Displaced abomasum

Cause
A displaced abomasum, also known as a twisted stomach, is the result of the movement of the abomasum from its normal position on the right lower side of the abdomen to a higher position on either the left or right abdominal side. This movement often is accompanied by excessive production and accumulation of gas in the abomasum resulting from a decreased emptying rate of the abomasum. Although cases of a DA can be found throughout the lactation, the majority are associated with early lactation. More than half of the left displacements are found in cows less than 14 DIM and over 80% occur within the first 30 DIM.

Identifying Problem Cows
Cows having other fresh cow issues are more likely to also develop a left displaced abomasum. Cows with a displacement are often off-feed and gaunt with milk production being lower than expected. Studies have shown that rumination times decrease four days prior to a decrease in milk production. Using a stethoscope and pinging the upper left abdominal side of the cow, the displaced and gas-filled abomasum can often be detected. Surgery often is needed to return the abomasum to its correct position. The goal is to have less than 3% incidence of displaced abomasa within the first month of lactation, with many farms experiencing less than 1% of fresh cows experiencing a DA.

Why Prevention Is Important
Cows diagnosed and successfully treated still have decreased performance for the lactation. Just like all of the post-calving disorders or diseases, production and/or reproductive performance will be negatively affected.

Preventative Management Practices
Cows with subclinical (no visible disease symptoms) ketosis and hypocalcemia (milk fever) are more likely to develop a displaced abomasum. Thus, prevention of these disorders has a direct impact on the incidence rate of DA in transition cows. As with all of these metabolic disorders/diseases, prevention starts during the previous lactation. Cows should enter the dry period in good, but not excessive body condition, and be fed to meet, not exceed, their energy requirements. Proper mineral and vitamin nutrition is imperative for a smooth transition from a non-lactating to a lactating cow. Heat stress and other stresses should be minimized during both the dry period as well as early lactation. Proper feedbunk management before and after calving involves cleaning bunks out daily and providing 30 to 36 inches of bunk space, properly balanced rations, and adequate resting space (1 stall or at least 100 sq. ft. per cow). The use of headlocks decreases the number of times a cow is forced to change location at the feedbunk and thus, decreases stress. In addition, adequate amounts of effective fiber should be provided to stimulate cud chewing, saliva production, and buffering of the rumen contents.

Author:  Donna M. Amaral-Phillips
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