Beat bloat

Aim for feed efficiency and careful grazing

Recently, a customer asked about bloat prevention in stocker calves weighing 500 to 600 lbs. He wondered if there is a mineral source for preventing bloat. And what about feed?
I have a short answer and a long answer.

To avoid a situation in which bloat occurs, I recommend feeding for maximum efficiency. Using a supplement such as Trendsetter with Rumensin (that’s my first choice) or Bovatec gets you there, and fine-tuned rumen helps prevent bloat. Likewise, I’d use Stocker BT Mineral (because calves that size will not eat enough of Rumensin 1620 mineral, and it is not a standard item).

Alternatively, I would feed Bloat Guard, either as bloat blocks or in the supplement. And, of course, I would try to limit things that encourage bloat—
alfalfa, soyhulls, wheat pasture, etc.

The longer answer in how to prevent bloat is to understand what causes bloat and how bloat affects cattle.
Animals bloat because they can’t pass gas from the rumen. While gasses from the rumen would normally back flow into the lungs and expel as belching, bloat occurs when the gasses mix with the content of the rumen (think lush grass cud) to form a foam.

The gas then becomes trapped in the rumen because the animal’s body reflexively will not allow foam back into the lungs.
I tell producers it’s like straining cream through cheesecloth. I can pour cream through cheesecloth. But if I whip air into it and beat the cream into “stiff peaks,” it will sit on cheesecloth.

To solve bloat, you need to break up the foam, or better yet, keep it from forming.
The foam is basically stabilized by protein. (Consider the bubbles baked into bread. The matrix that traps gas in a raising loaf of bread is a protein/gluten matrix.)

Signs of bloat
•    animal will be high on the left side, behind the ribs
•    animal will not want to move
•    animal exhibits distress—eyes bulge, tongue may protrude, exhibits bawling
•    animal strains during urination/defecation
•    animal exhibits rapid breathing
•    animal staggers

Essentially, an animal suffering bloat smothers because the pressure on the lungs keeps them from getting enough air. An animal that dies from bloat will have congested lungs and a classic bloat/blood line. Observing the animal puffed up like an inflated disposable glove is not proof of death by bloat, however, as a different set of gasses kicks in after death.

Practical advice for mild cases of bloat
Treat with a surfactant—something that breaks down the foam (i.e. BloatGuard, detergents) Make sure animals keep moving and provide ionophores in the feed—ionophores have been shown to reduce the viscosity of rumen fluid/foam.
I use Rumensin as the product of choice for feed efficiency, but people with horses tend to fear Rumensin. If I have had problems with calves bloating on Cattle Charge, I use Cattle Charge with Rumensin, and have not had re-occurrence of bloat. Note that while Rumensin is approved for bloat in Mexico, it is not approved for bloat in the U.S. Here, we focus on using Rumensin for performance/feed efficiency.

Practical advice for severe bloat
For severe cases, immediate intervention is needed. Treatment is usually with a trocar. In my experience the trocar is placed at the crown of the bulge, with care taken to avoid veins and arteries. But do get veterinarian consultation and help before you intervene. Sometimes the trocar doesn’t seem to punch a big enough hole and the hole is opened up with a stiff bladed knife, again, the territory best trod by a vet. Once the trocar has done its work, surfactant is introduced through the hole. The cuts will need to be cleaned up and sewn up. Using a trocar is quick, but the subsequent clean up is tedious, and not without risk of infection. Alternatively a stomach tube can be introduced. Expect a splash.

Prevention of bloat
When faced with grazing risky pasture such as legume pastures dominated by alfalfa and to a lesser degree clover (mixed grass clover swards of less than 40 percent clover are relatively bloat safe) or wheat pastures, consider these steps:
•    Restrict pasture intake through limiting grazing time
•    Strip graze by allocating a fraction of the pasture to the herd
•    Feed hay or other feed prior to putting them out on the suspect pasture
•    Use a surfactant such as Bloat Guard
•    Supplement feed with an ionophore

Dr. Jim White is ruminant nutritionist for MFA Incorporated.