Relative transit time of chyme between duodenal and jejunal segments of the small intestine of cattle

Two steers (228 +/- 4.5 kg) equipped with "T" type cannulas in the proximal duodenum, duodenal-jejunal juncture, and distal ileum were used to measure transit time of chyme within the duodenum and jejunum. Steers were fed (as fed basis) with 5.75 kg of chopped alfalfa hay per day. The transit time was measured during 3 consecutive days using aniline dye, which was pulse-dosed via the duodenal and jejunal cannulas. The site of each cannula placement was confirmed and the small intestine was dissected and measured. Time required between the infusion of aniline dye into the proximal duodenal cannula and its appearance at the duodenal-jejunal and distal ileal cannulas was 2: 56 +/- 0.06 and 176:00 +/- 4.21 min:s, respectively. The lengths of the duodenal, jejunal, and ileal segments of the small intestine were 135 +/- 4, 2730 +/- 127, and 110 +/- 1 cm, respectively. The relative transit time of chyme within the duodenum and jejunum averaged 46 and 14 cm/min, respectively.