Pasture bloat is primarily a disease we see when cattle are grazing pastures of high percentage legume content. Sometimes it is referred to as ‘frothy” bloat due to the fact that a large amount of foam is produced, and the animal has difficulty releasing gas because of the foam.
Legumes with the highest likelihood to cause bloat include white clover, alfalfa, annual medics and Persian clover. Red clover, crimson clover and subterranean clover would be classified as moderately likely to cause bloat, while berseem clover and arrrowleaf clover are low risks for causing bloat. Legumes that don’t cause bloat are birdsfoot trefoil, sainfoin, and crownvetch.
Prevention is where you should focus your attention because treatment can many times be too late. Be sure to observe cattle frequently the first few days on new legume pasture. If cattle with bloat are treated quickly by passing a stomach tube and giving oral poloxalene, treatment is usually successful.
Prevention of bloat
Use poloxalene (Bloatguard®) for 5-7 days before cattle are turned out to legume pasture. Use these blocks as the only source of salt and minerals for the cows before turning onto legume pasture and continue their use for about a week after they are on this pasture. Fill cattle with dry hay before turning them onto a legume pasture.
Turn cattle out after midday when the pasture is dry (no dew or excess moisture). Turn cattle out and leave them out. Do not pull them in and out daily. Cattle will “learn” that they will be moved to the legume pasture and wait to eat until moved.
Interseed pure legume pastures with an appropriate grass to dilute the legume’s bloat-causing effect. We have seen numerous deaths due to bloat after a pasture is clipped. The white clover then grows rapidly due to less shading and competition from the grass, and the cattle graze an almost pure diet of white clover.
If you need to clip pastures, wait a few days after clipping to turn cattle back onto this pasture so the grass has a chance to grow. This will dilute the effects of the clover, and the cattle will have less chance of bloating. To be safe, adding poloxalene blocks a few days before and after moving on the clipped pasture is a good idea.
This information was reprinted from the Summer 2010 Hoos-Your Grazing Network.