Presentation on theme: "Jeff Reneau University of Minnesota"— Presentation transcript:
1 Jeff Reneau University of Minnesota P-MR-1Who Needs Cow Prep?Jeff ReneauUniversity of MinnesotaWho needs cow prep? The answer to this rhetorical question is easy……all dairies need consistently effective pre-milking cow prep procedures to assure high quality low bacteria and SCC milk and to reduce mastitis.
3 Clean, Stimulated, and Calm Cow Readiness?Photo courtesy of IBA Millbury, MAClean, Stimulated, and Calm
4 Routine removal of long hair from the udder Decrease clinical mastitisDecrease SCCImprove microbiological milk qualityDecrease prep timeIncrease effectiveness of prepPhotos courtesy of IBA Millbury, MA
5 Cow Handling Adverse effect of fear on milk yield and behavior Rushen, J. et al, JDS: 82, , 1999Staged photo courtesy of IBA Millbury, MACow HandlingCows avoided adverse handler10% less milk when adverse handler present2 times more residual milk when adverse handler is present
6 Milker Readiness ? On time Clean clothing Gloved hands Std procedures Routine trainingPhoto courtesy of IBA Millbury, MA
7 DefinitionsMilking Routine = Sequence of cow prep events used to facilitate optimum prep time and prep-lag-time.Cow prep = Procedure used to clean and sanitize teat surfaces, stimulate milk let down, apply and align milking units.
8 Definitions (cont) Optimum 10-20 seconds Optimum 60-120 seconds Prep time = time taken using tactile stimulation to clean teat surfaces and properly prep the cow for milkingOptimum secondsPrep-lag time = Time from the initial tactile stimulus during cow prep to application of the milking machineOptimum secondsContact time = time allowed for teat pre-dip sanitizer to kill bacteria before being dried offOptimum is 30 seconds
10 Reality of Milking Time Pressures Over 50% of dairy farm labor is used for milking cows Greatest investment $ for large dairies = milking parlor Time needed to get all the cows milked on large 3X dairies especially with high ratio of cows to size of milking parlor thus requiring higher throughput speed Time needed for a smaller labor force to complete other work on small dairies
11 Ideal milking procedure Minimizes water useFocuses attention on teat surfaces onlyUses a sanitizer (pre-dip)Assures complete pre-dip coverageAllows pre-dip 30 seconds contact timeProvides milk letdown with seconds of tactile stimulus by cleaning teats and/or fore-stripping
12 Ideal milking procedure Provides a prep-lag time of secondsRemoves all dirt and manure from teatsMinimizes variation between milkersMinimizes “machine-on” timeDoes not slow down milkingSee QCF- 11 Ideal Cow Prep Fact Sheet
13 Milk Letdown Mechanism Oxytocin Response&Autonomic Local ReflexMilk Letdown Mechanism
14 10-20 seconds of manual stimulation Oxytocin milk letdown responseAutonomic local reflexRelaxes teat sphincter and milk ductsIncreases mammary blood flowDecreases response threshold of myoepithelial cells to oxytocinOxytocin released to bloodstream from pituitary glandOxytocin attaches to oxytocin receptors and causes myoepithelial cell contraction and milk ejection
15 Interaction of milk ejection mechanism with reproductive hormones and dietary minerals OxytocinLocal NS ReflexProgesteroneOxytocin ReceptorsEstrogenTeat stimulation causes release of oxytocin from the pituitary which flows to the mammary gland via the blood attaching to oxytocin receptors on the smooth muscle myoepithelial cells surrounding each milk secreting alveolar cell in the mammary gland (also to the myometrial cells of the uterus). This will cause smooth muscle contraction resulting in milk ejection. The tactile teat stimulation also stimulates a local autonomic reflex response relaxing teat sphincters and increase mammary blood flow thus augmenting oxytocin delivery to the mammary gland. Under the influence of the hormone estrogen not only are there more oxytocin receptors present but they also have an increased sensitivity to the presence of oxytocin resulting in greater smooth muscle contraction. Progesterone, on the other hand reduces both oxytocin receptor numbers and sensitivity. Therefore in late lactation during pregnancy when the influence of progesterone predominates cows are not as responsive to oxytocin and thus may require a greater stimulus and longer prep-lag interval to consistently achieve complete milk ejection. Diet can also influence the intensity of smooth muscle contraction. Calcium, magnesium, cobalt and manganese need to be supplied by the diet in adequate amounts to assure fully functional smooth muscle contraction.CalciumMagnesiumCobaltManganeseMilk Ejection
16 Myometrial oxytocin receptors in relationship to the estrus cycle. This slide demonstrate the effect of estrogen in increasing the oxytocin receptor site affinity for oxytocin during the estrus cycle thus explaining the physiological reason for the increased smooth muscle tone in the uterus during estrus. Producers who do AI on their cows will be familiar with the increased uterine muscle tone at the time of breeding when a cow is in “heat”.Roberts et al., 1976
17 Increase of oxytocin receptors in the mammary gland. Note here that in response to the increasing circulating estrogen at the end of gestation and during early lactation that the number of oxytocin receptors in the mammary gland increase. This partially explains the reason eliciting a milk let-down in an early lactation cow is easier than in a late lactation pregnant cow where the more dominant reproductive hormone is progesterone which not only reduces the number of oxytocin receptors it also reduces the sensitivty of oxytocin receptors to oxytocin. Therefore in mid-late lactation achieving consistent milk let-down response will require a greater amount of tactile stimulation than in early lactation.
