Absorption, excretion and tissue distribution of natural organic and inorganic zinc-65 in the rat.

The absorption and tissue distribution of organic and inorganic forms of 65-Zn were studied in the rat following single tracer oral doses. Rats dosed with 65-Zn grown into young corn and rye plants (organic form) absorbed and retained more 65-Zn in tissues than those given 65-Zn mixed with tissue paper (inorganic forms). A part of the beneficial effect was evident when 65-Zn was mixed with forage. The relatively high absorption values indicate that both forms were readily available, and thus incorporating zinc into young forage protein is not of major practical importance.