TY - JOUR
T1 - Estimating true digestibility of nonstructural carbohydrates in the small intestine of steers
AU - Branco, A. F.
AU - Harmon, D. L.
AU - Bohnert, D. W.
AU - Larson, B. T.
AU - Bauer, M. L.
PY - 1999/7
Y1 - 1999/7
N2 - Four Angus steers (318 ± 16 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 4 × 4 Latin square design to determine carbohydrate disappearance from the small intestine (SI). Steers were fed fescue hay at 1.8% of BW and abomasally infused with starch hydrolysate (SH) at 10, 20, or 40 g/h or glucose (G) at 30 g/h. Starch hydrolysate was raw cornstarch digested by a heat-stable α-amylase. Experimental periods were 10 d with 6 d of adaptation, 3 d of digesta and feces collection, and 1 d of rest. Glucose (% of infused) had greater (P < .001) apparent small intestinal and postruminal disappearance (% of infused) compared with 20 and 40 g/h SH. Starch hydrolysate infusion linearly increased (P < .001) apparent SI, large intestinal (LI), and total intestinal starch disappearance (g/d) and quadratically increased (P < .003) apparent SI and total intestinal starch disappearance (% of infused). Ileal starch flow from infusion increased quadratically (P < .03) as SH infusion increased. True SI and total intestinal starch disappearance increased linearly (P < .001; g/d) with SH infusion. However, SH infusion quadratically decreased (P < .02) efficiency of true SI starch disappearance (% of infused). True LI starch disappearance (g/d and % of infused) quadratically increased (P < .03) as SH infusion increased. These data demonstrate that, even in animals fed all-forage diets, there is a significant flow of α-glucosides, and these need to be considered when evaluating intestinal carbohydrate digestion.
AB - Four Angus steers (318 ± 16 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 4 × 4 Latin square design to determine carbohydrate disappearance from the small intestine (SI). Steers were fed fescue hay at 1.8% of BW and abomasally infused with starch hydrolysate (SH) at 10, 20, or 40 g/h or glucose (G) at 30 g/h. Starch hydrolysate was raw cornstarch digested by a heat-stable α-amylase. Experimental periods were 10 d with 6 d of adaptation, 3 d of digesta and feces collection, and 1 d of rest. Glucose (% of infused) had greater (P < .001) apparent small intestinal and postruminal disappearance (% of infused) compared with 20 and 40 g/h SH. Starch hydrolysate infusion linearly increased (P < .001) apparent SI, large intestinal (LI), and total intestinal starch disappearance (g/d) and quadratically increased (P < .003) apparent SI and total intestinal starch disappearance (% of infused). Ileal starch flow from infusion increased quadratically (P < .03) as SH infusion increased. True SI and total intestinal starch disappearance increased linearly (P < .001; g/d) with SH infusion. However, SH infusion quadratically decreased (P < .02) efficiency of true SI starch disappearance (% of infused). True LI starch disappearance (g/d and % of infused) quadratically increased (P < .03) as SH infusion increased. These data demonstrate that, even in animals fed all-forage diets, there is a significant flow of α-glucosides, and these need to be considered when evaluating intestinal carbohydrate digestion.
KW - Digestion
KW - Glucose
KW - Small intestine
KW - Starch
KW - Steers
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U2 - 10.2527/1999.7771889x
DO - 10.2527/1999.7771889x
M3 - Article
C2 - 10438037
AN - SCOPUS:0033159068
SN - 0021-8812
VL - 77
SP - 1889
EP - 1895
JO - Journal of Animal Science
JF - Journal of Animal Science
IS - 7
ER -