Management of the dry cow and transition program is often complicated by displaced abomasum (DA, a common post-partum syndrome. This physical anatomical disease is caused by entrapment of the abomasum between the rumen and the left side of the cow (Figure 1). The normal abomasum position is in the cranial, lower right quadrant of the abdominal cavity (Figures 2 and 3). Since abomasum entrapment rarely resolves by itself, surgical intervention is usually necessary. Both open and closed surgical techniques are commonly used for correction. The closed technique methods include toggling or blind stitching the abomasum in place. Depending on the surgical technique used, losses are estimated at $250-$400 per incident.

   

Primary Risk Factors
Two primary factors at calving put the cow at risk for a displaced abomasum:

• The creation of more space in the body cavity for the abomasum to move around.

• The build up of gas in the abomasums, causing it to rise.

 Two factors are responsible for the space increase in the abdominal cavity, which allows the abomasum to shift position:

• Birth of an 80-100 lb calf creates space. If the cow could consume a sufficient amount of feed post-calving, the amount of space would be reduced.

• Hormonal changes needed to induce calving and stresses associated with calving reduce cow appetite, thus feed intake. This leads to less volume of feed in the rumen, which adds to the empty space created by calving.

Consequently, the sudden increase in abdominal space allows the abomasum to shift position, increasing the possibility of displacement. Since neither of these factors can be completely alleviated, producers should strive to prevent DAs by providing an environment that encourages the cow to eat as much as possible. Managing to minimize stress during pen changes and ensuring fresh, palatable feed and water are easily accessible at all times is essential to help keep the rumen as full as possible.

Secondary Risk Factors
Secondary factors that may put the cow at risk include any circumstances that decrease abomasum motility. Theoretically, these risk factors could cause the abomasum to fill with gas and float up on the left side of the cow. Two factors are known to decrease abomasal motility:

• Low serum calcium levels

• Presence of volatile fatty acids (VFAs) in the abomasum.

The Calcium Connection
Adequate calcium is needed for muscles to contract properly. Low calcium levels not only cause milk fever, they can also cause less smooth muscle contraction in the abomasum, leading to a build-up of gas in the organ. In addition, cows with low blood calcium have decreased appetites. Blood calcium levels typically drop at calving. Rations for pre-fresh cows can be formulated to minimize the drop in blood calcium. Formulating for low potassium levels and raising magnesium levels to 0.4% of the diet, help hold calcium levels closer to normal ranges. Other methods to manage calcium at calving include feeding anionic salt rations (to offset high potassium levels) or keeping calcium levels low enough to stimulate bone release of calcium into the blood while keeping dietary phosphorus at reasonable levels.

Rumen Prep
Volatile fatty acids (VFAs) are absorbed through the rumen papillae. Volatile fatty acid production in the rumen increases as “hotter” rations containing more readily available carbohydrates are fed. Butyric and propionic acid, produced when readily available carbohydrates are fermented, stimulate growth of rumen papillae. During the dry period when lower energy rations are fed, rumen papillae may decrease in size. This will result in less surface area available to absorb the VFAs. Preparing the rumen to better absorb VFAs could decrease the amount that would leak out of the rumen and cause decreased abomasal motility. Feeding sources of readily available carbohydrates (grain) before calving will help increase the surface area of the rumen papillae. In addition, feeding readily available carbohydrates before calving will build-up a population of lactic acid utilizing bacteria. Fermentation of readily available carbohydrates leads to the production of lactic acid in the rumen. A low level of lactic acid utilizing bacteria along with a build-up of VFAs in the rumen may lead to acidotic conditions and leakage of VFAs into the abomasum. Preparing the rumen before calving to handle readily available carbohydrates will result in more surface area to absorb VFAs, which will help reduce rumen acid level and increase energy available to the cow. This should also help build a population of lactic acid utilizing bacteria, which will help maintain a higher rumen pH.

Nutritional Solutions
ADM Alliance Nutrition offers several dry, transition products that can help alleviate the incidence of DA. Anionic salt products can be used to help the cow maintain calcium levels at calving. In situations where cows may have an aversion to consuming anionic salts, a 10 lb top-dress product is available. Alliance Nutrition anionic salt products also include sources of starch to prepare the rumen for a lactation diet. For producers who desire to use their own corn, a 2.5-3 lb/head/day product is available.

To prevent milk fever by stimulating the bone to secrete calcium into the blood, Alliance Nutrition offers products low in calcium, potassium, and phosphorus. These products are also formulated to provide higher levels of magnesium. Proper magnesium levels are necessary for the cow to release parathyroid hormone, which is essential for proper calcium metabolism. Glucose precursors and high-quality bypass protein are also included in the product offerings. Dry cow products from Alliance Nutrition are also fully fortified with trace minerals, vitamins A, D, and E, and additional magnesium.

Prevention of acid build-up in the rumen can be aided with Prosponse® Nutrium. This product contains a lactic acid producing strain of bacteria along with Prosponse yeast. The low level of lactic acid produced helps maintain a stable population of lactic acid utilizing bacteria. Then, when the cow starts consuming the lactation ration, bacteria in the rumen are already available to help keep the lactic acid level low. Prosponse Nutrium should be fed beginning three weeks pre-partum and continued through the first month of lactation.

Conclusion
While producers have limited control over primary risk factors associated with DAs, secondary risk factors can be nutritionally influenced to help alleviate incidences of DAs. Minimizing blood calcium drop, conditioning the rumen to utilize VFAs post-calving, and ensuring a lactic acid utilizing bacteria population is present in the rumen will facilitate the transition from dry to lactating phases while helping minimize occurrence of DAs. Alliance Nutrition products are formulated to help keep cows healthy and producing at profitable levels.