Kansas State University professor Jeff Stevenson started the monthly Hoard’s Dairyman webinar with a timeline overview of management tools that have aided in the reproduction progress of dairy cows over the past four decades. These advances started with hormones, synchronization programs, and most recently sexed semen.
The majority of attendees (74 percent) use visual observation while a small portion uses little detection and relies nearly all on timed artificial insemination (TAI). These results are in line with the National Animal Health Monitoring System (NAHMS) report that shows 93 percent of producers use visual detection. These results helped craft the discussion.
Early pregnancy loss is a mystery not totally solved. There is loss to technician interference in the first month, genetic issues, and mastitis. Yes, cows with mastitis can lose pregnancies due to the toxin produced by the udder infection. But, there are some losses that still cannot be explained.
For those who tail chalk, Stevenson suggested using different colored chalk for various functions, and even writing numbers (day of the month) on the rumps of cows to easily see breeding dates. “Saves time looking up a breeding date on a cow on your phone or tablet if you can see the exact day she was bred on her rump,” remarked Stevenson.
There are just over a dozen activity monitors on the market to assist in heat detection. Some are located on the rump, ankle, and now ear. A few even track eating bouts to aid in determining estrus. Based on one dairy’s research, activity monitors added value when looking at the number of cows pregnant at 150 days in milk because they have nearly double the estrus detection rate of timed A.I.
The main reason for the value of activity monitors is the ability to identify cows in silent heat. Of the cows not visually detected in heat, over half to three-quarters of those cows did indeed ovulate. And by not catching them in heat, they were not bred, and therefore did not conceive, and important time was lost.
In the cases of synchronization programs, Stevenson shared several options including ovsynch and presynch. Some were longer in protocol duration, others required more injections, but all needed careful attention to timing.
It was interesting to note that the length of the estrus cycle has been extending over time, now averaging between 21 and 23 days between heats.
“Adding heat detection to synchronization programs adds value to a dairy operation,” concluded Stevenson.
As far as pregnancy diagnosis, transrectal ultrasonography can be done as early as 28 to 32 days. Transrectal palpation can be done as early as 35 to 40 days. For those using PAG tests for milk and blood to determine pregnancy, day 32 to 35 is the target. If tests are completed on day 32, results are back in a few days and a timed A.I. program can begin immediately and not wait as long for a natural heat to determine that the cow did not conceive.
“The purpose of a pregnancy diagnosis is not to find pregnant cows, but to find the open ones,” shared Stevenson. Those open cows need to be found and serviced.
Next Month’s Topic:
Join us for the webinar, “FARM in 2017” on Monday, February 13, at noon (Central time).
Farmers Assuring Responsible Management (FARM) is dairy’s comprehensive quality assurance program encompassing over 98 percent of America’s milk supply. Join FARM’s Emily Yeiser Stepp, Ryan Bennett, and Jamie Jonker as they give an overview on animal care, antibiotic, and environmental stewardship.
Register at www.hoards.com/webinars.
The author is the online media manager and is responsible for the website, webinars, and social media. A graduate of Modesto Junior College and Fresno State, she was raised on a California dairy and frequently blogs on youth programs and consumer issues.