Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may impro...Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.展开更多
Objective To establish allergic airway inflammation model in late-phase airway reaction of Sprague-Dawley (SD) rats. Methods Thirty-six SD rats were randomly divided into three groups-, control group (Group Ⅰ) ,singl...Objective To establish allergic airway inflammation model in late-phase airway reaction of Sprague-Dawley (SD) rats. Methods Thirty-six SD rats were randomly divided into three groups-, control group (Group Ⅰ) ,single challenge group (Group Ⅱ ),consecutive challenge group (Group Ⅲ). The rats in Group Ⅱ and Group Ⅲ were sensitized twice by injection of ovalbumin (OA) together with aluminum hydroxide and Bordetella pertussis as adjuvants, followed by challenge with aerosolized OA for 20 min once in Group Ⅱ or one time on each day for one week in, Group Ⅲ. The rats in Group Ⅰ received 0. 9% saline by injection and inhalation. Results Compared with group Ⅰ , there were positive symptoms observed in the group Ⅱ and group Ⅲ; the amount of total leucocytes and eosinophil percentage in brochoalveolar lavage fluid (BALF) significantly increased (P<0.05 or P<0. 01 respectively) in Group Ⅱ or Ⅲ ; histopathologic changes of lung showed acute allergic inflammation changes in Group Ⅱ: Disrupted epithelium damaged subepithelial structure and eosinophil infiltration in the airway wall. As for the Group Ⅲ, there were allergen- induced characteristic features of chronic allergic airways inflammation: hypertrophy and hyperplasia of bronchial smooth muscle, goblet cell hyperplasia, basement membrane thickening, eosinophil in filtration, edema. Conclusion The model of allergic airway inflammation in late-phase response of SD rats was successfully established by OA sensitization (twice) and consecutive challenge.展开更多
随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法...随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法与改进的早-晚功率锁相环(phase-locked loop,PLL)结合,不仅简化了锁相环结构,更保证了测距精度;同时搭建了基于5G机会信号定位的原理样机,并对改进算法方法的有效性和可行性进行了验证,试验结果表明伪距均方误差为3.03 m。本文所提出的算法不仅结构简单、系统稳定,而且在测距精度上也有一定的优势。展开更多
Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance...Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance and quality in late-phase laying hens.This study was aimed to investigate the potential effects of EO on production performance,egg quality,intestinal health and ileal microbiota of hens in the late phase of production.A total of 28860-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet(control)or basal diets supplemented with oregano EO at 100,200 and 400 mg/kg(EO100,EO200 and EO400).Results:Dietary EO supplementation resulted in a quadratic decrease(P<0.05)in feed conversion ratio with lower(P<0.05)feed conversion ratio in EO200 group than the control during weeks 9–12 and 1–12 of the trial.Compared to the control,EO addition resulted in higher(P<0.05)eggshell thickness at the end of week.4,8 and 12 and higher(P<0.05)chymotrypsin activity.There was a quadratic elevation(P<0.05)in ileal chymotrypsin and lipase activity,along with a linear increase in villus height to crypt depth ratio.Quadratic declines(P<0.05)in mRNA expression of IL-1β,TNF-α,IFN-γ and TLR-4,concurrent with a linear and quadratic increase(P<0.05)in ZO-1 expression were identified in the ileum with EO addition.These favorable effects were maximized at medium dosage(200 mg/kg)of EO addition and intestinal microbial composition in the control and EO200 groups were assessed.Dietary EO addition increased(P<0.05)the abundances of Burkholderiales,Actinobacteria,Bifidobacteriales,Enterococcaceae and Bacillaceae,whereas decreased Shigella abundance in the ileum.Conclusions:Dietary EO addition could enhance digestive enzyme activity,improve gut morphology,epithelial barrier functions and modulate mucosal immune status by altering microbial composition,thus favoring feed efficiency and eggshell quality of late-phase laying hens.展开更多
基金supported by China Agriculture Research System(No.CARS-40-S25)National Key R&D Program of China(No.2022YFD1601905)+1 种基金the Industrial Innovation Talent Project of the“Xing Dian Talent Support Program”of Yunnan Province in 2022(XDYC-CYCX-2022–0029)the Young Talent Project of the“Xing Dian Talent Support Program”of Yunnan Province in 2023。
文摘Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.
