Dietary abomasal impaction in a herd of dairy replacement heifers.

An episode of dietary abomasal impaction in a herd of dairy replacement heifers was found to be caused by excess almond shells in the ration. Clinical signs and necropsy findings led to the diagnosis. Removal of the almond shells and increasing the energy and digestibility of the ration corrected the problem. Factors contributing to the dietary impactions included advanced stages of pregnancy, high energy demands of growing heifers, and cold weather. Dietary abomasal impactions are not common in dairy cattle because of the high-quality ration a dairy cow generally receives. Replacement heifers in advanced stages of pregnancy have nutritional requirements similar to those of dairy cows, yet are often nutritionally neglected. The clinical findings in this report may help make veterinarians aware of the possibility of dietary abomasal impactions in dairy replacement heifers fed low-quality feeds.