Effect Of Nano Selenium Supplementation On Growth Performance,Intestinal Health,Meat Quality And Tissue Selenium Deposition Of Broiler

The purpose of this experiment was to investigate the effect of supplementing different concentrations of nano-selenium in the diet on growth performance,intestinal health,meat quality and tissue deposition of broilers.A single factor experimental design was used to select 576 one-day-old broilers with consistent body weight and good health status.According to the principle of consistent average body weight,they were randomly divided into 8 treatments,with 6 replicates for each treatment and 12 for each replicate.CON group was fed basal diet(without selenium,CON);Inorganic group feeding basal diet+0.3 mg/kg sodium selenite(SS),The nano group was fed the basal diet supplemented with 0.1,0.2,0.3 and 0.4 mg/kg nano-selenium(NS0.1,NS0.2,NS0.3 and NS0.4),respectively,and the yeast selenium group was fed the basal diet+0.3 mg/kg yeast selenium(SY),methionine selenium group was fed basal diet+0.3 mg/kg methionine selenium(SM),the experimental period was 42 days.The results show:(1)Effects on growth performance:In each test period,there was no significant difference in daily weight gain,feed intake and feed-to-meat ratio among different treatments(P>0.05).The addition of nano-selenium 0.3 mg/kg had a tendency to increase the final weight,but the difference was not significant(P>0.05).From the perspective of the whole period,compared with CON,the addition of selenium to the diet can increase the daily weight gain and daily feed intake of broilers,compared with CON,the SS,NS0.2,NS0.3 and SY groups could reduce the ratio of feed to meat,and the ratio of feed to meat was the lowest in the NS0.2 group,but the difference was not significant(P>0.05).(2)Effects on immune organ index:At 21 and 42 days of age,compared with CON,there was no significant difference in the thymus index,spleen index and bursa index of each experimental group(P>0.05).(3)Effects on slaughter performance and meat quality:At 42 days of age,compared with CON,there was no significant difference in slaughter performance among the experimental groups(P>0.05).In terms of meat quality:compared with CON and the SS group,except for the NS0.1 group,the other groups significantly improved the redness a*of the breast and thigh muscles(P<0.01),and the NS0.3 group had the highest a*.Compared with CON,except for the NS0.2 group,all the other groups reduced the drip loss of breast muscle but the difference was not significant(P>0.05),except for the NS0.1 group,the other selenium-added groups significantly reduced the compression loss of the pectoral muscle(P<0.01).Compared with CON,the other groups all decreased the drip loss of breast muscle but the difference was not significant(P>0.05),except for the SS and NS0.3 groups,the other groups significantly reduced the pressure loss of the thigh muscles(P<0.01).(4)Effects on tissue deposition:At 21 days of age,liver selenium content in SM,SY and NS0.4 groups was significantly higher than that in control group(P<0.01);The selenium content of the tibia in the SM,SY,NS0.2,NS0.3,and NS0.4 groups was significantly higher than that in CON(P<0.01);The content of selenium in the breast and thig muscles of the SM group was significantly higher than that of CON(P<0.01 and P=0.007);Except for the NSO.1 group,the renal selenium content of the other groups was significantly higher than that of CON;The jejunal selenium content of all the experimental groups supplemented with selenium was significantly higher than that of CON(P<0.01).At 42 days of age,the content of selenium in the tibia of the SM group was significantly higher than that of CON and other experimental groups(P<0.01).At 42 days of age,the content of selenium in the tibia of the SM group was significantly higher than that of CON and other experimental groups(P<0.01).At 42 days of age,the content of selenium in the tibia of the SM group was significantly higher than that of CON and other experimental groups(P<0.01).At 42 days of age,the content of selenium in the tibia of the SM group was significantly higher than that of CON and other experimental groups(P<0.01),The selenium content of breast muscle in SM,SY,SS,NS0.3 and NS0.4 groups was significantly higher than that in control group;except for NS0.1 group and jejunum except NS0.1 group in thigh muscle,and NS0.1 and NS0.2 group in kidney The content of selenium in the other experimental groups was significantly higher than that in CON(P<0.01).(5)Effects on the morphological structure of the jejunal mucosa:At 21 days of age,the jejunal villus height and VH/CD in each selenium-added group were significantly higher than those in CON(P<0.01),The crypt depth was significantly lower than that of CON(P=0.003).At 42 days of age,compared with CON,the jejunal villus height/crypt depth(V/C)in the NS0.1,NS0.2,SY,and SM groups increased significantly(P<0.01);Compared with CON,except for the NS0.3 and 0.4 groups,the crypt depths of the other selenium-added groups were significantly decreased(P<0.01).(6)Effects on cecal microbes:Compared with CON,the addition of nano-selenium to the diet had no significant difference in the alpha diversity of the cecal flora of broilers at 21 and 42 days of age(P>0.05).Firmicutes,Bacteroidetes,Tenericutes and Proteobacteria were the predominant phyla of the 21 and 42-day-old cecal microbes in broilers,and their total abundances all exceeded 99%.A total of 102661 OTUs were detected in the 21-day-old cecum samples,and only 283 OTUs were common to the eight groups.In CON,SS,NS0.1,NS0.2,NS0.3,NS0.4,SY and SM groups,contained 14677,11721,15692,13422,13620,7724,13320 and 12485 unique OTUs.A total of 58,946 OTUs were detected in the 42-day-old cecum samples,and 973 OTUs were common to the eight groups.In CON,SS,NS0.1,NS0.2,NS0.3,NS0.4,SY and SM groups,contained 7169,7124,8699,8623,8408,5885,5779 and 7259 unique OTUs.LEfSe analysis of 21-day-old cecal microbes showed that the abundances of o-Pasteurellales,f-Pasteurellaceae,and g-Haemophilus were significantly different in NS4 group;c-Alphaproteobacyeria,o-Rhodospirillales,o-Rhodocyclales,f-Acetobacteraceae in SY group,There were significant differences in the abundance of f-Rhodocyclaceae,gAcidocella,and g-K82 genera;p-Verrucomicrobia,c-Verrucomicrobiae,fVerrucomicrobiaceae,and g-Akkermansia genera were significantly different in CON.LEfSe analysis of 42-day-old cecal microbes showed that there were significant differences in the genus g-Thermoanaerobacterium in the NS-4 group;o-Rhodocyclales,f-Rhodocyclaceae,and g-K82 in the SY group;and s-S24-7 in the SS group.Family differences were significant;CON increased the abundance of o-Pasteurellaceae,f-Pasteurellaceae.In conclusion,dietary supplementation of nano-selenium can improve meat quality and intestinal morphology,increase tissue selenium deposition,and improve cecum microbial composition of white-feathered broilers,among them,adding 0.3 mg/kg NS had the best effect.