Study On The Suitable Fermentation Time And Nutritional Value Of The Fermented Total Mixed Ration

The purpose of this experiment was to study the effect of wrapped fermentation technology on total mixed ration（TMR）,and determine the fermentation quality,nutritive value and aerobic sta-bility of the fermented total mixed ration in different fermentation days.Ruminal degradation in situ and fermentation gas production characteristics in vitro were used to determine the suitable fermentation days,and its rumen fermentation and degradation characteristics provided a theoretical basis for the application of fermented total mixed ration in pasture.Experiment 1:Effect of fermentation time on the quality of FTMR fermentationThe fresh TMR was packaged and fermented.The samples were collected at 0,3,7,15 and30d,and named as five treatment groups:D0,D3,D7,D15 and D30 with 8 replicates each.The fermentation quality,nutrient composition and microbial changes were determined.The results showed that with fermentation time prolonging,the content of dry matter,acid detergent fiber and starch and pH value decreased and the content of crude fat,crude ash,ammonia nitrogen,lactic acid and acetic acid increased.There was no significant difference in the content of crude protein and neutral detergent（P>0.05）.The content of lactic acid was 3.31³.52%DM,pH value was 4.43⁴.39and ammonia nitrogen was 2.58³.33%TN after 7 days fermentation.Propionic acid was only de-tected in D7 and D30 treatment group and less than 0.2%DM.Butyric acid was not detected in all treatment groups.These findings showed that fermentation quality of FTMR was great after 7,15and 30 days of fermentation,and there was no corruption and deterioration.Experiment 2:Effect of fermentation time on the aerobic stability of FTMRAt the same time,FTMR was exposed to air,the fermentation quality,nutrient composition and microbial changes were determined.The temperature changes were recorded with a multi-chan-nel temperature recorder,and the aerobic stability was assessed at 1,3 and 5 days after aerobic exposure.During the aerobic exposure,the pH value of the D0 and D3 groups increased sharply after the 5 days of exposure,and the lactic acid and acetic acid content decreased sharply,the num-ber of molds and yeasts were more than 1×10⁵ cfu/g,and the temperature of the samples was higher than the ambient temperature of 2℃.These indicated that corruption has occurred.In D7,D15 and D30 group,the difference of pH was not significant during exposure（P>0.05）,lactic acid and acetic acid content gradually decreased,the number of molds and yeasts less than 1×10⁵ cfu/g,the sample temperature was lower than the ambient temperature of 2℃.These indicated that D7,D15 and D30had high aerobic stability.The results showed that FTMR showed good fermentation quality after 7days of fermentation,and had high aerobic stability.Experiment 3:Effect of FTMR with fermentation time on in vitro fermentation and microbial populationsThis experiment was used in vitro gas production method to investigate the in vitro fermenta-tion parameters and microbial flora of FTMR feeds at different fermentation times.The experi-mental results showed that:with fermentation time of FTMR feed increasing,the feed production of each group had an increasing trend at 48 h.The pH values in each group ranged from 6.65 to6.88,all within a reasonable range,and had no effect on the activities of rumen microorganisms and the in vitro gas production.The concentration of NH₃-N in each group was between 20.48 to 26.58mg/dL.Within the normal range of rumen,it had no effect on the growth of rumen microbes.With fermentation time of FTMR feed increasing,the value of TVFA in each group increased significantly,and the change of pH value was inversely related to TVFA.And the number of bacteria also had an upward trend.Experiment 4:Effect of FTMR with fermentation time on rumen degradation characteristics of dairy cowsThe objectives of this study were to research the effect of rumen degradability characteristics and intestinal digestibility of fermented total mixed ration.Two ruminally cannulated Holstein cows averaging 600 kg of body weight were used to evaluate ruminal degradability of dry matter,crude protein and neutral detergent fiber.The results showed that along with the storage time prolonging,fermentation significantly increased dry matter,crude protein and neutral degradation fiber rumen disappearance and effective degradability of TMR（P<0.05）,the dry matter effective degradation rate of 15 and 30 d was over 50%,the effective degradation rate of crude protein was over 55%and the effective degradation rate of neutral degradation fiber was approximately 30%;Fermentation significantly increased（P<0.05）fraction of immediately degraded of crude protein and neutral deg-radation fiber.In summary,（1）After TMR was treated by wrapping fermentation,it showed good fermentation quality after 7 days and high aerobic stability,so it could be opened and used.（2）Wrapped fermentation could effectively maintain the nutritional value of the total mixed ration diet,ensure rumen stable and healthy,and increase the rumen degradability of nutrients in the total mixed ration diet.