| The experiment was conducted to study the effects of palygorskite on broilers after clostridium perfringens (Cp) infection, and to compare the effects of palygorskite and Zinc Bacitracin on broilers. The study includes three parts and the results are presented as follows:Trial1:The aim of this experiment was to study the effects of Cp on body weight gain, lysozyme activity in serum and intestinal lesions scores of broilers infected with Cp.144AA broiler chicks were randomly allocated to control group (non-infection) and three infection groups (Ⅱ,Ⅲ,Ⅳ), and each group had6replicates with6broilers per replicate. The broilers of group Ⅱ were orally inoculated with Eimeria coccidian once at16d, and those in group Ⅱ, Ⅲ, Ⅳ were infected with Cp once a day at20-22d at a dose of1,1,5mL/bird, respectively, while the control group were orally administrated1ml of aseptic culture medium. The results showed that:the body weight gain of Cp-dosed broilers decreased (P>0.05) at4,7,11,17d post-infection, and that in the group Ⅱ was significantly decreased (P<0.01). The lysozyme activity in serum of Cp-dosed broilers enhanced after Cp infection, the lysozyme activity of group III was higher than that of group IV, and the lysozyme activity of Cp-dosed broilers was the same as that of broilers in the control group at17d post-infection. The intestinal lesion scores of group II was increased (P<0.01) compared with control group.Trial2:This experiment was conducted to study the effects of palygorskite on performance, serum biochemical indexes, intestinal morphology and immune indexes of broilers infected with Cp.480AA broilers were randomly allocated to the control group and four test groups infected by Cp. Broilers of control group were fed basal diet, and the Cp infected broilers were fed basal diet (infection group), and the same diet supplemented with40mg/kg zinc bacitracin (antibiotic group),2%palygorskite (palygprskite group) or2%modified palygorskite (modified palygorskite) respectively. The broilers of the test groups were orally challenged with Cp (Type A) once a day at14-16d (one time per day) at a dose of1ml/bird. The results showed that Cp reduced the performance (P>0.05), which was raised by palygorskie and modified palygorskite supplementation in diet. Spleen and thymus index in infection group decreased (P>0.05) at7d post-infection, which were relieved by antibiotic, palygorskite and modified palygorskite supplementation in diet; AKP activity in serum enhanced5.47%(P>0.05) at11d post-infection, which was decreased by antibiotic and palygorskite addition. The content of IgG in intestinal mucosa had no significant change at7,11d post-infection; The SIgA content in intestinal mucosa of infection group increased by26.30%and22.01%(P>0.05) at7,11d post-infection, which was decreased by antibiotic, palygorskite and modified palygorskite addition. The crypt depth of anterior jejunum in infection group increased (P<0.05) at7d post-infection, which was decreased by antibiotic, palygorskite and modified paltgorskite supplementation in diet, the value of V/C in anterior jejunum decreased by36.89%(P>0.05), antibiotic, palygorskite and modified paltgorskite had the value raised by71.62%(P>0.05),76.45%(P>0.05),71.42%(P>0.05), respectively.Trial3: The aim of this experiment was to study the effects of palygorskite clay on antioxidant and immune function of broilers infected with Clostridium Perfringens. Treatments were the same as in Trial2. The results showed that serum MDA content of broilers in infection group increased (P<0.01) at7d post-infection, which was reduced39.38%,51.25%and63.83%by antibiotics, playgorskite and modified palygorskite supplementation in diet. The SOD activity in infection group decreased (P>0.05), which was enhanced by antibiotic, palygorskite and modified palygorskite supplementation in diet. The SOD activity in intestinal mucosa decreased by15.23%(P>0.05) at7d post-infection, but antibiotic, palygorskite and modified palygorskite had the SOD activity raised by16.31%(P>0.05),25.66%(P＜O.05), and6.55%(P＞0.O5), respectively. The MDA content in intestinal mucosa in infection group rose (P<0.05) at7d post-infection, which was reduced by antibiotic, palygorskite and modified palygorskite addition. The serum NO content of infection group increased (P＜O.05) at7,11d post-infection, while antibiotic, palygorskite and modifide palygorskite reduced it (P>0.05). The content of TNOS and iNOS in serum increased (P<0.01) at7d post-infection, which were decreased by paltgorskite and modified palygorskite addition (P>0.05). The NO content in intestinal mucosa of infection group enhanced (P>0.05), but the content of NO had a increased tendency (P>0.05) by antibiotic, palygorskite and modified palygorskite addition in diet, the TNOS and iNOS content in intestinal mucosa of broilers had no change at7d post-infection. |
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