|FOOTE, ANDREW - University Of Kentucky|
|KRISTENSEN, NIELS - Southern Cattle|
|MCLEOD, KYLE - University Of Kentucky|
|BUSH, LOWELL - University Of Kentucky|
|HARMON, DAVID - University Of Kentucky|
Submitted to: American Forage and Grassland Council Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/5/2012
Publication Date: 1/7/2013
Citation: Foote, A.P., Kristensen, N.B., Klotz, J.L., Mcleod, K.R., Bush, L.P., Harmon, D.L. 2013. Ergot alkaloids produced by endophyte-infected tall fescue decrease rumen epithelial blood flow of cattle. American Forage and Grassland Council Conference Proceedings. Pg. 8.
Technical Abstract: Ergot alkaloids have been shown to induce vasoconstriction of both peripheral and ruminal vessels. Constriction of ruminal vessels could lead to a reduction in epithelial blood flow thereby reducing nutrient absorption. The objectives of this experiment were to determine if steers receiving endophyte-infected or endophyte-free tall fescue seed have decreased rumen epithelial blood flow and volatile fatty acid absorption rates in the presence of differing levels of ergot alkaloids. Ruminally cannulated steers received endophyte-infected or endophyte-free seed for 7 days. On day 8 a washed rumen experiment was conducted. Three buffer treatments including a control, a low concentration of ergot alkaloids, and a high concentration of ergot alkaloids were incubated and epithelial blood flow and volatile fatty acid absorption were evaluated. Results show that ergot alkaloids induce a large reduction in epithelial blood flow as well as a reduction in volatile fatty acid absorption. The observed alterations in nutrient absorption could contribute to the decreased growth rates of cattle consuming endophyte-infected tall fescue.