Changes

In the last 20 years, selective breeding and improved genetics have dramatically increased the individual dairy cow's milk yield and hence the energy requirements for lactation. In order to meet these increased energy demands and avoid prolonged negative energy balance in early lactation, the energy density of the ration has also been increased. This has been achieved by feeding high levels of concentrate feed and energy-rich maize silage. Although these are effective in helping to meet energy requirements, they also contain large quantities of rapidly fermentable carbohydrates that cause increased production of acid in the rumen. The results in a fall in rumen pH below the optimum range of 6-7. This is known as subacute rumenal acidosis. Subacute rumenal acidosis is a herd problem that is often never recognised, let alone controlled. However, it can contribute to many aspects of ill-health in cattle, and reduces productivity, and so management of the condition makes good economic sense.

In the last 20 years, selective breeding and improved genetics have dramatically increased the individual dairy cow's milk yield and hence the energy requirements for lactation. In order to meet these increased energy demands and avoid prolonged negative energy balance in early lactation, the energy density of the ration has also been increased. This has been achieved by feeding high levels of concentrate feed and energy-rich maize silage. Although these are effective in helping to meet energy requirements, they also contain large quantities of rapidly fermentable carbohydrates that cause increased production of acid in the rumen. The results in a fall in rumen pH below the optimum range of 6-7. This is known as subacute rumenal acidosis. Subacute rumenal acidosis is a herd problem that is often never recognised, let alone controlled. However, it can contribute to many aspects of ill-health in cattle, and reduces productivity, and so management of the condition makes good economic sense.

Beef cattle and sheep  may also face this problem, but generally to a lesser degree as they are raised more extensively and their energy demands are considerably lower.

Beef cattle and sheep  may also face this problem, but this is less common as they are raised more extensively and their energy demands are considerably lower.

==Pathogenesis==

==Pathogenesis==