Dr. Jeff Reneau, Professor and Extension Animal Scientist – Dairy Management

April 28, 2007

There are many dairies in Minnesota who have made progress lowering their herd somatic cell count (SCC) over the past three years.  Some have been exceptional in keeping herd SCC below 100,000.  How do they do it?  Since they are the real experts, a survey was prepared and sent to the top 100 Minnesota DHI milk quality dairies to find out how they achieve milk quality success.  These herds rank in the top 5th percentile of 3,700 dairies for which bulk tank SCC data has been gathered for the past 2+ years. 

Seventy-two dairies completed the survey.  The average bulk tank SCC was 118,000 with a day-to-day variation of 19,700.  Their average standard plate count was 3,400.  Milk production was 23,323 pounds per cow.  Other than these items, they are pretty much like many Minnesota dairies including:

• Housing – 51% tie stall, 43% free stall, 6% compost barn
• Bedding – 82% organic (sawdust, straw, etc.), 18% sand
• Milking System – 58% pipeline, 17% herringbone, 13% parallel, 8% step up, 4% other
• Milking Frequency – 87% milk 2X, 13% milk 3X

Attitude has a great influence on herd management.  Henry Ford once said, “If you think you can, you can, and if you think you can’t, you’re right”.  Survey questions reflecting personal attitudes and management skill indicate that these low SCC dairies:

• are proactive and plan ahead to prevent SCC problems;
• prioritize work, being sure the most important things are done first;
• value teamwork and clear communications with everyone on the farm;
• build cooperative and productive relationships with employees and farm consultants;
• feel it is important to keep up to date with the latest in milk quality management;
• and, feel that doing a job right is more important than getting it done fast.

Each dairy was also asked to describe current management practices and to assess the quality of cow hygiene.  Responses indicate that:

• On average these herds have cleaner lower rear legs and udders
• 76% of those using organic bedding re-bed stalls daily
• 64% use more than 1 inch of organic bedding
• 83% of those using sand bedding place fresh sand in stalls weekly
• 94% report always keeping sand level with the stall curb
• 72% report using a full 10 to 20 second premilking cow prep
• 75% routinely forestrip
• 91% dry treat all quarters of all cows
• 67% use internal teat sealers at dry off
• 78% report using specially formulated dry cow diets

The final observation is that these dairies are very CONSISTENT. The magnitude of the bulk tank SCC variation can be a good indicator of the quality and consistency of farm management processes that result in milk quality.  Day-to-day bulk tank SCC variation was assessed for each dairy surveyed. 

How can you utilize BTSCC variation for improving your herd SCC?  For herds subscribing to MILKLAB, this calculation is automatically done on a daily basis. Herds selling milk to LOL, AMPI or First District Association, or whose milk is being tested at the Dairy Quality Control, Inc. milk testing laboratory, can get this automated service.  You can also evaluate your herd variation by following these simple steps:

• Take your last 20 to 30 bulk tank pickup SCC results and calculate the mean. 
• Subtract the difference between each consecutive pickup’s SCC results and average the differences.  This number is an estimate of your daily variation. 
• Plot them on the following table.  

SCC mean and day-to-day SCC variation for 3,700 Midwestern and Eastern U.S. dairies.

If your variation is higher as compared to the corresponding mean SCC, this suggests a need to evaluate and improve compliance to protocols and/or the consistency with which protocols are followed. SOPs (standard operating procedures) should be written, if they are not in place. Routine training should be implemented to be sure that each employee understands their duties and is committed to following all SOPs. Recent University of Wisconsin studies indicated that herds with more frequent training for milkers had lower BTSCC.

When the variation is low, the good news is that the employees are being consistent in their work. The bad news is that if the dairy is still not producing milk of desired quality, some things are being done consistently wrong. Take a closer look at how all tasks are performed, take measurements and make observations. Some indicators that might help identify the root cause of the problem include: cow density, cow hygiene score, bedding cultures, and bulk tank cultures.

While many dairy herds are doing most of the right things not all are succeeding in getting those things done consistently right all the time. This seems to be the greatest difference between our milk quality leaders and other Minnesota dairies.