Dealing with Acidosis in the Beef Herd

Ruminal acidosis continues to be a common ruminal digestive disorder in beef cattle and can lead to marked reductions in cattle performance. It is a metabolic disorder, where pH levels decrease very rapidly below 5 to 6, which supports lactic-acid producing bacteria.

The fall in pH stops the rumen from moving, becoming atonic of which depresses appetite and production. The influx of acid produced is absorbed through the rumen wall causing metabolic acidosis, which in severe cases can lead to shock and death.

The three main causes of ruminal acidosis are excessive intake of rapidly fermentable carbohydrates such as barley or other cereals, inadequate buffering capacity and inadequate ruminal adaption to a highly fermentable diet.

There are two types of acidosis: acute and sub-acute. Acute acidosis is a more serious condition, which can cause death where cattle have obtained access to excess feed. Sub-acute ruminal acidosisis not as a severe as clinical acidosis, but the consequences are still significant and can include laminitis, infertility, depressed intake, drop in rumen pH and low butterfat.

Symptoms of sub-acute acidosis include low fat solids, rumen fill-poor, diarrhea, faeces with gas bubbles, laminitis and undigested fibre in particles in the faeces. Animals look lethargic and appear weak.

The rumen lining will be damaged depending on the extent of infection on the rumen wall. Inflammation occurs in the abomasum which may destroy the villi that are responsible for nutrient absorption from the rumen wall. This will also suppress the immune system, and liver abscesses are common, leading to reduced feed intake, feed efficiency, weight gain and carcass yield.

Prevention is key in reducing the risk of acidosis in cattle and sheep. Roughage should always beprovided with any grain diet. This will help with ease of digestion whilst preventing the microbes in the rumen from digesting a high-concentrate ration too quickly.

Roughage should be coarsely chopped to have effective scratching of the rumen wall. Introducing long-fibres in the diet will encourage saliva production during chewing and increase rumination after feeding.

The key is to reduce the amount of readily fermentable carbohydrate consumed at each meal with the correct balance of fibre and non-fibre carbohydrates. These long-fibre particles are incorporated into the diet to provide adequate buffering.

Dietary buffers such as sodium bicarbonate or potassium carbonate can be used to control pH. Yeast can also be used as a prevention aid for this metabolic order of acidosis. Injection of Thiamine is often recommended as it halts the attack of acidosis in cattle.

When introducing grain, it should be offered in a gradual manner and it is important that feeding schedules are kept to a routine and the best scenario would be offer feed twice or three times daily.

Ruminal Acidosis is a preventable condition with the correct feed management practices.