As already indicated in our previous blog, low blood calcium levels affect ruminal function, with associated effects on rumen and abomasum contractions leading to reduced and often erratic feed intakes during the immediate post calving period. In such situations, cows are likely to increase body tissue mobilisation in order to meet their lactation demands; which in turn may give rise to fatty livers and ketosis, due to failure of the cow to completely metabolise mobilised adipose tissue.

Of most immediate concern however, is the possibility of displaced abomasum (DA’s), which can occur when feed intake is erratic and muscle function is poor. The incidence of this condition is increasing on many farms can often result in the need for veterinary intervention and undoubtedly affects the cow’s subsequent lactation performance. Avoidance of DA’s is certainly a better route to providing a cure and is best achieved by providing a well-presented and palatable ration, at the same time ensuring the cow’s calcium status is not compromised.

It is important that this ration contains adequate levels of physically effective fibre, as DA’s can also occur in freshly calved cows turned out to fresh lush pasture or when rations containing extremely short chopped silage (either grass or maize) are fed. Such rations contain inadequate levels of physically effective fibre, which will reduce rumination times, with knock-on negative effects on rumen health and feed intake. In such situations rumen fill will be reduced, therefore allowing the abomasum to move within the abdominal cavity and hence becoming displaced.

Good nutritional management is the only solution to the avoidance of displace abomasum.

Author: Denis Dreux