In Vitro Application of Exogenous Fibrolytic Enzymes from Trichoderma spp. to Improve Feed Utilization by Ruminants

Treating ruminant feeds with exogenous fibrolytic enzymes may potentially increase forage cell wall degradability and thus feed efficiency. In nature, fungi biosynthesize lignocellulolytic enzymes that can break down lignocellulosic material into its sugar components, thereby providing ready fermentable substrates. This work showed the in vitro fibrolytic activity of three Trichoderma strains (T. atroviride strain P1, T. afroharzianum strain T22, T. reesei strain T67). Total protein concentration and enzymatic (e.g., glucanase, cellulase, and xylanase) activities were determined in fungal culture filtrates after 7 and 14 days of growth on different fiber-based media. The enzymatic mixtures produced by Trichoderma spp. showed the highest concentration of fibrolytic enzymes and were added to industrial feed to test their ability to hydrolyze insoluble fibers. The supplementation of industrial feeds containing medium-fiber or low-fiber concentrates with T22 enzymes produced in the presence of lyophilized mushrooms and durum wheat fiber reduced hemicellulose concentration up to 33% and 24%, respectively. These results may offer novel opportunities to develop livestock feeds with improved fiber digestibility.