Intestinal cannulation of cattle and sheep with a T-shaped cannula designed for total digesta collection without externalizing digesta flow.

An intestinal cannula was prepared that was designed to have the advantages of a reentrant cannula without permanently exteriorizing digesta flow or adding significantly to the resistance of digesta flow. The cannula was fabricated in the shape of a T from a Teflon fluorocarbon polymer. Total passage of digesta through the lumen of the cannula was accomplished by suturing a support boot around the outside of the intestine at the cannulation site. The support boot prevented the intestine from stretching away from the cannula. Digesta leakage around the barrel of the cannula was eliminated by a special peritoneal ring attached to the cannula in a position that interrupted the continuity of the tubular scar tissue that formed from the intestine alongside the barrel to the skin. The cannula was supported by an outer ring held in place by a simple stainless steel retaining ring. The low external profile of the cannula minimized mechanical disturbance of the cannula and cannula site. Diet consumption and growth rates were normal, and no blockage was encountered in either the duodenal or the ileal cannula with a wide variety of diets, indicating that the cannula added no significant resistance to digesta flow. Total digesta collection or simultaneous collection and addition were easily accomplished with special collection gates. The cannula preparation has a long functional life; in one case, the cannula remained functional for more than 2 1/2 years.