To determine the selection of forage woody species foliage in the diet of dual purpose cows handled as a agro forestry system in a tropical dry forest during the day and in grass paddocks during the night, in the rainy season, a histological techniques of the fecal analysis was used, it was compared the epidermal fragments present in the feces with the epidermal reference patterns elaborated with the foliage (adaxial and abaxial epidermis) of 17 species that for visual observation were consumed by the animals. A group of 28 dual purpose lactating cows was used. For the coloration of the epidermal fragments toluidina blue (1%) was used, and then for its identification the characteristics anatomical structures were taken in to account (presence of hair or trichomes, epidermal typical cells and size and form of the stomas). There was demonstrated that 12 reference species appeared in animals feaces, where
Apidosperma cuspa
resulted with the higher relative frequency, 15.5% of their fragments appeared in the feces. The possibly fact that some species could not be identified in the feces, It could be related to the absence of vegetable protective elements in its morphology during the traffic in the ruminants digestive tract or to the lack of refringence to the used coloring. The relative frequency in feces of the woody species turned out to be higher (83%) to the value found for the grass (17%) in these management conditions. The foliage of the tropical dry forest is an alternative resource for ruminant feeding.
