A chick assay for determination of available iron from biological material and its application to fish protein concentrates.

A dose response assay for the assessment of available iron in biological materials using chicks as experimental animals is described. Day-old chicks were fed on an iron-deficient diet for 2 to 3 weeks at which time the hematocrit had decreased to about 20%. After this depletion period, the standard groups were fed graded levels of iron sulphate up to a maximum level of 30 ppm iron. The test groups were fed two levels of biological material giving a total dietary iron concentration within the standard range. The response was measured by hemoglobin concentration (g/100 ml), and the dose by the consumption of iron per gram of body weight gain. Contents of available iron (relative to iron sulphate-iron) in the test substances were calculated from the dose response regression equations obtained on the standard groups, and hemoglobin (g/100 ml), feed consumption and body weight gain in the test groups. Statistical evaluation of the data revealed that the assay complied with the requirement for statistical and fundamental validity. Results from application of the method on six different samples of fish protein concentrate (FPC) are reported.