Study On The Process Of Solid State Fermented Flaxseed Cake And Its Effect On Growth Performance Of Broilers

The purpose of this study was to screen natural microbial strains that can efficiently remove cyanogenic glycosides（CGs）in flaxseed cake（FSC）,optimize the solid-state-fermentation processing of flaxseed cake and investigate the effects of solid-state-fermentation flaxseed cake（SFFSC）on the growth performance of broilers.The study consists of three experiments:Exp.1:The screening of strain for removing cyanogenic glycosidesFour strains with the ability to secreteβ-glucosidase were initially screened by the selection medium containing esculin and Fe³⁺.L4 strain was proved to be the one with the strongest ability to remove CGs,after fermenting FSC with the four strains,respectively.It was determined that L4 strain was Bacillus subtilis by morphological observation and 16S rDNA sequence analysis.Exp.2:The optimization for solid-state-fermentation processing of flaxseed cakeThe single-factor experiment was carried out to investigate the effects of time,temperature,the ratio of material to water,and inoculation amount on the removal of CGs in FSC by fermentation with the Bacillus subtilis.Based on the single-factor experiment,the L₉（3⁴）orthogonal optimization was performed about the time and other fermentation parameters.According to the optimized fermentation process,the verification test and the expansion test were performed and the content of nutrients and CGs in FSC before and after fermentation were detected.The results showed that the best process for fermenting FSC by the Bacillus subtilis was:time 72 h,temperature 39℃,the ratio of material to water1∶0.6,and inoculation amount 4%.The removal rate of CGs in FSC exceeded 90%and the content of crude protein,peptides and ether extract in FSC were significantly increased,after fermented（P<0.05）.Exp 3:Effect of SFFSC on the growth performance of broilers420 one-day-old broilers were randomly divided into 7 groups with 6 replicates per group and 10chickens per replicate.Broilers in the control group were fed the basal diet,and the others in the experimental group were fed the basic diet supplemented with 5%,10%,15%FSC or SFFSC,respectively.The experiment lasted for 42 days.The results showed as follows:1)The diet supplementated with 5%SFFSC had no significant effect on the ADG、ADFI、F/G of broilers during 1to 21 days of age（P>0.05）;10%or 15%SFFSC supplementation in the diet could very significantly reduce the ADG and increase F/G of broilers during 1 to 21 days of age（P<0.01）;the diet supplementated with 5%or 10%SFFSC had no significant effect on the ADG、ADFI、F/G of broilers during 22 to 42 days of age（P>0.05）;15%SFFSC supplementation in the diet could very significantly reduce the ADG and increase F/G of broilers during 22 to 42 days of age（P<0.01）;at the same supplementation level,the growth performance of broilers in SFFSC group was higher than that in FSC group.2)The diet supplementated with 5%or 10%SFFSC had no significant effect on dressed percentage,percentage of eviscerated yield,percentage of breast muscle,percentage of leg muscle and percentage of abdominal fat of broilers（P>0.05）;15%SFFSC supplementation in the diet could significantly reduce percentage of eviscerated yield of broilers（P<0.05）;at the same supplementation level,the slaughter performance of broilers in SFFSC group was higher than that in FSC group.3)The diet supplementated with 5%,10%or 15%SFFSC had no significant effect on the content of IgA,IgG and IgM in serum of broilers（P>0.05）;at the same supplementation level,the serum immune function of broilers in SFFSC group was higher than that in FSC group.4)The diet supplementated with 5%,10%or 15%SFFSC to the diet had no significant effects on the activity of T-SOD,the content of MDA and T-AOC in serum of broilers（P>0.05）;at the same supplementation level,the serum antioxidant function of broilers in SFFSC group was higher than that in FSC group.In summary,the solid-state fermentation could significantly reduce the adverse effects of FSC on the growth performance of broilers,the maximum amount of SFFSC added in the diet of broilers was:5%during 1 to 21 days of age and 10% during 22 to 42 days of age.