Compliance of Milk Quality and Safety Measures Among Milk Producers and Milk Collection Centers in South Region of Punjab Province,Pakistan

The present study was conducted in four districts of Punjab Province to examine the attitude of milk producers and milk collection agents toward compliance of milk quality and safety parameters. In current scenario, the attitude of consumers for safe food in accordance to quality standards is ever increasing. The dairy industry in Pakistan is confronting many challenges to adapt these food safety and quality measures. This study was purposely conducted in the south region of Punjab Province, as this region has rich population of livestock and milk production. To collect essential data, field study was carded out in selected four districts of Punjab Province. Field survey for dairy farmers and milk collection centers was performed in two phases. The analysis of primary data was carried out by calculating the Likert scale mean value, analysis of variance （one-way） and other descriptive statistics tools. The results showed that 76.4% milk producers had no awareness about Punjab food quality laws; as Likert-scale mean value was 1.93. The compliance level for the management practices such as Hazard Analysis of Critical Control Point （HCCAP）, Good Animal Practices （GAP） and Good Veterinary Practices （GVP） etc. was also very poor. Approximately, 32.57% milk collectors （very frequently） applied milk quality testing parameters whereas 50.72% milk collectors merely used sensory quality inspection methods at the time of milk purchase from dairy farmers. For a sustainable supply of good quality raw milk to the dairy industry in Pakistan, it was recommended that the departments for hygiene and food inspection should be vigilant. The prescribed food safety laws relating to milk production and marketing activities should be enforced properly to improve the situation.

Effects of Milk Quality on Growth and Development of Suckling Calves

[Objectives]This study was conducted to study the effects of cows'milk quality on suckling calves'growth and development.[Methods]A total of 80 regular milk samples from Simmental and Angus cows were collected to complete the detection of conventional milk components.[Results]Under the same feeding and management conditions,the chemical composition of Simmental cows'milk was better than that of Angus cows'milk.High milk fat in Simmental cows'milk was beneficial to calves'early growth and development,and high milk protein in Angus cows'milk composition was conducive to calves'early weight gain.[Conclusions]This study provides a theoretical basis for reducing calves'mortality,alleviating calves'stress,and improving the economic benefits of beef cattle breeding.

Effect of Bacterial Content and Somatic Cell Count on Sheep Milk Quality in Kosovo

The main objective of this study was to analyze the effect of bacterial content (CFU) and somatic cell count (SCC) in milk quality in sheep (Ovis aries) farms according to the existing standards for fresh milk quality in Kosovo. A total of 2256 milk test day records from 379 Bardhoka (BAR), Sharri sheep (SHA), Kosovo sheep (KOS) and Balusha (BAL) ewes in eight herds across the country were collected and analyzed through a period April-October 2010. The general linear model and Duncan’s test were used to analyze the effect of different variables on presence of CFU and SCC in fresh milk. The effect of all variables was considered as a fixed. The overall results show that farm (P 0422), respectively, had a significant effect on presence of SCC. For CFU farm (P 0422) and breed (P 1211.17 to 6425.76 CFU/mL and 846.07 to 2043.15 SCC/mL milk, respectively. Although the rate of fresh milk contamination with SCC tends to be relatively low compare with CFU, by all means both variables should not be underestimated bearing in mind that a high rate of them on fresh milk are negatively correlated with farmer’s profit, consumer food safety and overall animal health.

Test of Feeding Dairy Cows with Chinese Herbal Additive for Improving Production and Quality of Milk

At Baiyin dairy farm, the Chinese herbal additive was added into feed which was then fed to dairy cows from August to October, 2014, and the changes in milk production and quality were observed. The test showed that the additive added into the feed had obvious milk-increasing effect, the milk production was im- proved by 12.67%-17.26%, and the milk quality was improved. The additive has the effects of preventing miscarriage, expelling parasite and preventing diseases. The nutritional components in the feed additive were determined, and the results showed that the contents of protein, crude fat, Ca and P in the additive were 12.29%, 2.66%, 1.8% and 0.22%, respectively.

Effects of 5% Biological Compound Premix on Milk Perform ance and Quality in Dairy Cow

This study was to investigate the effect of biological compound premix on the performance and milk quality in dairy cows. Twenty Holstein cows, with the similar age, parity, lactating month, gestation period, milk quantity and body weight, were randomly divided into two groups. The cows in two groups were fed with either common compound premix as control or 5% biological compound premix as treatment group. Two treatments contained same basal diet but different composi- tions of premix. The feeding experiment lasting 74 days displayed that daily milk quantity in treatment group was significantly higher than control group （P 〈 0.05 ）. The milk fat percentage was increased significantly in treatment group with the extended lactation time than control group （P 〈 0.05 ）. The milk protein and solids percentage were raised, but no significant difference was found between the two treatments （P 〉0.05 ）. The results indicated that 5% biological compound premix supplied in basal diet could facilitate to increase the milk performance and to ameliorate the milk quality of dairy cows.

