Effects of different additives on growth performance， immune function and microbial diversity in cecum of Lingyun black bone chicken

【Objective】 This experiment was conducted to investigate the effects of different additives on growth performance， immune organ indexes， serum immune indexes and microbial diversity in cecum of Lingyun black bone chicken to provide reference for the selection of antifungal products in Lingyun black bone chickens.【Method】 Five hundred oneday-old Lingyun black bone chicken were randomly divided into 5 groups［（5 treatments， T1-T4 added additives and control（CK）］. Chickens in the CK were fed a basal dietand normal water， and those in the T1， T2， T4were fed the water with 3.0% compound Lactobacillus， 3.5% Bacillus subtilis， organic selenium 0.5% Chinese herbal medicine， respectively. T3 were fed a basal diet with 0.3mg/kg organic selenium （as selenium）. The growth performance of chickens aged from 1 to 6 weeks and immune organ index，serum immune index， cecum microbial diversity at 6 weeks were measured.【Result】 The results showed as follows： at 1week of age， the average daily feed intake （ADFI）of CK， T2， T3， T4 were significantly lower than those of T1（P<0.05， the same below）， the feed conversion ratio（F/G）of T1 and T4 were significantly lower than those of T2， T3 and CK. At 2 weeks of age， the average daily gain （ADG）of C and T1 were significantly higher than others of T2， T3 and T4， the F/Gof T2 and T3 were significantly lower than those of CK，T1 and T4. At 3-6 weeks of age， there was no significant differences in the ADG（P>0.05， the same below）， the ADFI， the feed conversion ratio between CK and treatment groups. Compared with CK， the spleen indexes of treatment groups increased， bursa of fabricius indexes of T1， T3 were significantly increased， bursa of fabricius indexes of T2， T4 had no significant differences compared with CK， thymus indexes of T1， T3 increased by 13.11% and 14.75% compared with CK respectively. Compared with CK， the immunoglobulin A， immunoglobulin M of treatment groups increased， the immunoglobulin G of T1， T2 and T4 increased， and the T1 was the highest. There was no significant differences in Shannon index， Simpson index， Chao1index among treatment groups， but those of T1 increased compared with CK and other treatments， Pielou’s evenness of T1 were significantly higher than that of CK and T3. At the phylum level， the number of the dominant bacteria whose relative abundance was over 1.00% of T1， T2， T3，T4 and CK were 5， 6， 5， 7 and 5，with relative abundance of 95.92%， 98.11%， 95.96%， 97.97% and 97.10%. At the genus level， the number of the dominant bacteria of T1， T2， T3， T4 and CK were 18， 21， 19， 19 and19， with relative abundance of 80.46%， 83.11%， 81.58%， 79.23%， 81.31%.【Conclusion】 It is concluded that， adding compound Lactobacillu， organic selenium， Chinese herbal medicine and B. subtilis in water can increase ADG decrease feed conversion ratio，improve immune organ indexes， serum immune indexes，and improve the cecalmicrobial diversity and relative abundance of microorganisms of Lingyun black bone chicken， and the compound Lactobacillus has the optimal effects.