SomaticCellCountinDairyCattle

奶牛的體細(xì)胞計(jì)數(shù)美國(guó)谷物協(xié)會(huì)供稿馬春生翻譯WhatisNormalMilk?

什么是正常牛奶Defineddifferentlyineverycountryandovertime

各國(guó)不同時(shí)間的定義不同。SCCofnormalmilk(quartersample)isalmostalways<100,000/ml

正常牛奶的體細(xì)胞計(jì)數(shù)（乳區(qū)樣品）每毫升幾乎總是低于10萬(wàn)。IfSCC>200,000/mlthequarterislikelytobeactivelyinfected,orrecoveringfromaninfection

如果每毫升體細(xì)胞計(jì)數(shù)大于20萬(wàn)，那么這個(gè)乳區(qū)可能受到感染或正在從感染恢復(fù)。SCCbetween100,000to200,000–questionable

體細(xì)胞計(jì)數(shù)在10萬(wàn)-20萬(wàn)之間為可疑。Normalmilkhasnoclotsorflakes,andisnotdiscolored

正常牛奶沒有凝塊和絮片，顏色也沒有變化。SCCanalysis-fromwhichlevel?

體細(xì)胞計(jì)數(shù)分析-在哪種水平上？Quarter

乳區(qū)Cow(compositesampleofallquarters)

個(gè)體母牛（所有乳區(qū)的混合樣品）Herd–BulkTankSample(compositeofallcows)

群體–罐乳樣品（所有母牛的混合奶）Quartersamplesversuscompositecowsample

乳區(qū)樣品與個(gè)體母?；旌夏虡悠繁容^Don’tforgetthatcompositecowsampleshaveadilutioneffectoflowSCCinnormalquarters

別忘記，個(gè)體母?；旌夏虡悠肪哂斜黄湔Ｈ閰^(qū)低體細(xì)胞計(jì)數(shù)稀釋了的效應(yīng)。Ex:cowwithcompositesampleSCCof500,000andthreenormalquarters(SCC=50,000)

例如：母?；旌夏虡悠返捏w細(xì)胞計(jì)數(shù)為50萬(wàn)，而三個(gè)正常乳區(qū)的體細(xì)胞計(jì)數(shù)為5萬(wàn)。ThemastitisquarterhasaSCCof1,850,000!!

患乳房炎乳區(qū)的體細(xì)胞計(jì)數(shù)為185萬(wàn)。SCCandProductionLoss

體細(xì)胞計(jì)數(shù)和產(chǎn)奶量損失SCCRange(1,000)SCC范圍（單位千）SCCScoreSCC分級(jí)MilkLoss(kg/day)產(chǎn)奶量損失（千克/頭日）0-180019-351036-712072-14130.7142-28341.4284-56552.0566-1,13062.71,131-2,26273.42,263-4,52384.14,524-9,99994.8MilkYieldLossduetoSCC(Source:NMC)

體細(xì)胞計(jì)數(shù)造成的產(chǎn)奶量損失LactationAverage胎次平均LossofMilkYield(kg)產(chǎn)奶量損失（千克）SCC(1,000)SCC（單位千）LinearSCS體細(xì)胞線性評(píng)分Lact1一胎Lact2+二胎以上25100502001003911822004182364400527354680063647281,6007455910USPasteurizedMilkOrdinance(PMO)

美國(guó)巴氏消毒牛奶法令Bacteriacountsinrawmilk–nottoexceed100,000/mlinbulkmilkfromanysingleproducer

原料鮮奶的細(xì)菌計(jì)數(shù)–任何單一生產(chǎn)者（奶牛場(chǎng)）的罐乳不得超過每毫升10萬(wàn)。Somaticcellcount–nottoexceed750,000/mlinmilkfromanyproducer

體細(xì)胞計(jì)數(shù)-任何單一生產(chǎn)者（奶牛場(chǎng)）的牛奶不得超過每毫升75萬(wàn)。Freeofresiduestospecifieddrugs

無(wú)規(guī)定藥物的殘留。StandardPlateCount(1,000)inNewYorkDairies

紐約州奶牛場(chǎng)的標(biāo)準(zhǔn)平板細(xì)菌計(jì)數(shù)（單位：千）855samples(Source,JDS81:Boor)ColiformCountinNewYorkDairies

