Influence of nematophagous fungi, earthworms and dung burial on development of the free-living stages of Ostertagia (Teladorsagia) circumcincta in New Zealand

Dynamics of the free-living stages of sheep intestinal parasites on pasture in the North Island of New Zealand. 1. Patterns of seasonal development

“…Recovered faeces and herbage were weighed before larvae were extracted in Baermann funnels (100 mm and 200 mm in diameter, respectively) for 24 h. The herbage was then dried at 558C for 12 h, and reweighed. L3 were initially extracted from soil samples using a modification of the tray method described by Whitehead and Hemming (1965), and then cleaned by baermannisation (Waghorn et al 2002). Cleaned samples were concentrated to 20 mL by sedimentation, and stored at 58C, before the larvae present were identified and enumerated following staining with Lugol's iodine (BDH Laboratory Supplies, Poole, UK).…”

“…Results of small-scale studies conducted in the Manawatu region (Waghorn et al 2002;Leathwick et al 2011) suggested complex spatial dynamics of L3 on pasture, with large numbers of larvae being recovered from both faeces and soil. Transmission of parasites to grazing hosts occurs by ingestion of L3 with herbage, and the presence of large numbers of L3 in microhabitats other than on herbage suggests that many larvae (Waghorn et al 2002), the infectivity of herbage could potentially change rapidly, not only by the development of eggs to L3, but by the migration onto herbage of L3 already present in other habitats. This could potentially happen rapidly and under conditions which are unsuitable for the development of eggs and larvae, and make predicting the infectivity of pastures based on season or weather conditions even more difficult.…”

Occurrence, morphological characteristics and ribotyping of New Zealand isolates ofDuddingtonia flagrans,a candidate for biocontrol of animal parasitic nematodes

“…In the present study, an isolate of D. flagrans from decomposing vegetation (NZ 48hC) was shown to survive passage through the gut. This isolate has also been shown to reduce numbers of Ostertagia (Teladorsagia) circumcincta larvae in faeces deposited in the field (Waghorn et al 2002). The close relationship between the ITS1-5.8s-ITS2 sequence data for two New Zealand isolates of D. flagrans and two from the Northern Hemisphere could possibly suggest that the fungus is a relatively recent import into New Zealand, perhaps when livestock was introduced in the early days of European settlement.…”

Plants and their medicinal potential for controling gastrointestinal nematodes in ruminants

“…The lack of knowledge of epidemiological factors, the low costs of treatment with chemical substances [3] and the corresponding mass use of these substances have led to the development of resistance to anthelmintics, an increasingly vexing problem that cannot be ignored by breeders [8] . Because of the increasing resistance of parasites, the impact of verminosis on livestock production and the growing consumer demand for animal products produced organically [9] , many auxiliary methods to control parasites have been extensively studied, such as use of vaccines, rotated grazing [10] , provision of nutritional supplements [11] , selection of resistant breeding stock [12] , use of nematophagous fungi [13,14] and phytotherapy [15] . The last of these is considered particularly promising for control of GINs [16] .…”