Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2005
Publication Date: 3/22/2005
Citation: Obeidat, B. ., Loest, C.A., Thelen, T.M., Strickland, J.R., Sawyer, J.E., Taylor, J.B., Hallford, D.M. 2005. Effects of various exposure routes of swainsonine on serum constituents, rumen characteristics, and nutrient metabolism of sheep. Journal of Animal Science Supplement. 83(Supp2):110 Interpretive Summary: Same as abstract
Technical Abstract: Nineteen mixed breed wethers (42.6 +/- 1.5 kg initial BW) were used in a two period (14-d treatment period plus 8-d post-treatment period) experiment to determine the effects of swainsonine via subacute ruminal, abomasal, or intravenous exposure on ruminal characteristics, serum constituents, diet digestibility, and N retention. The animals were fed once daily at 1.8% of BW (DM basis) a diet of 95% fescue hay and 5% alfalfa hay (DM basis). Treatments were: 1) no (CON; n = 5), 2) ruminal (RUM; n = 5), 3) abomasal (ABO; n = 4), and 4) intravenous (I; n = 5) infusions of a locoweed extract to deliver 0.6 mg of swainsonine/kg BW/d on d 1 to 14 of the experiment (subacute exposure). Serum concentrations of aspartate aminotransferase werre greater (P < 0.05) for RUM, ABO, and IV versus CON on d 8, 12, 16, 18, and 20 of the experiment. Serum alkaline phosphatase was greater (P < 0.05) for TUM when compared to CON on d 2, 4, 8, 12, 16, and 18, but were not different (P < 0.11) among ABO, IV, and CON on d 4 to 20. No differences (P > 0.25) were observed for serum concentrations of glucose, non-esterified fatty acids, and serum urea N. Ruminal concentrations of VFA, pH, and ammonia collected on d 14 and d 23 of the study wer not different (P > 0.15) among treatments. Nutrient intake and digestibility, and N retention werre not affected (P > 0.11) by treatments. Results demonstrated that subclinical intoxication occurs when sheep are exposed to swainsonine, but appearss to have little effect on ruminal fermentation, nutrient digestibility, and N retention.