Influence of Ruminal, Abomasal and Intestinal Fistulation on Digestion in Steers1,2

One set of dizygous and three sets of monozygous twin steers weighing approximately 950 lb. each were used in digestion trials. Apparent digestion coefficients for dry matter, energy, crude protein, ether extract, crude fiber and nitrogen free extract were used in the following comparisons: (1) rumen-fistulated steers with their intact twins, (2) steers having fistulas in both the rumen and abomasum with their rumen-fistulated twins, (3) steers having fistulas in both the rumen and small intestine with their twins having fistulas in both the rumen and abomasum, and (4) the pre- and post-fistulation performances of each steer. Fistulation did not significantly affect apparent digestion coefficients.