The objective of this study was to determine the effect treating pomegranate seed (PS) and peel (PP) whit polyvinyl polypyrrolidone (PVP), polyethylene glycol (PEG) and urea on their nutritive value, phenolic compounds and digestion coefficients. The PP and PS samples were sprayed with PEG, PVP and urea solutions and kept in airtight plastic containers for 3 days at room temperature. Samples were analysed for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), ash,mineral content, total polyphenolic compounds (TP), total tannins (TT), condensed tannins (CT) and hydrolysable tannins (HT). The in vitro gas production method was used to estimate the DM fermentation parameters. The results showed treating PS and PP with urea led to a significant (P<0.05) reduction TP, TT and HT contents. Treating of PS and PP with 10% PEG was probably associated with reduction (P<0.05) in TP and HT contents of PS and reduction (P<0.05) in CT content of PP sample. Inclusion of 10% PVP had no effect on TP and HT contents of PS and PP samples. Treating of PP with PEG and PVP at a level of 10% or treating with urea led to a significant (P<0.05) increasment in gas production compared to the control sample. The results suggest that urea solution was more effective in reduction of tannins in PP and PS samples, in comparison with PEG and PVP application. Spraying PP sample with urea or PEG and PVP reduced the tannin concentration, increased accumulative gas produced and improved organic matter digestibility,metabolizable energy and in vitro DM disappearance for PP sample. However more research are needed for better understanding the nutritional value of these by-products specially under in vivo conditions

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