| The study used Rhodococcus erythropolis,Lactobacillus casei,Lactobacillus bulgari-cus strains mixed solid-state fermentation cottonseed meal and explore free gossypol(FG)the optimum fermentation conditions for fermentation of cottonseed meal.We made a pro-portion of 0%(control group),6%(test group 2)and 9%(test 3 group)and 12%(test group 4)with the optimal fermentation conditions to substitute the soybean meal feeding 28 week old Hyline Brown laying hens,and set the 6%of common cottonseed meal to replace soyb-bean meal as the test group 1.To explore the significant of fermented cottonseed meal to hens growth,egg quality,serum biochemical indices,immune organ index and intestinal than cashmere,we maked a comprehensive evaluation the laying hens feeding effection of the fermentation of cottonseed meal.The results are as follows:Study One:the research about the technological parameters of cottonseed meal by solid state fermentation with mixed bacteria.Observed Rhodococcus eiythropolis,Lactobacillus casei and Lactobacillus bulgaricus growing in LB culture medium and gossypol culture medium by scanning electron micro-scope and transmission electron microscope(TEM).The results showed that gossypol cou-ld inhibit the growth of bacteria and damage the cell membrane of the strains.The growth curve was drawn by the independent culture of Rhodococcus erythropolis,Lactobacillus casei and Lactobacillus bulgaricus.According to the growth curve,the 20 h was selected as the transition stage.The three strains were inoculated into cottonseed meal with a 20%inoculation amount under the condition of pH 6.0,30?,material and water ratio of 1:0.5 and 3 days.The resu-lts showed that the inoculation proportion of Rhodococcus eiythropolis,Lactobacillus cas-ei and Lactobacillus bulgaricus was 1:2:2,the degradation rate of free gossypol was the hi-ghest and reached 81.6%.Rhodococcus erythropolis,Lactobacillus casei and Lactobacillus bulgaricus was ino-culated 20%with an inoculation proportion of 1:2:2 to ferment cottonseed meal at the con-dition of different pH,temperature,the ratio of material to water and the time.The results showed that the fermentation conditions was that pH 5.0,30?,material water ratio of 1:0.5 and 8 days,the content of free gossypol was degradated from 655.1 mg/kg to 103.4 mg/kg.After the optimal fermentation,the content of crude protein increased 23.56%,crude fiber and crude fat content than before fermentation reduced 23.02%and 8.69%,respecti-vely,crude ash without significant changes.It is suggested that the fermentation can remo-ve the anti-nutritional factors and improve the nutritional quality of cottonseed meal.Study Two:the research about the effect of feeding laying hens with fermented cottonseed meal.Effect of the fermented cottonseed meal for laying hens on growth performance:the results showed that the diets adding the unfermented cottonseed meal had decreased sign-ificantly on production performance of laying hens(P<0.05),the diets adding different proportion of the fermented cottonseed meal to substitute the soybean meal had no signi-ficant differences on production performance of laying hens(P>0.05),so the best alter-native is appropriate ratio of 6%.Effect of fermented cottonseed meal on egg quality:the results showed that the diets adding unfermented cottonseed meal had decreased significantly on egg quality(P<0.05),the diets adding different proportion of fermentated cottonseed meal to substitute the soy-bean meal had no significant effect on egg quality(P>0.05),so the best alternative is app-ropriate ratio of 6%.Effect of fermented cottonseed meal on serum biochemical indexes of laying hens:the test results showed that the diets adding unfermented cottonseed meal had decreased signi-ficantly on serum biochemical indexes of laying hens(P<0.05),the diets adding different proportion of fermentated cottonseed meal to substitute the soybean meal had no significa-nt effect on serum biochemical indexes of laying hens(P>0.05),so the best alternative is appropriate ratio of 6%.Effect of fermented cottonseed meal on immune organ index in laying hens:the test re-sults showed that the diets adding unfermented cottonseed meal had decreased significantl-y on the thymus,spleen and liver(P<0.05),the diets adding different proportion of ferme-ntated cottonseed meal to substitute the soybean meal had no significant effect on the thy-mus,spleen and liver(P>0.05),but with increase of addition amount,the differences gradually produced.The influence of fermented cottonseed meal on villus height and crypt depth ratio of laying hens:the results showed that the laying hens fed the diets adding unfermented cottonseed meal,the villus height and crypt depth ratio of duodenum,ileum and jejunum decreased significantly(P<0.05),however,the laying hens fed the diets adding different proportion of fennentated cottonseed meal,the villus height and crypt depth ratio of duodenum,ileum and jejunum increased significantly(P<0.05).Comprehensive analysis,the best alternative was appropriate ratio of 6%of fermentated cottonseed meal to substitute the soybean meal on feeding laying hens. |
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