Reducing or Eliminating Displaced Abomasums
Dr. Ronald L. Boman
USU Extension Dairy Specialist
This past month I had occasion to be on a dairy that was experiencing a 30+% incidence of displaced abomasums (DA�s or �twisted stomach�) during the first month after calving. We know all too well that DA�s cause economic loss in dairy herds because of treatment costs, premature culling, lost production, and in some cases, death. Nationally the average incidence of DA�s in lactating dairy cows ranges from 1.5 to 6%, however some herds rarely have DA�s and others may have an incidence as high as 25%.
There are four main factors associated with the occurrence of DA�s in cows:
1. Around calving time cows reduce their feed intake. This is a time when the calf (fetus) has been occupying a rather large portion of the abdominal cavity and pushing against the rumen and abomasum. If the cow has not kept her rumen full of feed (especially roughage), then after calving there is a chance for the abomasum to move under the rumen and become �displaced.�
2. The second factor associated with DA�s is cows coming down with milk fever or being on the verge of coming down with milk fever (hypocalcemia). An adequate level of blood calcium is necessary for the maintenance of normal rumen and abomasal contractions and to keep them in their proper location.
3. The third factor associated with DA�s occurs when an abnormal amount of volatile fatty acids and gas get into the abomasum causing a decrease in the motility of the abomasum and also the rumen. This excess gas can cause the abomasum to float and become displaced.
4. The fourth factor associated with DA�s is cows that are too fat when they are dried off and are still too fat at calving time. Over conditioned cows don�t have good appetites just prior to calving and don�t eat well after calving. Lack of appetite leads to less rumen fill and lack of maintenance of the rumen mat or raft (normal rumen function). Fat cows that don�t eat well start mobilizing their fat reserves for energy and are prone to have ketosis, retained placentas and other problems that can increase their chance of getting DA�s
A. Manage cows in the close-up dry pen at least 3 to 4 weeks before calving:
1. If available, feed low (1 to 1.5%) potassium, long stemmed or coarsely chopped forage. Limit corn silage to 10 to 15 lbs/cow/day. To further reduce the chances of milk fever, include anionic salts designed specifically for your feeds or 1 to 2 lbs of SoyChlor or similar product and monitor the pH of the urine. The urine pH should be acidic (6.0 to 6.6).
2. Feed 8 to 10 lbs of a grain mix based primarily on barley and corn along with free choice forages. The starch in the grain enlarges the rumen papillae so they can absorb and utilize the extra volatile fatty and lactic acids that are produced when cows are switched to higher energy transition and lactating rations. The grains fed during the close-up dry period also allow the rumen microbes to adjust their populations to the higher energy ration. Recent research suggests that ration crude protein should be 14% for the close-up dry cow.
3. Keep the cows eating by feeding and pushing up feed often. Some producers have included � lb of an additive such as Diamond V Yeast/cow/day to enhance feed intake and rumen function prior to and after calving. It is preferable to feed the grain mix in a TMR along with some long stemmed hay. If the grain is fed separate from the forage it should be fed at least two, and preferably more, times per day. These close-up cows also need ample bunk space, ready access to fresh water and clean and comfortable free stalls or lounging area.
4. Overly fat cows (body condition scores above 3.75) require all of the above suggested management techniques and in addition the judicious use of such products as Reashore Choline and NutroCAL (fed according to manufacturers� recommendations). These two products (and there are others) help reduce the fatty acids and ketone levels in the blood and reduce the fat build-up in the liver. This helps to keep the cow eating and to prevent ketosis and other metabolic problems which can set the cow up for a DA.
B. Manage cows in a transition or �fresh cow� pen for 3 to 4 weeks after calving:
1. Ideally you will have a special transition pen for cows after calving where they have plenty of manger space, free access to water and comfortable free stalls or a lounging area. This helps reduce stress and contributes to the cow�s ability to eat and keep her rumen full and functioning normally.
2. Once the cows have calved some producers administer various forms of calcium pastes (to further prevent milk fever) and they certainly provide a mineral package with recommended amounts of calcium, other major and minor minerals and vitamins. Research from Texas suggests that careful drenching of the rumen with up to 5 or more gallons of water as soon as possible after calving helps to keep the rumen and abomasum in place and thus reduces the incidence of DA�s. Certainly the cows should have ample opportunities to drink water.
3. The ration during this time ideally should be higher in protein, energy and effective fiber than the lactation ration because feed intake is down. From a DA prevention point of view it is a good idea to feed 5 to 8 lbs of really palatable long stemmed hay and include a similar amount of whole cottonseed. Both of these feeds help maintain the integrity of the rumen mat or raft, which captures the grain particles and reduces their chance of being fermented in the abomasum causing it to float and become displaced.
C. Manage cows in the high producing herd:
Once the cows leave the fresh cow pen and go into the high herd, make sure that you don�t over process the hay and other forages in your TMR mixer. Provide the recommended amounts of effective fiber (particle length and fiber content) from forage and fibrous by-product feeds. Also feed and push up feed often so that cows clean up the feed (stems and all). This reduces the opportunity for cows to sort out the grain portion and maintain the fiber level in the rumen. Be certain that cows have adequate manger space, as well as free access to water and comfortable and clean housing.