| Ketosis is a nutritional metabolic disease with high incidence in perinatal cows.It seriously threatens the health of cows and the economic benefits of pasture,by inducing fatty liver disease,uteritis,fetal lamination and other diseases,increasing the elimination rate and costs for treating and leading to the decrease of milk yield and milk quality of cows,although the mortality rate is not high.It always leads to different degrees of liver damage in cows suffering from ketosis,and also other liver abnormalities.Monoammonium glycyrrhizin can protects the liver from inflammatory and oxidation.In this study,the changes of productivity and serum biochemical in perinatal cows were monitored to define the clinical characteristics of subclinical ketosis,and the effect of monoammonium glycyrrhizate on steatosis of liver cells and the preventive effect on ketosis were discussed,which provided theoretical basis for clinical application.1:The inflouences of subclinical ketosis on productivities and blood biochemical indexes of peripartum dairy cows.The subjects of the resarch were forty perinatal Holstein cows with similar body condition and parity.Venous blood was collected from tail at 21d,14d and 7 d before birth,13d,5d,7d,14d and 21d after birth,respectively.According to the level of BHBA in blood,the forty cows were divided into subclinical ketosis group(SCK)and healthy group,comparing the changes of productivity and blood indexes in the two groups at different time.The results showed that there was no significant difference in lactation yield between two groups within 8 weeks postpartum,then the milk fat percentage in SCK group were significantly higher than those in healthy group.The somatic cell number and urea nitrogen content in SCK group were higher than those in control group,but the differences were not significant.The milk protein percentage in SCK group was lower than that in control group(P>0.05).The body condition score of SCK group was lower than that of control group in 1 to 3 weeks postpartum(P>0.05).Serum BHBA and NEFA contents in both groups increased one week before the birth,but significantly higher in SCK group after the birth,while serum Glu level was lower than control group(P<0.05).To some extent,Serum liver function,renal function,metabolic hormone,antioxidant,inflammation and other related indexes of SCK group were changed,but there was no significant difference between SCK and healthy group(P>0.05).The results indicated that there is high incidence of outbreaking subclinical ketosis in three weeks postpartum.The cotents of Serum BHBA and NEFA could be used as the basis for the diagnosis of subclinical ketosis,and the somatic cell number and milk protein content are affected by ketosis.2:Protective effect of monoammonium glycyrrhizin on hepatic steatosis of dairy cow in vitro.According to different processing,the original generation of calf liver cells were divided into several groups,control group(with no treating),model group(the hepatocytes induced by 0.25 mmol/L sodium oleate were cultured for 9 h to establish the steatosis model in vitro),the MAG group(pretreat the liver cells with 0.1,0.25,0.5,1,5 mm/l ammonium glycyrrhetate 12h before sodium oleic acid induced as Preliminary protection).The results showed that comparing with the control group,the group induced by sodium oleate could accumulate a large number of lipid droplets in the liver cells,the cell activity reduced and the apoptosis rate increased,and the levels of ALT and AST in the supernatant of cell culture were significantly increased(P<0.05).MDA and LDH,the indexes of cell oxidation in model group were significantly higher than those in control group(P<0.05),and GSH and CAT,the antioxidant indexes in model group were significantly lower than those in control group(P<0.05).The expression of lipid synthesis gene SREBP-1c and the transcription levels of lipid transport and metabolism genes PPAR?,MTP,CPT1 and CPT2 in model group were significantly higher than those in control group(P<0.05).The transcription of inflammation-related genes TLR4,MyD88,TNF-?,IL-1?,NF-?B and IL-6 in model group were significantly higher than those in control group(P<0.05),and the protein expression of TLR4,NF ?B and IL-6 in model group were significantly higher than those in control group(P<0.05).The transcription and protein expression levels of apoptosis-related genes Cyt-c,caspase9,caspase8,caspase3 and Bax in model group were significantly higher than those in control group(P<0.05),and the transcription and protein expression levels of Bcl-2 were significantly lower than those in control group(P<0.05).Comparing with the model,MAG pretreatement could improve the activity of hepatocytes,reduce the accumulation of intracellular fat,and significantly reduce the activities of ALT and AST in the supernatant(P<0.05).The levels of MDA and LDH in MAG group were significantly lower than those in model group(P<0.05),and GSH and CAT in MAG group were significantly higher than those in model group(P<0.05).The transcription of lipid synthesis gene SREBP-lc in MAG group was significantly lower than that in model group(P<0.05),and which of ChREBP was not significantly different(P>0.05).The transcription of lipid transport and metabolism genes PPAR?,MTP,CPT1 and CPT2 in MAG group were significantly higher than that in model group(P<0.05).The transcription of inflammation-related genes TLR4,MyD88,TNF-?,IL-1?,NF-?B and IL-6 in MAG group were significantly lower than those in model group(P<0.05),and the protein expression of TLR4,NF-?B and IL-6 in MAG group were significantly lower than those in model group(P<0.05).The transcription and protein expression of apoptosis-related genes Cyt-c,caspase9,caspase8,caspase3 and Bax in MAG group were significantly lower than those in model group(P<0.05),and the transcription and protein expression of Bcl-2 were significantly higher than those in model group(P<0.05).3.Effects of Monoammonium Glycyrrhizin on productivity and Serum Biochemical Indices of Perinatal Dairy Cows.Forty-five perinatal Holstein cows with similar body condition and parity were randomly divided into 3 groups,control group,3 g with MAG and 6 g with MAG.MAG was added into the diet,and the experiment lasted from 21 d before the birth to 21 d after the birth.Venous blood was collected from tail at 21d,14d and 7 d before birth,and 1d,3d,5d,7d,14d,21 d after birth,to testing the serum biochemical index.The changes of body condition scores and the incidence of common nutritional metabolic diseases were recorded in different groups during the experiment,and also the changes of milk yield and milk composition of postpartum on day 60th.The results showed that the body condition and milk yield were not affected by MAG during perinatal period(P>0.05),but the contents of milk fat and milk protein in group 3g with MAG were significantly increased(P<0.05),and the incidence of common postpartum diseases in MAG group was lower than that in the control group comparing the control group.Comparing with the control group,the contents of NEFA and LDL-C in postpartum serum in MAG group were significantly decreased(P<0.05),and which of glucose in serum were significantly increased(P<0.05),but there were no significant differences in the contents of GC,LEP and INS in serum(P>0.05).The activities of serum ALT and AST were decreased,and the contents of serum TP and GLB were increased in MAG group(P<0.05),but the indexes related to serum renal function had no significant changes(P>0.05).Group 3g with MAGsignificantly increased the level of serum Ca in postpartum cows(P<0.05),and group 6 g with MAG significantly increased the level of serum P in postpartum cows(P<0.05).MAG could decrease the contents of MDA and NO in serum,and increase the activities of GSH-Px,SOD,CAT and T-AOC in serum(P<0.05).MAG could decrease the levels of IL-1,IL-12 and IL-6 in serum and increase the level of IL-2 in perinatal cows,but had no significant effects on the contents of IgG,IgM and IgA in serum(P>0.05),but the level of IgG in group 3g with MAG was significantly lower than that in group 6g(P<0.05).These results indicate that MAG supplementation in the diet of perinatal dairy cows can improve the performance of dairy cows,reduce the level of serum lipid metabolism related indexes,improve the antioxidant capacity,improve the metabolic status of the body,and thus reduce the incidence of postpartum diseases. |
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