Alterations in Quality Parameters of Mastitic Milk

Quality milk production in modern dairy systems is facing many challenges.Salient in them is mastitis which is responsible for decline in milk production,altered milk composition and compromised udder health.The malaise consists of multiple bacterial etiologies which can be broadly classified into contagious pathogens and environmental pathogens S.aureus is being isolated invariably in all epidemiological studies,followed by E.coli.Pathogenic virulence in mastitis is often accounted due to microbial ability of producing wide array of virulence factors that enhances pathogenicity and sustainment potential in the epithelial linings of udder.Mastitis affects quality parameters of milk i.e.constitutional as well as mineral profile due to local damage and inflammatory mediators.It decreases the lactose secretion because of oxidative stress generated due to the formation of free radicals in the milk.In mastitic milk,IgG2 becomes the predominant antibody which is thought to be the main opsonin supporting neutrophil phagocytosis in the bovine mammary gland.Therefore,it plays a significant role in the battle against mastitis pathogens.Mastitis infected cow shows a notable elevated level of the sodium and chloride and demoted level of calcium,potassium and inorganic phosphorus.In micro minerals,mastitis effects are pretty much same as in most macro minerals i.e.lower down their concentration in milk secretion.Consistent preventive strategy alongside strict surveillance and biosecurity is recommended for combating this challenge.

Evaluation of Milk Compositional Quality and Mammary Gland Health of Dairy Herds in the Southwestern Brazilian Amazon

Samples of raw milk from bulk cooling tanks were collected in five municipalities of the Southwestern Brazilian Amazon to establish the prevalence of Staphylococcus aueus and Streptococcus agalactiae, as well as to evaluate the milk composition and its correlation with the bulk tank somatic cell count (BTSCC). A total of 250 samples were collected to investigate the causal agents of bovine mastitis in whole milk, from 50 bulk milk tanks in each municipality. Under laboratory conditions, the samples were diluted to 1/10 and 1/100, and samples of 0.1 ml from each dilution were plated in triplicate on selective media for Staphylococcus aureus and Streptococcus agalactiae. To evaluate the correlation between the major milk components (fat, protein and lactose) and the BTSCC, samples were collected for 18 months from 73 dairy herds. The presence of the above-mentioned contagious mastitis pathogens was detected in 97.2% (243/250) of refrigerated raw milk samples evaluated. Analysis of the major milk components and BTSCC demonstrated that during the study period, fat compo-nent showed the largest variance, followed by protein and lactose, which also showed significant variances.

Effect of Pennisetum purpureum Schum cv. Guiminyin on Milk Yield and Quality of Jersey Cattle at Lactation Stage

The study aimed to research the forage value of Pennisetum purpureum Schum cv.Guiminyin in dairy industry and then provide scientific support for feeding jersey cattle with P.purpureum Schum cv.Guiminyin.Totally 20 jersey cattle at lactation stage were selected and divided into two groups randomly,10 cattle each group.The cattle were fed with P.purpureum Schum cv.Guiminyin and P.purpureum cv.Mott×（P.americanum×P.purureum）cv.Guimu No.1,respectively.The results showed that P.purpureum Schum cv.Guiminyin performed well in both nutritional value and palatability,and received remarkable effects on jersey cattle.The milk yield was 5.4%higher than that of before test,and the average daily milk yield was（11.65±0.07）kg/cattle.Compared with control group,milk fat percentage,lactoprotein content and overall milk-solid content were improved somewhat.Feeding jersey cattle with P.purpureum Schum cv.Guiminyin at lactation stage could increase their milk yield and milk quality.

