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Bloat is a seasonal ruminant disease caused by extremely accumulation of fermentation gases within the rumen during digestion process. Promptly after cattle feed, the digestion system creates gases in the rumen. Most of these gases are eradicated by eructation.
Any obstruction of the process of eliminating these gases can lead to bloat. Primary bloat or frothy bloat is the more common form of the condition.
Usually the condition occurs as an epidemic in several animal within a determinate space, in the view of the fact that those animals fed on pastures that contain high levels of leguminous plants (especially clover and alfalfa) during spring.
Once the froth has formed in the rumen and the natural eructation is obstructed, the rumen motility is initially increased, causing further frothing. With that occurring loss in muscle tone and rumen motility take place. The cows can die for different reasons, including the depressive effect of rumen distension on the heart and lungs and absorption of toxins from the rumen.
RELEVANT SIGNS AND SYMPTOMS
Generally cows affected by the disease manifest the following symptoms:
- generally exhibit a distended left abdomen (is the most visible sign);
- Usually associated with pain, discomfort, and bellowing;
- no longer graze;
- a reluctance to move;
- generally strain to urinate and defecate;
- rapid breathing – mouth may be open with tongue protruding;
MAIN CAUSES OF THE BLOAT
- A condition secondary to acidosis indigestion;
- certain proteins in forage;
- the amount, rate of intake, and coarseness of the roughage;
- rate of digestion of grains as a result of processing (grinding too fine);
- host-parasite reaction following grub treatment choking;
- an inherited tendency for bloat.
PRACTICES TO REDUCE AND PREVENT BLOAT IN CATTLE
The prevention of bloat is not only advantageous to reduce cattle death, but it can also can reduce the undesirable effect on the cow’s performance.
Fast growing and leguminous pastures should be avoided. Many paddocks will have areas of bloat inducing pasture during the spring and autumn growing seasons. The clover content in the pasture can vary markedly over a paddock. Cows will additionally select succulent grasses and legumes to graze, which makes assessing the risk of a pasture difficult.
Pasture management should not be solely relied on to control bloat. Increasing the fibre intake of cattle will reduce bloating. Feeding grass hay daily can help to reduce the intake of “bloaty” pasture. However some animals will eat the pasture in preference to the hay. The protective effect is likely to be very short term (a few hours) but has been found to be effective on some farms.
Treatment of bloat usually requires the passing of a rumen tube and administration of vegetable oil or anti-bloat agents. Under organic conditions, proprietary anti-bloat agents require a milk withdrawal period twice as long as the label withdrawal period. The ones that do not indicate a statutory milk withdrawal require a minimum milk withdrawal of 48 hours. The prolonged withdrawal periods should be taken into consideration for meat withdrawal as well. Some certification bodies may operate a stricter withdrawal policy, and this should be checked before the inclusion of milk from the treated animals into the bulk tank.
In severe cases, where death is imminent and the animal is lying down, emergency surgery (rumenotomy) by a veterinarian is necessary.
GENERAL ADVISES TO CONTROL BLOAT
Make sure to slowly introduce the cows into new pasture, owing to the fact that you will be able to control and follow the signs of bloat.
Always check your cows during the process of grazing. Be aware of “danger seasons” and pay attention to what they feed on, during those seasons.
Ensure access to long fibre during the whole grazing season at pasture or prior to going to pasture.