| The Lactobacillus plantarum bred in the previous stage of this study was a model strain,which was domesticated for stress resistance,and then optimized its fermentation parameters,developed a specific medium formula,combined with emulsified gelatinized microcapsule coating and giant embedding.The Lactobacillus plantarum bred in the previous stage of this study was a model strain,which was domesticated for stress resistance,and then optimized its fermentation parameters,developed a specific medium formula,combined with emulsified gelatinized microcapsule coating and giant embedding Post-coating method,forming a stable and high-resistance multi-layer coated Lactobacillus plantarum product preparation process,which is compounded with Enterococcus faecium RS047 and chitosan to form a synbiotic.The study of synbiotics in weaning piglets and growth and fattening the application effect of pig feed without antibiotics is intended to provide technical support for the replacement of antibiotics in livestock and poultry feed and the improvement of livestock and poultry breeding environment.Experiment 1 Domestication of Lactobacillus plantarum LP15-1 and optimization of fermentation parameters of the domesticated strainIn this experiment,Lactobacillus plantarum LP15-1 was domesticated by gradually increasing the domestication temperature,medium acidity and bile salt concentration,and the tolerance of the domesticated strains at each stage was evaluated,and the heat-resistant strain LP15-1a was selected.The fermentation parameters of strain LP15-1a were optimized.Optimization results:The culture conditions are initial p H=8.0,temperature 30℃,and static culture for 20 hours;the optimum nitrogen source for the medium is peptone-G0309(14.41g/L),and the optimum carbon source is molasses(28.57 g/L).Experiment 2 The application of synbiotics composed of highly resistant Lactobacillus plantarum in feeding of weaned pigletsIn the experiment,108 piglets of 28-day-old weaned piglets with similar weights,similar ages and good health conditions were selected and randomly divided into 3treatments,each with 6 repetitions,and each repetition 6 pigs.The three treatment groups are:control group(CON):feeding basal diet;antibiotic group(ANT):feeding basal diet+0.03%chlortetracycline;synbiotic group(SYN):feeding basal diet+Synbiotics(Lactobacillus plantarum+Enterococcus faecium+0.05%Chitooligosaccharides,each gram of complete feed contains 1.0×10~6 CFU of Lactobacillus plantarum,1.0×10~6 CFU of Enterococcus faecium,and oligochitosan 500 mg).The test period is 60 days.The results showed that:(1)There was no statistical difference between the three groups’growth performance(including average daily gain,average daily feed intake and feed-to-weight ratio).However,compared with the control group,the daily gain of the synbiotic group increased by 38 g/d,that is,an increase of 9%,and the feed-to-weight ratio was reduced by 7%;it reduced the mortality of weaned piglets(SYN vs.CON:7.5%vs.12%)),but higher than the mortality rate of the antibiotic group(SYN vs.ANT:7.5%vs.5%);significantly reduced the fecal index of weaned piglets(SYN vs.CON:1.49 vs.2.07,P=0.0204),a 28%reduction;The stool index of the synbiotic group was not statistically different from that of the antibiotic group(SYN vs.ANT:1.49 vs.1.63).(2)The content of skatole in the feces of weaned piglets in the synbiotic group was significantly lower than that of the control group(P<0.01),but there was no significant difference compared with the antibiotic group;the content of indole in the feces of the three groups of piglets was not significantly different.(3)Compared with the control group,the synbiotic group significantly increased the expression level of the mucous protein MUC2 in the jejunum of weaned piglets(P<0.05);there was no significant difference compared with the antibiotic group.(4)Compared with the control group,the synbiotic group significantly increased the number of acidic goblet cells in the duodenum,jejunum and ileum(P<0.01);compared with the antibiotic group,it significantly increased the duodenum The number of acidic goblet cells in the intestine and jejunum(P<0.01),while the number of acidic goblet cells in the ileum was not statistically different.There was no statistical difference in the number of sulfur-containing goblet cells in each intestinal segment of the three groups(CON,ANT,and SYN).Experiment 3 The application of synbiotics composed of highly resistant Lactobacillus Plantarum in feeding of growing and finishing PigsIn the experiment,90 pigs with similar weight(33±6 kg),similar ages and good health condition were selected.According to weight and sex,they were randomly divided into 3groups,each with 6 replicates(3 replicates for male and female,among which boars were castrated boars),with 5 pigs for each replicate.The three treatment groups were:control group(CON):fed basal diet;antibiotic group(ANT):mid-pig stage(30-60 kg)fed basal diet+0.002%virginiamycin(speed Large fat),large pigs(60 kg-slaughter)feeding basic diet;Synbiotics group(SYN):feeding basic diet+synbiotics(0.05%Lactobacillus plantarum+0.05%Enterococcus faecium+0.05%Chitooligosaccharides).The pre-test period is 7 days,and the trial period is 120 days.The results showed that:(1)Sex had no significant effect on the daily weight gain of growing-finishing pigs(P>0.05),but it could significantly affect the daily feed intake and feed-to-weight ratio(P<0.05),the daily feed intake of sows and The feed-to-weight ratio was lower(P<0.05)than castrated boars.However,compared with the control group,whether castrated boars or sows,feeding antibiotics during the growing period and feeding synbiotics during the growing and finishing periods had no significant effect on their growth performance(P>0.05).However,feeding the feed supplemented with synbiotics can effectively reduce the mortality of growing-finishing pigs.In this experiment,the SYN group of growing-finishing pigs,regardless of male or female,has a total mortality of 0;however,there is 1 boar in the CON group died(3.33%mortality in the CON group),2 sows in the ANT group died(6.67%mortality in the ANT group).(2)Compared with the control group,feeding antibiotics(ANT)during the growing period and feeding synbiotics(SYN)during the growing and finishing periods had no significant effect on the carcass quality of growing and finishing pigs(P>0.05).However,compared with the CON group,the backfat thickness of pigs in the SYN group tended to decrease(0.05≤P<0.1).(3)Compared with the control group,feeding synbiotics(SYN)to the growing-finishing pigs can significantly reduce the shear force of the pork(P<0.05),that is,significantly improve the tenderness of the pork.However,other meat quality indicators,such as p H 45 min,drip loss,meat color at 45 min and 24 h after slaughter,and marble pattern,were not significantly different between the three groups of pork(P?0.05).(4)The tenderness of pork tenderloin in the SYN group was significantly better than that of the ANT group(P<0.05),but not significantly different from the CON group(P?0.05).In addition,the tenderness of the ham meat of the SYN group was significantly better than that of the CON group(P<0.05),and it was not significantly different from the ANT group(P?0.05).However,there were no significant differences in the color,smell,taste,elasticity and overall acceptability of tenderloin and hind leg meat in the three groups(P?0.05). |
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