As I sat and watched my tractor tire go flat (I actually had a spring from the swather puncture it)... I had an epiphany of what thoughts in the dairy industry have had the air go out of them. In business terms, this is called a paradigm shift.
You don't need history, that's like driving while looking through the rear-view mirror!
Never has it been more important to record and look at treatment history.
(History also tells you what person or persons need the training.)
I highly recommend using industry software to help. DHI-Plus does a nice job of tying treatment protocols to the diagnosis helping you understand what pen, what group, and what success you are having with your treatments.
All you need to know is your 21-day pregnancy rate.
First and foremost, 21 days is just three weeks of time. It is not and never has been the estrus cycle of a cow.
Adding information on services/conception, breeding information by technician, days of the week when breeding is occurring, and other relevant information is critical.
Treating the DHI hot sheet
What we have to remember is that somatic cell count includes all cell types—not only the white blood cells and bacteria—but, somatic cells that line the interior of the udder.
What you want to do with somatic cell counts is to look for large changes... and what is happening over time.
To decrease your calving interval, you lower your voluntary waiting period.
This only works if you have cows that are in a positive energy balance early and are cycling.
Again, it is about efficiency.
“Can I wait and have the cow’s cycle once or twice before breeding and get more pregnant?”
The answer is yes. Your service per conception goes down.
You have an equal chance of getting a cow pregnant on any days-in-milk.
This works with large numbers of cows over multiple farms. However, on a single dairy, all of us have had reproductive culls that are bred numerous times.
Their chances of success are lower the more times they are bred.
What caused all of these paradigm shifts?
It comes back to one thing... taking the time to record the things you do on the farm—including treatments and cow-related events.
When you compare these recorded events to your protocols, you will begin to see the difference between your perceptions and reality.