Adult cow death loss is right around 10 percent for most U.S. dairy herds, but Colorado State University’s Dr. Franklyn Garry believes doing one thing could significantly reduce the number of cows that die on your dairy.

Coffeen peggy
Coffeen is a former editor and podcast host with Progressive Dairy. 

“I believe we can get down to 3 percent on really good dairies, or at least 4 to 5 percent on most dairies,” Garry said. “The way to get that down is by understanding what went well versus what went wrong.”

How can you do that? By performing postmortem examinations. Borrowing a common practice from the feedyard business, Garry encouraged dairy producers to dig deeper into the true cause of cow death by opening up the animal and studying her from the inside.

All too often, the only recorded data regarding a cow’s death is the word “dead.” But, as Garry pointed out, “That doesn’t tell me why she died.”

Even dairies that identify a suspected cause of death are only making their best guess. Garry spent time on a few large dairies, comparing the recorded cause of death to what he determined to be the actual reason from a necropsy. He found a high level of error, noting, “About 50 percent of the time, the dairyman was wrong about the cause of death.”


Garry encouraged dairies to perform necropsies during these instances in order to determine the real reason the cow died:

  1. Sudden death
  2. The cow was treated for sickness, but efforts were ineffective

The dairyman certainly stands to benefit from determining the true cause of death. A postmortem examination and diagnosis with the help of a veterinary professional can identify disease within a herd, thus preventing further losses by having an effective treatment plan in place for the sickness.

“This isn’t rocket science. It’s relatively simple stuff,” Garry added. He offered a few simple words of advice.

Tips for performing a necropsy:

  • Conduct the necropsy as soon as possible after the animal has died in order to obtain fresh tissues for sampling and accurate diagnosis. Within the first few hours of death is ideal.
  • Always place the cow on her left side, so the rumen will not obstruct access to organs.
  • Keep the cow’s hide as intact as possible. This will add value to the carcass if it is later picked up by a rendering plant.
  • A good location to perform a necropsy is a cemented area that is well lit and protected from the elements. An ideal location has running water.
  • Avoid areas where fluids from the carcass could drain into feed or places where live animals are kept.
  • A shingle knife works well for cutting through the tough hide while avoiding puncturing the guts and stomach.
  • Cut down the midline, starting from the throat, through the front legs to the udder, then up and around the udder to the back leg.

Collecting and submitting samples to a diagnostic lab:

  • Obtain samples from the organ(s) thought to be associated with the disease symptom (i.e., if respiratory disease is suspected, sample the lungs).
  • Sample any other tissue that looks abnormal (red, swollen, discolored).
  • In some cases, a photo is all that is needed to make a diagnosis:
    1. Before opening the carcass, place the ear tag on the cow so the ID numbers are visible and snap a photo.
    2. Once the carcass is open, take pictures of the infected tissue and email to the diagnostics lab.
    3. If a diagnosis cannot be made from the photo, mail in a sample at the veterinarian’s recommendation.
  • Keep in mind that testing for metabolic diseases requires a blood sample, while testing for neurological diseases requires brain tissue. If this is required, send the entire head to the lab instead of opening it up.
  • Be sure to send samples in leak-proof containers.
  • If sending a sample in a syringe, remove or cap the needle.

What to do when you are done:

  • Dispose of the carcass in a compost pile, or have it picked up by a rendering plant.

For the rendering plant: Open the carcass systematically so that once the necropsy is performed, it can be shut and appear mostly intact from the outside. Hold it together by tying or “sewing” it in place.  PD

For a complete guide to performing a proper dairy cow postmortem examination, view the “Dairy Cattle Necropsy Manual” published by Colorado State University and Integrated Livestock Management.

Dr. Franklyn Garry, along with Dr. Don Sockett and Dr. Christine Watson from the Wisconsin Veterinary Diagnostics Laboratory, presented this information at the 2016 PDPW Business Conference.

Peggy Coffeen

PHOTO: Staff photo.