Nicotinamide Regulates Glucose And Lipid Metabolism Of Transition Dairy Andintestinal Development Of Offspring:Effects And Potential Mechanisms

The perinatal period?-21 to 21 d relative to calving?is the special physiological period for dairy.During this period,they not only experience the physiological changes of pregnancy,birth and lactation,but also suffer diet conversion,and changes of environment and management,resulting in negative energy balance and multiply metabolic disorders.In addition,the maternal nutrition metabolism during the perinatal period plays major roles in fetal development and the productive life of the animal.Biotin?BIO?is the cofactor of the rate-limiting enzyme in gluconeogenesis.Nicotinamide?NAM?,the amide form of nicotinic acid?NA?,is required for the synthesis of NAD and NADP and widely participating in oxidation-reduction reactions.Glucose and lipid metabolism is main part of energy metabolism.However,more studies are still needed for some unclear points in existed studies:the effect of BIO and NAM on glucose and lipid metabolism of transition dairy cow is unclear,wherher there are differences in nutrition strategies applied at different perinatal period and the effect of maternal effect on the development of offspring.In this study,based on the results of productive performance and glucose and lipid metabolism in perinatal dairy supplemented with BIO and NAM,we further studied the effect of NAM supplemented at different perinatal period,and the metabolomics was applied to analyzed the metabolites of blood and milk,and transcriptomics was applied to compare the key different metabolic function in the liver,hoping to specify the potential mechanism of NAM on energy metabolism in perinatal dairy and the maternal NAM function on offspring.Experiment 1 Effects of biotin and nicotinamide supplementation on productive performance and blood parameters of transition dairy cowsGlucose is very important form of energy utilized by the animal.BIO and NAM act as cofactors in hepatic gluconeogenesis.This study aimed to evaluate the effect of supplementing BIO,NAM and their interaction on feed intake,milk production,and energy metabolism of transition dairy cows.Forty multiparous Holsteins were assigned randomly within block to 1 of the following 4 treatments:control?no supplementation?,30 mg/d BIO,45 g/d NAM,and 30 mg/d BIO+45 g/d NAM.Cows were fed the same basal diet and received the supplements in drenches daily from about d-14 to 35 relative to parturition.Feed intake,energy balance and calf birth weight were not affected by BIO supplementation whereas NAM supplementation tended to increase prepartum dry matter intake and decrease body weight loss.Tendencies of BIO×NAM×week interaction were observed on energy balance during prepartum and entire period.The interaction of BIO×NAM was found on milk lactose percentage and fat yield.Supplementation of BIO resulted in increased concentration of BIO in plasma and decreased triglyceride concentration.The BIO×week interaction effects were detected for triglyceride,very-low-density lipoprotein cholesterol and low-density lipoprotein cholesterol concentrations.Supplementation of NAM increased plasma NAM and glucose while decreased nonesterified fatty acid,?-hydroxybutyric acid,triglyceride,high-density lipoprotein cholesterol and low-density lipoprotein concentrations.The BIO×NAM×week interaction effect was observed on nonesterified fatty acid concentration during entire period.Blood insulin and total cholesterol concentrations were not affected.Supplementing BIO and NAM in a combination did not show additional benefits above those observed for BIO or NAM supplementation alone for most of the variables.In conclusion,NAM could increase blood glucose and regulate lipid metabolism of transition dairy cow,and BIO supplementation did not benefit the productive performance.Experiment 2 Metabolomics for the effect of biotin and nicotinamide on transition dairy cowsBased on the result of experiment 1,the objective of this study was to evaluate alterations in serum metabolites of transition dairy cows affected by BIO and NAM and explore the relationship among metabolites and metabolisms.Forty multiparous Holsteins were paired and assigned randomly within block to 1 of the following 4 