基金Supported by the Natural Science Foundation of Jiangsu Province(BK2001160)
文摘Objective To establish allergic airway inflammation model in late-phase airway reaction of Sprague-Dawley (SD) rats. Methods Thirty-six SD rats were randomly divided into three groups-, control group (Group Ⅰ) ,single challenge group (Group Ⅱ ),consecutive challenge group (Group Ⅲ). The rats in Group Ⅱ and Group Ⅲ were sensitized twice by injection of ovalbumin (OA) together with aluminum hydroxide and Bordetella pertussis as adjuvants, followed by challenge with aerosolized OA for 20 min once in Group Ⅱ or one time on each day for one week in, Group Ⅲ. The rats in Group Ⅰ received 0. 9% saline by injection and inhalation. Results Compared with group Ⅰ , there were positive symptoms observed in the group Ⅱ and group Ⅲ; the amount of total leucocytes and eosinophil percentage in brochoalveolar lavage fluid (BALF) significantly increased (P<0.05 or P<0. 01 respectively) in Group Ⅱ or Ⅲ ; histopathologic changes of lung showed acute allergic inflammation changes in Group Ⅱ: Disrupted epithelium damaged subepithelial structure and eosinophil infiltration in the airway wall. As for the Group Ⅲ, there were allergen- induced characteristic features of chronic allergic airways inflammation: hypertrophy and hyperplasia of bronchial smooth muscle, goblet cell hyperplasia, basement membrane thickening, eosinophil in filtration, edema. Conclusion The model of allergic airway inflammation in late-phase response of SD rats was successfully established by OA sensitization (twice) and consecutive challenge.
文摘随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法与改进的早-晚功率锁相环(phase-locked loop,PLL)结合,不仅简化了锁相环结构,更保证了测距精度;同时搭建了基于5G机会信号定位的原理样机,并对改进算法方法的有效性和可行性进行了验证,试验结果表明伪距均方误差为3.03 m。本文所提出的算法不仅结构简单、系统稳定,而且在测距精度上也有一定的优势。
基金supported by Shandong Key Science and Technology Innovation Program(2019JZZY010704)China Agriculture Research System(CARS-40-K12)+1 种基金Beijing Innovation Consortium of Agriculture Research System(BAIC04-2020)Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences.
文摘Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance and quality in late-phase laying hens.This study was aimed to investigate the potential effects of EO on production performance,egg quality,intestinal health and ileal microbiota of hens in the late phase of production.A total of 28860-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet(control)or basal diets supplemented with oregano EO at 100,200 and 400 mg/kg(EO100,EO200 and EO400).Results:Dietary EO supplementation resulted in a quadratic decrease(P<0.05)in feed conversion ratio with lower(P<0.05)feed conversion ratio in EO200 group than the control during weeks 9–12 and 1–12 of the trial.Compared to the control,EO addition resulted in higher(P<0.05)eggshell thickness at the end of week.4,8 and 12 and higher(P<0.05)chymotrypsin activity.There was a quadratic elevation(P<0.05)in ileal chymotrypsin and lipase activity,along with a linear increase in villus height to crypt depth ratio.Quadratic declines(P<0.05)in mRNA expression of IL-1β,TNF-α,IFN-γ and TLR-4,concurrent with a linear and quadratic increase(P<0.05)in ZO-1 expression were identified in the ileum with EO addition.These favorable effects were maximized at medium dosage(200 mg/kg)of EO addition and intestinal microbial composition in the control and EO200 groups were assessed.Dietary EO addition increased(P<0.05)the abundances of Burkholderiales,Actinobacteria,Bifidobacteriales,Enterococcaceae and Bacillaceae,whereas decreased Shigella abundance in the ileum.Conclusions:Dietary EO addition could enhance digestive enzyme activity,improve gut morphology,epithelial barrier functions and modulate mucosal immune status by altering microbial composition,thus favoring feed efficiency and eggshell quality of late-phase laying hens.
