| The usage of antibiotics as feed additives has improved the production efficiency of animalhusbandry, but it causes some extra problems, such as endogenous infection, double infection,and bacterial drug resistance, decreases of immune capacity and drug residues and so on, whichraised people’s attention. Extensive researches showed that adding the lactobacillus as probioticsto the animal feed or drinking water can effectively improve immune function and productionperformance of animals. Because of probiotic lactobacillus with probiotic functions, and withoutenvironmental pollution, therefore the product is expected to be a substitute for antibiotics.With the proposing of VBNC state of bacteria (Viable but Non-Culturable), people have amore profound understanding of the life and death of bacteria. Current research on VBNC oftenfocused on pathogens. Before this study we did some extra researches, including induction ofLactobacillus, and obtained two kinds of lactobacillus, mutant strain of lactobacillus plantarum(ZTVBNC), lactobacillus plantarum (ZVBNC bacteria). They were in VBNC state. So in thisresearch, in order to discuss the effects of lactobacillus association with ND vaccine on theimmune function in broilers, we added three kinds of bacteria strains (ZTVBNV, ZVBNC and Z,Z represents lactobacillus plantarum) as probiotics to the drinking water and collaboration withthe Newcastle disease (ND) inactivated oil emulsion vaccine. In this article, there were8groups;the groups’ names are as follows: group1-ZTVBNC with Vaccine, group2-VBNC with Vaccine,group3-Z with Vaccine, group4-PBS with Vaccine, group5-ZTVBNC, group6VBNC, group7-Z, and group8-PBS. The different kinds of lactobacillus were added to the drinking waterstarting from the first day, and the dosage is1ml per broiler per day.ND vaccines were infected to the broilers in7d and17d, then collecting blood samplesevery other day to measure the valence of ND antibody. The results showed that antibody levelsof the groups with ND vaccine were significantly higher than unvaccinated groups, includingthat in the vaccinated group, the antibody levels of the first group and third group were muchhigher, in the unvaccinated groups, the first group was much higher than others. So the resultsindicated that different kinds of lactobacillus play a vital role in increasing the antibody levelsand strengthen the humoral immunity of broilers. Secondly, in terms of the immune organs’development, the thymus index and spleen index of the treatment group and vaccine group aremuch higher than the control group and unvaccinated group in the45th day. The thymus indexof group1and group3are31%higher and39%higher than group4(P<0.05), the thymus indexof group5is49%higher than group8(P<0.05). The spleen index of group1is respectively23% higher and35%higher than the group2and group4(P<0.05). The spleen index of group5is31%higher than group8. For the bursa of fabricius index, the group1and group3are52%lower and73%than group2(P<0.01), group6is54%higher and43%higher than group5andgroup7(P<0.01), the above results demonstrate that, to some extent, the three kinds oflactobacillus could promote the development of immune organs. For the cellular immunity, thelymphocyte transformation ratio of treatment group is significantly higher than the control group,details are as follows, group one’s lymphocyte transformation ratio is16%higher and31%higher than group3and group4(P<0.05), the group two’s is24%higher than the forth group’s(P<0.05), the fifth group’s is32%higher than8th group’s (P<0.05). So these results show thatdifferent lactobacillus collaboration with the Newcastle disease will improve the activation oflymphocyte and enhance the disease resistance. Thirdly, the IL-10concentration of group1isthe highest, up to50pg. the first group’s is6%higher and13%higher than the third group’s andthe4th group’s (P<0.01). The forth group’s is7%less than the second group’s (P<0.01), the7thgroup’s is12%more than the8th group’s (P<0.05).To do a further research, preparation of immune organ (spleen, thymus, bursa of fabricius)tissues of broilers were used to observe the mRNA expression profiles of TLR4and TLR5geneby semi-quantitative RT-PCR, The result reveals that the mRNA expression levels of TLR4andTLR5gene in vaccine groups were all higher than unvaccinated groups, the results reveal thatdifferent lactobacillus collaboration with the ND vaccine play an very important role in theToll-like pathway regulating the progress of immune response.In conclusion, The results demonstrate that the collaboration with various probiotics andND vaccine could improve broiler NDV antibody levels, immune organ index (thymus index,spleen index and thymus index) and lymphocytes conversion rate, in addition increase therelative expression of immune genes, so to a certain extent, the results indicated that thedifferent states of lactobacillus could improve the immune performance of broilers, and thenenhance disease resistance of animals. Therefore, this article provides a new solution for theresearch of VBNC state of lactobacillus, and expands the road for the development of probioticsproducts... |
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