Nitrate Toxicity in Dairy Heifers. 2. Erythropoietic Responses to Nitrate Ingestion during Pregnancy

Abstract

The effects of feeding sublethal levels of nitrate were studied under conditions of management and feeding practices recommended for dairy cattle. Heifers ingesting nitrate at levels of 440 and 660 mg/kg body weight for a long period of time were capable of adapting to a deficiency of oxygen in their blood. This compensatory mechanism consisted of a marked increase in the number of circulating erythrocytes, and consequently increased hemoglobin concentration and blood volume. These increases were not due to a reduced plasma volume because plasma volumes of nitrate-fed heifers were normal. © 1964, American Dairy Science Association. All rights reserved.