Dairy MMA: Parlor Throughput vs. Optimal Milk Harvest

Train milkers to follow proper milking procedures. ( Mike Opperman )

Have you heard about Dairy MMA (Mixed Milking Arts)? 


This activity is not new to the dairy industry.  The last 5 years of low profit margins has produced more Dairy MMA than ever. Some owners are trying to get more milk per cow, some are trying to ship more components per day, most are simply trying to milk more cows.  The milking parlor has become ground zero for financial survival tactics.

Dairy MMA is the constant balancing act between parlor throughput and harvesting milk from well-stimulated cows with clean, dry teats.  The competition pivots around what is best for the cow versus how many cows can be milked per hour. 

How to identify Dairy MMA in your parlor
Research has established the important steps necessary to prepare a cow for milk harvest.  The ultimate goal is to invite your cow to fully participate in the process.  The chart below defines the key goals, their time requirements and Dairy MMA I have observed.
 

prep steps

 

 

 

 

 

 

 

Can we push too hard for production?
When working with biological systems, changes made to increase performance may reach a point of diminishing returns.  An example of this phenomenon is research recommending stocking densities of 120% in free stalls as the most profitable compromise between milk shipped and cow comfort.  The most comfortable would be one cow per stall.  The most milk shipped will occur by adding more and more cows per pen. The key word in this discussion is “profitability”.  I

I recently visited a dairy that had reduced their herd size from 3700 cows down to 3200 cows and were now shipping more milk per day with 500 fewer cows.  This is improved profitability.

I have visited a few dairies operating at 150% stocking densities and achieving very high milk production per cow. In these cases, excellent managers are pushing the envelope of the stocking density rule without seeing the diminishing return phenomenon. 

The assumption from milking more cows per hour through a parlor is shipping more milk per day with no other ramifications.  Excellent management however cannot overcome the physiology of the milk letdown reflex.  Short cuts or total elimination of key prep procedures do have negative consequences that may be dragging down your profitability.

Why is Dairy MMA Important?  
The milk letdown is hard wired in the cow so pre milking stimulation and the time from first touch to unit attachment has biological time requirements.  Additionally 80-90% of the milk in the cow’s udder is stored in the glandular compartment and can only be harvested with the release of oxytocin.  Increasing parlor throughput steals time from teat stimulation and lag time necessary to prevent double (bimodal) letdowns. 

Additionally teat end hygiene has a strong correlation with the quality of milk harvested and the risk of new mammary infections.  Why then are there so many variations in how cows are prepped and milked around the country?  Why do we have Dairy MMA?

Two Big Problems with Dairy MMA:
1.  Milking dirty teats has never been acceptable.  Attaching a cup to a dirty teat increases the risk of mastitis.  Every dairy farm system has its challenges. 

  • Grazing: Wet spots; rain; thin manure creating dirty parlors        
  • Pack: No deep stirring; not adding dry material regularly
  • Stanchion: Not keeping stalls clean & dry; cow positioning    
  • Free stalls: Poor grooming; bedding material choice; cow positioning
  • Alternative bedding: Recycled sand or manure; moisture content; CFU levels
  • Cross vents: Humidity increasing CFU’s in bedding; air quality
  • Open lots: Excellent in dry weather & challenging in wet weather
  • Employee milkers: No one cleans a teat like an owner

Parlor throughput has a negative correlation with teat end hygiene scores.  Increased new infection rates are expensive even if you choose not to treat any clinical mastitis.  The highest dollar loses from mastitis result from decreased milk production over the lactation and the increased cull rate.  Overall a case of mastitis can steal $200 - $500 from your checkbook.

2.  Bimodal letdowns have traditionally been criticized for lengthening average unit on-times and for exposing teat ends to elevated vacuum levels just like overmilking from delayed unit detachment.  New research has revealed that the elevated teat end vacuum is real but the waste of time is not happening. Statistically a bimodal letdown is not longer then a good letdown because less milk is harvested on average from the gland. At this time it is assumed that the elevated claw vacuum is producing changes to the teat end, narrowing the streak canal and impeding milk flow. 

This phenomenon appears to be dose-related, the longer the bimodal event, the less milk harvested. A 30-60 second bimodal milking may harvest up to 3 lbs. less milk during a single event.  A bimodal milking greater than 60 seconds may harvest as much as 6 lbs. less milk.  The milk left in the gland is beyond residual milk and an acceptable strip yield.1 

The Blind Side of Dairy MMA
Bulk tank somatic cell count (BTSCC) is not a good barometer of Dairy MMA.  Remember, if your milkers are identifying new, clinical mastitis cases consistently, your BTSCC may not increase a lot because the high cell count cows are in your hospital string.  If you “don’t have time to fore strip”, you no longer have a consistent method to ID clinical mastitis.  Add to this decision the fact that more and more dairies no longer have individual cell count data and you create a milk quality management challenge akin to driving blind in a fog.  All you have is the BTSCC and at best this is a 30,000-foot view of your herd.

Rates of mastitis are a better evaluation of Dairy MMA.  New clinical mastitis rates should be less than 2%/month in the milking herd.  New infection rates (this requires individual somatic cell count data) should be less than 7% per month with heifers lower than mature cows.

An acceptable goal for herd level bimodal milking events should be less than 15%.  Pregnant and mid to late lactation cows typically have a higher frequency than fresh and peak production cows.  I am finding more and more herds with bimodal events averaging 40-50%.  The most extreme example was a herd with 90% bimodal events.  

Field reports typically reveal that adjusting a dairy’s MMA to milk cleaner teat ends can produce a reduction in new infection rates.  A new experience in a select few herds has shown reducing the percentage of bimodal letdowns produces more milk shipped per day.  What is your herd’s new infection rate or bimodal percentage?  For the sake of parlor throughput, have you pushed your herd beyond the point of diminishing returns?

For more information on milking procedures, watch an eight-part video series on the entire milking process at www.dairyherd.com/DHMHowTo 

 

1 Decreased milk yield is associated with delayed milk ejection 
R. J. Erskine,1*  B. Norby,1  L. M. Neuder,1  and R. S. Thomson2 

1Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824 
2Department of Animal Sciences, Michigan State University, East Lansing 48824 
J. Dairy Sci. 102:6477–6484 https://doi.org/10.3168/jds.2018-16219 

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