Contents from different parts of the gut system of moose were collected in different seasons in central Sweden and analysed for concentrations of phenols, nitrogen (N) and fibre contents (NDF). Faecal and rumen concentration of phenols and nitrogen were positively correlated suggesting that N in faeces could be use as indicator of diet quality. NDF content varied throughout the digestive tract and was consistently lower in the summer compared to winter digesta content. Total phenols in digesta content showed no significant difference between seasons and Rumen liquor from different seasons was used to determine In Vitro Organic Matter Digestibility (IVOMD) of winter twigs of silver birch (Betula pendula L) but no significant difference in IVOMD was found between seasons, only variations between individual moose in their ability to digest browse were noted. The ability of summer and winter rumen microorganisms to digest birch at different phenol concentrations showed no difference but was dependent on concentration of phenols.These results show that the food quality consumed by moose varies between winter and summer season as reflected by N and NDF in the gut and faeces but that the role of phenols remains unclear.