紐約州奶牛場(chǎng)的大腸桿菌計(jì)數(shù)855samples(Source,JDS81:Boor)Coliform<10canbeconsumedasrawmilkNormalSCC

正常的體細(xì)胞計(jì)數(shù)Thereisnoevidencethatparity,stageoflactation,orheatstresswillraisetheSCCabovethe200,000levelinnormalcows

沒有證據(jù)表明，產(chǎn)犢、所處泌乳階段或熱應(yīng)激會(huì)使正常母牛的體細(xì)胞計(jì)數(shù)升高超過20萬(wàn)。OnestudyfoundthattheaverageSCC(geometricmean)of4,200bacterialculturenegativequarterswas29,000

一項(xiàng)研究發(fā)現(xiàn)，4,200

例細(xì)菌培養(yǎng)陰性乳區(qū)的體細(xì)胞平均數(shù)（幾何平均）為29,000。SCCandestimatesofquarterinfectionrate

體細(xì)胞計(jì)數(shù)和乳區(qū)感染率的估計(jì)BulktankSCCof200,000–estimate15%ofquartersareinfected

罐乳體細(xì)胞計(jì)數(shù)20萬(wàn)–估計(jì)有15%的乳區(qū)受到感染。EachadditionalincreaseinSCCof100,000isduetoanadditional8-10%quarterinfectedquarters

體細(xì)胞計(jì)數(shù)額外增加10萬(wàn)是由于受感染乳區(qū)又增加了8-10%。SCCof400,000–estimate33%ofcowsareinfected

體細(xì)胞計(jì)數(shù)40萬(wàn)–估計(jì)有33%的母牛受感染。SCCof700,000–estimate67%ofcowsareinfected

體細(xì)胞計(jì)數(shù)70萬(wàn)–估計(jì)有67%的母牛受感染。RiskofAntibioticResidueViolationswithHighSCC

因體細(xì)胞計(jì)數(shù)高造成的抗菌素殘留違規(guī)的風(fēng)險(xiǎn)AsSCCexceeds250,000cells/mltherelativerisk(RR)ofantibioticresidueviolationsincreaserapidlyintheUS

在美國(guó)，由于每毫升體細(xì)胞計(jì)數(shù)超過25萬(wàn)，抗菌素殘留違規(guī)的相關(guān)風(fēng)險(xiǎn)迅速增加。250,000Risk（風(fēng)險(xiǎn)）=1.0251,000to400,000RR（相關(guān)風(fēng)險(xiǎn)）=1.43401,000to550,000RR=2.38551,000to700,000RR=2.78>700,000RR=7.10SourceJDS83:Ruegg)SCCbeforeandafterstaphaureusinfection

金黃色葡萄球菌感染前后的體細(xì)胞計(jì)數(shù)X=heifersSquares=adultcowsSource:JDS85:deHaas,etal.SCCbeforeandafterE.coliinfection

大腸桿菌感染前后的體細(xì)胞計(jì)數(shù)X=heifersSquares=adultcowsSource:JDS85:deHaas,etal.SCCbeforeandafterstrepdysgalactiaeinfection

停乳鏈球菌感染前后的體細(xì)胞計(jì)數(shù)X=heifersSquares=adultcowsSource:JDS85:deHaas,etal.SCCbeforeandafterstrepuberisinfection

乳房鏈球菌感染前后的體細(xì)胞計(jì)數(shù)

X=heifersSquares=adultcowsSource:JDS85:deHaas,etal.LactationcurvesforSCC(Source:JDS85deHaas)

體細(xì)胞計(jì)數(shù)的泌乳期曲線AdultcowsLactationcurvesforSCC(Source:JDS85deHaas)

體細(xì)胞計(jì)數(shù)的泌乳期曲線HeifersAverageSCCLactationCurve–AdultCows

平均體細(xì)胞計(jì)數(shù)的泌乳期曲線–成年母牛

(Source:JDS85deHaas)AverageSCCLactationCurve–Heifers

平均體細(xì)胞計(jì)數(shù)的泌乳期曲線–青年母牛

(Source:JDS85deHaas)CMTFormulation

加利福尼亞乳房炎測(cè)定（CMT）試劑的配方Sodiumlaurylsulfate-30grams/literwater(3%solution)

十二烷基硫酸鈉–每升水30克（3%溶液）Bromocresolpurple–addasmallamountasacoloringagent

溴甲酚紅紫

–添加少量作為色劑SCCandCaliforniaMastitisTest(CMT)inEarlyLactation

泌乳早期的體細(xì)胞計(jì)數(shù)和加利福尼亞乳房炎測(cè)定IsSCCorCMTausefultooltoidentifyquartersofcowsaftercalvingforbacterialculture?