treatments:control?T₀?,30 mg/d BIO?T_B?,45 g/d NAM?T_N?,and 30 mg/d BIO+45 g/d NAM(T_B+N).Supplemental BIO and NAM were drenched to cows from 14 days before the expected calving date.GC-TOF/MS was used to analyze serum samples collected from 8 cows in every groups at 14 days after calving.As compared with T₀,all T_B,T_N and T_B+N had higher serum glucose concentrations,while nonesterified fatty acid in T_N and T_B+N and triglyceride in T_B+N were lower.ATP was significantly increased in T_B+N.Both T_N and T_B+N+N had higher glutathione and lower reactive oxygen species.Moreover,T_B significantly increased inosine and guanosine concentrations,and decreased beta-alanine,etc.Certain fatty acids concentrations?included linoleic acid,oleic acid,etc.?were significantly decreased in both T_N and T_B+N.Some amino acids derivatives(spermidine in T_N,putrescine and4-hydroxyphenylethanol in T_B+N,and guanidinosuccinic acid in both T_N and T_B+N)were affected.Correlation network analysis revealed that the metabolites altered by NAM supplementation were more complicated than by BIO supplementation.These findings showed that both BIO and NAM supplementation enhanced AA metabolism and gluconeogenesis,and NAM supplementation improved the glucose metabolism and altered biosynthesis of unsaturated fatty acids metabolism.The improved oxidative status and glutathione metabolism further indicated the effect of NAM on oxidative stress alleviation.Experiment 3 Effect of NAM supplementation at different perinatal period on productive performance and blood parameters of perinatal doesOur previous studies showed that the NAM regulation in glucose and lipid metabolism was better than the BIO in the transition dairy cow.Thus,this study was further explored the effect and mechanism of NAM.Due to the physiological and metabolic status of pre-and post perinatal is different,and the maternal nutrition have the profound influence on offspring,this study was aimed to clarify the various effect of NAM supplementation at different perinatal period,providing theoretical basis for the subsequent study of influence on offspring.The liver is an important metabolic organ in animals which plays an important role in energy and glucose and lipid metabolism.In this study,metabolomics and transcriptome methods were applied to analyze the effects of NAM on liver tissue,so as to elucidate the possible mechanism by which NAM regulated liver metabolism.Fifteen multiparous does were paired and allocated into 3 treatments:control?C?,postpartum?P,supplemented post-kidding?,and entire-perinatal?EP,supplemented from d-21 to 28 around kidding?.NAM was drenched to does at 5 g/d and at 0700 h every day.The liver tissues of does were determined by GC-TOF/MS and Illumina HiSeq 4000,and the comparison was named C_P:C,C_EP:C and C_EP:P,respectively.The results showed:?1?The DMI and lactation performance were not affected.NAM has a tendency to reduce NEFA and TG in blood,but no effect on blood glucose and TC.?2?In abdominal adipose,TG content was significantly reduced in EP,NEFA was significantly reduced in P and EP,and TC was significantly reduced with the extension of NAM supplementation.NAM has a tendency to increase the activity of adipotriacylglycerase?ATGL?and decrease the activity of DGAT2.?3?In liver,NAM significantly reduced the content of glycerol,and the activity of fatty triacylglycerase?ATGL?was increased with the NAM supplementation extension,while TG tended to decrease,and VLDL content,the activity of pyruvate kinase?PK?and phosphoglyceryl transferase 6?AGPAT6?tended to increase.Moreover,the gene expression levels of glucose transporter 2?GLUT2?and AGPAT6 in EP group were significantly increased.?4?There was no significant GO enrichment and KEGG metabolic pathway in C_P:C.The process was related to lipid metabolism,TG catabolic process,RNA metabolism,protein assembly,synthesis and localization in C_EP:C,and differentially expressed genes significantly enriched ribosomal metabolism,metabolic disease-related metabolism,oxidative phosphorylation and other energy metabolism.The results of metabolomics profiles showed that the contents of cystine,3-aminoisobutyric acid,cytidine-monophosphate,prostaglandin and diglycerol were decreased and malonamide was increased of in C_P:C.And the metabolism of