Abstract

Carbohydrates from lignocellulosic feed can be released by basidiomycete fungi for ruminal fermentation. This study aimed to evaluate the bioconversion of hay of ryegrass-fescue (Lolium perenne-Festuca arundinacea) by solid state fermentation with Pleurotus ostreatus, to obtain superior quality hay. After only 14 days of fermentation, crude protein (CP) (4.73 to 5.16%), and non-fibrous carbohydrates (NFC) (20.84 to 25.04%) increased, while neutral detergent fiber (NDF) (68.72 to 64.87%) and acid detergent lignin (5.88 to 1.98%) decreased. The enzymatic biodegradation carried out by P. ostreatus was verified, through measurements of enzymatic activity. Lignin peroxidase (LiP) and laccase (Lac) reached the higher activity on day 14 (19.51 U/L and 34.17 U/L, respectively), whereas manganese peroxidase (MnP) displayed stability up to 21 days of fermentation (between 6.54 and 7.75 U/L). In conclusion, results indicate that lignocellulosic feed bioconversion by P. ostreatus is promising to improve the ruminal fermentation of fibrous feedstocks and 14 days were considered to be optimal for hay fermentation.