為鑒別產(chǎn)后母牛做細(xì)菌培養(yǎng)的乳區(qū)，SCC或CMT是有用的工具嗎？WhatistherelationshipbetweenSCCandintramammaryinfection(IMI)incowsimmediatelyaftercalving?

體細(xì)胞計(jì)數(shù)與母牛產(chǎn)后立即發(fā)生乳房?jī)?nèi)感染之間是什么關(guān)系？Source:JDS84,SargeantSCCandCMTinearlyLactation(2)

泌乳早期的體細(xì)胞計(jì)數(shù)和加利福尼亞乳房炎測(cè)定Individualquartersfrom131cowsweretestedforSCCandCMTat12hoursaftercalvingandonceeachdayuntil10daysaftercalving.

對(duì)131頭母牛的每個(gè)乳區(qū)在產(chǎn)后12小時(shí)進(jìn)行體細(xì)胞計(jì)數(shù)和加利福尼亞乳房炎測(cè)定每日一次，一直做到產(chǎn)后10第十天。Resultswerecomparedwithbacterialcultureresultsfromeachquartertakenatdays1and3post-calving

其結(jié)果與產(chǎn)后第一天和第三天每個(gè)乳區(qū)的采樣的細(xì)菌培養(yǎng)結(jié)果進(jìn)行對(duì)比。SCCandCMTinearlyLactation–Results

泌乳早期的體細(xì)胞計(jì)數(shù)和加利福尼亞乳房炎測(cè)定–結(jié)果36%ofallquarterswereculturedpositiveforbacteria

所有乳區(qū)細(xì)菌培養(yǎng)結(jié)果陽(yáng)性的占36%Majorpathogens(15%):Environmentalstrep,Coliforms,Staphaureus

主要的病原體（15%）：環(huán)境性鏈球菌、大腸桿菌、金黃色葡萄球菌Minorpathogens(21%):Coagulasenegativestaph,Corynebacterium

bovis

次要的病原體（21%）：凝固酶陰性葡萄球菌、棒狀桿菌SCCinearlyLactation–Conclusions

泌乳早期的體細(xì)胞計(jì)數(shù)–結(jié)論OptimaltimeforSCCtesttodiagnosemastitiswithallpathogensis5dayspostcalving

為診斷所有病原菌造成的乳房炎，進(jìn)行SCC測(cè)定的最佳時(shí)間是產(chǎn)后5天。Thresholdof100,000cells/ml

初始水平每毫升10萬(wàn)。Sensitivity(%ofpositivesidentified)=57.4%

敏感性（鑒別出的陽(yáng)性率）=57.4%。Sensitivityformajorpathogenswas66.2

主要病原體的敏感性為66.2。Specificity(%ofnegativescorrectlylabeled)=77.4%

敏感性（正確標(biāo)明的陰性率）=77.4%。CMTinearlyLactation–Conclusions

泌乳早期的加利福尼亞乳房炎測(cè)定–結(jié)論OptimaltimeforCMTtesttodiagnosemastitiswithallpathogensis3dayspostcalving

為診斷所有病原菌造成的乳房炎，進(jìn)行CMT測(cè)定的最佳時(shí)間是產(chǎn)后3天。ThresholdofCMTscore>0

開始時(shí)CMT分級(jí)評(píng)分大于0。Sensitivity(%ofpositivesidentified)=56.7%

敏感性（鑒別出的陽(yáng)性率）=56.7%。Sensitivityformajorpathogenswas66.7%

主要病原體的敏感性為66.7。Specificity(%ofnegativescorrectlylabeled)=56.2%

敏感性（正確標(biāo)明的陰性率）=56.2%。AssessingTestResults–Sensitivity

判斷測(cè)定結(jié)果–敏感性Sensitivity–thenumberoftruecasesofadiseasedetectedbythetestdividedbythenumberofalldiseasedanimals

