Abstract:

The study evaluated the effects of different additives on nutritive value， fermentation quality， nitrogen components and protease of Broussonetia papyrifera silage. Molasses was added to B. papyrifera after 1.5 h drying in the air as a control treatment （CK）. In the additive treatments， formic acid （FA）， cellulase （CE） or lactic acid bacteria （LB） were added to the B. papyrifera with molasses， with 3 replicates of each treatment. The changes in nitrogen components and enzyme activity were measured at 0， 3， 7， 15， 30 and 45 days of ensiling， and nutritional quality and fermentation quality were measured after 45 days. Results showed that contents of dry matter， crude protein， lactic acid and acetic acid were increased， while crude fiber， neutral detergent fiber， acid detergent fiber， propionic acid content， pH and ammonia nitrogen/total nitrogen were decreased （P<0.05） in FA， LB and CE treatments relative to CK. pH value， total nitrogen content， activities of acid protease， carboxypeptidase and aminopeptidase decreased with increase in time ensiled， while non-protein nitrogen， ammonia nitrogen and free amino acids gradually increased as fermentation progressed， and these indexes mentioned above in FA， LB and CE treatments were lower than in the CK treatment at each sampling time （P<0.05）. The contents of peptide-N in FA， LB and CE groups were higher than in the CK treatment at each sampling time. As ascertained by membership function analysis， the overall nutritional value of B. papyrifera silage treated with different additives， ranked from high to low was： LB>CE>FA>CK.

Key words: additives, silage paper mulberry, nutritional value, fermentation quality, protein degradation