Herd-level ketosis monitoring available from AgSource

Today we have low-cost ways to monitor whether cows have ketosis, including cow-side blood tests that cost from $0.24 to $2.00 per test. In an ideal world, producers would have time and money to test every fresh cow for ketosis twice between 5 and 20 days in milk, and some are. At $4/cow/year, that adds up to $6,000 including heifers in a herd of 1,000 cows, which is a small price to pay compared to an estimated cost of $289/cow/case of ketosis.

But sometimes it's time, not money, that's the most limiting factor on a farm.

If you suspect that your herd has a low incidence of ketosis, it's hard to commit to spending the time and money on testing. But Gary Oetzel, D.V.M., suggests that just because your ketosis incidence is low today does not mean it will be tomorrow.   

"Ketosis prevalence is quite variable between herds and even within herds month-to-month, according to data I've seen," Oetzel explained during the AgSource annual meeting on Wednesday, held in Bloomington, Minn. The announcement of the new product was held in conjuction with the annual meetings of AgSource and Genex, both of which are subsidiaries of Cooperative Resources International (CRI). 

That variability is why University of Wisconsin researchers teamed with AgSource to develop a tool to take the guesswork out of herd-level ketosis incidence. The new tool, KetoMonitor®, will be available to AgSource Holstein customers immediately at $0.10 per active cow per test. For those enrolled on MyAgSource, a $30/year and $0.35/cow collection of digital reports, the service would be free.

But as a non-patented model, similar versions could be available through other DHI labs with an investment in technology - AgSource purchased 3 new milk testing lines at a price tag of $500,000 each in the last year, allowing them to test milk for beta-hydroxybutyric acid (BHBA) and acetone. 

Surprising research

Last summer, the University of Wisconsin team of Oetzel, Heather White, Ph.D, and Tawny Chandler, set out to do find a better way to test for ketosis — through milk — after an April discussion with AgSource. They tested over 500 fresh cows using both blood-based (the gold-standard) and milk-based ketosis tests, using BHBA and acetone, and some follow up work on 100 additional cows later to verify results.

They knew that the milk fat to protein ratio (F:P) was correlated as a herd-level ketosis indicator with 22% accuracy. After 3 months of testing, in May, June, and July, both milk and blood from the same cows, they found they were getting accuracy to match blood tests was above 95% for heifers, and above 80% for cows. Overall, it's nearly a 70% correlation for accuracy to predicting ketosis using milk BHBA and acetone, tripling the accuracy of the F:P indicator. 

After creating a model that would help find the cows most likely at risk for ketosis, they ran 28,711 fresh cows from beta-testing herds through the new technology and found that there was 18% herd prevalence; 7% for first-calf heifers and 25% for cows.

Their model suggested 15,808 of those cows were negative for ketosis, while 3,261 were positive. But the positive cows were nearly 4 times more likely to be culled (3.5% versus 1%), meaning if they had been caught earlier they could have possibly been saved.

With these results, the KetoMonitor® was validated and quickly turned into a product. Currently, the results are available for Holsteins, with a Jersey model due in May. Crossbreds run through the model have behaved the same as Holsteins.

The researchers aren't suggesting that you can replace blood testing with this herd-level milk testing. But they are aiming to make testing cheaper. You can use your January KetoMonitor® results to make your February results look better, if you make some changes within the herd.

"A 1,000-cow herd pays just $100/month for the milk testing," said Heather White, an assistant professor in the Department of Animal Science. "We're recommending that if you have over 15% incidence in your herd, you test fresh cows weekly or every-other week using a cow-side test. If it's over 50%, a blanket treatment of all your cows is in order."

That results in a savings of $3,000 per year in testing, and lots of time, if you have a 1,000-cow herd that only reaches above 15% for four months of the year. But the savings could be much greater if you can prevent displaced abomasums, involuntary culls, and other veterinary costs. A spike in incidence can force you to look at crowding in your dry pen, bunk space, or other issues.

White, Oetzel, along with graduate research assistant, Tawny Chandler, will present the results at the American Dairy Science Association annual meeting this July in Orlando, Fla., less than a year after results were collected. "I'm pretty proud, and that's why I worked so hard on it," Chandler said of the quick research-to-product findings.

Future findings

With this equipment purchased, Robert Fourdraine, AgSource Vice President of Product Services and Development, suggested that future research could work to look at genetics and ketosis or whether ketotic cows were more likely to have mastitis. 

But current beta-test herds seem happy with the product, the team said, one telling Oetzel, "This could be the biggest thing since somatic cell count."