Effects Of Lactobacillus Plantarum And Molasses On Fermentation Characteristics And Rumen Degradation Rate Of Hop Leaf Silage

Objective: Hop branches and leaves are by-products of hop processing and are mostly discarded as industrial waste.Abandoned hop branches and leaves still contain many nutrients.Reasonable processing of them can be used as a supplement to animal feed.It can not only provide a way for the supply of forage for herbivorous livestock breeding,but also solve the problems of breeding cost,land output efficiency,environmental pollution,lack of high-quality forage resources to a certain extent,and further broaden the business model of modern agricultural development.Method:(1)Microbial quantity analysis of hop branches and leaves silage : The gradient dilution method and the four-zone line method were used to cultivate the target microorganisms in MRS medium,maltose extract agar medium,high-salt Czapek medium and nutrient agar medium.The main microorganisms were counted by traditional colony counting method,and the growth of the main microorganisms was observed.The number of lactic acid bacteria(LAB),aerobic bacteria(AB),mold and yeast in hops branches and leaves silage was determined at different stages of silage fermentation.(2)Three treatments were designed :no additive treatment(CK treatment),adding 5 % molasses(Molasses,M0 treatment),and adding 5%molasses +1×105CFU/g FM Lactobacillus plantarum(Molasses and Lactobacillus plantarum,M1treatment).The nutritional quality and fermentation quality were measured on the 0,7,15,30,60 and 90 days of silage fermentation.The sensory quality of hop branches and leaves was evaluated after silage fermentation(90d).(3)The rumen fistula test of sheep was carried out by nylon bag method.After the fermentation of hop branches and leaves silage(90d),the rumen degradation rates of main nutrients in each treatment at 12,24 and 48 hours were determined.Results:(1)The number of LAB in each treatment increased first and then decreased with the extension of fermentation time of hop branches and leaves silage.The number of LAB in M1 treatment was significantly higher than that in CK treatment on the 7th and 60 th day of silage fermentation(P<0.05),and significantly higher than that in CK and M0 treatment on the 15 th,30th and 90 th day of silage fermentation(P<0.05).The number of yeasts in each treatment showed a decreasing trend with the prolongation of fermentation time.The number of yeasts in CK treatment was significantly higher than that in M0 and M1 treatments on the 7th,30 th,60th and 90 th days of fermentation(P<0.05),and there was no significant difference between the treatments on the 15 th day of fermentation(P>0.05).The number of molds in M0 and M1 treatments was significantly lower than that in CK treatment on the 7th and 15 th day of fermentation(P<0.05),and the number of molds in M0 and M1 treatments was lower than the detection limit on the 30 th,60th and 90 th day of silage fermentation.The number of aerobic bacteria in each treatment showed a decreasing trend with the prolongation of fermentation time of hop branches and leaves silage.The number of aerobic bacteria in M0 and M1 treatments was significantly lower than that in CK treatment on the 7th,15 th and 30 th day of fermentation(P<0.05).(2)The sensory evaluation of M0 and M1 treatments was good,and the sensory evaluation of CK treatment was general.With the extension of fermentation time,DM,CP,DNF,ADF CP,DNF,ADF,p H showed a downward trend,NH3-N/TN,LA,AA content showed an upward trend,WSC,PA content showed a downward trend after the first rise.After silage fermentation(90d),the DM content of M1 treatment was significantly higher than that of CK treatment(P<0.05),the contents of CP,LA and AA were significantly higher than those of CK and M0treatments(P<0.05),the NDF content was significantly lower than that of CK and M0 treatments(P<0.05),and the ADF content was significantly lower than that of CK treatment(P<0.05).The WSC content of M0 and M1 treatments was significantly higher than that of CK treatment(P<0.05),and the NH3-N/TN,PA content and p H value were significantly lower than those of CK treatment(P<0.05).(3)With the increase of retention time,DMD,OMD,NDFD and ADFD of hop branches and leaves silage in rumen showed an upward trend.At 48 h of rumen fermentation,DMD and ADFD of M1 treatment were significantly higher than CK and M0 treatment(P<0.05),OMD and NDFD of M0 and M1 treatment were significantly higher than CK treatment(P<0.05).Conclusion: In this study,the addition of molasses was 5%,and the addition of Lactobacillus plantarum was 1×105CFU/g.The molasses and Lactobacillus plantarum played a good synergistic effect in the fermentation of hop branches and leaves silage.After silage fermentation(90d),the number of lactic acid bacteria could theoretically increase by 39.70%,and the lactic acid content increased by 2.2 times.It effectively improved the quality of hop waste branches and leaves silage,inhibited the growth of harmful microorganisms during hop branches and leaves silage,promoted the activity of rumen microorganisms,and improved DMD,OMD,NDFD and ADFD in the rumen.The addition of molasses alone and the combined addition of Lactobacillus plantarum and molasses can improve the silage quality of hop branches and leaves to varying degrees,and the combined addition of molasses and Lactobacillus plantarum has the best effect.