Cobalt Tolerance in Young Dairy Cattle

Abstract

An experiment was carried out with growing Holstein dairy cattle to determine the amount of cobalt they can consume continuously with safety over a considerable period of time. There was considerable individual variation in the tolerance level. The oral consumption of a small excess of cobalt sulfate produced an increase in hemoglobin and packed red cell volume. The oral consumption of a greater excess of cobalt sulfate resulted in loss of appetite, decreased water consumption, rough hair coat and a lack of muscular coordination, as well as an increase in hemoglobin and packed red cell volume. High levels of cobalt as fed during this experiment increased the cobalt content of kidney and liver tissues to several times that of the controls, but in light of the levels fed and the duration of the feeding, these accumulations are considered to be low. Growing dairy animals as maintained on this experiment appeared to be able to consume daily up to approximately 50 mg. of cobalt per 100 lb. of body weight from cobaltous sulfate for many weeks without definite harmful effects. The levels of cobalt generally added to concentrate rations by feed manufacturers and those generally recommended for inclusion in mineral mixtures appear to afford a wide margin of safety. © 1949, American Dairy Science Association. All rights reserved.