| The antioxidant capacity of cows are closely related to their health coditions.The high producing dairy cattle are susceptible to oxidative stress which could cause diseases associated with oxidative stress.Raising the level of nutrition and monitoring the health to the cows can reduce disease and monitor disease,which is of great value.Grape seed proanthocyanidin extract(GSPE)belongs to polyphenol compounds and has a strong antioxidant properties.However,it is rarely reported as a cow feed additive.Three tests were conducted in this study.Test one:To investigate the effect of GSPE on plasma antioxidant capacity and energy metabolism in the early lactating dairy cattle.Test two:To investigate the effect of GSPE on antioxidant capacity of milk,and to evaluate its effect on dairy cows.Test three:Screening index to be as body condition index for cows from milk.Specific studies were as follows:Test one:effect of GSPE on plasma antioxidant capacity and ketosis-related indicators to the early lactating dairy cattleSixteen dairy cattle in early lactation were selected which had the similar conditions with samilar lactation days,milk yield,weight,body condition score.All of them were without clinical disease.According to the completely random design,they were divided into four groups(GO,G20,G40,G80).And each group was randomly accepted one test treat to be offered 0,20,40,and 80 mg GSPE/kgBW/day.Collecting the blood samples at the time of Oh(before filling)?3h?6h?12h?24h?48h?72h?96h?120h?144h?168h.Determination of following oxidation/antioxidant indicators,total antioxidant capacity(TAC),glutathione peroxidase(GPX),superoxide dismutase(SOD),malondialdehyde(MDA),hydrogen peroxide(H2O2).Detection of ketosis-related indicators:glucose(GLU),non-esterified fatty acid(NEFA)and ketone body(KET).Compared with GO,G20,G40,G80 had no significant effect on TAC,GPX,SOD,MDA and H2O2 in plasma oxidation(P>0.05).In the metabolic changes,the mean values of GLU in G20,G40 and G80 groups were higher than those in GO group.Feeding GSPE had a significant effect on plasma GLU at "test time ×grouping" effect(P<0.01).While G40 group was better than G20,G80.The content of NEFA in G40 was significantly higher than that in GO within the physiological concentration range(P<0.05)at "test time × grouping" effect.Feeding GSPE had no significant effect on the ketone body(P>0.05).The results showed that feeding GSPE could improve the plasma glucose level to the early lactating dairy cattle and have a positive effect on reducing the negative balance energy in early lactation.Meanwhile the dose of 40 mg GSPE/kg BW/day was better.Test two:effect of GSPE on milk antioxidant capacity and ketone content to the early lactating dairy cattle.Forty-eight cattle were chosen and divided into four groups according to the completely random design:GO,G20,G40,G80.The control group(GO)was offered original diet as a basic diet.The G20,G40 and G80 group were added 20?40?80 mg/kg BW/day GSPE in the basic diet respectively.The trial period was 42 days.GSPE groups were fed the GSPE solutions every morning.At the same time,the GO group was fed an equal dose of drinking tap water.the milk samples were collected at the time of 0 d(before GSPE doseing)?7 d?14 d?21 d?28 d?35 d?42d and whey was separated.the following indicators were determined:TAC?GPX?H2O2 and KET.Result,G40 had of was significantly higher whey GPX level than GO,and GPX activity of GSPE groups were higher than G0 during the test.In addition,whey TAC,H2O2 of GSPE groups had not significant difference with G0(P>0.05).Compared with G0,the TAC was higher and the H2O2 was lower in G40 group.From the changes of milk oxidation status,the dose of 40 mg/kg BW/day could improve the antioxidative status and was better one than others.There was no significant difference between GSPE groups and G0 in ketones(P>0.05).The result suggested GSPE had no negative effect on milk antioxidant performance,and the dose of 40 mg GSPE/kg BW/day could improve the GPX activity of milk.Test three:The content of antioxidant and ketone parameteres and their relationship between plasma and whey in dairy cows.Forty-eight cattle were collected and their samples were obtained in 7 weeks.The blood and milk samples were taken in the morning every weekend on an empty stomach of cows.At the same time,promptly preparating plasma samples and whey samples.336 samples were obtained.the following indicators were determined:TAC?GPX?H2O2 and KET.The results showed that the contents of TAC in whey and plasma were 6.89±1.96U/mL and 4.97±1.99U/mL respectively.The GPX were 38.96±18.23U/mL and 122.17 ±64.43U/mL.The H2O2were 7.78±2.97mmol/L and 16.80±5.31mmol/L.The KET were 8.54±2.56mg/dL and 3.25±1.48mg/dL.The difference between plasma and whey was extremely significant(P<0.01).There was a significant positive correlation between whey and plasma GPX(r = 0.552,P<0.01).TAC was positively correlated(r = 0.113,P<0.05)and H2O2was positively correlated(r =0.124,P<0.05).The KET was no significant correlation between whey and plasma to the healthy cattle(r = 0.052,P>0.05).Yet the KET was negatively correlated with plasma TAC(r =-0.122,P<0.05)and significant negatively correlated with plasma GPX(r =-0.326,P<0.01).The results showed that TAC,H2O2,KET in whey could be used as an index to evaluate the health status of dairy cows.GPX could be used as an evaluation index.In summary,the addition of GSPE in the diet can improve the plasma glucose level in the early-lactating dairy cattle and improve the activity of milk GPX.The dose of 40 mg GSPE/kg BW/day was better.Detection of GPX activity in whey can be used as a parameter for census,monitoring health status and body GPX levels to the dairy cattle in early lactation. |
PDF Full Text Request