OBSERVATIONS ON DIGESTION IN THE PIG USING A RE-ENTRANT INTESTINAL FISTULA

Abstract

Sixty-four 12- to 24-hour collections were made of digesta flowing from re-entrant ileal fistulas of two pigs used to study the digestibility and rate of passage of various materials in the proximal digestive tract. An average of 88 per cent of the digestible dry matter and 91 per cent of the digestible protein of a 20 per cent protein ration was digested in the stomach and small intestine. The ration was very finely ground and fed only for short periods. The dry matter content of the fistula digesta was considerably higher when the concentrate ration was fed than when dried skim milk powder or various soluble carbohydrates were fed. Glucose was the most completely digested of all carbohydrates tested, usually followed in decreasing order by corn starch, galactose, sucrose, lactose and potato starch. Undigested soluble carbohydrates were accompanied by large volumes of fluid which seldom exceeded isotonic concentrations. Undigested potato starch resulted in digesta which at times contained 42 per cent dry matter. Fats fed with dried skim milk were well digested with maximum digestion coefficients of 91 recorded for corn oil and 84 for tallow. There were few changes in the composition of the digesta flowing from the fistula at various times of the day but there was a significant increase (P <.01) in the protein and ash content from the first to second 6-hour interval after feeding dried skim milk.