Reducing cell counts takes far more work than culling cows
The conventional wisdom is that you only need to cull a few high-cell-count cows for your bulk tank average to magically fall below 400,000. Think again.
Eric Diepersloot is herd manager of the University of Florida’s Dairy Research Unit, located 10 miles north of Gainesville. In the fall of 2006, when Diepersloot took over management of the 520-cow unit, his department head ordered him to get the herd’s somatic cell count (SCC) below 400,000 cells/ml.
"It wasn’t until 2008 that we were able to get our cell count below 400,000," he says. "In that time, we culled 90 head. You can cull your way out of a high cell count, but you can’t cull your way out and stay in business."
More on University of Florida protocols
The biggest thing Diepersloot had to do was to change the culture of the dairy. "We needed to change employee expectations, so we developed written goals, written standard operating procedures [SOP] and then held monthly meetings to help employees understand the ‘why’ of what we were doing," he says.
The new SOP, now at more than 90 pages, is the guide to all operations at the unit. All employees have access to it. It details step-by-step milking procedures, all treatments that have been approved by university veterinarians and reproduction protocols.
When Diepersloot took the new milking procedures to the milking crew, it was immediately met with resistance because of the perceived extra work that it would entail.
A second meeting was required, this one to explain the need for the new procedures:
- The unit’s SCC was between 500,000 and 600,000.
- The unit had far too many clinical cases.
- Following the procedures would properly stimulate cows’ letdown and actually increase milking speed. Overall milking time would decrease.
- The procedures are designed to lower SCCs and clinical cases. As a result, there would be fewer cows in the hospital.
"Nobody likes to milk the hospital pen anyway, so let’s change things so we have less cows in the hospital pen. Everyone can agree on that," Diepersloot says.
Monthly meetings are now held to reinforce the SOP in the minds of employees. Last month, for example, Diepersloot had a university veterinarian do teat dip scoring as cows left the parlor.
"Our milkers were a little too much in a hurry, and they weren’t getting all the teats covered adequately," he says.
Diepersloot presented the scoring results at the next meeting. This wasn’t done to blame anyone; it was simply to reinforce the need for adequate coverage.
There are three key areas dairies should address for driving down cell counts, Diepersloot believes: milking prep procedures, freestall management and reproduction.
One of the first orders of business was to provide more detail for each of these protocols.
Rather than just say "dip, strip and attach," the milking prep SOP outlines specific steps for each process, including how many cows to prep and in what order before moving on to the next group.
Next, Diepersloot attacked freestall management. He worked with longtime University of Florida dairy adviser David Bray and his shop crew to design a tractor attachment to clean and level freestall beds twice daily. Sand bedding frequency was doubled to twice weekly, though the amount of actual sand delivered each week was kept the same.
The third area, reproduction, is important for two reasons. First, good reproduction gets cows bred sooner so that days in milk don’t string out. Cows long in milk don’t produce much anyway, and if they are chronically infected, they contribute a significant number of somatic cells to the bulk tank average.
Second, good reproduction rates mean there are more heifers coming through the system. That allows heavier culling of older, chronic cows. Without that push, most dairy managers choose to keep these cows simply to maintain cash flow.
The first change made by Eric Diepersloot, herd manager of the University of Florida’s Dairy Research Unit, was to provide detail for milking standard operating procedure (SOP). The original SOP was very general:
1. Wash all groups in the wash pen for four minutes.
2. Bring in one line of cows.
3. Starting with the first cow, take two strips of milk from each quarter.
4. Attach unit.
The new SOP has milkers work with groups of four cows. Workers predip and strip each cow, going back to dry teats with a new towel for each cow and attaching units. They are then instructed to go to the next four cows and so on, until units are attached to all 12 cows on that side of the parlor.
Diepersloot used milk flow graphs, which showed increased milk flow and more cows milked per hour. These results confirmed that the procedural changes were working.