Coordinated response of milk bacterial and metabolic profiles to subacute ruminal acidosis in lactating dairy cows

Background Bovine milk is an important source of nutrition for human consumption,and its quality is closely associated with the microbiota and metabolites in it.But there is limited knowledge about the milk microbiome and metabolome in cows with subacute ruminal acidosis.Methods Eight ruminally cannulated Holstein cows in mid lactation were selected for a 3-week experiment.The cows were randomly allocated into 2 groups,fed either a conventional diet(CON;40%concentrate;dry matter basis)or a high-concentrate diet(HC;60%concentrate;dry matter basis).Results The results showed that there was a decreased milk fat percentage in the HC group compared to the CON group.The amplicon sequencing results indicated that the alpha diversity indices were not affected by the HC feeding.At the phylum level,the milk bacteria were dominated by Proteobacteria,Actinobacteria,Bacteroidetes,and Firmicutes both in the CON and HC groups.At the genus level,the HC cows displayed an improved proportion of Labrys(P=0.015)compared with the CON cows.Results of both the principal components analysis and partial least squares of discriminant analysis of milk metabolome revealed that samples of the CON and HC groups clustered separately.A total of 31 differential metabolites were identified between the two groups.Of these,the levels of 11 metabolites decreased(α-linolenic acid,prostaglandin E2,L-lactic acid,L-malic acid,3-hydroxysebacic acid,succinyladenosine,guanosine,pyridoxal,L-glutamic acid,hippuric acid,and trigonelline),whereas the levels of the other 20 metabolites increased in the HC group with respect to the CON group(P<0.05).Conclusion These results suggested that subacute ruminal acidosis less impacted the diversity and composition of milk microbiota,but altered the milk metabolic profiles,which led to the decline of the milk quality.

Impact of Bacterial and Somatic Cells Content on Quality Fresh Milk in Small-Scale Dairy Farms in Kosovo

The basic goal of this research was to determine the impact of the presence of bacterial (CFU) and somatic cells count content (SCC) in quality of fresh milk in some small cattle farms in Kosovo. The survey was based on existing standards for milk quality in Kosovo placed under administrative guidance MA-no. 20/2006. The study was based on fresh milk analysis of 150 farms performed during the period September-December 2012, which was obtained in 9 different localities (collection points) of the Kosovo. Our study reveals that CFU and SCC in fresh milk were significantly affected by a number of factors, as: sampling period (repetition), locality, breed, and time of sampling (evening or/and morning). According to the results for CFU and SCC, there were big differences between the farms (milk collection points) included in the study (P < 0.0403) and (P < 0.0293). The results show that small size breed like Busha and its crosses tend to be less exposed to SCC/mL in milk (72.840) and (293.592), compared to Black Holstein (613.462), Simmental (521.519) and Brown Swiss (418.44). Milk produced in evening tended to be of better quality (259.854 CFU/mL) compared to the one from morning milking (576.689 CFU/mL). Fresh milk quality analyzed in the third repetition was better for about 33.3% compared with the repletion first. For CFU and SCC, the analyses show that about 74.7% and 64.7% of milk produced belongs to extra quality, while lower quality of milk of category three is 12.0% and 23.3%, respectively. Considering that about 85% of milk produced in Kosovo comes from small-scale dairy farms, the current study sets out that small-scale milk production system cannot be neglected by interest parties in dairy sector and needs permanent following up and improvement.

Evaluation and application of a milk antibody ELISA for assessing the prevalence and incidence of bovine tuberculosis in dairy herds in Hubei Province,China

Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.

Evaluation of a new qPCR test to identify the organisms causing high total bacterial count in bulk tank milk

Milk quality in bulk tank milk （BTM） is measured by flow cytometry technology as total bacterial count （TBC） and somatic cell count （SCC）. To investigate SCC problems, culture or PCR can be used to identify mastitis causing bacteria, e.g., Mastit 4, a commercially available qPCR test. TBC in BTM can be investigated further using culture-based methods such as standard plate count, laboratory pasteurization count, coliform count, and spore counts. To our knowledge, no qPCR addressing the bacteria involved in TBC has been commercially introduced. The aim of this study is to evaluate a recently introduced 3-h qPCR test, TBC 4. The TBC 4 qPCR detects four target groups, Pseudomonas, Streptococci, Enterobacteriacea/ Enterococcus, and Bacillus/Clostridia. These target groups relate to problems on the farm such as cooling, mastitis, environment, and silage. We will continue with new research to compare the TBC 4 qPCR test with traditional culture. For this study, BTM samples from different TBC intervals were selected based on BactoCount results found at routine payment investigation at Eurofins laboratory （Vejen, Denmark）. These samples were analyzed using TBC 4 qPCR assay within 24 h. In total, 346 BTM samples were divided into six different intervals of colony forming units （CFU）. For all four targets in each of the different intervals of CFU, the percent of positive samples, the average Ct-value, the percent of positive samples with Ct〈30 and Ct〈25 were calculated. For Pseudomonas, Streptococci, and Enterobacteriacea/Enterococcus, the number of positive samples with lower Ct-values （high bacteria content） correlated with the CFU mL-1. We found Enterobacteriacea/ Enterococcus, Pseudomonas, and Streptococci in high number of bacteria （Ct〈25） in 25, 19 and 56％ of samples with CFU mL-1 between 50001-100000 and 53, 44, and 39％ in samples with CFU mL-1〉100000. The TBC 4 qPCR test showed to be a strong and fast tool for farmers, advisors and service technicians to address problems with high TBC and ensuring the delivery of good quality milk to the dairy.

