Paul Beck, Oklahoma State University State Extension Beef Cattle Nutrition Specialist
Imagine, a disease that creates a paralyzing fear in cattle producers preventing them from utilizing all the forage options available to them. Wheat pasture bloat, also known as frothy bloat is that disease and is one of the most preventable nutritional diseases in cattle. Make no mistake, it is a shocking sight to drive past a lush pasture and see cattle with swollen egg-shaped protrusions from their sides and dead swollen carcasses. To avoid this, producers simply need a little education, a plan, and a supplement.
Wheat and other small grain pastures have been short due to lack of rain this winter, but when growing conditions improve with warmer temperatures and rain, forage growth comes on rapidly. Rapidly growing small grain forage can lead to bloat of grazing cattle, bloat potential can be enhanced when frost damages immature wheat forage.
The rapid onset of pasture bloat and the short time window from the occurrence of initial symptoms and death may be the scariest part of this disease. Bloat can be an issue on small grain pastures and legume pastures such as clover or alfalfa and can impact calves or mature cows. Death losses can be as high as 15 to 20% of cattle on a pasture, which can be a massive economic loss for the producer. Lost production from subclinical bloat may actually be greater than producers realize. Much of the cost associated with bloat is from lost production due to the producer’s fear of encountering bloat. Cattle grazing small grain pasture can gain in excess of 2.5-3.0 pounds per day, avoiding these pastures based a fear of bloat is unreasonable especially when there are affordable and user-friendly methods for control.
There are several grazing management alternatives that can be used to decrease the incidence of bloat. Because bloat is a bigger issue for cattle on unlimited pasture that can consume large amounts forages in a short period of time, over stocking cattle on pastures to a point that forage intake is limited has potential to decrease bloat. Alternatively, where rotational grazing is used, cattle can be placed on pastures after the forages have accumulated sufficient growth and maturity to increase the fiber content of the forages which can also decrease bloat potential.
An overview of research of growing calves on bloat provoking pastures (alfalfa, clover and wheat pastures) showed that monensin supplementation decreases bloat by 20% and reduces the severity of bloat. This option is attractive because ionophores increase average daily gains by 10% (0.17 pound per day increase) for a cost of about 3 cents per day above the cost of the carrier supplement, which is an economic benefit to stocker cattle producers. Even though monensin decreases the incidence and severity of frothy bloat on pastures, it does not eliminate the issue altogether. Poloxalene (Bloatguard) is a surfactant and works to disrupt the froth, which can form in the rumen causing bloat. Research shows that monensin works fairly well at preventing bloat, but poloxalene has been proven to be a more effective remedy for frothy bloat than monensin. Providing poloxalene in a self-fed supplement (blocks or other supplements) costs 15 to 20 cents per calf per day depending on the cost of the supplement. If poloxalene is fed only during the period that forages are most bloat provocative then the total cost of bloat control can be covered by the prevention of the loss of a single animal.
As a management strategy producers may consider using monensin until there are bloat cases then switching to poloxalene once cattle show clinical signs of bloat. Economic benefits will be gained from the increased gains from feeding monensin and the reduced incidence and severity of bloat allows for timing to acquire alternative feed additives, such as poloxalene, to control bloat.