SELENITE AND SELENIUM YEAST AS FEED SUPPLEMENTS TO GROWING FATTENING PIGS

Twenty-four cross-bred fattening pigs weighing, on average, 24 kg were divided into three equal groups and fed a basic diet containing 0.1 m g selenium/kg. The diet of group A was supplemented with 0.3 mg seleni um/kg derived from selenium yeast, group B with 0.1 mg selenium/kg fro m the same source, and group C with 0.3 mg/kg from sodium selenite. Th e pigs were slaughtered after 103 days. There was no significant diffe rence between the mean whole blood selenium concentration of the pigs supplemented with selenium yeast neither after five nor after nine wee ks of supplementation (group A, 201 and 213 mu g/litre; group B 192 an d 201 mu g/litre, respectively), but the group supplemented with selen ite had significantly lower concentrations both after five and nine we eks (158 and 159 mu g/litre, respectively). There were no significant differences between the mean activity of glutathione peroxidase (GSH-P x) in the whole blood of the three groups (group A, 348 and 327 mu kat /litre; group B, 342 and 302 mu kat/litre; group C, 332 and 300 mu ka t/litre, after five and nine weeks, respectively). The concentration o f selenium in the liver of the pigs supplemented with organic selenium was significantly higher than in the pigs supplemented with selenite (group A, 0.54 mg/kg wet weight; group B, 0.54 mg/kg; group C, 0.40 mg /kg). No deposits of lipofuscin or ceroid pigments mere observed in th e histological preparations of liver and heart from any of the pigs.