Search

Bison (Bison spp) are being reintroduced into semi-wild, spatially constrained herds across North America and Europe. Herd managers are concerned about gastrointestinal (GI) nematode parasites as they care for the health of their bison. We examine how demographics, grazing location, herd management, and anthelmintic treatments affect the fecal egg counts (FECs) of GI nematodes within a reintroduced Plains bison (Bison bison bison) herd in the Great Plains. Our results suggest that younger bison ( 6 yrs of age). FECs of both Trichuris spp. and particularly Nematodirus spp. were much more abundant, relatively, during the first year of a bison's life. This pattern was also true of Moniezia spp. and Eimeria spp., however, strongyle-type spp. FECs appeared to peak in relative abundance during the second year of life. Our data also indicate that FECs are influenced by differences in land-use histories of pastures previously grazed by cattle or by the proportion of frequent flooding in different pastures. Treatment results suggest that fenbendazole may more effective than moxidectin at lowering FECs of bison over the long-term, and lasting effects of at least one administered anthelmintic treatment. Multiplex PCR assays revealed that American bison share GI nematodes with cattle including: Ostertagia spp., Haemonchus placei, Cooperia onchophora, and Oesophagostomum spp, but did not detect the presence Trichostrongylus columbriformis. Our results may have wider conservation implications for reintroduction efforts of American bison, as well as the endangered European bison (Bison bonasus)., Graphical abstract Image 1, Highlights • Younger plains bison (

Gastrointestinal parasitism is a global problem for grazing ruminants which can be addressed in a sustainable way through breeding animals to be more resistant to disease. This study estimates the genetic parameters of common and new disease phenotypes associated with natural nematode and coccidian infection in Scottish Blackface sheep to underpin future genetic improvement strategies for parasite control. Data on faecal egg counts (FEC) from different species of strongyle parasites and faecal oocyst counts (FOC) from coccidian parasites were collected on 3-month-old lambs together with a faecal soiling score in the breech area dagginess (DAG) and live weight (LWT). Faecal count data were obtained for Strongyles (FECS), Nematodirus (FECN) and Coccidia (FOC). Data from 3 731 lambs sampled between 2011 and 2017 were included. Faecal egg counts and DAG records were log-transformed prior to analysis. Data were analysed using linear mixed models. Average age at sampling was 92 days with a mean LWT of 24.5 kg. Faecal soiling was not evident in 69% of lambs. Coccidia were the most prevalent parasite (99.5%), while Strongyles and Nematodirus had a prevalence of 95.4% and 72.7%, respectively. Heritability estimates (± SE) were 0.16 ± 0.03, 0.17 ± 0.03, 0.09 ± 0.03, 0.09 ± 0.03 and 0.33 ± 0.04 for FECS, FECN, FOC, DAG and LWT, respectively. Strongyles faecal egg count had a strong and positive genetic correlation with FECN (0.74 ± 0.09) and a moderate positive correlation with FOC (0.39 ± 0.15) while DAG was negatively genetically correlated with LWT (− 0.33 ± 0.15). The significant positive genetic correlations between FECS, FECN and FOC at 3 months of age show that co-selection of sheep for resistance to these different parasites is feasible. Selection for increased resistance to parasite infection is not expected to adversely affect live BW, as no significant antagonistic genetic correlations were found between LWT and FEC. There were significant antagonistic phenotypic and genetic relationships between DAG and LWT being − 0.19 ± 0.02 and − 0.33 ± 0.15, respectively, indicating that the expression of the manifestation of disease in lambs may be a more meaningful indicator of the impact of parasite burden on productivity.

Sheep internal parasites (nematodes) remain a major health challenge and are costly for pasture-based production systems. Most current breeding programmes for nematode resistance are based on indicator traits such as faecal egg counts (FEC), which are costly and laborious to collect. Hence, genetic markers for resistance would be advantageous. However, although some quantitative trait loci (QTL) have been identified, these QTL are often not consistent across breeds and few breeding strategies for nematode resistance in sheep are currently using molecular information. In this study, QTL for nematode resistance on ovine chromosomes (OAR) 3 and 14, previously identified in the Blackface breed, were explored using commercial Suffolk (n = 336) and Texel lambs (n = 879) sampled from terminal sire breeder flocks in the United Kingdom. FEC were used as the indicator trait for nematode resistance, and these were counted separately for Nematodirus and Strongyles genera. Microsatellite markers were used to map the QTL and the data were analysed using interval mapping regression techniques and variance component analysis. QTL for Nematodirus and Strongyles FEC were found to be segregating on OAR3 at 5% chromosome region-wide significance threshold in both Suffolk and Texel sheep, and Nematodirus FEC QTL were segregating on OAR14 in both breeds. In addition, QTL for growth traits were also found to be segregating at 5% chromosome region-wide on OAR3 and OAR14. The confirmation that FEC QTL segregate in the same position in three widely used breeds widens their potential applicability to purebred Blackface, Suffolk and Texel sheep, with benefits likely to be observed in their commercial crossbred progeny.

