The study was conducted on 18 laying hens from Lohman Brown at 23 weeks of age. There were two research groups and one control group with six animals each. In the last four weeks of age, the animals were fed follows: Control group (Group C) complete diet; Group I diet containing zinc added via the biosorption process and; Group II: diet containing zinc as an organic chelate complex. The levels of short chain fatty acids (SCFAs) such as acetate, propionate, iso-butyrate, butyrate, iso-valeriate and valeriate were determined. It was observed that using a diet with additives obtained via biosorption does not have a negative influence on fermentation processes in the hen's caecum.