Carbohydrase activities in the bovine digestive tract

Abstract

1. The carbohydrase activities of homogenates of mucosa from the abomasum, small intestine, caecum and colon, and of the pancreas of cattle were studied. 2. The disaccharidase activities were located mainly in the small intestine and showed a non-uniform pattern of distribution along the small intestine; trehalase activity was highest in the proximal part, lactase and cellobiase activities were highest in the proximal and middle parts and maltase activity was highest in the distal part. 3. The intestinal lactase and cellobiase activities were highest in the young calf and decreased with age, whereas the intestinal maltase and trehalase activities, which were very low compared with the lactase activity, did not change with age. 4. No intestinal sucrase or palatinase activity was detected in the calf or in the adult cow. 5. Homogenates of intestinal mucosa also exhibited amylase and dextranase activity. 6. Homogenates of the pancreas possessed a strong amylase activity and a weak maltase activity. The maltase activity did not change with age, whereas the amylase activity increased with age. 7. No marked differences were observed between the carbohydrase activities of calves fed solely on milk and those of calves given a concentrate-hay diet from 6 weeks of age.

Activity of intestinal mucosal membrane carbohydrases in cattle of different breeds

“…These activities compare well with reported values of 4.2 µM maltose hydrolysed mg protein -1 h -1 (Shirazi-Beechey et al 1991) for proximal intestines of lambs fed milk replacers, but are lower than values of 12.1 µM maltose hydrolysed mg protein -1 h -1 for hay-fed cattle (Siddons 1968). Additionally, Russell et al (1981) provide evidence that animals fed alfalfa hay diet had higher maltase activity than corn fed cattle.…”

“…In the distal intestines the lactase activity for W × A steers was lower (P < 0.05) than that of W × O steers. Reported values for lactase activity in cattle range from 0.2 to 2.2 µM lactose hydrolysed mg protein -1 h -1 from various intestinal regions (Siddons 1968) while the values obtained in the present study range from 0.1 to 8.6 µM lactose hydrolysed mg protein -1 h -1 .…”

“…Incubation of tissue homogenate with cellobiose resulted in formation of glucose, indicating that cellobioase type activity ranged from 0 to 1.2 µM of cellobiose hydrolysed mg protein -1 h -1 (Table 7), while Siddons (1968) observed values that ranged from 0.04 to 0.32 µM of cellobiose hydrolysed mg protein -1 h -1 . Small correlation coefficients P, 0.5 m distal from the pyloric sphincter; M, mid-jejunum; D, 0.5 m proximal to the ileocecal junction.…”

A titration approach to identify the capacity for starch digestion in milk-fed calves

“…The measurement of activities of luminal or brush border enzymes is usually conducted in calves fed little or no starch. Under these conditions, lactase activity is usually high, up to 180 U/g mucosal protein, maltase activity does not exceed 27 U/g protein and isomaltase activity is even lower than maltase activity (Siddons, 1968;Toofanian et al, 1973;Le Huerou et al, 1992). α-Amylase activity measured in pancreatic juice varied considerably between individual milk-fed calves, but was overall considered low (19 mg glucose equivalent/ml pancreatic juice), because no significant amount of starch would be cleaved at this level of α-amylase activity (Morrill et al, 1970).…”

Factors affecting intestinal starch digestion in ruminants: A review

“…At birth calves have low concentrations of pancreatic α-amylase (Siddons 1968), which increase with age (Morrill et al 1969), as does total pancreatic secretion (McCormick and Stewart 1966). It is thought that the near continuous flow of digesta in ruminants minimizes large diurnal fluctuations in intestinal flow and pancreatic juice secretion that occur in the nonruminant (Merchen 1988).…”