Climate influences assemblages of abomasal nematodes of sheep on steppe pastures in the east of Algeria

Age-specific impacts of vegetation functional traits on gastrointestinal nematode parasite burdens in a large herbivore

Gastrointestinal nematode (GIN) parasites play an important role in the ecological dynamics of many animal populations. Recent studies suggest that fine-scale spatial variation in GIN infection dynamics is important in wildlife systems, but the environmental drivers underlying this variation remain poorly understood. We used data from over two decades of GIN parasite egg counts, host space use, and spatial vegetation data from a long-term study of Soay sheep on St Kilda to test how spatial autocorrelation and vegetation in an individual's home range predict parasite burden across three age groups. We developed a novel approach to quantify the plant functional traits present in a home range to describe the quality of vegetation present. Effects of vegetation and space varied between age classes. In immature lambs, strongyle parasite faecal egg counts (FEC) were spatially structured, being highest in the north and south of our study area. Independent of host body weight and spatial autocorrelation, plant functional traits predicted parasite egg counts. Higher egg counts were associated with more digestible and preferred plant functional traits, suggesting the association could be driven by host density and habitat preference. In contrast, we found no evidence that parasite FEC were related to plant functional traits in the host home range in yearlings or adult sheep. Adult FEC were spatially structured, with highest burdens in the north-east of our study area, while yearling FEC showed no evidence of spatial structuring. Parasite burdens in immature individuals appear more readily influenced by fine-scale spatial variation in the environment, highlighting the importance of such heterogeneity for our understanding of wildlife epidemiology and health. Our findings support the importance of fine-scale environmental variation for wildlife disease ecology and provides new evidence that such effects may vary across demographic groups within a population.

Epidemiological study of goat's gastrointestinal nematodes in the North West of Algeria

An epidemiological study of gastrointestinal nematodes was carried out in naturally infected goats in the North West of Algeria. Coprological analyses were performed for 2 years from January 2014 to December 2015.Examination of 1591 goat samples revealed an overall prevalence of parasite eggs in feces of 96%; the values were very similar in both years at 97% in 2014 and 94.96% in 2015. Five types of nematode eggs were identified: strongyle (95.5%), Nematodirus spp. (19.4%), Marshallagia spp. (3.9%), Trichuris spp. (0.6%), and Skrjabinema spp. (2%).Also, fecal cultures showed the presence of Teladorsagia spp. (56%), Trichostrongylus spp. (20%), Chabertia spp. (10%), Haemonchus spp. (9%), and Oesophagostomum spp. (5%).Season, age, type of grazing, and area affected the epidemiology of gastrointestinal nematodes of goats. The season did not influence the prevalence observed in the 2 years, since no significant differences between the four seasons were observed. On the other hand, egg production was highest in winter and spring. The level of infection decreased with the animal's age. There were no significant differences between the prevalence in animals on irrigated and non-irrigated pastures, but there were differences in egg excretion. Additionally, no significant difference was observed between the coastal (Oran) and lowland (Mascara) regions in the prevalence or in average egg excretion.

Prevalence of gastrointestinal worms in Wonosobo and thin-tailed sheep on the slope of Mount Sumbing, Central Java, Indonesia

AIM

This study was conducted to determine the prevalence of gastrointestinal (GI) worms in Wonosobo and thin-tailed sheep from the slope of Mount Sumbing.

MATERIALS AND METHODS

Fecal samples (n=305) were collected directly from the rectum of Wonosobo and thin-tailed sheep during the dry and rainy seasons in Wonosobo Regency, Central Java Province, Indonesia. The presence of GI helminth eggs in the fecal samples was assessed using the modified McMaster egg counting technique. The identification of the eggs or oocysts was done on the basis of their morphology and size.

RESULTS

The highest prevalence of GI worms was observed in male thin-tailed sheep (76.47%) during the rainy season, whereas the lowest prevalence was observed in female Wonosobo sheep (47.36%) during the dry season. The types of GI nematodes observed in these two types of sheep were Haemonchus contortus, Ostertagia spp., Trichostrongylus spp., Bunostomumspp., Trichuris spp., and Moniezia spp. The GI worms with the highest prevalence were of Haemonchus spp. and were observed in male thin-tailed sheep. The prevalences of the two types of sheep assessed at an altitude of 1150 m above sea level were higher than those observed at the altitude of 1586 m. The prevalence of clinical and sub-clinical parasites infestation in Wonosobo and thin-tailed sheep in Kwadungan village was significantly different (p<0.05).

CONCLUSION

This study showed that two types of local sheep on the slope of Mount Sumbing are infected with various GI worms during the dry and rainy seasons. The highest prevalence of GI worms was found in thin-tailed sheep at an altitude of 1150 m above sea level during the rainy season, with H. contortus being the most prevalent GI parasites.