Left Displaced Abomasum or LDA

The Abomasum is one of the stomach compartments of the cow. It normally sits on the abdominal floor, slightly to the right of the midline. Under certain circumstances it can become enlarged with fluid and gas and subsequently is displaced to the left (Left Displaced Abomasum or LDA) or the top right (Right Displaced Abomasum or RDA) part of the abdomen. LDA’s are much more common than RDA’s and are seen most commonly in high producing adult dairy cows, within the first month of lactation. LDA is rarely seen in bulls or beef cattle.

 

The typical history of cows suffering from LDA’s include

  • Calving within the last month; extra space within the abdomen once the calf is born and a lower feed intake and therefore smaller rumen size post calving
  • Significant drop in milk production
  • Reduced intake of concentrates.

Many cows will also have elevated ketones and may have been treated for ketosis some days earlier. Often we hear that “she was doing really well for the first few days then went off her food and hasn’t responding to normal ketosis treatment”.

LDA’s are also often seen at the same time as retained membranes, mastitis, metritis and hypocalcaemia in freshly calved cows. Excess body condition score (BCS) prior to calving can also be a risk factor. Cows with an LDA do not usually have a fever but will have reduced rumen contractions and will pass small amounts of softer, pasty faeces. They are also not usually bloated although a slight bulge at the level of the last to second last rib can sometimes be seen from behind.

 

Treatment

While there has been the odd report of “rolling” the cow to correct, most cases of LDA will require surgery or toggles. When treated early the outcome is usually satisfactory although milk yield may not return to prior levels. The sooner they are treated the better the outcome is likely to be.

 

Prevention

It is not possible to eliminate all cases of LDA. However, paying close attention to nutrition and management of your cows during the transition period (2-3 weeks before and after calving) can greatly reduce the risks of the disease being a major problem in your herd.

 

During this period it is important to make sure the cows have adequate fibre as part of their ration. The volume and length of the fibre is one of the most important ways to reduce the likelihood of LDA’s in your herd.

Feeding concentrates/pellets prior to calving is a good way to prepare the cow for the higher energy diets given after calving. However, the balance of concentrates is important as feeding too much or too little concentrates can actually increase the risk of LDA’s.

The most effective means of controlling the number of LDA’s we see has been feeding a good quality transition diet (lead feed) for at least 14 days prior to calving. Minimising weight loss post calving and keeping the calcium levels well balanced will reduce the likelihood of LDA’s, as well as help to reduce ketosis, retained membranes or calcium disorders and lead to a more profitable and healthier herd.