Abomasum Emptying in Dairy Calves Fed Milk Replacers with Varying Fat and Sources of Protein

Abstract

Young Holstein male calves fitted with reentrant duodenal fistulae were in two 3 .times. 3 Latin square experiments. In the 1st experiment the calves were fed milk replacers containing 5, 15 or 25% lard. Total N, protein N and fat left the abomasum more slowly for the 5% fat milk replacer than for the other 2 milk replacers. In the 2nd experiment the calves were fed milk replacers containing whey proteins, whey and fish proteins (50:50) or whey and soybean proteins (50:50). Dry matter, total N, protein N and nonprotein N left the abomasum more slowly for the milk replacer containing whey and soybean proteins than for the other 2 milk replacers. In both experiments milk replacers did not differ in rates of passage of fresh matter, reducing substances, ash, gastric secretion of hydrochloric acid, gastric proteolysis and diarrhea. In experiment 1 milk replacers did not differ in rates of passage of dry matter and nonprotein N. In experiment 2 milk replacers did not differ in rate of passage of fat. Circadian rhythm had no influence.