Effects Of Probiotics And Bacteriocin On Performance,Intestinal Flora And Blood Metabolism Of White Feathered Broilers

With the implementation of the policy of total forage anti-resistance,the search for antibiotic substitutes has become an important field and direction of the current research on feed additives.Both probiotics and bactericins can regulate the intestinal flora of animals and inhibit the growth of bacteria.Probiotics and bacteriocins have broad application prospects in animal production.Therefore,this experiment was conducted to investigate the effects of different supplementation combinations of probiotics and bacteriotin on performance,blood indexes,intestinal morphology,intestinal flora and blood metabolism of broilers.Three hundred one-day-old Arbor Acres(AA)male broilers were randomly divided into 5 groups with 6 replicates per group and 10 broilers per replicate.Broilers in NC(control)group were fed a basal diet,and broilers in BP50(bacteriocin 50%+Probiotics 50%)group were fed the basal diet supplemented with bacteriocin 2.57 mL/kg and probiotics 0.84 g/kg.BP100(Bacteriocin 100%+Probiotics 100%)group was fed the basal diet supplemented with bacteriocin 5.13 mL/kg and probiotics 1.68 g/kg,BP 150(bacteriocin 150%+ probiotics 150%)group was fed the basal diet supplemented with bacteriocin 7.7 mL/kg and probiotics 2.52 g/kg.CTC50(antibiotic 50 mg/kg)group was fed the basal diet supplemented with aureomycin 50 mg/kg.The experiment was divided into the first stage(1-21 days of age)and the second stage(22-42 days of age).The experiment lasted for 42 days.The main research results are as follows:(1)The results of performance study showed that dietary probiotics and bactericin supplementation had no significant effects on performance of broilers at 1 to 24 days of age(P>0.05),but improved daily gain and feed to gain ratio of broilers at 22 to 42 days of age and 1 to 42 days of age.At 22-42 days of age,the average daily gain of BP150 and CTC50 groups was significantly higher than that of control group and BP100 group(P<0.05),and the average daily gain of BP50 and BP100 groups was also significantly higher than that of control group(P<0.05).The ratio of feed to gain in BP50,BP 150 and CTC50 groups was significantly lower than that in control group(P<0.05),and the body weight and daily gain of broilers in BP150 and CTC50 groups were significantly higher than those in control group and BP100 group at 1 to 42 days of age(P<0.05).The body weight and daily gain of BP50 and BP100 groups were significantly higher than those of control group(P<0.05).The heart weight of BP150 group was significantly higher than that of control group(P<0.05),and the liver weight of BP 100 group was significantly higher than that of control group(P<0.05).Compared with control group,the protein content in leg muscle and chest muscle of BP150 and CTC50 groups was significantly higher than that of control group(P<0.05).The cooked meat rate of BP 100 group was significantly lower than that of other groups(P<0.05).The flesh color a and b values of BP50 and BP 100 groups were significantly higher than those of control group(P<0.05).(2)The study on blood indexes showed that dietary probiotics and bacteriocin supplementation increased serum antioxidant capacity of broilers.The total antioxidant capacity of BP50 and BP100 groups was significantly higher than that of control group,BP50,BP 150 and CTC50 groups(P<0.05),and the highest antioxidant capacity of BP50 group was 12.76U/mL.Compared with the control group,the serum malondialdehyde content in BP50,BP 150 and CTC50 groups was significantly decreased(P<0.05),and the lowest in BP50 group was 3.42 nmol/mL.The content of superoxide dismutase in BP100 group reached 82.38 U/mL,which was significantly higher than that in control group by 42.28 U/mL(P<0.05).The interferon y content of chicken in BP 150 and CTC50 groups was significantly higher than that in control group,BP50 and BP 100 groups(P<0.05),and the interferon a content of chicken in CTC50 group was significantly higher than that in control group,BP50 and BP 100 group(P<0.05).The IgG content of control group was significantly lower than that of other groups(P>0.05).(3)Intestinal morphology and intestinal flora It was found that dietary probiotics and bacteriocin supplementation improved intestinal morphology and increased the number of beneficial flora.Compared with the control group,the villus height and crypt depth of duodenum in BP 100,BP 150 and CTC50 groups were significantly increased(P<0.05).Compared with the control group,the relative abundance of Firmicurium in BP 150 group was increased,while the relative abundance of Bacteroides and Proteobacteria was decreased.The abundance of euryarchaea in BP 100 group was significantly higher than that in control group and CTC50 group(P<0.05).At the genus level,the relative abundance of rumen coccus in group BP 150 was significantly higher than that in other groups(P<0.05),and the abundance of methanobelbacter in group BP100 was significantly higher than that in control group and CTC50 group(P<0.05).(4)Plasma metabolomics studies showed that a total of 741 metabolites were detected.These metabolites mainly included amino acids and their metabolites,carbohydrates and their metabolites,vitamins,etc.As substrates or intermediate metabolites,they participated in a variety of metabolism in vivo.The key metabolic pathways were significantly up-regulated including nucleotide metabolism,ketone body biosynthesis,ABC transporter,vitamin B6 metabolism,β-alanine metabolism,etc.(P<0.05),and significantly down-regulated included purine metabolic pathway(P<0.05).Bactericin combined with probiotics can promote the generation of active substance erythritol,enhance the metabolism of vitamin B6,stimulate the synthesis of pyridoxine and pantothenic acid,promote the deposition of succinic acid,slow down cell apoptosis,tissue damage,activate immunity,and improve the disease resistance of broilers.In conclusion,dietary supplementation of probiotics and bacteriocin can improve performance and serum antioxidant capacity of broilers.In addition,the addition of probiotics and bacteriocin can improve the intestinal mucosal morphology,regulate the microflora structure and promote the healthy development of the intestinal tract of broilers.It was found that probiotics(Bacillus subtilis 2.52×108cfu/g,Lactobacillus acidophilus 2.52×1010cfu/g,yeast 2.52×109cfu/g)and bacteriocin(Lactococcus Nisin7.7×106IU/g,Enterocin7.7×106IU/g)were suitable appropriate to add level.