Carbohydrate utilization in the pre-ruminant calf.

3. Maltose and fructose utilization was low in young calves and increased slightly with age. 4. Sucrose and starch were not utilized. 5. Studies with three older pre-ruminant calves (aged 53, 88 and 106 days) in which the carbohydrates were infused into the proximal duodenum showed that glucose, galactose, lactose and xylose all caused marked increases in the level of blood reducing sugar, whereas fructose and sucrose caused no increase, and maltose was intermediate. Xylose and galactose caused very little change in the blood glucose concentration. 6. It appeared that preferential uptake occurred of glucose from a glucose-galactose mixture. 7. A non-linear relationship was found between the concentration of glucose or galactose hydrate utilization in pre-ruminant calves aged between 10 and 50 days.