DICOUMAROL STUDIES: II. THE PROTHROMBIN TIME RESPONSE OF SHEEP TO VARIOUS LEVELS OF CONTAMINATION IN LOW COUMARIN SWEETCLOVER VARIETIES

• Published in: Canadian Journal of Animal Science
• Main Authors: Linton, J. H., Goplen, B. P., Bell, J. M., Jaques, L. B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1963
• Subjects: Animal Science and Zoology; Food Animals; Arctic
• Online Access: http://dx.doi.org/10.4141/cjas63-049; http://www.nrcresearchpress.com/doi/pdf/10.4141/cjas63-049

Experimental 500-pound samples of alfalfa and Cumino sweetclover were contaminated with Arctic sweetclover, a common high coumarin variety, and were severely spoiled. Continuous temperature recordings during 26 days of spoilage revealed that high spoilage temperatures were associated with high moisture contents of the forage. Subsequent feeding trials with yearling ewes indicated that high levels of dicoumarol had been formed at contamination levels of 50 per cent and over as determined by prothrombin time tests. It was concluded from these studies that low coumarin varieties with up to 25 per cent contamination with coumarin-bearing plants may be, safely fed to sheep, even when severely spoiled, without incurring "Sweetclover Disease".Because of a pronounced variation among sheep in prothrombin time response to dicoumarol, it is suggested that future studies should involve preliminary screening of the animals into reactor and non-reactor classes, as has been done for rabbits.