Effects Of Soybean Oligosaccharides On Growth,Immune,Skatole Concentration In Excreta And Cecal Microflora Structure In Broilers

Soybean oligosaccharides are produced from soybean and its processed by-products such as soybean meal,soybean molasses and soybean whey.The main ingredients are stachyose,gossypol and sucrose.The aim of this experiment was to study the effects of different levels of soybean oligosaccharides on growth performance,immune function,excrement skatole concentration and cecal microflora structure in 0?42 days broilers.Three hundred and sixty one-day-old broilers were randomly distributed into 6 treatment groups with 6 replicates per treatment and each replicate consisting of 10 broilers,respectively.The control group was fed with basal diet(containing 40 mg/kg of chlortetracycline),and the negative control group was fed with basal diet(without antibiotics).The test group added 0.5 g/kg,2.0 g/kg,3.5 g/kg and 5.0 g/kg to soybean oligosaccharides on the basis of negative control group.The experiment lasted for 42 days,divided into 0?21 days and 22?42 days,two stages.Feeding trial period,recording daily feed intake and mortality,and weighing the 0,21 and 42 sky abdomen respectively,and collecting blood samples,excreta and cecal content at the end of the test,measuring serum immune index,high performance liquid chromatography to determine excretory skatole and other related index concentration,and based on Illumina MiSeq second generation.A high throughput sequencing platform was used to determine the structure of the cecal.The results of the test are as follows:(1)Growth performance: compared with the negative control group,soybean oligosaccharides with 2.0 g/kg,3.5 g/kg and 5.0 g/kg increased the average daily feed intake(P<0.05)of 0?21 days broilers,and the average daily weight gain(P<0.05)of the 22?42 days broilers except 0.5 g/kg soybean oligosaccharides(P<0.05);the control group,3.5 g/kg and5.0 g/kg soybean oligosaccharides groups significantly increased the average daily weight gain(P<0.05)of 0?42 days broilers,while the control group and soybean oligosaccharides groups significantly decreased the weight ratio of 22?42 days broilers(P<0.05).(2)Immune function: except the control group and the addition of 0.5 g/kg soybean oligosaccharides group,the other groups significantly increased the serum complement content(P<0.05)of 42 days broilers compared with the negative control group,and the content of serum lysozyme of 42 days broilers was significantly increased by adding 3.5 g/kg and 5.0 g/kg soybean oligosaccharides(P<0.01).Compared with the control group,the difference was significant(P<0.05).(3)Excrement skatole and organic acid concentration: compared with the negative control group,the content of formic acid(P<0.01)was significantly increased by adding 3.5g/kg and 5.0 g/kg soybean oligosaccharides,and 3.5 g/kg soybean oligosaccharides groups significantly reduced the excreta pH value of broilers(P<0.05),and significantly increased the content of acetic acid in the discharge of broilers(P<0.01).Except for 0.5 g/kg soybean oligosaccharides group,the other groups significantly reduced the content of indole(P<0.05)in the excrement of broilers,while the control group and the soybean oligosaccharides groupssignificantly reduced the concentration of the excrement skatole of the broilers(P<0.01).(4)The structure of the cecal microflora: there was no significant effect of soybean oligosaccharides on the level of bacteria in the cecal gate of broilers(P>0.05).The main dominant bacteria were Bacteroidetes and Firmicutes.At the level of the genus,the addition of soybean oligosaccharides significantly affected the cecal Bacteroides and Ruminococcus in broilers(P<0.05).The proportion of Escherichia was not significant in each treatment groups(P>0.05).Indicating that adding soybean oligosaccharides could produce a similar result to the positive control group in the effect of the cecum.In conclusion,under the conditions of this experiment,adding soybean oligosaccharides can improve the growth performance of broilers,improve the immune function,significantly reduce the concentration of the spice of broilers,And optimize the structure of the cecal.The recommended addition amount of soybean oligosaccharides is 3.5 to 5.0 g/kg.