Studies with Radioactive Cobalt 



To obtain furthei information on the way in which cobalt functions 

 in the ruminant, an experiment was carried out using radioactive cobalt. 

 When radioactive cobalt sulfate was injected intravenously into cobalt 

 deficient sheep, it was found that a small amount of the cobalt reached the 

 rumen. This explained why injected cobalt could bring about a slow recovery 

 from the deficiency even if it was required only in the rumen. 



When radioactive cobalt carbonate, a compound which is relativelv in- 

 soluble in water, was fed to normal sheep, it was found to be soluble enough 

 in the digestive tract to be absorbed in appreciable quantities. This was 

 shown by the presence of radioactive cobalt in the blood stream and in the 

 urine. 



Present Status 



Cobalt deficiency was found to affect the health of cattle, sheep, and goats 

 generally throughout the state of New Hampshire. The effects of the deficiency 

 have been practically eliminated by the use of cobalt-supplemented, manu- 

 factured feeds, salt, and mineral mixtures. The need for supplemental cobalt 

 is very small; one pound of cobalt sulfate being enough to treat 225 tons 

 of manufactured feed. The cost is negligible. 



Studies now in progress at the New Hampshire Agricultural Experiment 

 Station show that the cobalt content of forage may be reduced to the deficien- 

 cv level in heavy vields resulting from the use of chemical fertilizers as well 

 as from poultry manure. One surprising result of this study was the finding 

 that the presence of a considerable percentage of ladino clover in a mixture 

 is no guarantee against cobalt deficiency as is generally believed. In fact, 

 the cobalt content of the ladino clover plant itself has been below the de- 

 ficiency level in several cases. These studies emphasize the continued need 

 for supplemental cobalt by cattle, sheep, and goats which may be fed forage 

 produced under heavy fertilization. 



The most recent information indicates that cobalt deficiency symptoms 

 in ruminants are due to a lowered production of vitamin B 1: > by the flora of 

 the. rumen. The principal symptom is a lack of appetite. The other symptoms 

 appear to result largely from an inadequate feed intake. In addition to the 

 feeding of cobalt, the deficiency can be cured by the injection or feeding of 

 adequate amounts of vitamin B 1: _>. which contains cobalt in its molecule. 

 According to Cornell I niversity workers, the deficiency also can be cor- 

 rected by the injection of a special liver extract containing a high potency 

 of vitamin B] o- 



12 



