The Effects Of Lactobacillus Plantarum And Fructooligosaccharides On Antioxidant Performance In Laying Hens

In recent years,with the development of modern breeding technology and the improvement of breeding system,the elimination week of laying hens has been extended from 72 weeks to 100 weeks,and the laying period of laying hens has been extended greatly.After the peak of egg production,the egg production rate,eggshell quality and egg nutrients gradually decreased,mainly due to the decrease of nutrient absorption,the decrease of antioxidant and immune capacity,and the intensification of oxidative stress caused by aging of the body.How to improve the performance of laying hens in late laying period by means of nutritional regulation is one of the key issues that laying practitioners pay attention to.The purpose of this experiment was to study the changes of performance,egg quality,oxidative substance accumulation and tissue antioxidant capacity of laying hens of different weeks of age,to establish a oxidative stress model of laying hens in late laying period,and on the basis of this model,to study the regulatory effects and mechanisms of Lactobacillus plantarum and oligosaccharides on performance,egg quality and antioxidant capacity of laying hens in late laying period,in order to delay the aging of laying hens.Prolonging the laying cycle of laying hens provides theoretical basis.1.Study on the changes of performance and antioxidant capacity of laying hens from peak to late stage of layingA total of 135 healthy 34-week-old Hyline brown laying hens were selected and 9replicates were set with 15 hens per replicate.The experiment lasted for 48 weeks.Samples were collected at 34 weeks of age,46 weeks of age,58 weeks of age,70 weeks of age and82 weeks of age to determine egg quality,plasma markers of oxidative damage and antioxidant enzyme activities.Markers of oxidative damage and activities of antioxidant enzymes in liver,tubal dilation and uterus of laying hens at 34 weeks of age,58 weeks of age and 82 weeks of age were determined,so as to reveal the rule of antioxidant capacity increasing with week age of laying hens.The results showed as follows: with the increase of week age,the laying rate and egg weight were significantly decreased,while the egg weight and broken egg rate were significantly increased(P<0.05).The eggshell strength,yolk color,white height and Haugh unit of laying hens at 82 weeks of age were significantly lower than those at 34,46 and 58 weeks of age.The eggshell index of laying hens at 58,70 and 82 weeks of age was significantly higher than that at 34 and 46 weeks of age(P<0.05).The contents of malondialdehyde(MDA),8-hydroxy-deoxyguanine(8-OHd G)and Nitrotyrosine in plasma,liver,tubal enlargement and uterus of laying hens at 82 weeks of age were significantly higher than those of laying hens at 34 weeks of age and 58 weeks of age.The contents of superoxide dismutase(SOD)and glutathione peroxidase dismutase(GSH-Px)in plasma,tubal dilation and tubal uterus of laying hens at 58 weeks of age were significantly higher than those at 34 and 82 weeks of age(P<0.05).The content of total antioxidant capacity(T-AOC)in uterine part of tubal enlargement of laying hens at 58 and 82 weeks of age was significantly lower than that at 34 weeks of age(P<0.05).From peak laying to late laying,the performance,egg quality and antioxidant capacity of laying hens decreased.2.Effects of Lactobacillus plantarum and fructooligosaccharides on performance and egg quality of laying hens in late laying periodA total of 540 Hyline brown laying hens aged 82 weeks were randomly divided into 4groups with 9 replicates per group and 15 hens per replicate.Control group(CON)was fed a basal diet,and experimental groups were fed a basal diet supplemented with 0.1%Lactobacillus plantarum(MLP,107CFU/g),0.1% FOS,0.1% Lactobacillus plantarum +0.1%oligosaccharides,respectively.The experiment lasted for 18 weeks,and the production performance and egg quality related indexes were determined.The results showed as follows:compared with the control group,the laying rate of MLP group,FOS group and MLF group at 92 weeks to 100 weeks was significantly increased(P<0.05);The ratio of feed to egg in MLP and MLF groups was significantly decreased(P<0.05);The feed to egg ratio in 82-100 weeks MLP group was significantly decreased(P<0.05).Yolk color of laying hens in MLP,FOS and MLF groups was significantly increased(P<0.05),and there was interaction between MLP and FOS on yolk color of laying hens of 100 weeks of age(P<0.05).The Haugh unit of laying hens of 100 weeks of age was significantly increased in MLP and MLF groups(P<0.05).Lactobacillus plantarum and fructooligosaccharides can improve the laying rate and yolk color of laying hens in late laying period.3.Effects of Lactobacillus plantarum and fructooligosaccharides on antioxidant performance of laying hens in late laying periodThe antioxidant capacity of plasma,liver,tubal dilation and uterine tissues,and the expression levels of upstream and downstream genes of MAPK/Nrf2 pathway in tissues of laying hens in late laying period were determined.The results showed as follows: compared with the control group,the activities of T-AOC in plasma and SOD and T-AOC in liver of laying hens of 100 weeks of age in FOS group and MLF group were significantly increased(P<0.05).The activities of SOD,T-AOC and GSH-Px in tubal enlargement of laying hens in MLP,FOS and MLF groups were significantly increased(P<0.05),and the activities of GSH-Px in tubal uterus were significantly increased(P<0.05).There were significant interaction effects of MLP and FOS on plasma GSH-Px,content of MDA in fallopian tube uterus and activity of GSH-Px in fallopian tube dilation of laying hens at 91 weeks of age(P<0.05).Compared with the control group,the expression levels of GST in liver,Nrf2,GCLC,Keap1 and NQO1 in tubal enlargement and Keap1,GST and NQO1 in tubal uterus of laying hens of 100 weeks of age in FOS group and MLF group were significantly increased(P<0.05).The expression levels of GST in tubal enlargement and Nrf2 in tubal uterus of laying hens in MLP,FOS and MLF groups were significantly increased(P<0.05).The expression level of p-ERK in liver,tubal enlargement and tubal uterus of 100-week-old laying hens in FOS group and MLF group was significantly increased(P<0.05).The expression level of p-P38 in tubal dilation of laying hens of 100 weeks of age in MLP group and FOS group was significantly increased(P<0.05),and the expression level of p-ERk in uterine part of FOS group was significantly increased(P<0.05).These studies indicate that Lactobacillus plantarum and fructooligosaccharides can up-regulate the phosphorylation levels of P38 and ERK1/2 in the fallopian tubes of laying hens in late laying period through MAPK/Nrf2 pathway,enhance the nuclear translocation of downstream nuclear transcription factor Nrf2,and up-regulate the expression levels of antioxidant genes GST,NQO1 and GCLC.It can enhance the activities of antioxidant enzymes SOD,GSH-Px and T-AOC,alleviate the oxidative damage of oviduct caused by aging in late laying period,reduce the ratio of feed to egg,and improve yolk color and Haber unit.In summary,with the increase of week age,the oxidative stress products in blood and tissue increased,and the activity of antioxidant enzymes decreased,which led to the decrease of laying rate and egg quality of laying hens.Lactobacillus plantarum and fructooligosaccharides can alleviate oxidative damage of laying hens in late laying period through MAPK/Nrf2 pathway,and have better effects on fallopian tube of laying hens,so as to improve laying rate,yolk color and Haber unit of laying hens,and reduce feed to egg ratio.