Reasons That Cattle Bloat

Bloat --- known as "Ruminal tympany" --- is created by the excessive build up of gasses in a cow's stomach or rumen; it was first recorded as a problem with cattle in A.D. 60. Under normal healthy conditions, cattle can release this gas buildup through belching. However, there are many factors that can contribute to the cow's inability to release these gasses as quickly as the body requires. Bloat is a serious problem because it can be fatal from the first hour up to four days from onset.

  1. Frothy Bloat

    • Frothy bloat is caused when stomach gas is trapped in the rumen by a frothy substance that prevents the cow from belching --- known as "eructation." The first contributing cause of this type of bloat is feeding small particle feed and quickly digestible foods and grains, which results in a slimy substance that captures the gas in the rumen.

      The second cause of this type of bloat is a result of feeding fresh or green alfalfa. As with small particle foods, these particular plant species break down quickly creating an increase in foam as well.

    Free-Gas Bloat

    • Free-gas bloat is caused by a secondary problem such as esophageal blockage that prevents the gases from escaping the rumen. Blockages can be a result of food --- including potatoes, apples, turnips or kiwifruit --- or from physical causes such as nerve damage within the stomach or an enlargement pressing against the esophagus that prevents the cow from expelling gas build-up.

      Unfortunately, calves are at risk for free-gas bloat even under low bloat-risk conditions; however, if all other factors have been ruled out, calves normally outgrow this type of bloat by maturity.

    Prevention of Bloat

    • Feeding fresh alfalfa will cause a steer to produce 2 liters of gas per minute.

      The prevention of bloat is highly dependent upon the genetics of the cattle, type of pasture grass, hay and diet. However, there are some preventative methods that seem to have a history of success. Cattle that are free-fed coarse hay before being let out to pasture reduces bloat risks. Also, abstaining from seeding pastures in bloat-causing grasses --- blue grass, clover and immature alfalfa --- and crop cereals --- including kale and rape --- will reduce the risk of bloat as well. Feeding coarse, rolled grains in place of dense pellets and fine, rolled grains is highly recommended for all cattle.

    Treatment of Bloat

    • The most effective treatments for severe bloat is to use external methods that quickly remove the gases from the rumen before the cow begins to hemorrhage. A veterinarian can insert a cannula into the cow's stomach through the mouth or through the side of the animal's flesh and muscle to release the buildup of gas. In cases where the cow's life is in danger, anti-foaming agents such as peanut oil, Dioctyl sodium sulfosuccinate and Poloxalene may also be used in conjunction with a cannula. However, treatment methods are dependent upon the source and severity of the bloat.