The aim of this paper was to recognise the effect of feed modification, with standard feeding enriched with mineral-humine preparations and antioxidants (vit. A + E) on the activity of lysozyme and cystatin. Experimental materials were eggs from 3 groups of Tetra SL laying hens: A control group with standard feeding (17% protein, 2700 kcal/kg); B with addition vitamins A (10 000 unit/kg) and E (20 mg/kg); C with addition 2% humobentofet (HB), humocarbovit (HK) and vitamins A +E. Experiment occurred fresh Eggs stored 4 weeks at 15°C. Lysozyme activity was analysed spectrophotometrically by measuring changes in optical density of Micrococcus lysodeicticus solution during enzymatic lysozyme reaction. Inhibitory activity of cystatin was measured according to Nishida et al [7] and Siewiński [8]. Differential feeding significantly affected the level of cystatin activity in fresh egg white. In control group (A) this activity was the highest (421 units/100 mg protein). Lower cystatin activity was estimated in eggs from groups B and C laid by hens with enriched feeding. In group C this activity was lower on about 26.2% and in group B on 26%in comparison to control group. This protein did not have storage stability. The activity of cystatin in all samples decreased during storage for 4 weeks. The highest decrease of cystatin activity (35% related to fresh egg white) was analysed in group A. Feeding modification had a positive effect on lysozyme activity in fresh egg white. The level of lysozyme enzymatic activity was higher in groups B and C than in control group. The highest lysozyme activity was obtained in egg white derivated from layers fed with vitamins A and E (group B).