Effect of Adding Cornzyme on Fermentation and Nutritive Quality of Mixed Silage of Hullessbarley Straw and Perennial Ryegrass in Tibet

The study aimed to improve the fermentation characteristics and nutritive quality of mixed silage of hullessbarley straw and perennial ryegrass in Tibet,and enhance the utilization efficiency of straw resource in Tibet.Mixture of hullessbarley straw and perennial ryegrass(6︰4) were ensiled with Cornzyme at four levels(0,1.5,2.0 or 2.5 mL·kg-1 of fresh weight).Triplicate silos per treatment were opened on 7,14,30 and 60 days after ensiling,respectively,the fermentation characteristics and in vitro degradability of silages was analyzed.Cornzyme addition significantly improved the fermentation quality of mixed silages,indicated by higher(P0.05) lactic/acetic acid,lactic acid and water soluble carbohydrate content,and lower(P0.05) pH value and ammonia/total N(AN/TN) than that of the control silage.The pH value of Cornzyme addition silages maintained to about 4.0,which inhibited the production of acetic acid,propionic acid and butyric acid.After 60 days of ensiling,AN/TN in Cornzyme addition silages were half of that in control,but WSC content were double of that in control.The contents of crude protein were higher and neutral detergent fiber were lower in Cornzyme addition silages.These results suggest that adding Cornzyme to mixture of hullessbarley straw and perennial ryegrass at ensiling appears to be a feasible strategy to improve the fermentation and nutritive quality of straw-grass silages.