Selenium availability and metabolism in the chick

The biological activity or availability or feedstuff selenium was determined by comparing the effectiveness of the feedstuff with that of dietary sodium selenite in preventing the incidence of exudative diathesis in the chick. The available selenium in ten wheat samples varied from 62 to 178 percent with a mean of 105 percent. The selenium availability in rapeseed meal ranged from 27 to 89 percent with a mean of 61 percent. Selenium metabolism in the chick was investigated by adding graded levels of sodium selenite to the basal selenium deficient diet and comparing the dietary selenium concentration to the selenium concentration in the tissues (l.e. Blood, liver, kidney, and muscle of the chicks). The selenium content in the tissues examined increased proportionately to an increase in dietary selenium supplementation from 0 to 0.2 ppm. Blood and liver selenium concentration remain relatively constant (a slightly increasing plateau) from 0.2 to 1.0 ppm of dietary selenium. Above 1.0 ppm dietary selenium, blood and liver selenium levels increase steadily. These results show that either blood or liver selenium levels represent the selenium status of the bird. A similar response in tissue selenium levels of the chick was observed when selenium was supplied either as sodium selenite Or a feedstuff (brewers yeast). Furthermore, selenium levels birds fed wheat diets were similar to those fed equivalent selenium (sodium selenite) supplied in the basal diet.Land and Food Systems, Faculty ofGraduat