Effects Of Compound Bacteria Agent On Milking Performance,Blood Indexes And Rumen Fermentation In Dairy Cows

The purpose of this study was to investigate the effects of the ethanol extracts of Clostridium butyricum,Bacillus subtilis,Lactobacillus,yeast,Bifidobacterium,Bacillus licheniformis,Streptococcus faecalis and Enterococcus faecium mixed in equal proportion on biochemical,immune,antioxidant and hormone indexes in serum of Holstein dairy cows.A blank control experiment was conducted.Twenty-eight Holstein cows with similar parity,lactation amount and body condition in the middle lactation period were selected and randomly divided into control group and experimental group,with 14 replicates in each group and one cow in each replicate.The control group was fed with TMR,and the treatment group was fed with TMR+compound bacteria（400 g/head·day）.The experiment lasted for 60 days,including 15 days of pre-feeding period and 45 days of feeding period.Milk production was recorded every day during the positive feeding period,and feed intake was measured every 15days for five consecutive days.Blood and milk samples were collected,rumen fluid was collected at the end of the experiment.The dry matter intake,milk composition,milk yield,immunity,antioxidant,hormone and rumen fermentation indexes were measured.The results are as follow:（1）The addition of compound microbial agents in diets had no significant effect on dry matter intake,milk yield and milk composition of dairy cows（P>0.05）,but the somatic cell count in milk composition of the experimental group at the positive feeding stage was significantly lower than that of the control group at 30 d（P<0.05）.（2）The blood glucose concentration of dairy cows was significantly lower than that of the control group at 45 d after the addition of compound microbial agents in the diet（P<0.05）.BUN in the experimental group was higher than that in the control group at 15 d,and the difference was extremely significant（P<0.01）.The concentration of Ig G in the experimental group was significantly lower than that in the control group at 30 d（P<0.05）.s CD3 level in the experimental group was significantly higher than that in the control group at 30 d（P<0.05）.IL-1βconcentration in the experimental group was significantly lower than that in the control group（P<0.01）.The concentration of IL-4 in the experimental group was higher than that in the control group at 30 d（P<0.01）.The concentration of IL-6 in the experimental group was significantly higher than that in the control group at 30 d（P<0.05）,significantly lower than that in the control group at 15 d（P<0.05）,and significantly lower than that in the control group at 45 d（P<0.01）.The IL-8 concentration in the experimental group was significantly different from that in the control group at the time point except 0 d（P<0.01）,and was significantly lower than that in the control group at 45 d（P<0.01）.The concentration of IFN-γin the experimental group was lower than that in the control group at 45 d（P<0.01）.The TNF-αconcentration in the experimental group was lower than that in the control group at 45 d,and the difference was extremely significant（P<0.01）.The SOD concentration in the experimental group was higher than that in the control group except for 30 days,and the difference was significant（P<0.05）.The T-AOC level of the experimental group was higher than that of the control group at 15 d,and the difference was significant（P<0.05）.IGF-I concentration in the experimental group was lower than that in the control group at 15 d and45 d,and the difference was extremely significant（P<0.01）.The concentration of LEP in the experimental group was lower than that in the control group at 30 d（P<0.01）.PRL concentration in the experimental group was higher than that in the control group at 45 d,and the difference was extremely significant（P<0.01）.The INS concentration of the experimental group was lower than that of the control group at 45 d,and the difference was very significant（P<0.01）.The concentration of COR in the experimental group was higher than that in the control group at 30 d,and the difference was significant（P<0.05）.（3）There was no significant effect on p H,NH₃-N and BCP of dairy cows by adding compound bacteria in diet;The concentration of propionic acid in the experimental group was significantly higher than that in the control group（P<0.05）,and the concentration of pentanoic acid was higher than that in the control group（P<0.01）.In conclusion,the addition of compound bacteria in the diet can significantly reduce the number of somatic cells in the milk of dairy cows after 30 days,and has no significant effect on other production performance indexes.It has a significant effect on the immune and antioxidant capacity of dairy cows,and can improve the utilization efficiency of rumen feed in dairy cows.