Summary
This work with the use of the shrub Trema micrantha Blurry and the grass Aripuanã, as possible feed source for livestock. These plants are at A.R.C., MT and were studied through its "in vitro" fiber degradation. Their "in vitro" digestibility was determined in the laboratoties of Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal. São Paulo, the following fractions being analysed: neutral detergent fiber (NDF). acid detergent fiber (ADF). celulose (Cel.) and lignin (Lig.). A sample of elefante grass was used as reference. The results indicated that NDT amount in Trema are maintained during all the fermentation period, whilein the grass the fraction present degradation between 40.36% and 48,84% in a period of 48 hours. Acid detergent fiber presents the same pattern as that of NDT. the digestibility of this fraction being 40% and 65% for Aripuanã grass and elefant grass respectively while in Trema there was no significant difference. A possible explanation would be a higher amount of lignin on Trema, this amount being probably time as that of grasses. Such higher amount of lignin would difficult the microrganisms as lignin presented no degradation during fermentation time. It is concluded that Trema would be useful as feed to ruminant livestock, but its use would depend on a low fiber content because is not digestible. Aripuanã grass apresented the same performance as elefant.