Influence of Dietary Protein on Susceptibility to Alert Downer Syndrome

Abstract

Dry cows (53) of the Ohio Agricultural Research and Development Center [USA] dairy herd were placed in 1 of 4 groups for the entire dry period. All received a corn silage-concentrate ration. Groups 1 and 2 were maintained on an intake of 8% crude protein while groups 3 and 4 received a 15% ration. Groups 1 and 3 received .65% of their dry matter as Ca and .29% as P while group 2 received .70% Ca and .70% P and group 4 received .66% Ca and .65% P. 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 8 alert downer cows, 6 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 plasma urea N. 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.