Abstract:

This study explored the effect of mixture ratio and inoculation with compound Lactobacillus on the quality of mixed tomato pomace and alfalfa silage in order to provide a theoretical basis for improving resource utilization and broadening forage resources in this region. The vacuum bag method was used to prepare the mixed silage samples for testing. There were ten experimental treatments； five mixture ratios ［tomato pomace∶alfalfa=3∶7 （T₁）， 4∶6 （T₂）， 5∶5 （T₃）， 6∶4 （T₄）， 7∶3 （T₅）］， each mixture ratio either without or with added compound Lactobacillus culture made up from a 1∶1 of Lactobacillus brucei and Lactobacillus plantarum， 1×10⁶ CFU·g^-1. The Lactobacillus culture was evenly added and the five inoculated treatments were designated JT₁， JT₂， JT₃， JT₄ and JT₅，5 replicates in each group， 2 kg in each bag. After 60 days of fermentation， the bags were opened for sensory evaluation； The nutritional quality， fermentation quality， and rumen degradability were analyzed. The membership function analysis method was used to evaluate the optimal treatment. It was found that， the smell and texture of mixed silage of tomato pomace and alfalfa were improved by inoculation with compound Lactobacillus. Sensory evaluation results for the mixed silage treatments T₁， JT₁， T₂ and JT₂ were excellent. When inoculated with compound Lactobacillus， the dry matter （DM）， crude protein （CP）， lactic acid （LA） and acetic acid （AA） of the mixed tomato pomace and alfalfa silage were significantly increased （P<0.05）， and water-soluble carbohydrate （WSC）， neutral detergent fiber （NDF）， acid detergent fiber （ADF）， pH， propionic acid （PA）， butyric acid （BA）， ammonia nitrogen∶total nitrogen （NH₃-N∶TN） were significantly decreased （P<0.05）. Among the tested mixed silage treatments， the DM and CP contents of JT₂ were the highest， the WSC content of T₂ was the highest， the NDF and ADF contents of JT₂ were the lowest， pH values of JT₁ and JT₂ treatments were lower， LA contents of JT₁ and JT₂ were higher， the AA contents of T₁ and T₂ were lower and the PA and BA contents and NH₃-N/TN of JT₁ and JT₂ treatment were lower. After rumen degradation for 24 hours， the dry matter degradability （DMD）， neutral detergent fiber degradability （NDFD） and acid detergent fiber degradability （ADFD） of mixed tomato pomace and alfalfa silage were significantly increased （P<0.05） by inoculation with compound Lactobacillus culture. The DMD and NDFD of JT₁ and JT₂ treatment were higher than other treatments， and the ADFD of JT₂ was the highest. It was concluded that the nutritional quality， fermentation quality and rumen degradation rate of tomato pomace and alfalfa mixed silage were significantly improved by inoculation with compound Lactobacillus. On membership function analysis of 14 measured indexes of each mixed silage treatment， JT₂ （tomato pomace∶alfalfa ratio=4∶6， inoculated with compound Lactobacillus culture， dry matter content=30.64%） was identified as the best treatment， and this formulation can be recommended for wider use.

Key words: compound Lactobacillus, tomato pomace, alfalfa, mixed storage, fermentation quality, rumen degradability