Marshallagia

Rijal, Samridhi, Neuhaus, Peter, Thorley, Jack, Caulkett, Nigel, Kutz, Susan & Ruckstuhl, Kathreen E., 2024, Patterns of gastrointestinal parasite infections in bighorn sheep, Ovis canadensis, with respect to host sex and seasonality, International Journal for Parasitology: Parasites and Wildlife 24, pp. 100950-100950 : 100950-

3.3. Marshallagia

Season and sex significantly affected fecal Marshallagia fecal counts in an interaction (X 2 = 36.50, df = 3, p <0.001), while age had no effect (X 2 = 2.34, df = 1, p = 0.13; Table 3).

Female fecal egg counts of Marshallagia were significantly higher during late gestation/spring (April–June) compared to lactation (lowest after returning from the alpine areas September/October), the rut or winter ( Fig. 2c –Appendix A3). Males had significantly higher Marshallagia egg counts during the rut than during the late gestation season ( Fig. 2c –Appendix A3). Females shed significantly higher numbers of Marshallagia eggs in their feces compared to males during the late gestation period, while males had higher egg counts during lactation and the rut. There was no difference between the sexes in winter ( Fig. 2c –Appendix A3). The mating tactic males employed during the rut did not affect their fecal Marshallagia egg count (Estimate = – 0.15, SE = 0.20, X 2 = 0.57, df = 1, p = 0.45).

Figures

Fig. 2. Seasonal differences in fecal egg counts in female (blue) and male (red) bighorn sheep. Point intervals display the mean count ±95% confidence intervals as predicted by generalised linear mixed effects models. Seasons are: Late gestation (Late gestation/early lactation between April to June); Lactation/summer (between July and October); Rut (November and December); Winter (Winter/early gestation from January to March). Parasites are a) Strongyle; b) Nematodirus; c) Marshallagia; d) Protostrongylus lungworm; e) Eimeria. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)