To provide baseline parasitological data for health surveillance in free-ranging Alpine ibex (Capra ibex ibex), we assessed the endoparasite population and level of parasitism in apparently healthy ibex. Faecal samples from 148 ibex were collected between 2006 and 2008 in two different Swiss ibex colonies. They were analysed by coprology, including combined sedimentation/flotation method, sedimentation method, Baermann funnel technique and Ziehl-Neelsen staining. Gastrointestinal parasites and lungworms were identified in 100% and 81.8% of the examined animals, respectively. Highest prevalences were recorded for gastrointestinal strongylids other than Nematodirus/Marshallagia spp. (100%), Eimeria spp. (100%), Muellerius spp. (79.8%) and Nematodirus/Marshallagia spp. (79.0%). We report for the first time Cryptosporidium sp. in free-ranging Alpine ibex and Cystocaulus spp. in free-ranging ibex from Switzerland. On average, ibex were infected with 3.9 different parasites taxa (range: 1-8). Parasite prevalence and diversity varied significantly between sexes, study sites and seasons. Parasite egg output was low in 95.7% and moderate in 5.3% of the samples. Overall, the results indicate that Alpine ibex are widely infected with endoparasites and suggest that multiple infections are very common in apparently healthy populations. Furthermore, our data underline the potential influence of factors such as sex, study site and season on parasitological findings.

4 páginas, 5 tablas.-- Available online 30 july 2010., We have evaluated the efficacy in sheep of a combination drench formulation at the recommended dose rate of 0.2 mg moxidectin/kg bodyweight and 10 mg triclabendazole/kg bodyweight against an experimental infection with Fasciola hepatica and a natural infection with gastrointestinal nematodes. We confirmed that the efficacy of reducing fecal egg output was 98.3% for trichostrongyle eggs and 100% for F. hepatica eggs. Based on adult worm and fluke recovery, the efficacy varied according to the target species. A reduction was found in the number of Teladorsagia circumcincta, Trichostrongylus spp., Nematodirus spp., and Trichuris spp. greater than 95%, but the efficacy for Oesophagostomum spp. varied, with values below 90%. The reduction in F. hepatica was higher than 95% for all stages. The effectiveness of the formulation was also confirmed by an increase in total proteins and albumin following treatment., This study was supported by a research project of Fort Dodge Animal Health (Spain) (Study number 0987-O-SP-01-06) and by the National Spanish project of the Ministry of Science and Innovation (ref. No. RTA2006-00183-C03-02).

Publisher Summary Efficacy of pyrantel for the prevention of parasitic gastroenteritis in sheep is well established in field trials with lamb flocks harboring variable, but moderate infections of Nematodirus, Ostertagia, Trichostrongylus, and Haemonchus. Under the conditions of these trials, pyrantel is found to result in somewhat greater average daily weight gains than the other anthelmintics used for comparison, such as bephenium, methyridine, and thiabendazole. Pyrantel tartrate represents a new class of anthelmintics. All three are broad-spectrum and are efficacious against many species of important nematodes parasitizing the entire gastrointestinal tract of cattle and sheep. Poor control of Trichuris is a weakness common to all three. Tetramisole is effective against lungworms. Differences in the effects of these three anthelmintics against lungworm infections may be because of the varied physiological dispositions of these drugs, reflecting differences in absorption and metabolism. An impressive breadth of spectrum for tetramisole is suggested in the preliminary announcement of this drug, in which activity against at least 56 species of nematodes in thirteen hosts is listed. Pyrantel tartrate has a somewhat higher safety factor than tetramisole though neither approaches the high therapeutic index reported for thiabendazole. Thiabendazole, which is rapidly metabolized, has been shown to have a significant effect against lungworms (vide infra), although special dosing schedules are required. Pyrantel tartrate, not being well absorbed from the intestine, is said to be inactive against lungworms.

Publisher Summary This chapter focuses on the epidemiology of nematode parasitism of sheep in Norway. During the period 1960–1964, a study was carried out on nematode infection in sheep of lowland farm flocks near Oslo. The grazing period was only five months, and the sheep were housed continuously for seven months. Using wormfree lambs as test animals, it was found that Ostertagia spp. and Nematodirus spp. are the only nematodes that will survive the winter in the pasture in great numbers. In ewes , the number of nematode eggs in feces is low most of the year. In lambs there appear eggs of Ostertagia spp. and Nematodirus spp. in late May and June, Nematodirus eggs usually show a maximum in July. Examinations of slaughtered lambs have shown that the seasonal variations in the egg production are based on a true variation in the population of adult nematodes.

Publisher Summary This chapter discusses a study in which a single fallow deer for intestinal parasites was examined and this examination was followed up by some other examinations of the intestines, hearts, and lungs of 12 red deer and 21 fallow deer shot during the hunting season was examined. The rate of infection was so distributed between the species of deer that 67% of the red deer and about 80% of the fallow deer were infected by various parasites and all in all 17 species of parasites were found in the material. The number of parasites known from Danish red deer and fallow deer can be said to number 25 different species of which the dominant group consists of nematodes of different genera. As was to be expected, a large number of the species found are well-known in Denmark from domestic animals, but in addition to these, there are four species that never before have been reported from Denmark; neither in domestic animals nor in our deer, that is, Spiculopteragia asymmetrica, S. spiculoptera, Apteragia quadrispiculata, and Nematodirus roscidus.