敏感性–被測(cè)定檢出的真實(shí)病例數(shù)量除以所有病牛的數(shù)量。Ex:100cowswithmastitisaretestedbyanewmethodofdetection.Thetestispositivefor60cows,sensitivity=60/100,or0.60

例如：采用一項(xiàng)新的測(cè)定方法測(cè)定100頭患乳房炎的母牛。這種試驗(yàn)結(jié)果顯示為陰性的為60頭，敏感性等于60/100，或?yàn)?.60.AssessingTestResults–Specificity

判斷測(cè)定結(jié)果–特異性Specificity–thenumberoftruenegativesdetectedbythetestdividedbythenumberofactualnegativeanimals

特異性-被測(cè)定檢出的真實(shí)陰性數(shù)量除以實(shí)際陰性牛的數(shù)量。Ex:100cowswithoutmastitisaretestedbyanewtest.Thetestinnegativefor75ofthecows.Specificity=75/100,or0.75

例如：采用一項(xiàng)新的測(cè)定方法測(cè)定100頭無(wú)乳房炎的母牛。這種試驗(yàn)結(jié)果顯示為陰性的為75頭，敏感性等于75/100，或?yàn)?.75.Example:SensitivityandSpecificity

敏感性和特異性舉例PresencesofIntramammaryInfection出現(xiàn)的乳房?jī)?nèi)感染TestResult測(cè)定結(jié)果Bact.Culture+細(xì)菌培養(yǎng)陽(yáng)性Bact.Cult–細(xì)菌培養(yǎng)陰性Test+陽(yáng)性2820Test-陰性745

totals合計(jì)3565Sensitivity（敏感性）=28/35=0.80Specificity（特異性）=45/65=0.69Falsepositivesandnegatives

假陽(yáng)性和假陰性Falsepositives（假陽(yáng)性）=(1-specificity)特異性Falsenegatives（假陰性）=(1-sensitivity)敏感性IsSCCof200,000anIndicatorofIntra-MammaryInfection?

體細(xì)胞計(jì)數(shù)20萬(wàn)是乳房?jī)?nèi)感染的標(biāo)志嗎？CoworQuarter母牛或乳區(qū)Pathogens病原體Sensitivity敏感性Specificity特異性Cow母牛All全部82.776.8Cow母牛All全部89.075.0Cow母牛All全部72.685.5Cow母牛Major主要83.458.9Quarter乳區(qū)Major主要74.589.6Resultsoffivedifferentstudies(Source:NMC2001,Dohoo)5項(xiàng)不同研究的結(jié)果PositiveandNegativePredictiveValue

陽(yáng)性和陰性預(yù)測(cè)值PositivePredictiveValue:Theprobabilitythatacowoverthethresholdlevelisinfected

陽(yáng)性預(yù)測(cè)值：超過初始水平被感染的母牛數(shù)量概率。NegativePredictiveValue:Theprobabilitythatacowbelowthethresholdisnotinfected

陰性預(yù)測(cè)值：低于初始水平未被感染的母牛數(shù)量概率。PredictiveValueswillchangewiththeherdprevalenceofinfection(evenwiththesametestsensitivityandspecificity)

預(yù)測(cè)值將隨牛群感染的流行而變化（即使有相同的測(cè)定敏感性和特異性）。SCCinEarlyLactation

泌乳早期的體細(xì)胞計(jì)數(shù)(KSUDairyDays1999–Sargeantetal,)EffectofBacterialCultureonSCCinEarlyLactation

細(xì)菌培養(yǎng)對(duì)泌乳早期體細(xì)胞計(jì)數(shù)的影響CMTSCCEffectofBacterialCultureonCMTinEarlyLactation

細(xì)菌培養(yǎng)對(duì)泌乳早期加利福尼亞乳房炎測(cè)定的影響NationalSCCbyMonth1996-1997(JDS83:Norman)

1996-1997全國(guó)體細(xì)胞計(jì)數(shù)月報(bào)AverageSCCbyHerdSize(JDS83:Norman,etal)

不同規(guī)模牛群的平均體細(xì)胞計(jì)數(shù)USSCCbyRegionsandHerdSize(JDS84:Oleginni)

美國(guó)不同地區(qū)和不同規(guī)模牛群的體細(xì)胞計(jì)數(shù)SCCPre-andPostTreatment(millions)fromNickerson

