Effects of organic selenium supplemented to layer diet on table egg freshness and selenium content

The aim of the research was to determine the effects that organic selenium supplemented in layer diets has on its content in the edible part of egg, on egg freshness and activity of glutathione peroxidase (GSH-Px) in hens' blood. The experiment lasted for 30 days and was completed on 240 laying hens of the Hy Line Brown hybrid. Hens were divided into 2 experimental groups (E-1 and E-2), each consisting of 120 hens housed in 24 cages. Hens were fed a commercial diet containing 18% of crude protein and 11.60MJ ME/kg. The experiment was set up in two different feeding treatments. The E-1 group had diets supplemented with 0.2ppm of selenium, and E-2 had diets with 0.4ppm of selenium (organic selenium Sel-Plex (R), Alltech, inc.). The GSH-Px activity was higher in blood of hens in the E-2 group than in the E-1 (P<0.05). Furthermore, statistically the E-2 group had a significantly higher portion of selenium in egg yolks and albumen than the E-1 group (P<0.05). Analysis of effects that feeding treatments have on egg freshness over three examined periods (fresh eggs, eggs stored for 14 and for 28 days at 4 degrees C) showed better results for HU (Haugh units) and TBARS (thiobarbituric acid reactive substances) in the E-2 eggs than in the E-1 eggs.