[Objective]The paper was to study the effects of xylooligosaccharide(XOS)and probiotics(PRO)and their interaction on the production performance,egg quality and intestinal short-chain fatty acids of laying hens in late...[Objective]The paper was to study the effects of xylooligosaccharide(XOS)and probiotics(PRO)and their interaction on the production performance,egg quality and intestinal short-chain fatty acids of laying hens in late laying period.[Method]A total of 36074-week-old Romain brown laying hens were randomly divided into four groups,six replicates each group and 15 chickens each replicate.The trial lasted 63 d.The laying hens in control group(CON)were fed with basal diet,and those in experimental groups were fed with the basal diets adding with 150 mg/kg XOS(XOS group),100 mg/kg probiotics(PRO group),150 mg/kg XOS+100 mg/kg probiotics(XOS-PRO group).[Result]Compared with the control group,the laying rate,daily egg production,yolk ratio,colonic acetic acid and caecal propionic acid in XOS group increased significantly(P<0.05),and the feed gain ratio decreased remarkably(P<0.05).PRO had no significant effect on the production performance and egg quality of laying hens in late laying period(P>0.05),but significantly increased colonic acetic acid(P<0.05).XOS and PRO had no interaction effect on the production performance,egg quality and intestinal short-chain fatty acids of laying hens in late laying period(P<0.05).[Conclusion]Adding XOS to the diet of laying hens in late laying period could increase the content of short-chain fatty acids in the hindgut of laying hens,and effectively improve the production performance and egg quality of laying hens in late laying period.Adding PRO to the diet did not significantly improve the production performance and egg quality of laying hens,and there was no interaction effect between XOS and PRO.展开更多
Although ge ne tic algorithm has become very famous with its global searching, parallel computi ng, better robustness, and not needing differential information during evolution .However, it also has some demerits, suc...Although ge ne tic algorithm has become very famous with its global searching, parallel computi ng, better robustness, and not needing differential information during evolution .However, it also has some demerits, such as slow convergence speed. In this pap er, based on several general theorems, an improved genetic algorithm using varia nt chromosome length and probability of crossover and mutation is proposed, and its main idea is as follows:at the beginning of evolution, our solution with sho rter length chromosome and higher probability of crossover and mutation; and at the vicinity of global optimum, with longer length chromosome and lower probabil ity of crossover and mutation. Finally, testing with some critical functions sho ws that our solution can improve the convergence speed of genetic algorithm sign ificantly, its comprehensive performance is better than that of the genetic algo rithm which only reserves the best individual.展开更多
文摘[Objective]The paper was to study the effects of xylooligosaccharide(XOS)and probiotics(PRO)and their interaction on the production performance,egg quality and intestinal short-chain fatty acids of laying hens in late laying period.[Method]A total of 36074-week-old Romain brown laying hens were randomly divided into four groups,six replicates each group and 15 chickens each replicate.The trial lasted 63 d.The laying hens in control group(CON)were fed with basal diet,and those in experimental groups were fed with the basal diets adding with 150 mg/kg XOS(XOS group),100 mg/kg probiotics(PRO group),150 mg/kg XOS+100 mg/kg probiotics(XOS-PRO group).[Result]Compared with the control group,the laying rate,daily egg production,yolk ratio,colonic acetic acid and caecal propionic acid in XOS group increased significantly(P<0.05),and the feed gain ratio decreased remarkably(P<0.05).PRO had no significant effect on the production performance and egg quality of laying hens in late laying period(P>0.05),but significantly increased colonic acetic acid(P<0.05).XOS and PRO had no interaction effect on the production performance,egg quality and intestinal short-chain fatty acids of laying hens in late laying period(P<0.05).[Conclusion]Adding XOS to the diet of laying hens in late laying period could increase the content of short-chain fatty acids in the hindgut of laying hens,and effectively improve the production performance and egg quality of laying hens in late laying period.Adding PRO to the diet did not significantly improve the production performance and egg quality of laying hens,and there was no interaction effect between XOS and PRO.
文摘Although ge ne tic algorithm has become very famous with its global searching, parallel computi ng, better robustness, and not needing differential information during evolution .However, it also has some demerits, such as slow convergence speed. In this pap er, based on several general theorems, an improved genetic algorithm using varia nt chromosome length and probability of crossover and mutation is proposed, and its main idea is as follows:at the beginning of evolution, our solution with sho rter length chromosome and higher probability of crossover and mutation; and at the vicinity of global optimum, with longer length chromosome and lower probabil ity of crossover and mutation. Finally, testing with some critical functions sho ws that our solution can improve the convergence speed of genetic algorithm sign ificantly, its comprehensive performance is better than that of the genetic algo rithm which only reserves the best individual.
