Long-term effects of corn, soybean meal, wheat bran, and fish meal on manganese utilization in the chick.

A 7-week assay was conducted to investigate the long-term effects of several natural feed ingredients on Mn utilization. Chicks were fed a Mn-deficient casein-dextrose diet supplemented with fish meal, wheat bran, or a corn-soybean meal mixture. Although these feed ingredients contain significant quantities of Mn, they actually depressed performance and reduced the Mn concentration in key tissues when dietary Mn was near the chick's minimal requirement. At deficient levels of dietary Mn, fish meal also had detrimental effects on those parameters, and it increased the severity of perosis as well.