Bacillus subtilis Co-transfected with a Lysine-rich and a Methionine-rich Protein Gene and Its Effect on Cow Milk Production

The probiotic Bacillus subtilis （B. subtilis） was widely applied in animal production as feed additive. Lysine （Lys） and methionine （Met） were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn＇t know whether Lys- rich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, mRNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g· cow^-1· d^-1, transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subalis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality.

Effects of a soybean milk product on feto-neonatal development in rats

Since estrogenic pollutants and phytoestrogens can cause the disorder of the reproductive system, the effects of a soybean milk product（Vegemil^（？） containing 162 ppm isoflavones） on the feto-neonatal development, including male reproductive function, were investigated. Pregnant rats were fed the soybean milk（5% or 100% in drinking water）from gestational day（GD） 6 to parturition or to post-natal day（PND） 56. Specifically, the rats were divided into 4 groups： the control group（drinking water）, the GD5% group（5% soybean milk during only the GD period）, the GDPND5% group（5% soybean milk during the GD and PND periods）, and the GD-PND100% group（100% soybean milk instead of water during the GD and PND periods）. During the gestational, lactational, and developmental periods, the reproductive and developmental parameters of dams and offspring were observed. Feeding soybean milk did not affect the birth and physical development of both male and female offspring. At PND57, the weights of the testes and epididymides of F1 males significantly increased by feeding a high concentration of the soybean milk（GDPND100%）. In addition, feeding of the soybean milk during both the GD and PND periods（GD-PND5% and GDPND100%） enhanced the sperm counts and motility. The results indicate that soybean milk is safe for embryos,fetuses, and offspring, and improves the post-generational development of male reproductive function.

Effects of Fleckvieh on the Performance of Dual-Purpose Cattle Improved by Hybridization with Local Beef Cows

[Objective] The paper aimed to study the improved effect of local beef cattle with Fleckvieh cattle and provide theoretical basic data for local cattle industry in central plain agricultural area in China. [Method] With 500 local beef cattle as female parents and Fleckvieh cattle as male parents,hybridization improvement was conducted via artificial insemination. The growth performance,slaughter performance,milk performance and milk components of F1 and F2 hybrids were measured. [Result] The birth body weights of F2 were significantly higher than those of local beef cow,but there was no remarkable difference between F1 and local beef cow or F1 and F2. The growth rates of F1 and F2 at different stages were higher than those of local beef cattle. The slaughter performance,such as carcass weight( P < 0. 05),dressing percentage,net meat rate( P < 0. 05),marbling score of F1 and F2 were higher than those of local beef cow. Milk production performance,such as actual milk yield,305 d corrected milk yield and 4% standard milk yield of F2 were signally higher than those of F1 and local beef cattle( P< 0. 05),and F1 was markedly higher than local beef cattle( P < 0. 05). For milk composition,although milk fat percentage,milk protein rate,lactose rate and total solids( TS) of F1 and F2 were slightly lowered compared with local beef cattle at varying degrees,they were still at high levels compared with Holstein cows.[Conclusion]Fleckvieh cattle,as a male parent,can significantly improved growth performance,slaughter performance and milk performance of offsprings. It would also increases the economic efficiency of local beef cattle by higher quality and price,as well as changing production model from beef to dual purpose of beef and milk.

Effect of Fruit-flavored Agent and Green Pigment on Production Performance of Simmental Cows

[Objective] The paper was to increase utilization rate of roughage to solve current shortage of forage and improve production performance of Simmental cow.[Method] Fruit-flavored agent and green pigment were added in roughage of Simmental cow respectively,and their effects on feed intake,milk production and milk quality of Simmental cow were studied.[Result] After adding fruit-flavored agent and green pigment,the feed intakes of Simmental cow were increased by 30.69% and 12.27%,while the milk productions were increased by 1.74 and 2.25 kg,respectively,and the differences were all significant（P 〈 0.05）.[Conclusion]Adding 0.3% and 0.1% fruit-flavored agent and green pigment in roughage of Simmental cow could significantly improve feed intake and milk production,which can also delay the decline of milk production during late lactation stage and improve milk quality.

