By MICHELE F. MIHALJEVICH
FORT WAYNE, Ind. — The dairy industry could do a better job of pinpointing the causes of cow deaths, which have increased since the mid-1990s, according to a professor from Colorado State University.
Researchers have also done little to shed light on the subject, said Franklyn Garry, coordinator of Colorado State’s Integrated Livestock Management program.
Figures from the National Animal Health Monitoring System show about 3.8 percent of cows were reported to have died on dairy farms in 1996. That number increased to 4.8 percent in 2002 and to 5.7 in 2007, the most recent year statistics are available.
Garry estimated that death rates today could be 8-10 percent. “In the last 10 years or so, a lot of dairy cows have died,” he noted. “Doesn’t it seem that more die than used to? How much death loss is normal, and what is normal? What do we compare it to?”
In looking for research on the topic, Garry found there were only 19 studies conducted from 1965-2006.
“It’s not been a subject we’re particularly interested in,” he explained. “The dairy industry is saying whatever is going on is pretty much okay. It’s just considered one of those things and it’s not something that’s focused on. It means everyone is asleep at the wheel.”
Garry spoke April 23 during the first day of the two-day Tri-State Dairy Nutrition Conference in Fort Wayne. More than 500 people were expected to attend the 22nd edition of the conference.
Potential causes for dairy cow deaths include subclinical disorders such as hypocalcemia and rumen acidosis, he said. Clinical diseases such as ketosis and mastitis are also factors.
The increase in cow deaths is not just a U.S. phenomenon, Garry said, noting it’s happening worldwide. The increase suggests something has changed in the dairy industry that has led to the higher death rates.
“When a cow dies, that’s a lot of money,” he said. “You know the problems are out of hand when bad becomes the normal.”
Anyone trying to determine why dairy cows are dying must sometimes deal with less-than-adequate recordkeeping by producers, he said.
“Most producers do keep records, but the categories (for the various potential causes of death) are both wide and questionable as to what goes into the categories,” he stated.
“They can tell you how much each cow produced, but they don’t track diseases and health events are poorly defined.”
Producers should keep basic information about the animals and have a good record system, he said. “You want to look at what happened with that cow,” he explained.
“This is your Sherlock Holmes moment. If you want to answer the problem, you need to know the who, what, when, where, why and how.”
Garry recommends more producers consider necropsies to better determine the specific cause of death for their animals. With a necropsy, a veterinarian finds the cause, allowing producers to determine if their pre-necropsy assessments were correct.
A necropsy would also help discover which deaths may have been preventable, he noted. Thirty to 50 percent of all cows should receive a necropsy, he added.
Producers need to acknowledge the importance of dairy cow mortality and work toward monitoring, evaluating and decreasing the occurrence of death, he said. That, combined with more necropsies, will cause death rates to drop about a third within a year.
“In terms of dealing with this (death) problem, the industry is way behind the curve,” he said. “If you want to know how dairy cows died, at some point you’re going to have to take them apart.”