Culling cattle | Dairy experts say an emphasis on genetics has resulted in poor management and high death rates
RED DEER — Too many dairy cows are dying on farms, veterinarians said at the Western Dairy Seminar held in Red Deer earlier this spring.
Disease has not been controlled as well as it should be because more emphasis has been placed on milk production. Genetic tests are emerging to breed a stronger cow, but results are some way off.
“We have not really paid a lot of attention to generating animals or building a dairy cow that is more disease resistant,” said Dave Kelton of the Ontario Veterinary College at Guelph University, where he holds the Dairy Farmers of Canada cattle health research chair.
The national organization is launching a study next year to survey management practices, production rates and disease prevalence. An online survey opened March 1 to see what kinds of information producers want included in the main study.
The survey can be found at fluidsurveys.com/s/DFC_PLC_Needs_Assessment.
It’s common that farmers don’t know why a cow died, and necropsies are seldom conducted.
“It is tragic that people haven’t paid attention to this,” said Franklyn Garry of Colorado State University.
U.S. data shows that on-farm death losses were 3.8 percent in 1996 and 5.7 percent by 2007.
A Cornell University study found that some herds have death rates as high as 17 percent and others are as low as three percent.
“This is not a genetics problem, this is a management problem,” he said.
Cows may succumb to disease or accidents or they are put down because of lameness or calving injuries.
“Something was wrong with most of these cows for a relatively long time before they died,” he said.
A U.S. Department of Agriculture study in 2007 found that 20 percent died as a result of lameness or injury, 16.5 percent had mastitis, 15.2 percent had calving problems and 15 percent died of unknown causes.
No one is sure what normal death losses should be.
By comparison, beef death losses are around one percent and feedlots, often considered a high risk environment, lose about 1.5 percent of their cattle.
Dairy deaths are consistently six to 10 percent, Garry said.
“Death losses reveal significant health and welfare issues. This is a really big issue. It is manageable and we can do a lot better,” he said.
The United Kingdom is also studying cull and death rates.
A national study looked at more than 840 herds and found the overall culling rate was 22 percent with a wide variation in reasons for losses.
Farmers tend to think high culling rates and deaths are normal, said Dick Sibley of the West Ridge Veterinary Practice in Devon, England.
In the U.K., BSE rules state any animal that died or had to be killed on the farm at 24 months of age or older must be tested.
Farmers must give the government reasons for the death.
Of the 107,000 beef and dairy cows submitted for tests in 2006, 40 percent listed the cause of death as unknown.
Johne’s disease was listed as the highest infectious disease to cause death, but a large number died of calving problems, lameness or injuries.
A common management problem on British dairy farms is cows going down because they fell on a slippery, wet surface and their legs splayed out.
Some herds never have this happen while others reported that as many as six percent left the farm because they did the splits.
“Having six or seven cows out of 100 doing the splits every year is pretty dodgy,” Sibley said.
There are also cows that face high risk situations.
“The highest risk cows are those that just had a baby,” Garry said.
“We have heifers calving day in and day out, sometimes spending six to 10 to 12 hours trying to push out an over-sized fetus.”
Some care and analgesia would help in the first few days, but they are often turned out into the herd before they are ready.