Effect of a mixture of herbal extracts on broiler chickens infected with Eimeria tenella

摘要

The effect of dietary supplementation with Apacox (Apa-CT, s.r.l. Italy), a commercial preparation of herbal extracts, on the performance of broiler chickens experimentally infected with 6 x 10(4) sporulated oocysts of Eimeria tenella at 14 days of age, was evaluated. A total of 150 day-old Cobb-500 chicks separated into 5 equal groups with three replicates each, were used. Two of the groups, one challenged with E. tenella oocysts and the other not, were given a basal diet and served as controls. The remaining groups that were also challenged with E. tenella were administered a basal diet supplemented with Apacox at levels of 0.5 or 1.0 g(.)kg(-1) or the anticoccidial lasalocid at 75 mg(.)kg(-1). Throughout the experimental period from day I to day 35, performance parameters including body weight gain, feed intake, feed conversion ratio, mortality, caecal lesion score, bloody diarrhoea and oocyst output were recorded. Dietary supplementation with Apacox attained higher body weight gain and lower feed conversion ratio values than the non-supplemented challenged control group. The lasalocid and the non-challenged control groups exhibited body weight gain and feed conversion ratio values that did not significantly differ from each other, and were better than in the Apacox groups. Bloody diarrhoea was observed in all challenged groups except for the Apacox group at the dose of 1.0 g(.)kg(-1) diet, where it was milder and the lasalocid group where it was very weak. The mortality in the challenged control group was 23.4% whereas in the Apacox group at the dose of 1.0 g(.)kg(-)1, 13.4%. The caecal lesion scores of the Apacox groups were not significantly different from that of the challenged control group. The numbers of oocysts per bird in the Apacox groups were lower than that in the challenged control group but higher than that in the lasalocid group. These results indicate that Apacox exerted a coccidiostatic effect against E. tenella. This effect was, however, significantly lower than that exhibited by lasalocid.