The Retention of an Oral Dose of Radioactive Manganese in the Pullet and the Effects on Retention of the Intake of Inactive Manganese.

In the growing chick a large proportion, over 95 yo, of an oral dose of radioactive manganese was found in droppings collected during 72 h after dosing (Mohamed & Greenberg, 1943), indicating a very low retention of this element. The object of the study now presented was to make similar determinations of retention in the laying pullet and to observe the effects on retention of (I) giving a low-Mn diet for 10 weeks or more and (2) varying the quantity of inactive Mn with the radioactive dose. I t soon became evident that retention was very small in all treatments and in consequence, even if differences among treatments occurred, they were unlikely to be detected by the ‘difference method’. Therefore treatment effects were sought in the quantities of radioactive Mn present in the liver and blood. A brief report of part of the work has been published (Hill, 1964).