Response of whole blood glutathione peroxidase and selenium in chicks fed with sodium selenite, wheat and fish meal

Abstract

The biological availability of selenium (Se) in wheat and fish meal in comparison with that in sodium selenite was estimated in the chick. Newly hatched White Leghorn chicks with a low-Se status were fed a low-Se basal diet for 2 weeks post-hatching, followed by either continued depletion or a repletion period of 4 weeks with graded levels of Se (0.03, 0.06, 0.09 and 0.12 mg kg −1) provided via sodium selenite, wheat or fish meal. The efficacy of Se from these sources in inducing glutathione peroxidase (GSH-Px) activity and in increasing Se concentration in whole blood were used as indices. A slope ratio assay was employed to obtain estimates of the biological availability of Se in wheat and fish meal in comparison with the sodium selenite standard (100%). The bioavailability of Se in wheat and fish meal for increasing the activity of GSH-Px, when calculated as units per millilitre was 78% and 58%, respectively, and 81% and 54%, respectively, when this enzyme activity was calculated as units per gram of haemoglobin. The efficiency of wheat and fish meal Se for increasing Se concentration in the whole blood was 123% and 107%, respectively. Even though the Se obtained from wheat and fish meal was retained more in whole blood than was the Se from sodium selenite, its utilization for the synthesis of GSH-Px was inferior.