Epidemiology of bovine gastrointestinal helminthiasis

Abstract

The gastrointestinal helminths are etiologic agents which have a great important in the decreasing of bovine’s livestock productivity. Among the factors that affect the development of the cattle raising, the gastrointestinal and pulmonary helminthosis are really important as long as they cause economical waste related to the low rates of herd’s productivity, delay on animal’s growing, increased mortality rates of young cattle and excessive spending with management and medicaments. The gastrointestinal parasitism of bovines are often associated to the high numbers of animals in the farm and also to the intensive systems of handling, principally at the dairy cattle. However, talking about ruminants, the nutritional standards and particularly availability of minerals and proteins is an important factor in the optimization of animal’s productivity, interposing in the pathogeny and in the immune response of harborers to the gastrointestinal infections caused by nematodes. The effects of this parasitism in animal production can be reduced by changes in pasture control and application of anti-helmintics. For the success of this procedure, it is necessary to know the biology of the parasites of the region that is going to be studied. One stage of this parasite’s cycle occurs in the environment and many factors are involved in the development and survival of larvas in the pasture and in the maintenance of infection at the animals, such as: climatic and genetical factors and pasturage peculiarities. This revision aims to make an epidemiologic weighing of the main species of gastrointestinal helminths that attack bovines in tropical climate, availing helminthosis prevalence in animal population according to the age-group and to the interaction of this parasites with the economical wastes in bovine pecuary.