Abstract
The aim of this study was to investigate, under conditions similar to commercial broiler production, the effect of the herbal extract blend (HE) at a quantity of 1 g per kg feed (200 mg of each herbal extract, Allium sativum, Salvia officinalis, Echinacea purpurea, Thymus vulgaris and Origanum
vulgare), used individually or in combination with mannan oligosaccharide (MOS; 1 g per kg feed) or chitosan (3 ml containing 2% deacetylated chitin per kg feed) on the performance parameters of broiler chickens, the results of the slaughter analysis, litter moisture and the number of oocysts excreted in feces. The experiment was conducted on 4,500 broiler chickens of both sexes kept in straw-bedded pens. Chickens were randomly assigned to 5 experimental treatments with 5 replicates (pens) of 180 birds. The experimental design included negative and positive (diclazuril, 1 mg per kg feed) control groups. The examined herbal extract blend used individually during natural exposure to the coccidia improved, compared to the negative control diet, the performance parameters to a greater extent than coccidiostat, lowered the litter moisture content and reduced the oocyst output. Combined dietary supplementation with a herbal extract blend of chitosan or mannan oligosaccharide did not result in further improvement.