Development and survival of Haemonchus contortus larvae on pasture at Vom, Plateau State, Nigeria

Abstract

The development and survival of the eggs of Haemonchus contortus on pasture at Vom were studied by depositing faecal pellets on grass plots over a period of 12 months. Development and survival to the infective larvae occurred throughout the study except during the dry season months of December to April. More infective larvae were recovered from the herbage in June, July and August than in other months. The survival time of the infective larvae ranged from 2 weeks in October to 10 weeks in June, July and August. Rainfall was the most important epizootiological factor influencing the development and survival of the infective larvae. Temperature was not a limiting factor.

Climate change and infectious disease: helminthological challenges to farmed ruminants in temperate regions

“…Williams and Bilkovich, 1973;Bryan and Kerr, 1989;Stromberg, 1997). Such associations are most dramatic in semi-arid regions, where absence of rain may bring parasite transmission to a halt during the driest months and sharp peaks of larval emergence can be seen after periods of rainfall (Chiejina and Fakae, 1989;Onyali et al, 1990;Agyei, 1997;Sissay et al, 2007). Moisture is also prerequisite for both Galba spp.…”

“…and H. contortus, larvae takes place in dung, which is passed with a certain moisture reserve. Development of these larvae has been shown to cease only during summers of 2 to 3 months drought accompanied by relative humidities as low as 20% and maximum mean monthly temperatures approximating 328C (Onyali et al, 1990;Garcia Romero et al, 1997). On warm spring and summer days, such nematodes can reach the L3 stage even in dung, which becomes very desiccated before development is completed (Chiejina and Fakae, 1989).…”

Foraging height levels and the risk of gastro-intestinal tract parasitic infections of wild ungulates in an African savannah eco-system

“…Several investigations on the ecology of nematode larvae in temperate areas have focused on seasonal variation in the availability of GIT nematode larvae on the pasture of domestic herbivores (Brunsdon, 1970;Donald et al, 1978;Evans, 1974;Gibbs, 1967;Ollerenshaw & Smith, 1969;Southcott et al, 1976), or on the effect of vegetation height on pasture contamination (Angus, 1978;Gibson, 1966). Moreover, a number of studies have concentrated on the climatic (seasonal) variation in pasture contamination in tropical ecosystems carrying pure domestic stocks (Banks et al, 1990;Bekele et al, 1992;Cheijina & Fakae, 1984;Chartier, 1991;Dinnik & Dinnik, 1961;Kabasa, 1999;Onyali et al, 1990), or a mixed cattle/game stocking (Ocaido, 1995). Data on the contamination of latrines from a tropical (long-term) ……….…”

“…In this study, we investigated PCL in a central African savannah eco-system. The development and survival of infective larvae of GIT nematodes on pasture in tropical environments have been reported to be primarily affected by the seasonal climatic changes between the dry and the wet season (Banks et al, 1990;Bekele et al, 1992;Chartier, 1991;Chiejina & Fakae, 1984;Dinnik & Dinnik, 1961;Onyali et al, 1990). The effect of the vegetation height on larval availability in tropical climates, on the other hand, has so far barely been studied.…”

“…Therefore, our main goal was to determine whether there are differences in PCL between different feeding heights in our study area, Queen HELMINTHOLOGIA, 43, 3: 134 -138, SEPTEMBER 2006 Foraging height levels and the risk of gastro-intestinal tract parasitic infections of wild ungulates in an African savannah eco-system Elizabeth National Park. Following previous studies, we also asked if the change between the dry and the wet season has an effect on the larval availability of pasture, with a stronger pasture contamination during the wet season (Banks et al, 1990;Dinnik & Dinnik, 1961;Onyali et al, 1990).…”