Legend has it that a frog will sit in water while the water gradually heats up to the boiling point. It is just that — a legend or myth. A frog can detect changes in water temperature and will try to escape if things get too hot.

But how many times, as humans, do you just accept gradual changes in your environment? Sometimes, the change is so gradual that you lose your bearings, and what was once viewed as abnormal becomes normal.

This happened to Jim Reynolds 12 to 13 years ago. A bill was proposed in the California Legislature that would prohibit the movement of downer livestock. When Reynolds read the bill at home one night — his wife worked as chief of staff for a state senator, and many of her colleagues thought Reynolds should read the bill since he was a practicing dairy veterinarian — he realized that he had allowed the line to move too far when it came to downer cows on some of his clients’ farms. He raised his hand and smacked his palm against his forehead. “Gee,” he thought, “these guys (proposing the legislation) are right — at the very least, we shouldn’t be dragging downer cattle along the ground with chains to get them onto a truck.”

Today, downer cows are one of Reynolds’ pet peeves. He is quick to point out that downer cows are not normal; they are an aberration. Indeed, you can prevent a vast majority of downer-cow cases by stepping up your management.

Too many downers

According to the 1999 National Market Cow and Bull Audit conducted by Colorado State University, 1.5 percent of all dairy cows going to slaughter were downer or non-ambulatory. The audit was conducted at 21 slaughter plants.

If you apply that 1.5-percent against the 2.6 million dairy cows that are slaughtered each year at USDA-inspected slaughter facilities, it equals 39,000 downer cows.

Ninety percent of those cases could probably be prevented with better management on farm, says Temple Grandin, nationally recognized expert on animal handling. “We need to be working on preventing downers,” she adds.

Grandin bases her comments, in part, on the observation that “relatively few dairies are responsible for a huge majority of the downers.” She works with meatpacking plants on various facility design projects, and has observed that the plants can readily name the dairies that contribute the most downers. 

Well, you say, it’s easy for Grandin and Reynolds to make these comments because they are not dairy producers. (Grandin serves as assistant professor of animal science at Colorado State University, and Reynolds is a dairy
production medicine clinician at the Veterinary Medicine Teaching and Research Center in Tulare, Calif.)

Neither Grandin nor Reynolds suggests that all cases of downer cows can be prevented. They simply point out that the number can be reduced significantly.

   Don Bennink, managing partner of the 6,400-cow North Florida Holsteins in Bell, Fla., agrees that some downer cows will occur, despite everyone’s best efforts. “To say we can never have a downer cow is a little bit naïve,” he says.

Some cows will appear perfectly healthy one day, and then are down the next day due to a health condition known as bovine leukosis virus (BLV). “Sometimes, you suspect it (ahead of time), and sometimes you are totally unaware, Bennink says. BLV is virtually impossible to prevent — especially in the South — because insects can help spread the infection. 

North Florida Holsteins has tried different rubber mats over the years in order to find the kind of non-slip flooring surface that will help prevent cow injuries. In so doing, the dairy has minimized a major cause of downer cows — slippery flooring — that plagues other dairies across the country.

Critical control points

Reynolds says he only knows of one study that’s ranked the causes of downer cow syndrome. That study, conducted by researchers at the University of California-Davis and presented at the Livestock Conservation Institute annual meeting in 1996, found that “injury” was the most common cause. Of the 50 cows studied, 19 had injuries that led to their down condition, 12 experienced paralysis from difficult calvings, and the remaining cows had an assortment of problems.

Installing non-slip surfaces or keeping surfaces reasonably dry can prevent many injuries. Or, having a hoof trimmer come in and treat the lame cows quickly enough that their lameness doesn’t become debilitating. And, breeding cows to “calving ease” AI sires can reduce the number of difficult calvings.

Grandin says the critical ingredient on any dairy is the right attitude among the people in upper management. If upper management wants to cut down on the number of downers, it will get done.

Now that the U.S. government has banned downer cows from entering the human food supply — because of the Bovine Spongiform Encephalopathy case diagnosed in late December — you have a strong economic reason to prevent downers, because no one else wants them except perhaps the renderer.