Nickerson報(bào)導(dǎo)的治療前后的體細(xì)胞計(jì)數(shù)（單位-百萬(wàn)）TeatEndClassification1

乳頭口分類1TeatEndClassification2

乳頭口分類2TeatEndScoring–Smooth

乳頭口評(píng)分–平滑TeatEndScoring–Rough

乳頭口評(píng)分–粗糙HygieneScoring

牛體衛(wèi)生評(píng)分Score25%ofcowsineachgroup

給每組25%的母牛評(píng)分ScoreUdders,LegsandFlankseparately

分別給乳房，肢蹄和側(cè)腹部評(píng)分CowHygieneScoring-%withscoreof3or4

母牛衛(wèi)生評(píng)分–評(píng)分為3或4的百分?jǐn)?shù)FarmType奶牛場(chǎng)類型Udder乳房Legs肢蹄Flank&UpperLeg脅和腿上部Free-stallaverage自由散放圍欄平均20%61%19%Free-stallbest自由散放圍欄最佳4%38%7%Stanchionaverage拴系系統(tǒng)平均20%25%30%Stanchionbest拴系系統(tǒng)最佳0%13%5%HighSCCandMilkQuality(JDS83:Ma)

體細(xì)胞計(jì)數(shù)高和牛奶質(zhì)量USIndustrySCC

美國(guó)乳業(yè)的體細(xì)胞計(jì)數(shù)Nationalpenaltylevel750,000/ml

國(guó)家處罰水平為每毫升75萬(wàn)。EUcurrentlyat400,000

歐洲目前在40萬(wàn)。Currentlyabout80%ofUSmilkis<400,000

目前美國(guó)約80%的牛奶小于40萬(wàn)。NewYorkStateLNSCCSeasonalVariation(JDS85:vanSchaik)

紐約州自然對(duì)數(shù)體細(xì)胞計(jì)數(shù)的季節(jié)變化NewYorkAntibioticResidueViolationsbySCC(JDS85:vanSchaik)

由體細(xì)胞計(jì)數(shù)反映的紐約州抗菌素殘留違規(guī)NewYorkStatePlateLoopCount(LN)(JDS85:vanSchaik)

紐約州平板環(huán)形計(jì)數(shù)（自然對(duì)數(shù)）ReturnonEquitybySCC(Ruegg,U.ofWisconsin)

體細(xì)胞計(jì)數(shù)衡平回歸

CanSCCbeusedtoPredictMastitisintheNextLactation?

能用體細(xì)胞計(jì)數(shù)預(yù)測(cè)下一個(gè)泌乳期的乳房炎嗎？InlowSCCherds(average<300,000)isthereaspecificthresholdlevelofSCC(high,average,orlast)thatservesasanindicatorofmastitis(positivebacterialcultures)inthenextlactation?

在體細(xì)胞計(jì)數(shù)低的牛群（平均小于30萬(wàn)），是否存在一個(gè)特定的體細(xì)胞計(jì)數(shù)初始水平（高、平均或低）用來作為預(yù)測(cè)下一個(gè)泌乳期乳房炎（細(xì)菌培養(yǎng)陽(yáng)性）的指標(biāo)。Conclusion:Selectivecowtreatment(highSCCcowsonly)willnotaccuratelyidentifythecowsatriskatanythreshold.Inthiscase,athresholdof100,000hadsensitivityof0.58andspecificityof0.52

結(jié)論：有選擇性的治療母牛（只包括體細(xì)胞計(jì)數(shù)高的母牛）將不能準(zhǔn)確地鑒別出處于任何初始水平風(fēng)險(xiǎn)的母牛。在這種情況下，初始水平10萬(wàn)的敏感性為0.58，特異性為0.52。Source:JAVMA208,KirkStaphaureusdiagnosis–compositeorindividualglandsamples?