18 Prep Time Is ImportantLess than 10 seconds does not provide adequate milk letdown stimulation10-20 seconds is adequate for all stages of lactation in American Holstein cowsRasmussen et al.JDS 75:
19 Prep Time Is ImportantFore-stripping is a powerful milk letdown stimulus and should be used early in the cow prep procedureRasmussen et al.JDS 75:
20 Purpose of fore-stripping Early detection for clinical mastitisCreates a strong milk letdown stimulusAssures teat canal is openPhoto courtesy of IBA Millbury, MA
21 Pre-milking cow prep10-20 seconds tactile stimulation for optimal milk letdown response20-30 seconds pre-dip contact timeRemove all dirt & manure (bacteria) from teat surfacesPhoto courtesy of IBA Millbury, MA
22 Prep-lag timeTime from first tactile stimulation to machine attachment2X milking seconds3X milking secondsNever longer than 3 minutesPhoto courtesy of IBA Millbury, MA
23 Summary Milking Procedure Steps Pre-milking teat dippingCleaning teat endsFore-strippingDrying teatsPost-milking teat dippingApplying machines with sec prep-lag-timePhotos courtesy of IBA Millbury, MA
25 There are many combinations of the pre-milking cow prep procedures that will meet the criteria of an “ideal milking procedure”. Below are listed a couple of examples:Assumptions:pre-dip 4 teats takes ~ 3-5 sec per cowgloved hand wiping sides & teat ends + fore-stripping 2 squirts from each teat takes ~ sec per cowdrying including teat ends takes ~ 10 sec per cowapplying machines including alignment takes ~ 5-7 sec per cowtransit time between cows ~ 2-3 secCriteria:10-20 sec min tactile stimulation needed (cleaning, fore-stripping, drying)30 sec pre-dip contact timesec prep-lag time rangeExamples:Pre-dip 6 cows, return to first fore-strip + dry + attach 6 cows = ~ sec PLTPre-dip + clean & fore-strip 4-6 cows, return to first cow, dry + attach 6 cows = 60 – 110 sec PLTGet a stop watch and design a protocol that fits your farm and meets “ideal milking procedure” criteria.The point of the Pre-milking procedure diagram in the previous slide is not to prescribe a dogmatic milking procedure but rather to display milking procedure steps in the context of the timing criteria needed to establish a procedure that optimizes milk let down stimulus, pre-dip contact time and prep-lag time in order to minimize machine-on-time, maintain healthy teats/udder and achieve high quality milk production.The assumptions are estimates based on the authors experience in observing properly done milking procedures on farms where quality milk is consistently produced.The criteria are based on and supported by considerable research on lactation physiology of milk let-down response, teat sanitation procedures and milking efficiency.
26 Milk flow phases in kg/min Tancin et al., JDS 2006 Increase Plateau decline over-milkingTime / minutes8-10 seconds prep, No prep-lag, 10 month studyn = 19,300 udder milk flow curves
27 Factors effecting milk flow characteristics (Tancin et al 2007) Increase phaseCow prep time / intensityPrep lag timePlateau phaseAmount of milkMilkabilityDecline phaseRelease alveolar milk to cisternOxytocin/prep-lagOver-milking phaseFront quartersATO settingsManual override useMachine strippingMachine alignment affects all aspects of milk flow and may also effect teat health
28 Variation of expected milk flow rate based on PLT.
29 Timing of Machine Attachment (prep-lag time) Is Important! seconds acceptable range2X milking optimum seconds3X milking optimum secondsLess than 60 seconds not desirableLong delays of greater than 3-4 minutes may impair complete milk ejectionRasmussen M. et al., JDS 75:2131, 1992.Shehaden, K. & Bruckmaier, R., JDR 78:97, 2011.Waters, R. et al., JDS , 2011.
30 Either immediate or delayed (> 3 min) attachment resulted in more “abnormal” teats ends(Rasmussen 1992)1234
31 Maximum of 20% > Score 2 Teat End Condition Factors affecting teat conditionTeat size, shape, positionMilk productionParity, stage of lactation# milkings /dayPulsation vacuum, linersMachine-on time……OVERMIKING!12345Maximum of 20% > Score 2
33 Effect of standardized milking routine (Rasmussen et al JDS 1990) ExpprotocolDIM10 days100 days200 days270 daysStdPrepPrep-lagInterval1.2 minUnit-onTime8 min7 min6 minControl4.0 min2.5 min2.4 mintime10 min
34 Value of optimized and standardized milking routine 5.5% fat corrected milk yieldReduction in bacteria and spore counts in milkHigher milk flow rates and shorter machine on timeImproved teat end conditionLower SCC
35 Keep cows standing immediately after milking to allow time for teat canal closure
36 Monitor Performance Observe milk filters Periodic milking routine evaluationsRoutine SCC analysisRoutine milking systems maintenanceRoutine bulk tank culturingColiforms and Non-ag streps
37 Important Take Home Message! Teat hygiene & condition is very important! Whatever bacteria are on the teat surface when the milking machine is applied will end up in the milk!!!Photos courtesy of IBA Millbury, MAImportant Take Home Message!
38 Summary ideal milking routine Prep-time = seconds and teat surfaces are effectively cleanedPrep-lag time = seconds to maximize oxytocin effectStandardize: every cow is milked exactly the same at every milking for her entire lactation
39 Plan of action Analyze present milking routine Design routine ideal for farmSet standards of performanceProvide regular trainingMonitor results
40 Thank YouThank YouThis 800 cow Minnesota dairy consistently has a BTSCC under 150,000. Quality does COUNT! The picture tells the story better than words.