Effects Of Lycopene On Oxidative Stress And Milk Composition In Ketotic Dairy Cows

In recent years,the dairy farming industry in China has gradually changed from small-scale retail farming to large-scale intensive farming,and the incidence of metabolic diseases of dairy cows in perinatal period has also increased.From late pregnancy to early lactation,dairy cows transform from dry milk to lactation.From late pregnancy to pre-lactation,dairy cows transition from dry milk to lactation.At this time,lactating dairy cows need a lot of energy supply,but the appetite is not fully restored.The body's energy is insufficient,and eventually cows are prone to negative energy balance(NEB).At this time,dairy cows start fat mobilization,resulting in nonesterified fatty acid(NEFA)and hyperketemia.It has been found that hyper NEFA can produce a large amount of reactive oxygen species(ROS)in dairy cows,and the accumulation of a large amount of ROS cause oxidative stress.After oxidative stress,the milk yield of dairy cows drops significantly,which seriously affects the healthy development of dairy industry.Therefore,improving the antioxidant capacity of dairy cows is of great value to improve the milk yield and performance of dairy cows.Lycopene has anti-oxidation,anti-inflammation,anti-cancer,reducing blood lipid and improving production performance,but it is rarely reported as feed additive for dairy cow.Five experiments were carried out in this study.For this reason,in this experiment,Holstein cows with similar age during the perinatal period were administrated with different doses of lycopene,in order to clarify the influence of lycopene on the oxidative stress state and antioxidant capacity of ketosis cows,energy metabolism level,trace elements,liver and kidney function,immunity and milk composition.In this experiment,25 perinatal Holstein cows were selected from a dairy farms in Heilongjiang Province.5 cows were healthy cows and 20 cows were ketotic.During this period,they are usually fed with a diet of 38 kg/day twice every morning and evening,without affecting their drinking water intake.5 healthy cows were selected as health control group;The remaining20 ketosis cows were randomly divided into ketosis control group(Ketosis),LYC low-dose group(LYC-L)(0.6 g/cow/day),medium-dose group(LYC-M)(1.2 g/cow/day),and high-dose group(LYC-H)(2.4 g/cow/day).5 cows in each group was fed LYC for 7 days.The test period was 168 h,and the rats were fed once every morning.Feeding method: Pour LYC powder weighed by electronic balance into a filling bottle,mix with proper amount of drinking water,and feed;On the 3rd,5th and 8th day,20 ml of blood was collected from tail vein,and the serum was separated for 10 minutes by centrifuge at 3500 rmp,and stored at-80 rmp in time.The contents and activities of BHBA,NEFA,GLU,CAT,GSH-Px,MDA,SOD,T-AOC,AST,ALT,TG,BUN,direct bilirubin,K,Ca,Mg,P,Fe,GLB,ALB,ALP,TP and CREA in blood samples were detected.Milk samples were collected on the 3rd,5th and 8th day of the experimental period,and milk fat,milk protein,somatic cells and other indexes in milk were analyzed within12 hours by milk composition analyzer.Results: 1.In lycopene group,the ability of anti-oxidative stress was enhanced and the phenomenon of oxidative stress was reduced.The indexes of T-AOC,GSH-Px,SOD and CAT in the middle and high dose groups of LYC were significantly higher than those in the ketosis group(P < 0.01),and the activities of GSH-Px and SOD in the low dose group of LYC were significantly higher than those in the ketosis group(P < 0.01);The activity of catalase was significantly higher than that of ketosis group.Compared with the ketosis group(P < 0.05);Compared with the ketosis group,the content of MDA in the low-dose,middle-dose and high-dose LYC groups was decreased significantly(P < 0.01).2.Feeding LYC can significantly reduce the contents of NEFA,BHBA and triglyceride in the blood of ketotic cows,increase the content of glutamic acid,effectively improve the neuroendocrine of ketotic cows,and enhance their metabolism.The levels of GLU in the low,medium and high dose group of LYC were significantly higher than those in the ketosis group(P<0.01);the levels of BHBA,NEFA,BUN and TG in the high dose group of LYC were significantly lower than those in the ketosis group(P <0.01),and the contents of BHBA and BUN in the LYC medium-dose group were significantly lower than those in the ketosis group(P<0.01),and the contents of NEFA and TG were significantly lower than those in the ketosis group(P <0.05);Mg in the LYC medium-high-dose group The content of Fe and Fe were also significantly higher than those of the ketosis group(P <0.01).3.Feeding LYC can reduce liver and kidney damage and improve liver and kidney function.Compared with the ketosis group,the activity of ALT and ALP and the content of direct bilirubin in the high-dose LYC group were significantly lower(P <0.01);the activity of AST and the content of CREA in the high-dose LYC group were also significantly lower than those in the ketosis group.Ketosis group(P <0.01);AST activity and CREA content in LYC medium-dose group were significantly lower than those of ketosis group(P <0.05).4.Feeding LYC can enhance the immunity of ketotic cows.The content of TP and A/G in the high-dose LYC group were significantly higher than those in the ketosis group(P <0.01);the content of ALB in the high-dose LYC group was significantly higher than that in the ketosis group(P <0.01).The middle-dose group was significantly higher than the ketosis group(P<0.05);the GLB content of the LYC middle-high-dose group was significantly lower than the ketosis group(P <0.01).5.Feeding LYC can improve milk quality.LYC In the high-dose group,the milk fat rate and F/P were significantly lower than those in the ketosis group(P <0.01);SCC was significantly lower in the high-dose LYC group compared with the ketosis group(P <0.01),and the SCC in the middle-dose group was significantly lower than that in the ketosis group(P <0.05);the content of milk protein in the high-dose LYC group was significantly higher In the control group(P <0.01).Conclusion: Feeding LYC can effectively improve ketosis,oxidative stress,antioxidant capacity,liver and kidney damage,liver and kidney function,immunity,trace elements in the body,NEB and milk quality of perinatal dairy cows.The best feeding amount is 2.4 g/cow/day.