金黃色葡萄球菌診斷–混合或個(gè)體乳區(qū)樣品？Diagnosisofsubclinicalstaphaureusmastitisbycultureofcompositesamplesisimpairedbydilutionofbacteriaininfectedgland

通過混合樣品培養(yǎng)診斷亞臨床金黃色葡萄球菌乳房炎，因在感染了的乳區(qū)內(nèi)的細(xì)菌稀釋被削弱了。Staphaureussheddingmaybesloworintermittent,thereforemultiplecompositesamples,largerinoculums,and/orindividualglandsamplesmaybeneededtodetectbacteriainthesecows

金黃色葡萄球菌可能緩慢、間歇性地散發(fā)，因此可能需要多量的混合樣品、較大的接種體、和或個(gè)體乳區(qū)樣品來檢測(cè)存在于這些母牛的細(xì)菌。UseCMTtoscreenhighSCCglands,andthensampleforculture

先采用加利福尼亞乳房炎測(cè)定法篩選體細(xì)胞高的乳區(qū)，然后再采樣培養(yǎng)。Source–JAVMA208,Lam

GeometricvsArithmeticMeanSCC

體細(xì)胞計(jì)數(shù)的幾何平均對(duì)比算術(shù)平均Arithmeticmeanexaggeratestheimpactofextremelyhighvalues

算術(shù)平均數(shù)夸大了極高數(shù)值的影響。Geometricmeanistheaverageofbase10logofindividualcounts.Thenumericvaluecanbecalculatedbythebase10antilog

幾何平均數(shù)是個(gè)體計(jì)數(shù)基礎(chǔ)10對(duì)數(shù)的平均值。數(shù)值可用基礎(chǔ)10反對(duì)數(shù)來計(jì)算。ExampleofGeometricMean

幾何平均舉例Data（數(shù)據(jù)）:200,000220,000220,000240,000250,000270,0001,200,000Arithmeticmean（算術(shù)平均）=371,428(median中值=240,000)Averageofbase10log（基礎(chǔ)10對(duì)數(shù)的平均值）=5.468105.468=293,765Geometricmeanisclosertomedianvalue

幾何平均更接近中值。Geometricmeanisnevergreaterthanthearithmeticmean

幾何平均永遠(yuǎn)不會(huì)大于算術(shù)平均。BulkTankGeometricMeanSCC

罐乳體細(xì)胞計(jì)數(shù)的幾何平均SomaticCellCount(SCC)andSomaticCellScore(SCS)

體細(xì)胞計(jì)數(shù)（SCC)和體細(xì)胞評(píng)分（SCS)

UsedforstatisticalpurposesbyDHIinUS

在美國(guó)被奶牛群改良計(jì)劃（DHI）用于統(tǒng)計(jì)目的。SCS=log2*(SCC/100,000)+3SCC=2(SCS-3)*(100,000)Scaleof0to9.9（數(shù)值范圍）SomaticCellCountversusSomaticCellScore

體細(xì)胞計(jì)數(shù)與體細(xì)胞評(píng)分對(duì)比DoesdrycowtreatmentreduceSCCandmastitisinthenextlactation?

干奶牛治療能降低下一個(gè)泌乳期的體細(xì)胞計(jì)數(shù)和乳房炎嗎？Manystudieshavelookedatthisquestionwithconflictingresults

針對(duì)這個(gè)問題有許多的研究，但結(jié)果不一致。ThereisgoodevidencethatdrycowtreatmentdoesnotreduceSCCforthenextlactationinherdsfreeofcontagiousmastitisandlowaverageSCC

但有良好的證據(jù)表明，在沒有傳染性乳房炎并且體細(xì)胞平均計(jì)數(shù)低的牛群內(nèi)，干奶牛治療不會(huì)降低下一個(gè)泌乳期的體細(xì)胞計(jì)數(shù)。DoesdrycowtreatmentreduceSCC

andmastitisinthenextlactation?

干奶牛治療能降低下一個(gè)泌乳期的體細(xì)胞計(jì)數(shù)和乳房炎嗎？ThereismixedevidenceofwhetherdrycowtreatmentreducesclinicalmastitisinthenextlactationinlowSCCherds

對(duì)于體細(xì)胞計(jì)數(shù)低的牛群來說，干奶牛治療能否降低下一個(gè)泌乳期的臨床乳房炎證據(jù)是互相矛盾的。HighSCCherdswithpresenceofcontagiousmastitis(staphaureusandstrepag)benefitgreatlyfromdrycowtreatment

體細(xì)胞計(jì)數(shù)高、同時(shí)存在傳染性乳房炎（金黃色葡萄球菌和無(wú)乳鏈球菌）的牛群從干奶牛治療中受益很大。EconomicsofDryCowTreatment