Novel metabolic and physiological functions of branched chain amino acids: a review

It is widely known that branched chain amino acids（BCAA） are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA（isoleucine, leucine and valine） regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including：（1） Insufficient or excessive levels of BCAA in the diet enhances lipolysis.（2） BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.（3）Supplementation of leucine in the diet enhances meat quality in finishing pigs.（4） BCAA are beneficial for mammary health, milk quality and embryo growth.（5） BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.（6） BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood（decreased BCAA catabolism） are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.

Detection and quantification of Bacillus cereus and its spores in raw milk by qPCR,and distinguish Bacillus cereus from other bacteria of the genussBacillus

Introduction:Raw milk is the basic raw material of dairy products.Bacillus cereus(B.cereus)is a typical conditional pathogenic bacteria and cold-phagocytic spoilage bacteria in raw milk.Materials and Methods:In this study,a quantitative polymerase chain reaction(qPCR)method for detecting B.cereus in raw milk was established.The specificity of the method was verified by using other Bacillus bacteria and pathogenic bacteria;the sensitivity of the method was evaluated by preparing recombinant plasmids and simulated contaminated samples;and the applicability of the method was verified using pure spore DNA.The actual sample detection was completed by using the established qPCR method.Results:The qPCR established in this study can specifically detect B.cereus in raw milk.The limit of detection of the method was as low as 200 CFU/mL,the limit of quantification ranged from 2×10^(2)to 2×10^(8)CFU/mL,and the amplification efficiency of qPCR was 96.6%.Conclusions:The method established in this study can distinguish B.cereus from other Bacillus bacteria,and spore DNA can be used as the detection object.This method has the advantages of strong specificity,high sensitivity,wide application range,and short detection time,which isexpectedtobeapplied in thedairy industry.

Dietary supplementation with inulin improves lactation performance and serum lipids by regulating the rumen microbiome and metabolome in dairy cows

This study investigated the effects of inulin on rumen fermentation parameters,ruminal microbiome and metabolites,as well as lactation performance and serum indexes in dairy cows.Sixteen Holstein dairy cows with similar body conditions were randomly divided into 2 groups(n=8 per group),with inulin addition at 0 and 200 g/d percow.The experiment lasted for 6 weeks,including a 1-week adaptation period and a 5-week treatment period.At the end of the experimental period,the milk,serum and rumen fluid were sampled and analyzed.The microbiome and metabolome in the rumen fluid were analyzed via 16 S rRNA sequencing and untargeted metabolomics,respectively.The results showed that supplementation with inulin(200 g/d per cow)increased the milk yield(P=0.001),milk protein(P=0.032),lacto se rate(P=0.004)and proportion of saturated fatty acids(SFA)in milk(P<0.001),but decreased the proportion of unsaturated fatty acids(USFA)(P=0.041).Rumen pH(P=0.040)and the concentration of NH3-N(P=0.024)were decreased;however,acetate(P<0.001),propionate(P=0.003),butyrate(P<0.001)and lactic acid(LA)(P=0.043)were increased.The total cholesterol(TC)(P=0.008)and triglycerides(TG)(P=0.01)in serum were also reduced.Additionally,inulin addition elevated the relative abundance of several beneficial symbiotic and short-chain fatty acid(SCFA)-producing bacteria,such as Muribaculaceae(false discovery rate[FDR]-adjusted P<0.01),Acetitomaculum(FDR-adjusted P=0.043),and Bu tyrivibrio(FDR-adjusted P=0.036),while elevating the levels of L-lysine(FDR-adjusted P=4.24×10^(-3)),L-proline(FDR-adjusted P=0.0158),and L-phenylalanine(FDRadj usted P=0.027).In contrast,several pathogens and ruminal bacteria abu ndant in high-fat diets,such as Escherichia-Sh igella(FD R-adj usted P=0.022),Erysipelo trichaceaeUCG-004(FD R-adjusted P<0.01)and RF39(FDR-adjusted P=0.042)were decreased along with the reduction of lysophosphatidylcholine(LysoPC)(18:1(9 Z))(FDR-adjusted P=1.03×10^(-3)),LysoPC(16:0)(FDR-adjusted P=0.0108),LysoPC(18:2(9 Z,12 Z))(FDRadjusted P=1.65×10^(-3))and 8-methylnonenoate.In conclusion,dietary inulin supplementation could increase the relative abundance of commensal microbiota and SCFA-producing bacteria,upregulate amino acidmetabolism and downregulate lipid metabolism in the rumen of dairy cows,which might further improve lactation performance and the level of serum lipids.