|Garner, M - CORNELL UNIVERSITY|
|Hay, A - CORNELL UNIVERSITY|
|Guard, C - CORNELL UNIVERSITY|
Submitted to: Cornell Nutrition Conference for Feed Manufacturers
Publication Type: Proceedings
Publication Acceptance Date: September 5, 2003
Publication Date: October 21, 2003
Citation: GARNER, M.R., HAY, A.G., GUARD, C.L., RUSSELL, J.B. BOVINE LAMINITIS AND ALLISONELLA HISTAMINIFORMANS. CORNELL NUTRITION CONFERENCE FOR FEED MANUFACTURERS. 2003. p. 199-208. Technical Abstract: While the evidence to make all pathologic conditions affecting the soft tissue within the hoof capsule attributable to the action of histamine is unproven, it has long been assumed that histamine was an important factor in bovine laminitis. Bacteria responsible for ruminal histamine production had not been systematically evaluated, but our work indicates that a novel bacterium, A. histaminiformans, appears to play an important role in ruminal histamine production. A. histaminiformans is an obligate histidine decarboxylating bacterium that has relatively simple nutritional requirements, but it needs a growth factor that can be derived from yeast extract in vitro or silages in vivo. The involvement of A. histaminiformans in ruminal histamine accumulation is supported by the observation that cows fed dairy ration had relatively high numbers of A. histaminiformans and high concentrations of ruminal histamine while the converse was true for cows fed only timothy hay. A. histaminiformans is a highly pH-resistant bacterium, but cows fed commercial rations had high numbers of this bacterium even if the ruminal pH was near neutral. Cows fed dairy rations had relatively high concentrations of ruminal histamine without showing overt signs of laminitis, but this effect may be due to ruminal pH. Other researchers have demonstrated that rumen to blood histamine flux does not occur until ruminal pH becomes acidic.