Sodium deficiency of grazing cattle in Papua New Guinea.

Sodium deficiency was suspected from low saliva sodium concentrations in cattle at various sites in the lowlands of Papua New Guinea. In an experiment at Erap, Morobe Province crossbred and pedigree Brahman heifers supplemented with copper, cobalt and/or common salt showed no response to copper or cobalt supplementation. There was a significant growth response (P less than 0.01) to salt supplementation over a 16 week period confirming sodium deficiency in these animals. The response in the crossbreds was twice that in the purebreds. Supplemented crossbred animals grew 0.78 kg/day over the 16 week experimental period.