Influence of duodenal slaframine infusion on site of nutrient disappearance from the digestive tract of steers fed a high-concentrate diet.
The effect of duodenal slaframine (SF) infusion on site and extent of digestion was determined using four steers equipped with ruminal, duodenal, and ileal cannulas in a 4 x 4 Latin square. A 77% dry-rolled corn diet was provided in 12 equal portions daily at a DMI of 2.26% BW. Slaframine in a .9% saline excipient was infused into the duodenum every 12 h with total daily dose of 0, 30, 60, or 90 micrograms /kg of BW. Slaframine infusion had no effect on ruminal pH, ruminal NH3 N, or solids and liquids passage rate. Slaframine increased (linear, P < .10) total tract OM and starch disappearance and digestibility and tended to increase (linear, P = .14) total tract N digestibility. Ruminal starch disappearance tended to be decreased (quadratic, P = .16) by SF. Small intestinal OM digestibility was increased (linear, P < .10) but starch digestibility in the small intestine was not affected by SF. Increased total tract starch digestibility was caused by increased (quadratic, P < .10) starch fermentation in the large intestine. Ruminal feed N digestibility decreased at the intermediate doses of SF (quadratic, P < .10). Total N digestibility in the small intestine tended to be increased (cubic, P = .13) with 30 and 90 micrograms of SF/kg of BW. Decreased ruminal feed N digestion was compensated for by increased (quadratic, P < .10) small intestinal feed N disappearance for steers treated with intermediate doses of SF. The potential of SF to increase starch digestion in the rumen and small intestine seems to be limited.
Streeter
M N
MN
Department of Animal and Dairy Science, University of Georgia, Athens 30602-2771, USA.
Froetschel
M A
MA
Croom
W J
WJ
Hagler
W M
WM
D000470:Alkaloids / Q000008:administration & dosage / Q000494:pharmacology*; D000641:Ammonia / Q000032:analysis; D000818:Animals; D002404:Catheterization / Q000379:methods / Q000662:veterinary; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000592:standards / Q000662:veterinary*; D004063:Digestion / Q000187:drug effects* / Q000502:physiology; D004386:Duodenum / Q000502:physiology; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007082:Ileum / Q000502:physiology; D008297:Male; D009584:Nitrogen / Q000032:analysis; D010277:Parasympathomimetics / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry / Q000502:physiology; D013213:Starch / Q000378:metabolism
D000470:Alkaloids; D010277:Parasympathomimetics; C009275:slaframine; D000641:Ammonia; D013213:Starch; D009584:Nitrogen