Effect of humic-plant feed preparations on biochemical blood parameters of laying hens in deep litter housing system.

An influence of various humic-plant feed additives based on some herbs (nettle, chamomile, yarrow, perforatum), lucerne and humic materials on biochemical indices of Lohmann Brown (LB) layers blood plasma was estimated. Hens were housed in deep litter system, 20 birds in a group. Four groups were formed: control (C - standard feeding), and experimental, supplemented with prepara- tions: E-1 herbal-humic, E-2 humic-herbal and E-3--humic-lucerne.