The experiment was designed to investigate the effects of feed supplementation with selenite or selenized yeast on eggs quality of laying hens. Hens of laying breed Isabrown were randomly divided at the day of hatching into 4 groups (n=12) and fed ad libitum for 9 months on diets which differed only in amounts or forms of selenium supplemented. Hens were fed from 1st day by standard feed mixture. Control group get only native dose of selenium (0.1 mg/kg)
naturally presented in feed mixtures. First experimental group get selenium addition 0.4 mg/kg in a form of sodium selenite, second one the same dose of 0.4 mg/kg but in organic form of Se-yeast. The diet for the fourth group was supplemented with Se-yeast at Se dose 0.9 mg/kg DM. The both doses of organic selenium had significantly (P<0.05) beneficial influence on the egg weight (g±SD) (60.45±3.87a; 60.81±5.63a; 62.41±3.72b; 62.15±3.16b). Significantly lower values of egg shell weight and egg shell ratio were found out in experimental group with sodium selenite only.
The significantly lower egg shell strength (N/cm2) was in the experimental groups with supplementation of Se in both forms. Average egg shell thickness (μm) were not significantly affected (P>0.05) by the supplementation of Se into the feed mixture for laying hens.
