The development of organic or sustainable livestock systems production combined with the problems of drug resistance, the high input costs and the concern about toxic residues in food and in the environment, has strongly driven in the last decade the use of plants or their extracts both in the prevention and recovery of animal health. In this paper we present the resume of some studies carried out in Brazil, among several medicinal plants that had its action proven by official scientific bodies. The data show results of anti-parasitic and anti-microbial action. The studies were performed with cattle, buffalos, sheep, goats and chicken
