The Effects Of Probiotics Administration On The Milk Production,Milk Components And Fecal Bacteria Microbiota Of Dairy Cows

Probiotics plays an important role in host health.It is reported that the probiotics supplement in dairy cows can keep the balance of gut microbes,promote the absorption of nutrition,enhance dairy cows’ health and improve their milk production.Currently,most studies focus on the effects of Bacillus subtilis and Saccharomyces,however,few studies that focus on the effects of Lactobacillus on gut microbiota,milk yield and quality of dairy cows are carried out.The object of present study was to assess the effects of mixed probiotics(Lactobacillus casei Zhang and Lactobacillus plantarum P-8)on the milk yield,milk composition,and gut microbiota of dairy cow.700 lactating primiparous Chinese Holstein dairy cows were divided into two groups:the control and treated group.The dairy cows in control group were fed basal diet with on probiotics supplement,each treated animals received 50g/day(containing 1.3×109 CFU/g)probiotics mixed with basal diet.The feed intake and milk yield from two groups were recorded daily,respectively.The milk and feces samples were collected from 20 dairy cows,including 10 cows from the control group and 10 cows from the treated group,which were randomly chosen in each group.The somatic cell counts(SCC)and compositions of milk samples were detected,and the microbiota in fecal samples were assessed using the PacBio SMRT technology.The probiotics supplement significantly increased the milk yield,which increased 10.71%than before,and the contents of immunoglobulin G(IgG),lactoferrin(LTF),lysozyme(LYS)and lactoperoxidase(LP)in milk(P<0.05),while significantly decreased SCC(P<0.05).However,there were no significant differences in the milk fat,protein and lactose contents(P>0.05).During the experiment,the diversity and abundance of gut microbiota in the control group significantly decreased compared with 30d,while the treated group have no such phenomenon,which means probiotics supplement can keep the balance of fecal bacteria.Compared with dairy cow in control group,beneficial bacteria significantly increased in treatment group,such as Bacteroides,Ruminococcus and Faecalibacterium prausnitzii.In addition,some opportunistic pathogens,such as Bacillus cereus,Cronobacter sakazakii and Alkaliphilus oremlandii,decreased.Additionally,we found there were some correlations between gut microbiota,and milk yield as well as milk components.Specifically,Bacillus cereus had positive correlation with SCC,but negative correlation with milk yield,IgG,LYS,LP.At the same time,Bacillus cereus had negative correlation with Faecalibacterium prausnitzii,Roseburia hominis,Ruminococcas gnavus.The results indicate that probiotics may improve the beneficial bacteria and inhibit pathogenic bacteria to keep the balance of intestinal flora and affect their health and productivity characteristic.In conclusion,our study demonstrated that the beneficial effects of probiotics supplement on improving the quality and quantity of cow milk production,and promoting the health and productivity characteristic through keeping the balance of intestinal flora.This study provides new probiotics strains for healthy breeding,as well as new insights into how to improve the production and nutritional qualities of raw milk.