Influence of dietary protein on susceptibility to alert downer syndrome

Fifty-three dry cows of the Ohio Agricultural Research and Development Center dairy herd were placed in one of four groups for the entire dry period. All received a corn silage-concentrate ration. Groups 1 and 2, however, were maintained on an intake of 8% crude protein while groups 3 and 4 received .65% of their dry matter as calcium and .29% as phosphorus while group 2 received .70% calcium and .70% phosphorus and group 4 received .66% calcium and .65% phosphorus. Animals were bled through the dry period at regular intervals and within 6 h postfreshening or prior to initiation of any therapy. In groups 3 and 4 metabolic disturbance occurred in 69.2% of calvings. These included eight alert downer cows, six of which died during treatment. In groups 1 and 2, the incidence of metabolic disturbance was 7.14% with no downer cows. Blood constituents showed no significant differences except between groups for urea nitrogen of plasma. Individual animals showed no significant changes in blood constituents indicative of a cause of the disorder. Dietary protein influences incidence of the disease. Dietary mineral imbalance and clinical expression of the downer condition were unrelated.