Digestibilities and Diurnal Excretion Patterns of Several Carbohydrates Fed to Calves by Nipple Pail1,2

Abstract

Summary Four calves were employed, over the age period from 3 to 6 mo., to determine the apparent digestibility of seven carbohydrates. The calves were fed milk by nipple pail at a rate of 3lb. per 100lb. body weight daily. The carbohydrates were added to the milk at a level of 10%. Digestion coefficients for lactose, maltose, sucrose, amylose, amylopectin, Flojel, and tapioca starch were 94, 97, 57, 83, 89, 80, and 80%, respectively. The data suggest that disappearance of considerable sucrose and starch resulted from microbial fermentation in the lower part of the digestive tract. Essentially all of the soluble carbohydrate (about one-fourth of the total carbohydrate) in the feces of starch-fed animals was glucose. Responses in blood reducing sugar to ingestion of various carbohydrates agreed quite closely with digestibility data; the greatest increases resulted from lactose and maltose, the least from sucrose, and starches were intermediate. The diurnal pattern of carbohydrate in the fecal dry matter (based on samples collected every 2 hr. during a 24-hr. period) exhibited two peaks which were related to the time of feeding. Peaks for lactose, maltose, sucrose, and starch (all starches combined) occurred about 10, 8, 6, and 12 hr. after feeding, respectively. Estimated digestion coefficients (calculated from diurnal samples) for lactose, maltose, sucrose, and starch (all starches combined) were 95, 96, 32, and 80%, respectively.