Effects Of Lactobacillus And Yeast On Growth Performance,intestinal Health And Immunity In Broilers

A study was carried out to investigate the effects of compound lactobacillus and yeast preparation alone and in combination with virginiamycin in diets on the growth performance,slaughter performance,meat quality,intestinal morphology,bacterial enumeration,serum biochemical indices,antioxidant ability and immunity of broilers.This study could provide scientific basis for the reasonable application of this kind of probiotic to chicken diets and the substitution of antibiotic.A total of 400 one-day-old Arbor Acres male broilers were randomly allotted into 4 groups,each with 5replicates of 20 broilers.The experimental treatments were divided as follows: the control,basal diet;the antibiotic,basal diet + 30 mg/kg virginiamycin(VM30);the combination,basal diet + 15 mg/kg virginiamycin + 0.1% mg/kg compound lactobacillus and yeast preparation(VM15+LY1);the probiotic,basal diet + 0.1%mg/kg compound lactobacillus and yeast preparation(LY1).The whole experiment period was 42 days,including two phases of days 1 to 21(starter period)and 22 to 42(finisher period).The results showed as follows: 1)Average daily gain(ADG)of broilers fed VM15+LY1 and LY1 diets was significantly higher than those fed control and antibiotic diets(P<0.05),and the ratio of feed to gain(F/G)significantly decreased compared than those fed control diet aged from 22 to 42 days(P<0.05).Body weight of chicks fed VM30?VM15+LY1 and LY1 diets was significantly higher than those fed control diet aged 42 days(P<0.05),and body weight of chicks fed VM15+LY1 diet was significantly higher than those fed VM30 and LY1 diets(P<0.05).Treatments VM30 ? VM15+LY1 and LY1 exhibited significantly higher average daily gain(ADG),and treatments VM15+LY1 was higher than VM30 and LY1 diets from 1 to 42 days(P<0.05).Ratio of feed to gain(F/G)of VM15+LY1 and LY1 was lower than treatment control from 1 to 42 days(P<0.05).2)Breast muscle percentage of treatments VM30,VM15+LY1 and LY1 significantly increased compared with treatment control aged 42 days(P<0.05).What's more whole net carcass rate of treatment VM15+LY1 significantly increased compared with treatmentcontrol aged 42 days(P<0.05).3)In 45 minute after breast muscle was taken,redness of treatments VM30,VM15+LY1 and LY1 significantly increased significantly compared with treatment control(P<0.05).After 24 hours,redness of treatments LY1 significantly was higher than treatment control(P<0.05).4)Villus height in jejunum and the ratio of villus height to crypt depth in duodenum,jejunum and ileum significantly was increased(P<0.05),and crypt depth in jejunum and ileum significantly was decreased by dietary supplementation of compound lactobacillus and yeast preparation compared with control aged 21 days(P<0.05).The ratio of villus height to crypt depth in ileum of chicks fed VM15+LY1 diet significantly decreased compared with control aged 21 days(P<0.05).Villus height and the ratio of villus height to crypt depth in duodenum and jejunum of chicks fed VM15+LY1 and LY1 diets significantly increased compared with control group aged 42 days(P<0.05).5)The amount of E.coli and the ratio of lactobacillus to coliform in caecum of broilers fed VM15+LY1 and LY1 diets were higher than those fed control aged 42days(P<0.05).6)Serum total protein of treatments VM15+LY1 and LY1 significantly increased compared with treatment control aged 42 days(P<0.05).7)Malonaldehyde was significantly decreased in serum of three experiment treatments compared with control group aged 21 days.Serum glutathion peroxidase of chicks fed VM15+LY1and LY1 diets significantly was higher than those fed control aged 21 days(P<0.05).Activity of total superoxide dismutase and glutathion peroxidase of treatments VM15+LY1 and LY1 and total antioxidant capacity of treatments VM15+LY1significantly increased,and malonaldehyde significantly decreased in serum compared with treatment control aged 42 days(P<0.05).8)Spleen index of chicks fed VM15+LY1 and LY1 diets trended to improve compared with those fed control aged42 days(P>0.05).9)Ig G of treatments VM15+LY1 and LY1 significantly,and Ig A of treatment LY1 significantly increased compared with treatment contol aged 21days(P<0.05).Ig G of broilers fed VM15+LY1 and LY1 diets,Ig A and Ig M of broilers fed LY1 diets significantly were higher than those fed control aged 42 days(P<0.05).In conclusion,compound lactobacillus and yeast preparation alone or in combination with virginiamycin could significantly improve intestinalhealth,immunity and promote growth performance of broilers.