Gastrointestinal helminth parasites of Gallus gallus raised in extensive system in the city of Viçosa, Minas Gerais, Brazil

Extensive rearing systems enable higher occurrence of helminths, which is a hindrance in poultry farming, significantly affecting productivity. A survey was conducted to determine the prevalence of gastrointestinal helminths in chickens reared in extensive system in the city of Viçosa, Minas Gerais, Brazil between December 2017 to September 2018. A total of 5579 specimens were recovered from the gastrointestinal tracts of most animals (81.55% of prevalence). Of the positive poultries, only 41.67% had mixed infections, and of these, more than 90% were nematodes and cestodes co-infections. Three nematodes ( Ascaridia galli , Heterakis gallinarum , Capillaria sp.), seven cestodes ( Raillietina tetragona , R. echinobothrida , R. cesticillus , Choanotaenia infundibulum , Hymenolepis cantaniana , H. carioca and Davainea proglottina ) and two trematodes ( Postharmostomum commutatum and Echinostoma sp.) species were identified. The most dominant helminth species was H. gallinarum (60.19%), which also presented higher average intensity (35.46 ± 0.65) and abundance (21.34 ± 3.01) among all recovered species. The tapeworm species correspond to 42.23% of prevalence and the trematodes correspond to only 3.40%. Despite the scarcity of data in the Brazilian literature on poultry helminths reared in extensive systems, regional parasitological surveys are important. It is expected that these results will contribute to the adoption of prophylactic measures and alternative control strategies in order to reduce the risk of helminth infection in poultry. determinar