Field study analysis of the influences of deworming regimens and housing conditions on parasites and sperm output in 21 European boar studs

•Macrocyclic lactones are used most often for deworming quarantine boars.•Benzimidazoles are used most often for deworming boars in routine production.•Deworming regime, age of the boar and housing conditions affect presence of parasites.•Sperm output was significantly affected by deworming regime.•Yearly verification of the efficacy of anthelmintics is recommended.

The current study reports the parasitological results of a quality control audit in 21 European boar studs. Field investigations were performed over a 2-year period (2012-2013) during the winter and spring. From each stud, an average of 30 (range, 25-33) individual faecal samples and ejaculates from 615 randomly selected Pietrain boars were analysed. Statistical analysis revealed a significant effect (P < 0.0001) of deworming regimen (DR) × age class of boar (A) and housing condition (H) × A on the presence of parasites. A second model indicated a significant effect (P = 0.0262) of DR × H × A on the presence of parasites. Sperm output was significantly affected (P < 0.0001) by the DR. Based on this study, recommendations for deworming AI boars are proposed.