While lush pastures are a sign of spring, producers should be aware of the dangers of bloat

The change of seasons can bring a host of other changes, and this includes the necessity of watching out for potential bloat in cattle herds.

So, what is bloat? Bloat is a digestive disorder characterized by an accumulation of gas in the first two compartments of a ruminant’s stomach (the rumen and reticulum). Production of gas (primarily carbon dioxide and methane) is a normal result of rumen fermentation. These gases are usually discharged by belching (eructation) but, if the animal’s ability to release these gases is impaired, pressure builds in the reticulum and rumen and bloat occurs. Pasture, or “frothy” bloat, results from the production of a stable foam and if not relieved, the pressure created by the entrapment of rumen fermentation gases in the foam can lead to death by suffocation in as little as one hour or less. Bloat can occur on any lush forage that is low in fiber and highly digestible, but is most common on immature legume (clover and alfalfa) pastures.

As far as cases of bloat in the Ozarks area goes, Eldon Cole, University of Missouri livestock specialist, said bloat in grazing animals is relatively rare but anytime cattle are put on a high percentage legume pasture such as ladino, red clover or alfalfa, watch them closely the first few hours.

To avoid bloat and keep an eye out for the signs.

“Always fill the cattle up before turning them in on lush, damp pastures,” Cole said. “Many farmers routinely fill them up with hay and keep dry hay available while they’re on the bloat-prone pastures.”

According to Earl H. Ward, Northeast Area Livestock Specialist with the University of Oklahoma Extension. there are two main types of bloat and each one is caused by a different mechanism.

“The primary tympany is also known as frothy bloat,” he said. “This frothy bloat is when the small bubbles of fermented gas is trapped in a stable foam, which cannot be eructated. The secondary tympany or free gas bloat is caused when an animal cannot eructate the free gas built up in the rumen. This is largely due to an obstruction in the esophagus such as foreign bodies, abscesses or tumors. Another possibility might be the animal’s posture. Too often we find animals laying with their backs downhill, and in this position the animal cannot physically eructate.”

The clinical signs of bloat can be easily identified: a large protrusion of the rumen showing prominently on the animal’s left side, anxiety, rapid breathing and tongue out.

“Once an animal exhibits staggering and lays down, death will occur rapidly,” said Ward. “If an animal is bloated, it can be treated by inserting a trocar and cannula through the side of the animal into the rumen cavity. If the cannula is inserted and provides some relief, an antifoaming agent such as vegetable oils or mineral oils should be administered through the cannula into the rumen.”

“Bloat can be prevented by including ionophores such as lasalocid or monensin to the diet,” Carol Sanders with the University of Arkansas Pine Bluff of School of Agriculture said. “Be sure to check the label for approved uses and species.”