Science, Vol 201, Issue 4351, 153-155
Copyright © 1978 by American Association for the Advancement of Science
Monensin and the prevention of tryptophan-induced acute bovine pulmonary edema and emphysema
AC Hammond,
Carlson JR,
and
RG Breeze
3-Methylindole, a ruminal fermentation product of tryptophan, induces acute pulmonary edema and emphysema in cattle, and 3-methylindole is present in the ruminal fluid and blood of cows with a natually occurring form of this disease. Monensin, a polyether antibiotic and widely used feed additive for beef cattle, prevented tryptophan-induced acute bovine pulmonary edema and emphysema. Monensin acted by reducing the ruminal conversion of L-tryptophan to 3-methylindole both in vitro and in vivo. Lasalocid, also a polyether antibiotic, showed similar effects in vitro. These results provide a promising approach to prevention of this major respiratory disease of cattle.
