Displaced abomasum (DA) is a common cause of surgery on dairy farms and usually takes place within four weeks of calving.
Left displaced abomasum (LDA) accounts for up to 90% of DA on farms. When this happens, the abomasum moves from its normal position and becomes trapped between the rumen and the left abdominal wall.
This causes a restriction at the entrance and exit of the abomasum, causing it to fill with gas.
In the cause of a right displaced abomasum (RDA), the abomasum moves right and becomes trapped between the right abdominal wall and the omasum.
Displaced abomasum
The exact cause of a displaced abomasum is not fully known, but calving is a risk factor.
During pregnancy the abomasum is displaced by the expanding uterus, so once the cow calves the abomasum has to move back to its normal position.
If the abomasum does not return to its normal location, it can result in a displaced abomasum.
Symptoms
Cows that are affected by an LDA or RDA will have symptoms that are similar to ketosis.
Cows will go off their feed, become depressed and have a reduced milk yield. Cows with a RDA can suffer from more severe symptoms such as colic, elevated heart rates, scant faeces and diarrhoea.
If the abomasum becomes twisted the cow can go downhill very quickly.
At this time of the year it is always a good idea to look at troughs in the parlour after cows; a cow not eating meal should be a red flag.
Milk yield on many farms can be hard to monitor, but meal left in the trough is easy to detect.
If you suspect a cow has a LDA or RDA you should contact your vet as rapid intervention and treatment will reduce the recovery time.
Your vet will be able to determine if a displaced abomasum is the issue by using their stethoscope to listen for the presence of a ‘pinging’ noise. This noise is caused by the gas-filled abomasum.
Prevention
Good management during the transition period is important to prevent LDAs and RDAs.
Ensuring the animal has good rumen fill is important, so offering cows good quality forage is important during this period.
Some steps to take include ensuring cows are in the correct body condition score (BCS); having a high-quality feed; ensuring there is enough feed space; and slowly increasing concentrates after calving.