Effects Of Prepartum Exercise On Plasma Metabolites Of The Transition Dairy Cow-Based On Metabolomics

The health of dairy cow during the transition period contributes to the fertility,milk production.But the parturition stress and substantial metabolic changes during the transition from late pregnancy to early lactation do extremely easy cause metabolic diseases.Exercise as a safe and reliable method which have the functions of immune and endocrine regulation,have been used in the prevention and adjuvant therapy of many metabolic diseases.Prepartum exercise has been demonstrated that can reduce the metabolic disorder,increase dry matter intake,decrease the incidence of difficult labor and accelerate the discharge of the placenta,etc.However,the mechanism of how the prepartum exercise is involved in regulating plasma metabolites in dairy cow is unclear.Therefore,in order to clarify the metabolic influence of prepartum exercise on dairy cow and obtain the dynamic information of the metabolic regulation during the transition period,and furthermore to provide a theory basis for improving the health of the transition dairy cow,the following experiments were carried out in this study:1.24 healthy Holstein dairy cow with the similar age,body condition scores,parity,and due date were selected,and were randomly divided into two groups which defined as test group?T group?and control group?C group?.The test group was treatet with exercise for a targeted speed below 3 km/h at 9:00 and 16:00,respectively.And an extra 4±0.2 km/d amount of exercise than C group.Samples were collected from tail vein at 21 d and 7 d prepartum,calving day,and 7 d and 30 d postpartum anticoagulating with Sodium heparin,then centrifugated and preserved the plasma.The plasma energy metabolic biomarker of NEFA,BHBA and Glu,lipids metabolic biomarker of TG,CHOL,and protein metabolic biomarker of UREA and CREA were detected.The results showed that the test group have lower level of NEFA and BHBA?0.1<P<0.05?,and the levels of NEFA have a significant difference at-7 d between control group?P<0.05?.The Glu levels of T group were more smoothly changed and have a significant difference at 0 d?P<0.05?and significant difference at+30 d?P<0.05?compared with C group.The levels of TG extremely highly at+30 d?P<0.01?compared with C group while BUN and CREA levels have no significant difference.The results indicated that prepartum exercises for a targeted1 h/d at below 3 km/h can benefit to decrease plasma NEFA and BHBA levels.2.Based on the results of Experiment 1,the plasma metabolites were detected by UHPLC-Q/TOF-MS untargeted metabolomics at-7 d,0 d,+7 d,+30 d between T group and C group.And the differential metabolites were screened by Multivariate statistical analysis PCA,PLS-DA and OPLS-DA combined with univariate analysis t test.The results showed that there were total 74 identified differential metabolites at 4points in time.Compared T with C,45 metabolites contain 28 up-regulated and 15down-regulated at-7 d while 40 identified metabolites contain 21 up-regulated and 19down-regulated at 0 d.And 12 and 31 up-regulated metabolites were identified at+7 d and+30 d,respectively.Moreover,17 and 12 down-regulated identified differential metabolites were detected at+7 and+30 d,respectively.These identified differential metabolites contain amino acid and its derivatives?L-Leucine,L-Valine,L-Phenylalanine and?-ketoisovaleric acid,etc.?,lipids?Oleic Acid,Palmitic acid and cis-9-palmitoleic acid,etc.?and Vitamin and its derivatives?Vit D₃,?-Tocopherol,and 4-Pyridoxic acid,etc.?,etc.were mainly involved in amino acids and lipids metabolism.Conclusion:?1?Prepartum exercise can reduce the plasma NEFA and BHBA levels effectively and decrease the adverse effects of negative energy balance during the transition period.?2?Prepartum exercise can regulate the metabolic pathway of amino acids and lipids during the transition period,and decrease the burden of lipids metabolism,but the mechanism behaves differently at different physiological stages.