59Fe utilisation and excretion in anaemia of cattle caused by Pimelea trichostachya intoxication

Experimental chronic Pimelea poisoning, with severe anaemia, was produced in 4 calves by daily oral dose rates of Pimelea trichostachya of between 20 to 60 mg/kg body weight of whole plant. Bone marrow function was studied before and during intoxication using 59Fe to determine plasma iron clearance rates, intraerythrocytic iron incorporation rates and percentage iron uptake, and faecal blood loss was measured before and during intoxication. It was shown that bone marrow activity was neither significantly depressed nor enhanced during intoxication. There was however, evidence of a slight increase in erythrocyte maturation rate. Reticulocytosis was not observed during the development of anaemia, but did occur in 3 of the calves shortly before death.