Effects Of Solid-state Fermented Feed Of Lactobacillus Amylovorus TZR-PI001 On Growth Performance,antioxidant Performance And Fecal Microflora Of Pigs

China is a big country of pork consumption,and people’s demand for pork is higher and higher.However,the prohibition of antibiotics in feed has led to the decline of pig growth performance.Therefore,it is urgent to find an alternative feed antibiotics.The existence of anti nutritional factors in the diet will lead to the decline of feed utilization.After microbial fermentation,feed can reduce the level of anti nutritional factors and improve the nutritional value of feed.At the same time,microbial metabolites are beneficial to animal health.The purpose of this study was to clarify the prebiotic mechanism and resistance of Lactobacillus amylovorus TZR-PI001 in vitro,the effect of solid-state fermentation on the nutritional value of full price mixed feed for growing pigs,and the effect of the fermented feed on the growth performance and fecal microflora of growing pigs.The tolerance and hydrophobicity of Lactobacillus amylovorus TZR-PI001 to acid,bile salt and artificial digestive solution,automatic aggregation ability,amylase and cellulase production ability and cholesterol degradation ability in vitro were studied.The results showed that Lactobacillus amylovorus still had the ability to proliferate in p H=2.0and bile salt medium containing 0.4%.It was resistant to artificial digestive solution.The adhesion to xylene reached 68.52%,and the automatic aggregation rate reached 85.58%in 5 hours.Its extracellular amylase activity was 29.65 U/m L,cellulase activity was 13.25U/m L,and 43.69%cholesterol in the medium was reduced.L₁₆（4³）design was used to study the optimal inoculation amount,fermentation time and solid substrate water content of Lactobacillus amylovorus solid-state fermentation,as well as the effects of fermentation on feed nutritional value and biosafety.The results showed that the optimum fermentation conditions of Lactobacillus amylovorus TZR-PI001 were as follows:inoculation amount 5%,fermentation time 60 h,solid substrate water content 42.5%;After fermentation,the content of crude protein increased by 4.62%（P<0.05）,and the content of crude fiber decreased by 8.78%（P<0.05）;The number of lactic acid bacteria in the fermented feed reached 81.23×10⁵ CFU/g（P<0.01）;The total antioxidant capacity of feed increased from 8.12μmol/g to 11.77μmol/g（P<0.05）;The number of mold in feed was reduced to 6.67 CFU/g;E.coli was not detected in the feed before and after fermentation.36 Duroc×Landrace×Yorkshire growing pigs were randomly divided into three groups according to single factor:100%basic diet（Control group）,fed 75%basic diet+25%solid-state fermentation basic diet（25%addition group）,and fed 50%basic diet+50%solid-state fermentation basic diet（50%addition group）.The experimental period was 35days.The results showed that the daily gain and daily feed intake of the two experimental groups were significantly higher than those of the control group（P<0.05）.There was no significant difference in final weight among the three groups（P>0.05）;Feeding fermented feed improved the digestibility of thr,Val,met,ile,Leu,Phe and Lys essential amino acids（P<0.05）and ASP,Ser,Glu,ala,Cys and Arg non-essential amino acids（P<0.05）.The diet supplemented with Lactobacillus amylovorus solid-state fermentation decreased the concentrations of IL-6,Urea Nitrogen,Creatinine and TCHO in plasma（P<0.05）,and increased the activities of GSH-Px,SOD and the level of IL-10 in plasma（P<0.05）.Compared with the control group and the 25%addition group,the 50%addition group decreased the level of LPL-C in plasma（P<0.05）;Compared with the control group and the 50%addition group,the 25%addition group significantly reduced the levels of TG and MDA in plasma（P<0.05）,and increased the activities of CAT and T-AOC in plasma.The 50%addition group decreased the Faith pd index in the fecal microfloraαdiversity index（P<0.05）;At the class level,the relative abundance of Clostridia microorganisms in the feces of the fermented feed group was significantly higher than that of the control group（P<0.05）;At the order level,compared with the control group,the relative abundance of Clostridium microorganisms in the fermented feed addition group was significantly higher（P<0.01）,and the relative abundance of Lactobacillus microorganisms was significantly lower（P<0.01）;At the family level,compared with the control group,the relative abundance of Clostridium microorganisms in the fermented feed group increased significantly（P<0.05）,and the relative abundance of Streptococcaceae microorganisms decreased significantly（P<0.01）.There was no difference between the two experimental groups at the family level（P>0.05）;At the genus level,the Streptococcus microorganisms in the fermented feed group were significantly lower than those in the control group（P<0.01）,and there was no difference between the two experimental groups（P>0.05）.In conclusion,Lactobacillus amylovorus TZR-PI001has prebiotic effect in vitro and tolerance to gastrointestinal environment.Lactobacillus amylovorus TZR-PI001 can improve feed nutritional value,improve feed antioxidant capacity and improve feed biosafety.Feeding feed fermented by Lactobacillus amylovorus TZR-PI001 can improve the growth performance of growing pigs and enhance the antioxidant and anti-inflammatory functions of the body,it can improve the material metabolism of the body and reduce the Streptococcus in feces.Lactobacillus amylovorus TZR-PI001 can be further studied and applied as a safe and effective probiotic for pigs.