| Lymphocyte apoptosis is an important mechanism to maintain the stabilization of internal environment and immunity system.Apoptosis can cause autoimmune disease when it was excessive or insufficient.There are many factors that can induce cell apoptosis,usually research focuses on external environment or artificial add material to its influence.For the cell apoptosis rule of cows itself has few reported,and there is no founding that focus on the effect of lactation stage and milk production level on cell apoptosis.The purposes of this experiment is to find the difference of lymphocyte apoptosis rate in different milk yield and lactation stage.It has been reported that the lymphocyte apoptosis rate of dairy cows will increase enormously when they suffering heat stress in high temperature summer.This study designed 9 kinds of dairy rations with different energy levels,energy resources,and adding dose of rumen protected amino acids feding dairy cows to find the difference influence between rations on dairy cows.In order to find a way to decrease the lymphocyte apoptosis rate.The study includes several experiments as follows:Experiment 1: This study selected 48 heads of dairy cows,and divided into 6 groups.Among this 6 teams,we defined them as Peak Lactation and High Yield(PLHY),Peak Lactation and Low Yield(PLLY),Middle Lactation and High Yield(MLHY),Middle Lactation and Low Yield(MLLY),End Lactation and High Yield(ELHY),End Lactation and Low Yield(ELLY)according to their milk yield and lactation stage.The caudal vein blood of dairy cows was collected and detected for lymphocyte apoptosis rate using Flow Cytometry.It turns out that(1)lymphocyte apoptosis rate of team PLHY is extremely higher than team PLLY(P<0.01);(2)lymphocyte apoptosis rate of team MLHY is extremely higher than team MLLY(P<0.01);(3)there is no difference between ELHY and ELLY;(4)when take into account all the high yield team and low yield team,it turns out that the higher yield leads to higher lymphocyte apoptosis rate(P<0.05);(5)lymphocyte apoptosis rate of end of lactation is higher than the peak lactation(P<0.05).Experiment 2: This study selected 72 heads of dairy cows,and divided randomly into 9 teams according to their yield,weight,age,lactation stage after paired treatment.The L9(34)orthogonal experiment design was chosen,and energy levels,type of carbohydrates,adding dose of rumen protected amino acids were chose as there experimental factors to design 9 kinds of dairy cows rations.The caudal vein blood of dairy cow was collected and detected for lymphocyte apoptosis rate 30 days after feeding this 9 kinds of rations.The result shows that,(1)energy levels can significantly affected lymphocyte apoptosis rate;and(2)lymphocyte apoptosis rate will decline when energy level increases;(3)there is no difference effect between carbohydrates resource,and(4)when adding 10g/d.head and 30g/d.head separately of Met and Lys will achieve a better effect on reducing lymphocyte apoptosis.Experiment 3: This study selected 72 heads of dairy cows,and divided randomly into 9 teams according to their yield,weight,age,lactation stage after paired treatment.The L9(34)orthogonal experiment design was chosen,and energy levels,type of carbohydrates,adding dose of rumen protected amino acids were chose as there experimental factors to design 9 kinds of dairy cows rations.The caudal vein blood of dairy cow was collected,and the gene expression quantity of lymphocyte apoptosis related was detected 30 days after feeding this 9 kinds of rations.The result shows that,(1)expression quantity of Bcl-2 gene will rise when energy level increases,while the expression quantity of P53 gene decline;(2)expression quantity of Bcl-2 is ease affected by rumen protected amino acids,and expression quantity of Bcl-2 is highest when adding 10g/d.head and 30g/d.head separately of Met and Lys;(3)expression quantity of Bax gene and P53 gene will decline when the dose comes high. |
PDF Full Text Request