||The use of horse riding in natural areas has caused great concern due to social and environmental impacts. One of the problems that has been investigated in some countries is the relationship between the use of riding animals and the presence of exotic plants.This kind of study is very important, once invasive species are the second cause of biological diversity loss. Herbivores are able to disperse a wide variety of species through their feces (JANZEN 1984, Vellend et al 2003). However little is known whether these seeds will be able to grow and settle in places. It is estimated that only a small portion of seeds present in the feces of horses will be established. Therefore, this study aims to verify if seeds of Urochloadecumbens and Melinisminutiflora, after being eaten and defecated by horses, have the ability to germinate, grow and bear fruit in ideal conditions.