Pasture bloat is caused by the formation of a stable foam in the rumen and is often associated with grazing lush, rapidly growing legumes such as clover, but can also be seen on some rapidly growing young grasses. The foam formed prevents animals from belching gas and the rumen (first stomach) can rapidly inflate.
Ian Poe, District Veterinarian with North Coast Local Land Services said, “There are multiple options available to producers to help reduce the risk of pasture bloat, however unfortunately no single method is 100% effective; therefore, a multi-modal approach is recommended.”
The most important step is to ensure that cattle are not hungry when first introduced to high-risk pastures. This can be achieved by “filling them up” on hay or silage; or grazing alternative lower risk paddocks prior to introduction to risky paddocks. Limiting the grazing time, allowing free access to both high and low risk pastures concurrently, or using strip grazing to restrict the amount of high-risk pasture available can also be used. It is important however that grazing is not limited to a point where productivity may be affected.
Anti-bloat products may be added to water troughs, though water intake by cattle is frequently low on high-risk pastures, given the high water content of the pastures. If using this method, it is important that the treated troughs be the only water source available to the stock.
Bloat Oil can be sprayed directly onto pastures and may be an option where strip grazing is used but respraying may be required after rain. Bloat blocks are a convenient option, though intake of blocks can be quite variable and only those animals that consume sufficient quantities of the blocks on a regular basis will be protected.
“Rumen modifiers” and “ionophores” alter the microbial population in the rumen and can also be used as an aid to prevent bloat. These products are included in many loose licks or grain mixes.
Ian continued, “Whichever method, or combination of methods, is employed, monitoring stock after introduction is important as the onset of signs can be quite rapid after introduction.
“As well as the obvious distention of the abdomen on the left side, other signs include bellowing, lying down and getting up frequently and rapid breathing, often with the mouth open.”
North Coast LLS District Veterinarians also recommend that producers ensure their stock are up to date with 5-in-1, 7-in-1 or 8-in-1 vaccination, as enterotoxaemia (pulpy kidney) may also be seen in stock grazing early spring pastures.
Livestock producers who have a question about bloat control or livestock animal health, should contact their local private veterinarian or District Veterinarians at North Coast Local Land Services on 1300 279 299.
