Testing for subclinical mastitis should be part of your fresh-cow protocol, says Gary Neubauer, a veterinarian and senior manager of Dairy Technical Services for Zoetis.

“Besides monitoring fresh cows for signs of metritis, ketosis and other disorders, it also is the best time to test for high somatic cell counts (SCC),” he says. “Cows with individual SCC in excess of 200,000 cells/mL may indicate a subclinical mastitis infection.”

Somatic cell counts above 200,000 cells/mL can lead to clinical mastitis, and recent research with thousands of cows shows milk losses from higher cell counts can be substantial.

“Cows with a high SCC at first test (greater than 200,000) can experience an increased loss of 576 pounds of milk, when compared with cows having clinical mastitis in the first 60 days of lactation,” says Mark Kirkpatrick, also a managing veterinarian with Zoetis. Other research also shows cows with mastitis take longer to conceive, have days open, and often face other health issues.

That’s why Neubauer and Kirkpatrick recommend systemically testing every cow for subclinical mastitis shortly after calving. They suggest:

• Test all fresh cows for SCC on Day 2 or 3 after freshening (or at the earliest opportunity based on management). Options include the California Mastitis Test (CMT) or a digital SCC counter for fast and accurate results.
• Culture milk samples to identify mastitis-causing pathogens and to develop a herd profile to establish prevention and treatment protocols with your veterinarian.
• Consider treating cows with SCC greater than 200,000 cells/mL (CMT score of 2 or higher) plus a positive culture. “Ask your veterinarian about mastitis therapies specifically labeled to treat subclinical mastitis infections. Keep in mind that not every cow that tests positive for subclinical mastitis is a candidate for treatment,” says Kirkpatrick.
• Examine the cow’s health history before treatment and consider:
• Culture results
• Parity of the cow
• Number of previous clinical mastitis cases and what quarter was previously affected
• Previous SCC test data history, if available
• Chronicity of mastitis cases
• Other persistent health issues, such as pneumonia or lameness
• Production and reproductive records

Read more about Zoetis’ testing protocols, part of Zoetis’ Healthy Start Program, http://bit.ly/MoreMilkQuality