Development and survival ofhaemonchus contortus larvae on pasture in iraq

Abstract

The survival of Haemonchus contortus infective larvae on pasture and soil was studied over a period of 12 months in the Baghdad area. Infective larvae were found on herbage and soil at all times except in the summer months. During autumn and winter infective larvae in pasture survived for periods of up to 32 weeks. Little larval migration into soil was observed during this study and larvae did not survive for long in the faecal pellets during the summer.

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

“…Thus lack of moisture when the eggs were deposited on the grass plots might have been responsible for the eggs failing to develop to infective larvae. These findings are also in agreement with those of Silverman and Campbell (1959) and Rose (1963) in the United Kingdom, Okon and Enyenihi (1977) in the western region of Nigeria and Altaif and Yakoob (1987) in Iraq. However, in May to October, when larvae were recovered from pasture after one week, rain had fallen within that time.…”

“…At no time during the study did the mean monthly temperature exceed 31°C while the minimum was l5.K. This contrasts with the results from similar studies in the USA (Anderson et al, 1966), Australia (Donald, 1968) and Iraq (Altaif and Yakoob, 1987) which showed that the high temperatures during their summer months are very unsuitable for the development and survival of H. contortus larvae. It also differs from the situation in Southern England where the cold winter climate is not favourable for development (Gibson and Everett, 1976).…”

“…Investigations carried out by Shorb (1944) and Dinaburg (1944) in Australia, by Dinnik (1958, 1961) in the Kenya Highlands, by Silverman and Campbell (1959) in Scotland, by Rose (1963) in England and by Altaif and Yakoob (1987) in Iraq on the development and survival of Haemonchus contomts showed that the rate of development and the longevity of the eggs varied at different temperatures and humidity and in different parts of the world. H. contortus is the main cause of hehninthosis in sheep in the Plateau State of Nigeria and it is the most common strongyle found in most of the sheep brought for post morfem examination at the National Veterinary Research Institute in Vom.…”

Patrón espacio-temporal de larvas y huevecillos de nemátodos gastrointestinales en pastizales ganaderos de Veracruz, México

“…De igual manera, Silva et al (2010) indican que la precipitación favorece la migración larvaria, por lo que a mayor precipitación y humedad, mayor cantidad de larvas en los pastizales. En este sentido, Altaif & Jacobs (1987) y Arece & Rodríguez (2010) en Iraq y Cuba, respectivamente, atribuyen que la dinámica de las L 3 en el pasto se debe a los efectos positivos de las precipitaciones, la temperatura y la radiación solar. La especie H. contortus fue la más abundante, con una presencia de 80% del total de los meses de muestreo, incluyendo períodos de sequía.…”

Development of immunity in boer goats naturally infected with the nematode haemonchus contortus

“…Under favourable warm and humid climates, L3 may survive in pastures up to one year while under cooler climates, L3 survival usually is weeks to a few months (Shakya 2007). An earlier study by Altaif and Yakoob (1987) reported infective larvae in pasture survived up to 32 weeks during autumn and winter. The population of H. contortus increased in response to rainfall and declined when "self-cure" occurred within the period of optimal temperature (Gordon 1948).…”