The death rate among cows on U.S. dairy farms has increased over the last couple of decades.
The average rate was 3.8 percent in the 1996 National Animal Health Monitoring System report; 4.8 percent in the 2002 report, and 5.7 percent in the 2007 report. Other studies suggest that it is higher than that.
"Death is the most costly cause of ‘herd removal,"" Frank Garry, veterinarian and professor of Integrated Livestock Management at Colorado State University, told those attending the Vita Plus Dairy Summit on Dec. 12.
Not only is it an economic issue, it is a welfare issue, he said.
Why do cows die on dairy farms?
There are a number of ways to answer this, Garry said Intense genetic selection for milk yield (without as much emphasis on health and fertility) may have contributed to the problem over the past couple of decades — certainly, it was more of a concern 20 years ago than today. Then, there are management factors. Perhaps the animals are pushed too hard, there is some sort of stress or injury, or the cows fall victim to disease.
Few herds do a good job of tracking and evaluating the causes of death among their cows — even with the computerized record-keeping systems that are available to farms today.
"We have these phenomenal records systems," Garry said. "The problem is we have focused them on only a relatively narrow set of tasks," such as tracking production and reproduction. Farms know their rolling herd average and pregnancy rate, "but can't tell me how many cows really died from a particular problem," he added.
Death loss is a "big deal," he said, and it would behoove farmers to track it, figure out the causes and then take corrective measures.
Garry says farms should consider doing post-mortem exams or necropsies on cows that die. "If you want to know why cows die, you have to open them up," he added.
He encourages farms to work with their veterinarians or have one of their workers trained to do field necropsies to determine the cause of death. To access a manual on this subject, go to http://tinyurl.com/mwo68db
"Commit to evaluating, monitoring and decreasing occurrence (of death)," he said.