Co-grazing of sheep and goats may not be an issue from a parasitological perspective

TL;DR

This study found that co-grazing sheep and goats does not lead to similar parasite levels, with each species showing distinct infection patterns and intensities.

Contribution

The study provides new evidence on species-specific parasite dynamics in co-grazed sheep and goats in Central Europe.

Findings

Goats had higher egg shedding than sheep, with peak counts of 1240 EPG in June versus 620 EPG in February for sheep.

Haemonchus contortus was dominant in goats year-round, while Trichostrongylus/Teladorsagia spp. showed seasonal fluctuations in sheep.

Differences in infection intensity between species were statistically significant (U = 24 697.5, p < 0.001).

Abstract

Gastrointestinal nematode (GIN) infections have a significant impact on the health and productivity of small ruminants, while data on mixed-species grazing systems in Central Europe are scarce. This study aimed to compare GIN species richness and infection intensity in co-grazed dairy sheep and goats under a conventional grazing system in the Czech Republic. Over a 12-month period, 210 goat and 196 sheep faecal samples were analyzed using the McMaster method, followed by larval culture. Both hosts harboured Haemonchus contortus, Trichostrongylus/Teladorsagia spp., and Oesophagostomum columbianum. Goats exhibited consistently higher egg shedding, with a mean peak egg count of 1240 EPG in June, whereas sheep reached a markedly lower peak of 620 EPG in February. In goats, H. contortus predominated year-round, while in sheep, Trichostrongylus/Teladorsagia spp. showed pronounced seasonal fluctuations, comprising up to 60% of larvae in autumn. Differences in infection intensity between species were statistically significant (U = 24 697.5, p < 0.001). These results support the hypothesis that co-grazing does not homogenise parasite burdens between host species and demonstrate species-specific seasonal infection dynamics. Such insights directly address the study’s aim of characterising species composition and infection intensity in co-grazed sheep and goats, providing an evidence-based basis for optimising sustainable parasite management in mixed grazing systems.

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