase activity, there were not significant differences between the rearing and feeding regimens up to the age of three weeks. At the end of their fourth week of life the lactase activity in the suckling lambs was significantly lower than that in the lambs reared without ewes. The total maltase activity (= sum of the activities in the duodenal mucosa, the contents of the duodenum and in the pancreas) showed the highest values for the lambs reared without ewes and fed restrictively in the first three weeks of life. Saccharase activities in the duodenal mucosa or the contents of the duodenum could not be detected in any case.