Chemical Composition, Physical Characteristics, Digestibility and Degradability of Grape Pomace Processed with <i>Neurospora sitophila</i>

Abstract

The nutritive values of non- processed and processed grape pomace with <em>Neurospora sitophila</em> were evaluated. The chemical compositions and physical characteristics of samples were evaluated by laboratory analysis. An <em>in vitro</em> digestibility experiment was done to determine digestibility coefficients of dry matter, organic matter and also digestible organic matter in dry matter (DOMD) to estimate the metabolizable energy (ME) content of grape pomace samples. In addition, dry matter (DM), organic matter (OM) and crude protein (CP) disappearance of samples were determined by an <em>in situ</em> method by using 9 bags for each sample at 0, 3, 6, 12, 24, 48 and 72 h after incubation and their kinetics were described using the equation P= a + b(1−e^−ct). The nutritive value index (NVI) of samples was calculated using the equation; NVI= a + 0.4b + 200c. The collected data were analyzed in a completely randomized design. The average total phenolic compounds and extractable tannins, NDF, water holding capacity, soluble dry matter and digestion coefficients of DM, OM and DOMD were decreased (P<0.05) by processing of grape pomace, but percentage of CP, ash, acid detergent lignin, functional specific gravity, bulk density; effective degradability and NVI of DM, OM, CP were increased (P<0.05). After processing, water-soluble portion (a) for DM, OM and CP were increased, but the slow degradation rate and degradation rate of b were decreased (P<0.05). It can be concluded that, processing of this by product with <em>Neurospora sitophila</em>, increased protein content and decreased its tannins and phenols and therefore will improve the efficiency of using grape pomace in animals nutrition<em>.</em>