Every treated cow is the tip of the iceberg, so prevention is vital. The aim of any prevention regime is to give the cow time to adapt to change and not to expect the rumen to be able to adapt to whatever is thrown at it.

There are two types of sub-acute acidosis. The first occurs in freshly calved cows (up to 20 days after calving). This occurs because of a failure to adapt the rumen to the lactation diet before calving. In this case, dry cow management is the key to prevention. In particular, feeding a transition diet and minimising calving stress are important.

The second type of acidosis affects cows from peak to mid-lactation. At this time rumen adaptation to the diet should have occurred, so acidosis in these cows occurs as a result of feeding diets that are low in fibre and high in starch (or which allow for feed selection).

In all herds with an acidosis problem there needs to be a full assessment of the feeding, with attention paid to what the cows are being fed and to what they are eating. Each individual situation will be different and require a different range of solutions.

Nevertheless there are several factors which are likely to be of importance in most situations:

Forage to concentrate ratio. Except in very high yielding cows a ratio of 60:40 will significantly reduce the risk of acidosis

Feeding total mixed rations with forage and concentrates mixed can significantly reduce acidosis, provided selection of the concentrate portion doesn’t occur

Feeding space: If there is insufficient space average meal size will increase, increasing the risk of acidosis (even with a TMR). (This can also occur if feeding time is restricted or if feeding times are irregular)