The effect of a dietary herbal extract blend on the performance of broilers challenged with Eimeria oocysts

The aim of the experiment was to evaluate the anticoccidial efficacy of supplementing feeds with herbal extract blend containing garlic (Allium sativum), sage (Salvia officinalis), echinacea (Echinacea purpurea), thyme (Thymus vulgaris) and oregano (Origanum vulgare) extracts in broiler chickens experimentally infected with 170.000 sporulated oocysts of Eimeria acervulina, E. tenella, E. maxima and E. necatrix at 12 days of age. A total of 280 Ross 308 broilers were randomly allocated into 5 groups with 7 replicates of 8 chickens per replicate. The experimental dietary treatments were formulated by supplementing the basal maize-soyabean meal diet. The experimental design allocated the groups as follows: 1. uninfected birds and an unsupplemented diet; 2. uninfected birds and the diet supplemented with the herbal extract blend at a level of 1 g/kg feed (200 mg of each herbal extract/kg); 3. infected birds and an unsupplemented diet; 4. infected birds and a diet with the addition of coccidiostat diclazuril at a level of 1 mg/kg feed; and 5. infected birds and a diet supplemented with the herbal extract blend at a level of 1 g/kg feed (200 mg of each herbal extract/kg). Throughout the 42 days of the experimental period, performance parameters, mortality, lesion score, oocyst output, and serum carotenoid concentration were recorded. Dietary supplementation with the herbal extract blend increased growth performance to the level found in the group fed the coccidiostat and in the non-challenged groups. The number of oocysts per gram of excreta did not differ significantly between the groups fed the herbal extract blend and the group receiving the coccidiostatic supplement. The herbal extract blend had no effect on mortality, lesion score, with the exception of the duodenum, or blood carotenoid concentration.