Bloat Basics

By Becky Mills
Progressive Farmer Contributing Editor

There isn't much that boosts cattle or pasture productivity like a good dose of clover. The only thing that has a chance of beating it is alfalfa. But sometimes, too much of a good thing comes with its own set of problems. In this case, the drawback is well-known to cattle producers -- pasture bloat.

Most often, pasture bloat is caused by lush grass that includes significant amounts of legumes, said Richard Randle, University of Nebraska Extension beef cattle veterinarian. Producers often find this to be a problem when forages are abundant, immature and growing.

RISK LIST

Forages that are more commonly found to cause pasture bloat include white clover, winter wheat, alfalfa, lush annual ryegrass or small-grain pastures.

Legumes with leaf tannins that help break up the foam in the rumen are less often associated with bloat. Tannin-containing legumes include arrowleaf clover, berseem clover, birdsfoot trefoil, sericea lespedeza, annual lespedeza and crownvetch. Tropical legumes like kudzu, cowpea, perennial peanut and alyceclover also rarely cause bloat.

BLOAT BASICS

When bloat is a problem, Randle explained the fermentation gases produced in the cow's rumen get trapped inside bubbles. The cattle basically can't release the gases as they normally would through belching. That creates froth and bloat.

Bloat is usually easy to spot. Cattle look like they are carrying a calf high on their left side. It can happen in all cattle and shouldn't be ignored.

"The rumen swells and puts pressure on the diaphragm," Randle said. "They can have trouble breathing."

Bloat is one of those conditions that is a lot easier to prevent than it is to cure. Cattle can bloat rapidly and die within an hour without treatment. Sudden death from bloat is more often seen in feedlots, where the bloat can be caused by a high grain diet.

Scott Sell is always aware of the possibility of bloat. He believes in prevention. He is coordinator for Clemson University's Edisto Forage Bull Test (EFBT), located near Blackville, S.C. He also develops his own and other producers' bulls at his farm in Sylvania, Ga.

The EFBT program is focused on gain-testing bulls, keeping them on pasture for 168 days. It utilizes the Southeast's advantage in the cattle business to grow high-quality, lush forages year-round and performance-test bulls in the type of environment buyers expect their progeny to perform.

When bloat becomes a problem, some producers rely on the use of ionophores, specifically Rumensin. That use, however, is technically considered off label. Producers should contact their veterinarians for specific guidelines.

Randle, the Nebraska Extension veterinarian, said one option is poloxalene (e.g. Bloat Guard), which is an anti-foaming agent added as a top-dressing to feed or in blocks. He said in some situations it's considered too expensive to use as a preventative, so its role is more as a treatment.

Poloxalene can be administered through a stomach tube. It's a good idea to keep some on hand, he said. Be sure to check label recommendations for dosage.

MANAGE TO BEAT BLOAT

Since the bulls at the South Carolina test are on grazing and hay only, Sell said he tries to avoid the bloat problem altogether by keeping clovers to around a third of what the bulls will eat. In the cool season, they typically graze a mix of wheat, ryegrass and clover.

At the Edisto station, they are also grass-finishing steers for Whole Foods. No feed additives are allowed under terms of the contract. Sell explainedhey have to track fields closely and keep a check on cattle when the clover really starts growing.

"If we have a lot of clover, we'll limit-graze them for 30 to 45 minutes a day until it starts to mature," he said.

At White Hawk Ranch, in Buchanan, Ga., Josh Cabe uses intensive grazing management to help clover thrive in wheat and ryegrass, as well as fescue paddocks. However, the manager of this purebred Hereford operation said his goal is to not let clover make up more than 50% of the forage.

"We do have excellent clover on this place, so we keep an extra check on cattle when the clover is really growing," he said.

Randle said producers on an intensive grazing system like Cabe's can lessen the chances of bloat by waiting until midday, after the dew is off the paddocks, to turn in cattle.

Another tactic is to offset the amount of risky forages consumed by filling cattle up first on hay.

"Don't turn them in when they are so hungry they'll gorge themselves," he said.

TREATMENT TIME

If bloat develops, take action quickly. Randle said it's important to provide relief from the gas buildup as soon as possible. A stomach tube down the esophagus into the rumen can be used to give a dose of mineral oil, poloxalene or vegetable oil. This frees the gas trapped in the bubbles.

He pointed out that with forethought and instruction from a veterinarian, producers should be able to learn to safely insert a stomach tube.

"Make sure the tube goes down the esophagus and not the trachea or windpipe," he stressed. "If mineral oil gets into the lungs, it can cause a severe reaction. Get a little bit of experience before trying it on your own."

In severe cases where other treatments don't work, Randle said a trocar can be inserted into the rumen through the body wall on the left side. That requires veterinary intervention, he cautioned.

Cabe has been at that point. He took another step after the trocar experience. "We had a chronic bloater. She'd bloat on nothing. We treated her three times, and the fourth time, we had to troc her. We sold her.

(VM/CZ)

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