EFFECT OF COLLECTION INTERVAL ON NUTRIENT DIGESTION DETERMINED WITHIN THE GASTROINTESTINAL TRACT OF BEEF CATTLE
Duodenal digesta, ileal digesta, and feces were collected from steers fed diets containing 50% barley grain, 50% brome-alfalfa hay. These were composited over days 1–3, 4–6 and 1–6 of each experimental period. Acid detergent lignin and chromic oxide were used as digestibility markers. Three- or six-day collection intervals did not affect the estimate of organic matter digestion in the forestomach, small or large intestine, and total tract. Differences (P < 0.05) in estimates of nutrient digestion between 3-d collection periods occurred for neutral detergent fiber in the forestomach and crude protein in the small intestine. Key words: Collection interval, partitioning of digestibility, markers, cattle, gastrointestinal tract