Abstract

In vitro efficacy of aqueous and ethanolic extracts of Paecilomyces lilacinus and Trichoderma longibrachiatum was assessed in the egg hatching inhibition (EHI) and larval development inhibition (LDI) of Haemonchus contortus. For the EHI assessment, after 48 h of incubation with different concentrations of aqueous and ethanolic extracts, it was quantified blastomeres, embryonated eggs, and larvae of first stage. For the LDI assessment, a quantitative coculture adapted method was used. After seven days of feces incubation with different concentrations of aqueous extract of fungi, the infective larvae were collected and quantified, obtaining the number of developed larvae per feces gram. The aqueous extract of P. lilacinus at 1.96 mg mL^-1and the ethanolic extract of T. longibrachiatum at 1.90 mg mL^-1 completely inhibited the egg hatching. In the LDI, the aqueous extract of T. longibrachiatum at 1.90 mg mL^-1 showed efficacy of 92.88%. These fungi extracts showed potential to inhibition of the H. contortus cycle. 

Key words: Paecilomyces lilacinus, Trichoderma longibrachiatum, alternative control, sheep breeding, gastrointestinal nematodes.