Physical studies of the alimentary tract of grazing cattle

Abstract

Three sets of twin cows, each set containing one milking and one dry twin, were slaughtered in order to compare the dimensions of their alimentary tracts. The measurements of the length of the small intestine, the internal circumferences of the lumina in the small and large intestine, the waterf illed capacity of the reticulorumen, and the fat-trimmed weight of and the amount of digesta in each part of the tract were generally greater, within sets, in milking than indry cows. Relatively small amounts of abdominal fat were found in the milking as compared with the dry cows. These differences between milking and dry cows indicate that the alimentary tract showed hypertophy during lactation.