VANWYK, J.A. 1999. A comparison of the infectivity of cryopreserved versus unfrozen infective larvae of Haemonchus contortus, Trichostrongylus colubriformis and Trichostrongylus axei: Results of the Onderstepoort Veterinary Institute from 1977 to the present. Onderstepoort Journal of Veterinary Research , 66:285289 The infectivity for sheep of cryopreserved infective larvae (L3) of various stra...

Background: Haemonchus contortus is a blood sucking parasite whose habitat the abomasum of ruminants, which poses significant threat to health and production sheep goats in warm temperate tropical regions. H. leads anemia, hypoproteinemia, reduced exercise tolerance edema subcutaneous tissue that can result death animals. In acute infection, animals suddenly become anemic many are found dead. E...

The parasitic nematode Haemonchus contortus is an economically and clinically important pathogen of small ruminants, and a model system for understanding the mechanisms and evolution of traits such as anthelmintic resistance. Anthelmintic resistance is widespread and is a major threat to the sustainability of livestock agriculture globally; however, little is known about the genome architecture...

Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB). The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal worm egg count (FEC). A total of 29 Corriedale lambs were experimentally...

A previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with Haemonchus contortus over five consecutive Haemonchus seasons (November to January/February) on a farm in the summer rainfall region in South Africa, although only one season is discussed. The algorithm associates haemoglobin levels with worm...

Anthelmintic resistance is a major problem in livestock farming, especially of small ruminants, but our understanding of it has been limited by the difficulty in carrying out functional genetic studies on parasitic nematodes. An important nematode infecting sheep and goats is Haemonchus contortus; in many parts of the world this species is resistant to almost all the currently available drugs, ...

AIM The effects of N-P-K fertilizers in the form of urea, single super phosphate and muriate of potash on development of free-living stages of Haemonchus contortus were studied. MATERIALS AND METHODS Five parasite free experimental plots of 1 m×1 m area, each of paddy leaves (15-day-old) and an equal number of Cynodon dactylon grass were infested with about 10×104 eggs/ml phosphate buffer sal...

Diagnosis is often equated with identification or detection when discussing parasitic diseases. Unfortunately, these are not necessarily mutually exclusive activities; diseases and infections are generally diagnosed and organisms are identified. Diagnosis is commonly predicated upon some clinical signs; in an effort to determine the causative agent, identification of genera and species is subse...

This study was conducted on four sheep breeds, Karakul, Kajli, Thalli and Kachhi for their natural resistance against Haemonchus contortus. After deworming, 13 animals of each breed were ingested with doses of 5000 L3 of Haemonchus contortus and then evaluation of each was made on the basis of fecal egg count (FEC), body weight, FAMACHA score and packed cell volume (PCV) at different days of in...

The influence of microclimate on numbers of third-state larvae of haemonchus contortus and Haemonchus placei in four strata of irrigated Kikuyu pasture was assessed. On 36 different, interspersed days three replicates of pasture samples were collected on three occasions per day from 1990-1992 for larval recovery and the log10 mean counts of the larvae recovered were analysed by use of ANOVA mod...