| In this experiment, the mixed bacteria of Lactobacillus acidophilus and Streptococcus was used to ferment astragalus. Fermented astragalus preparations was developed by selecting the optimum ratio of the mixed powder and the optimal fermentation conditions.0.15%,0.25%and0.5%fermented astragalus preparations were studied on weaning growth performance and disease resistance of weaned piglets compared with basal diet group, unfermented group (0.25%astragalus) and antibiotic group and the optimal amount was determined. The results are as followed:1) The best ratio of Lactobacillus acidophilus and Streptococcus faecalis was2:8. The best exogenous carbon was2%glucose. Exogenous nitrogen has no effect for fermentation. The best combination of fermentation conditions were as follows:inoculum size was0.2%, water content was35%, fermentation time was6d. APS rate was23.23%and the growth rate was509%.2) Compared with the basal diet group,0.25%fermented astragalus make feed intake increase8.5%(p<0.05),daily gain increase26.5%(p<0.05), feed conversion rate reduce9.0%(p<0.05) and diarrhea reduced73.7%(p<0.05). Compared with unfermented group,0.25%fermented astragalus make daily gain increase6.6%(p<0.05), feed conversion rate reduce4.7%(p <0.05),diarrhea reduced58.3%(p<0.05) and feed intake had no significant difference (p>0.05). Compared with the antibiotic group,0.25%fermented astragalus make feed intake increase8.2%(p<0.05) and diarrhea reduced54.5%(p<0.05), but it was not as good as antibiotics in improving daily gain and feed efficiency.3) Experiment early:Compared with the basal diet group,0.25%fermented astragalus make IgA increase23.8%(p<0.05), IgG increase57.5%(p<0.05), IL-2increase17.4%(p<0.05), IL-4increase46.0%(P<0.05),TNF-a increase33.7%(p<0.05) and IgM content had no significant difference (p>0.05).Compared with unfermented group,0.25%fermented astragalus make IgA increase23.3%(p<0.05), IgG increase43.8%(p<0.05), IL-2increase14.6%(p<0.05), IL-4increase45.3%(p<0.05), TNF-a increase27.7%(p<0.05) and IgM content had no significant difference(P>0.05). Compared with the antibiotic group,,0.25%fermented astragalus preparations make IgG increase45.0%(p<0.05), IL-4increase46.0%(p<0.05) and other immune indicators (p>0.05)4) Experiment post:Compared with the basal diet group,0.25%fermented astragalus make IgG increase38.4%(p<0.05), IL-4increase30.9%(p<0.05)and other immune indicators(p>0.05). Compared with unfermented group,0.25%fermented astragalus preparations make IgG increase47.4%(p<0.05),IL-4increase34.2%(p<0.05) and other immune indicators (p>0.05). Compared with the antibiotic group,,0.25%fermented astragalus make IgG increase43.0%(p<0.05), IL-4increase25.9%(p<0.05) and other immune indicators (p>0.05)These results suggest that this experiment’s fermentation astragalus preparations could increase the feed intake, daily gain,and feed utilization of piglet and improve diarrhea and immunity of piglet. |
