Effects Of Probiotics On Growth,Nutrient Utilization And Intestinal Microflora In Early Growth Stage Of Layer Chickens

This experiment was conducted to investigate the growth performance,nutrient utilization and intestinal microflora of Lohmann Brown chicks in response to dietary probiotic or antibiotic.Five hundred and forty 1-day-old male chicks were randomly divided into three groups,with six replicates and 30 chicks in each replicate.The experiment was carried out over 70 days.The birds in probiotic group(group A)were fed basal diet containing probiotic mix(1 x 108 cfu Bacillus subtilis and 1×108 cfu Pediococcus acidilactici per gram).The birds in antibiotic group(group B)were fed basal diet containing zinc bacitracin premix(the contents of zinc bacitracin was 10%).And the birds in control group(group C)fed basal diet.The growth performance,intestinal development,nutrient utilization and caecal microflora were evaluated through animal feeding trial,metabolism trial and microorganism experiments.The results are shown as follows:1.Birds in the probiotic group and antibiotic group had greater body weight(BW)than the control group on day 56 and 70(P<0.05).ADG(0-70d)was increased in the probiotic and antibiotic treatment compared with the control(P<0.05),whereas was not different between the probiotic and antibiotic group during the entire experimental period(P>0.05).2.The probiotic group or antibiotic group had higher spleen weight(P<0.05)than the control,and the liver weight in the probiotic group was higher than that in control group(P<0.05)3.On day 63 the length and weight of duodenum in probiotic group or antibiotic group were higher(P<0.05)than those in control group.Compare to the control group,probiotic group had higher length and weight on day 73(P<0.05).The villus height of duodenum in probiotic group was higher than that in control group.Supplementation of probiotic could improve both villus height of ileum and V/C of ileum.4.Compare to the control group,the apparent utilization rate of CP in probiotic group(P=0.053)was improved,and the utilization rate of calcium was improved significantly(P<0.05).The apparent utilization rate of energy in antibiotic group was significantly improved(P<0.05).5.Supplementation of probiotic had improved the caecal microbial abundance and microbial diversity in probiotic group.There are more beneficial bacteria and less pathogen of cecum in probiotic group.Supplementation of antibiotic had reduced the caecal microbial abundance.There are less beneficial and pathogen of cecum in antibiaotic group.In conclusion,dietary supplementation of probiotic or antibiotic can promote the growth and development of birds in early growth stage.Adding probiotic can improve the nutrient utilization and increase the stability of structure of intestinal flora.Although supplementation of antibiotic can improve the nutrient utilization,it’s not conducive to the stability of intestinalflora.