Effect of Trichoderma spp. inoculation on the chemical composition and in vitro digestibility of wheat straw

To evaluate the cultural ability of some Trichoderma isolates on wheat straw and the influence of their exogenous enzyme activities on chemical compositions as well as in vitro digestibility and upgrading of the nutritive value of lignocellulolytic materials, sterilized and non sterilized wheat straw were inoculated withTrichoderma isolates (including Trichoderma harzianum isolate T447, T. hamatumisolate T 614, T. hamatum isolate T625 and T. harzianum isolate T 969). The experimental design used in this study was complete randomized design (CRD) through factorial experiment with 2 factors (factor A = effects of sterilization, factor B = effects of Trichoderma spp.) in three replicates for each treatment. Effects of the Trichoderma isolates on the substrate neutral detergent fiber (NDF), acid detergent fiber (ADF) and pH as well as in vitro dry matter (DM) digestibility (IVDMD), in vitro organic matter (OM) digestibility (IVOMD) and in vitro digestible OM in DM (IVDOMD) were analyzed. The obtained results showed that sterilization of wheat straw could decrease pH, NDF and ADF (P<0.05) but not IVDMD, IVOMD and IVDOMD. The isolates of T447 and T969 showed higher ability in improving the nutritive value of wheat straw. Comparatively, higher reduction in pH was recorded by T614 inoculating sterilized wheat straw. The least NDF content were observed in treated non-sterilized wheat straw with T447, also treated sterilized wheat straw with T447 showed maximum reduction in NDF content. Moreover, higher change in IVDMD, IVOMD and IVDOMD were obtained by T447 grown in sterilized wheat straw substrate.   Key words: Trichoderma, wheat straw, dry matter digestibility, organic matter digestibility, digestible organic matter in dry matter.