干奶牛治療的經(jīng)濟(jì)學(xué)Cowstreatedattheendoflactationproduced179kgmoremilkinthefirst4monthsofthenextlactation(JAVMA211:Berry)

泌乳結(jié)束時(shí)，對(duì)奶牛進(jìn)行干牛處理，可在下一個(gè)泌乳期的前4個(gè)月多產(chǎn)179千克的牛奶。Assumingmilkpriceof2.0RMB/kganddrycowtreatmentcostsof50RMB/cow;aproductionincreaseof25kgissufficienttojustifydrycowtreatmentinlowSCCherd

假設(shè)牛奶價(jià)格為每千克2元人民幣，而干奶牛處理的成本為每頭牛50元，那末增加25千克的產(chǎn)奶量就足以彌補(bǔ)在體細(xì)胞計(jì)數(shù)低的牛群進(jìn)行干奶牛處理的費(fèi)用。HighSCCherdswouldshowevengreaterbenefits

對(duì)體細(xì)胞計(jì)數(shù)高的牛群產(chǎn)生的效益更大。CausesofHighBulkTankSCC(BTSCC)inNYStateHerds

造成紐約州牛群罐乳體細(xì)胞計(jì)數(shù)高的原因Study843DairyherdsinNYState研究包括紐約州的843個(gè)奶牛群Each1%increaseinherdprevalenceofstaphaureus,strepag,orcorynebacterium

bovisisrelatedtoaBTSCCincreaseof5,000cells/ml.

牛群流行的金黃色葡萄球菌、無(wú)乳鏈球菌或棒狀桿菌造成的乳房炎每增加1%，罐乳體細(xì)胞計(jì)數(shù)每毫升就增加5,000。FactorsassociatedwithlowerSCCinclude:controlofcontagiousmastitis;useofprovenpredips

與體細(xì)胞計(jì)數(shù)低有聯(lián)系的因素包括：控制傳染性乳房炎和采用乳頭藥浴。(iodine,chlorhexidine);cleancowstall;andregularmonitoringofherdmastitis(SCCandcultures)（碘溶液、洗必太）清洗牛欄并定期檢測(cè)牛群的乳房炎。JAVMA210:Wilson

CausesofHighBulkTankSCC(BTSCC)inNYStateHerds

造成紐約州牛群罐乳體細(xì)胞計(jì)數(shù)高的原因Thisstudyfoundthataincreaseof17,500inBTSCCwasassociatedwithdropinproductionof454kg/lactation

這項(xiàng)研究發(fā)現(xiàn)，罐乳體細(xì)胞計(jì)數(shù)增加17,500，每個(gè)泌乳期產(chǎn)奶量就減少454千克。ColiformmastitishaslittlerelationshipwithBTSCC–generallyoflowincidenceintheseherds

大腸桿菌乳房炎通常與罐乳體細(xì)胞計(jì)數(shù)沒有什么聯(lián)系，因?yàn)樵谶@些牛群中大腸桿菌的發(fā)病率低。JAVMA210:Wilson

HerdProductivityandBulkTankSCC(BTSCC)

牛群生產(chǎn)力與罐乳體細(xì)胞計(jì)數(shù)Resultsof>2,500farmsurvey–Dairy962,500個(gè)以上的奶牛場(chǎng)調(diào)查結(jié)果–Dairy96TheecategoriesoffarmsbasedonBTSCC

以罐乳體細(xì)胞計(jì)數(shù)為基礎(chǔ)的三種奶牛場(chǎng)分類。Low低<200,000(30.1%ofherds)Medium中200,000to400,000(54.6%)High高>200,000(15.4%)？？？Source:JAVMA218:OttHerdProductivityandBTSCC(2)

牛群生產(chǎn)力與罐乳體細(xì)胞計(jì)數(shù)（2）LowBTSCCherdproduced372kgmoremilkthanMediumherds($103/cow)

體細(xì)胞計(jì)數(shù)低的牛群比體細(xì)胞計(jì)中等的牛群多產(chǎn)372千克牛奶（103美元/每頭牛）。LowBTSCCherdproduced959kgmoremilkthanHighherds($292/cow)

體細(xì)胞計(jì)數(shù)低的牛群比體細(xì)胞計(jì)數(shù)高的牛群多產(chǎn)959千克牛奶（292美元/每頭牛）。Note:LowBTSCCmaynotbetheonlyreasonforhigherproduction,b