As we enter into the autumn months, the risk of bloat increases as clover content is at its peak and many swards have a low level of dry matter (DM).
Clover certainly brings its benefits as it reduces your reliance on chemical nitrogen but the drawback of clover is that it poses a serious threat to livestock in the form of bloat.
With many farmers now reaping the benefits of sowing clover into their swards, they must be mindful of the threat it poses at this time of the year.
Ruminant animals produce large volumes of gas during digestion and this gas is either belched out or passes through gastrointestinal tract.
However, if something interferes with gas escape from the rumen, bloat occurs and usually happens when animals are grazing young, lush pasture or when the pasture has high legume content such as clover.
High risk season
Swards with a high sward clover content of over 40% will pose a serious threat to cows grazing it at this time of the year.
Bloat can be rampant when turning cows from grass only swards to graze grass clover swards. Likewise, turning hungry animals to graze mixed grass clover swards can encourage bloat.
Bloat usually occurs after heavy feeding and is more common in hungry cattle. If left untreated or if you delay your treatment, it can be fatal as the gas can quickly go to the head.
When the previous grazing saw the post-grazing height go down to less than 4cm, this can pose a threat for the following grazing.
After a heavy fall of rain, during wet weather or even after a heavy dew, the DM percentage will lowered and consequently pose a threat of bloat.
Very lush grass or even sending the cows into a paddock with a low pre-grazing herbage mass or sending them into a bit of after grass can see the onset of bloat in cattle.
Bloat prevention
An option a farmer can take to prevent bloat from occurring is to make sure all the cows enter the paddock as a full herd which may require holding the cows in the yard.
Make sure that all the water troughs in the fields and a long the roadways or in the collecting yard have a sufficient amount of bloat oil in them.
If it is possible to do so, introducing a bit of roughage and fibre can help or around 2-3kg DM/day of silage around milking time.
Avoid under feeding the cows as they will eat down to a low post grazing yield height. The use of strip wire can be beneficial, putting the cows into 2-3 hour breaks.
Try and avoid moving cows from grass paddocks to high clover content paddocks if it at all possible and keep your post grazing sward height at 4-4.5cm.
Identify high risk paddocks and monitor cows closely when they are grazing those paddocks, keeping a close eye during the high risk period.
To sum it all up, in order to reduce the risk of bloat occurring, farmers need to be consistent, reemploy the strip wire when allocating grass, use bloat oil, include fibre in the diet and manage the grazing group to avoid gorging.