Bioavailability of manganese sulfate and manganese monoxide in chicks as measured by tissue uptake of manganese from conventional dietary levels.

The biological availability of reagent grade manganese sulfate and manganese monoxide was determined in broiler chicks fed conventional dietary Mn levels. A basal corn-soybean meal diet (35 ppm Mn) was supplemented with 40, 80, or 120 ppm Mn from the two sources and fed ad libitum for 21 days. There were no differences in average daily feed intake, daily gain, or feed conversion among treatments. There was a linear (P less than .001) increase in bone, kidney, and liver Mn as dietary Mn increased. Manganese monoxide averaged 66% of the availability of manganese sulfate as determined by a combination of linear regression, multiple linear regression and tissue Mn increase. Bioavailability was similar to that obtained when sources were fed at high dietary levels in a previous study.