Objective  Effects of addition of lactic acid bacteria to the spent substrate of Pleurotus ostreatus cultivation on the fermentation and quality of the feed material for livestock and poultry industry were analyzed.

  Method  Lactic acid bacteria CCZZ1 and HT1 were added alone or in combination (MIX) to the spent culture substrate prior to fermentation. A blank control (CK) was included in the 3-treatment experimentation. Initially, 18 replicates for each testing group were conducted at room temperature. Triplicated analytical data and fermentation process evaluation criteria on the 1^st, 3^rd, 7^th, 15^th, 30^th, and 60^th day were collected for the study. Result During the fermentation, the contents of lactic acid, acetic acid, propionic acid, and dry matters increased, while those of hemicellulose, butyric acid, and crude protein declined. And, ammonia nitrogen was significantly lower in MIX than in control (P＜0.05). After fermented for 7 d, the pH of the treatment groups were significantly lower than those of CK (P＜0.05), and reached below 4.2 in 23 d less than it took CK. The acetic acid and dry matter contents in the treatment groups were significantly higher than those in CK (P＜0.05), while lactic acid increased, and crude protein reduced as compared with CK. On the other hand, the contents of ammonia nitrogen, crude ash, soluble carbohydrate, acid washed fiber, neutral water washed fiber, hemicellulose, propionic acid, and butyric acid in the treatment groups did not significantly differ from those in CK.

  Conclusion  The addition of lactic acid bacteria CCZZ1 and HT1 alone or in combination not only improved the quality of the fermented feed made from the spent mushroom culture substrate but also facilitated the fermentation process.