Investigation And Study On Population Metabolic Diseases Of Intensive Dairy Cow Farms In Northeast China

Nutrient and metabolic diseases often occur in dairy cows during the perinatal period,especially for high-yielding dairy cows in intensive dairy farms,which cause huge economic losses to intensive dairy farms.The purpose of this trial is to investigate the health effects of perinatal dairy cows’ nutritional metabolism and health status,dairy cows ’fatty liver,ketosis,calcium and phosphorus metabolism disorders,and subclinical vitamin E deficiency,and to establish early warning of related diseases.The dairy farm will lay a theoretical and practical foundation for more effective monitoring and prevention of postpartum nutritional metabolic diseases in dairy cows in the future.In this study,perinatal dairy cows(n = 120)were randomly selected from six intensive dairy farms in the three eastern provinces,and basic information such as BCS scores,lactation volume,and parity were collected.Based on the principle of similar age and body parity,the test cattle were selected for tracking,and blood was collected on the day of delivery,3-7d postpartum,14-21 d postpartum,60-90 d postpartum,and dry period(3 months before delivery)The biochemical analyzer and ELISA detection method were used to detect the energy metabolism indexes in test bovine serum: glucose(GLu),triglyceride(TG),cholesterol(TC),free fatty acid(NEFA),beta hydroxybutyric acid(BHAB),minerals Substance metabolism indicators: blood calcium(Ca),blood phosphorus(P),blood magnesium(Mg),liver metabolism indicators: serum alanine aminotransferase(GGT),serum alanine aminotransferase(ALT),serum aspartic acid Transferase(AST),serum alkaline phosphatase(ALP);total protein(TP),albumin(ALB),vitamins and oxidatiVe stress indicators: vitamin(Ve),vitamin C(Vc),glutathione Oxidase(GSH-Px),superoxide dismutase(SOD).Independent sample T test,Spearman correlation analysis,binary loglstlc regression analysis,and ROC analysis were performed by SPASS biostatistics.The results of energy metabolism indicators showed that 34.7% of the cows on the day of delivery entered a negative energy balance state(BHBA≥1.2mmol/L and GLu≤5.0mmol/L),the incidence of subclinical ketosis 3-7 days after delivery was 52.4%,14 The incidence of subclinical ketosis in the 21 st day was 47.6%.The average daily milk production of cows with subclinical ketosis during the entire lactation cycle was significantly lower than that of cows without subclinical ketosis(p<0.05).The post-partum cows that entered a negative energybalance state had a BCS body condition score decreased by 0.3±0.05 at 60-90 days compared with the day of delivery.The levels of GLu and TC in cow serum on the day of delivery were significantly higher than those in the other four periods(p<0.05).The test results of the mineral metabolism indexes of the test cattle showed that the blood Ca in the perinatal cows decreased to the lowest in 3-7 days after delivery,and then gradually increased,including 3-7 days after delivery,and the difference between the day of delivery and14-21 days after delivery(p<0.05),the difference between the day of delivery and 3-7 days postpartum was significant(p<0.05);the blood P was the lowest at 3-7 days postpartum and the difference was very significant with other time periods(p<0.01),60-90 postpartum d reached the highest value);blood Mg dropped to the lowest value from 14 to 21 d postpartum,which was significantly different from other time periods(p<0.05).The results of liver metabolic indicators showed that the levels of GGT,ALT,and AST in the 60-90 d postpartum cows were significantly higher than those in other periods(p<0.05),and the overall level increased from 14-21 d to 60-90 d postpartum.And after reaching the peak of the entire perinatal period,it drops.During 60-90 d postpartum,multiple liver function indexes of dairy cows were higher than normal,but the blood levels of TP and ALB in the dairy cows tested fluctuated in several stages after delivery.The liver function of dairy cows was abnormal in all five periods.Vitamin E and C in the blood showed different changes during the five periods(p <0.05).Vitamin E reached the highest value of 633.91 ± 42.98 nmol / L during the dry period,and reached the lowest value of 528.69 ± 58.74 nmol / 14 days after delivery L.Vitamin C had the highest value of 3538.83 ± 289.42 nmol / L on the day of secretion,and reached the lowest value of 2864.41 ± 231.84 nmol / L from 60 to 90 days postpartum.Serum oxidatiVe stress indexes GSH-Px,SOD and vitamin E are significantly correlated.Through independent sample T test,Spearman correlation analysis,binary loglstlc regression analysis,and ROC analysis,it is concluded that cows with subclinical ketosis 3-7 d postpartum 24 h before childbirth have a correlation with NEFA and AST content.The warning values are: NEFA > 0.41mmol/L,AST > 75.75U/L,GSH-Px < 772.63 U/L、Zn < 44.52μg/L、BHAB > 0.63mmol/L.There was a correlation between subclinical hypocalcemia and mineral element phosphorus 3 to 7 days after delivery 24 h before delivery,and its early warningvalue was: Ca < 1.86mmol/L,P < 1.93mmol/L.Early warning indicators of vitamin E deficiency 24 hours before delivery 3-7 days after delivery: GSH-Px <607.12 U / L,CAT<8.05nnol/ mL.Conclusion: The experiment has determined the incidence of common metabolic diseases in dairy cows during the perinatal period in Northeast China,and there are disorders of energy metabolism and mineral metabolism in the postpartum period.Early warning indicators for subclinical ketosis,subclinical hypocalcemia,and vitamin E deficiency in perinatal dairy cows in intensiVe dairy farms in Northeast China have been established.