Tips to manage and prevent DAs

Left displacement of the abomasum (LDA) is one of the most common surgical diseases we see in dairy cattle. The incidence rate of LDA varies widely between dairy farms, but a reasonable goal would be less than 3 to 5 percent of fresh cows developing a LDA.

If you are above this threshold, then it’s probably time to rethink your protocols and management. Check out these LDA risk factors and ways to handle cows that do develop a LDA.

Prevent first

Your efforts should focus on keeping cows eating and ruminating. Anything that decreases dry matter intake before or after calving will increase a cow’s risk of developing a LDA. Consider these factors:

• Ketosis. Identify ketotic cows after calving and treat them immediately to help prevent the development of a LDA.
• Low blood calcium. Cows that have low blood calcium levels, even if they are not clinically ill with milk fever, have decreased appetite and trouble after calving. 
• Fresh cow diseases. Anything that makes a cow sick can secondarily lead to a LDA.  Examples include metritis, pneumonia and lameness. 
• Close-up cow feed intakes. The goal for dry matter intake in a close-up Holstein cow is 27 pounds and 19 pounds for a Jersey cow. If fresh cows experience ketosis and a LDA, investigate is how much dry matter the close-up cows are actually eating.
• Factors that inhibit feed intake. How easy is it for your close-up cows to eat? Close-up and dry pens should have 100 square foot of space per cow and 3 feet of bunk space per cow. Only using headlocks in the close-up pen and nowhere else on the dairy can decrease intakes. Heat stress and poor ventilation will also decrease intakes.
• Poor quality forages. It can be challenging to get dry and close-up cows to eat enough forage, and it is nearly impossible if the forage is long-stemmed, fibrous, over-mature hay. Cows simply cannot eat enough of this non-digestible fiber to satisfy nutrient requirements.
• Overestimating the amount of long-stem hay consumed.  If you feed a large round bale in one feeder or feed free- choice hay, you often overestimate what the cow actually eats. One feeder limits the number of cows that can eat at a time. Often there is more hay on the ground than in the rumen! Ideally, hay should be chopped to 1.5- to 2-inch maximum particle length and mixed with other ingredients in a TMR to prevent sorting, maximize intakes and allow for more accurate monitoring.
• Moving cows too close to calving. Moving cows less than three weeks before they calve or isolating them for several days in a single maternity pen are significant risk factors for ketosis and LDA. 
• Fat cow syndrome. Sometimes ketosis and LDA are due to a reproduction problem from the prior lactation that leads to overly conditioned cows.

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