pyrimidine,cysteine and methionine were enriched.In C_EP:C,the contents of d-glyceric acid,guanosine,palmitoleic acid,ciliatine,3-aminoisobutyric acid,cytidine-monophosphate,hypoxanthine,prostaglandin,malonamide,sulfuric acid,3-methylamino-1,2-propanediol were decreased,and uracil and octadecanol were increased.And the metabolism of pyrimidine,purine,sulfur,glycerides,pantothenic acid and CoA biosynthesis,and metabolism of glyoxylate acid and dicarboxylic acid,beta alanine,glycine,serine and threonine were enriched.In C_EP:P,the content of malonamide was decreased and adenine was increased,while no enriched pathway.Thus,the regulation of NAM on liver metabolism was related to lipid,amino acid and nucleotide metabolism,and NAM supplemented from prenatal benefits liver regulation of perinatal dairy does.Therefore,NAM supplementation could improve the milk antioxidant capacity,and NAM supplementation from prepartum can reduce Inflammatory cytokines and promote the transport and utilization of glucose in the liver additionally.Moreover,NAM promoted abdominal fat decomposition for energy supply,and reduced TG accumulation in the liver by improving TG decomposition and transport in the form of VLDL,thus protecting the liver health.Experiment 4 The effect of maternal NAM supplementation at different perinatal period on milk metabolites and intestinal development of kidsCombined with the results of previous studies and experiment 3,the metabolomics and transcriptome methods were applied to analyze the effects of NAM on milk metabolites profile and intestinal development of offspring,respectively,so as to elucidate the maternal effect of NAM and its potential mechanism.On the basis of experiment 3,after kidding the kids were named L_C,L_P,and L_EP,respectively,and fed milk from their mothers until d 28 of life.The milk at d 14 and jejunum mucosa of kids were used for omic-analyses using GC-TOF/MS and Illumina HiSeq 4000,respectively.The milk metabolites were compared between any two means and named C_P:C,C_EP:C and C_EP:P.NAM increased the total antioxidant capacity of milk,and EP reduced the content of iL-1?in milk.Milk glycerol was significantly decreased in both C_P:C and C_EP:C,and the citramalic acid and sucrose concentrations were elevated in C_EP:C and C_EP:P.We found that the ribose was tended to increase in C_P:C but lower in C_EP:P.Myo-inositol was elevated in C_EP:P.Glycerolipid metabolism and galactose metabolism were enriched in both C_P:C and C_EP:C,and C_EP:CP:C had an additional enriched pathway of starch and sucrose metabolism.In C_EP:P,alterations in ascorbate and aldarate metabolism,galactose metabolism,pentose phosphate pathway,and inositol phosphate metabolism were found.Jejunal mucosal transcriptome profiles showed that the biological processes of organic acid and lipid metabolism were changed,and NAM regulated vitamin metabolism,fatty acid metabolism and intestinal immune function.In addition,the NAM supplemented from pre-kidding could regulate cell metabolism and amino acid metabolism additionally.Therefore,maternal NAM can affect the intestinal digestion,absorption and development of kids,and the postpartum NAM supplementation played an important role by elicit metabolic changes of milk.NAM supplementation from pre-kidding have more benefit on intestinal function,enhancing and enriching the early intestinal functional development of kids.To sum up,this study showed that?1?the energy metabolism:the transition dairy cow supplemented with BIO and NAM could enhance gluconeogenesis,and NAM improved glucose metabolism.NAM also reduced unsaturated fatty acid biosynthesis,promoted abdominal fat decomposition to provide energy,and improved decomposition and transport in the form of VLDL of hepatic TG,thus reducing accumulation of TG in the liver.Moreover,NAM was shown to improve the milk antioxidant capacity through glutathione metabolism and relieve oxidative stress.?2?maternal nutrition:maternal NAM supplementation could benefit the intestinal digestion,absorption and development of kids through regulating milk metabolites,NAM supplementation from pre-kidding enhanced and enriched the early intestinal functional development of kids.?3?supplementation period:the application of NAM on nutritional regulation should start from prenatal.