Effects of Dietary Supplementation of Humic Substances on Laying Performance of Oravka Hens

The aim of this study was to appraise the effect of humic substances (HS) on laying performance. In total, 20 Oravka hens were allocated to 4 treatments, each containing 5 birds. The control birds were fed a diet without additives (0.00% HS), other treatment birds were fed with diets containing HS at 0.50%, 0.75 and 1.00%. The birds in all treatments had available drinking water and feed mixtures ad libitum. The experimental period lasted 16 weeks. Feed consumption and egg production were determined daily, egg weight was measured biweekly, and live body weights were recorded at the beginning and the end of the experiment. At the end of the experiment, the supplementations of HS had a significant effect (P<0.05) on live body weight, egg production and feed efficiency. In liver, gizzard, spleen, ovary and oviduct relative to live body there were no significant differences (P>0.05) among the among treatments. Carcass weight and oviduct weight were the highest (P<0.05) in Oravka hens fed HS diets compared with control.