“Endemic” diseases are those that are constantly present to a greater or lesser extent in a particular location. Most endemic diseases in cattle fall into three categories — respiratory, reproductive and digestive. Poor preventive management of these diseases costs the cattle industry hundreds of millions of dollars each year.
Because of the difficulty in tracking the diseases, identifying concrete dollar amounts on costs to the industry is difficult. One study by USDA's Animal and Plant Health Inspection Service and Agricultural Research Service scientists compiled information from the USDA National Animal Health Monitoring System, state pilot studies and nutritional studies. They then developed an estimate of the cost of reproductive diseases and conditions in beef and dairy herds.
Stephen Ott, agricultural economist and livestock compensation specialist at USDA-APHIS, co-authored the paper. He cautions the numbers are ballpark figures estimated from studies done during the past 20 years.
In the study, “Cost of Reproductive Diseases and Conditions in Cattle,” published in The Professional Animal Scientist, March 2002, researchers determined the loss to beef producers was $441 million to $502 million/year.
Though the study didn't cover respiratory diseases, it compared them to reproductive losses. “This loss is greater than six times more costly than that resulting from respiratory disease,” the study reports, with an estimated $101 million lost to respiratory diseases every year.
Managing diseases is key
Many endemic cattle diseases can be prevented through a good herd health management program. Donald Hansen, Oregon State Veterinarian, recommends establishing a working relationship with a knowledgeable bovine practitioner, a good nutritionist and even the veterinarian for the feedlot where you send your calves.
Hansen says a relationship with the feedlot's vet is important to establish good coordination between your herd health program and the feedlot's program. This is especially important if you retain ownership of your calves in the feedlot.
“In the West, you can be rewarded for quality calves in the marketplace because buyers are aware of who's supplying quality calves. There's a noticeable added value for well-prepared calves,” he adds.
When managing your herd for diseases, Hansen says, “My process is always oriented toward prevention.”
There are three areas to be aware of when managing for respiratory diseases in calves, he says. One is the bug itself — whether it's bacterial or viral. The second is the calf's natural ability to fight the bug. And the third is environmental and stress factors that may trigger the disease in the animal.
“My advice to cow-calf producers is to be aware of those three things and try your best to keep them in balance,” Hansen says.
To accomplish that, good management starts with the cow — making sure she's in adequate body condition and recieving good prepartum nutrition. These are integral for the birth of a healthy calf and to ensure there's abundant high-quality colostrum to allow the calf to fully develop its immune system.
As the calf approaches weaning, it should be prepared for environmental challenges.
“I'm concerned about good nutrition for the calf. While it doesn't control immune response, it has an impact on it,” Hansen says.
In addition, a good vaccination program will enhance the calf's immune system and help provide protection. Producers should also work to minimize stress before weaning by castrating, dehorning, etc., at an earlier time and keeping dust levels low.
“You can't do much about the anxiety at separation time or change in feed, but you can greatly influence the rest of it,” he says.
What causes disease?
Clell Bagley, Utah State University Extension veterinarian and professor, lists five factors contributing to disease in calves.
- Biological agents
Vaccination can prevent diseases such as blackleg, which is found in the soil and ingested by calves.
“There are no other preventive measures for some diseases, like blackleg, except vaccination,” Bagley adds.
- Management defects that cause stress
For example, calves carry around disease agents that can cause bovine respiratory disease, but they're naturally able to fight them off unless extra stress factors are introduced.
“Whether the problem is dust, fatigue, dehydration or new feeders, these forms of stress make the animal more susceptible. Once the disease process begins, the agents become more pathogenic as the disease goes through the herd,” Bagley says.
If herds suffer from diseases such as calf scours, it's usually due to a management problem.
“With good sanitation practices, hygiene, proper animal density and manure control in calving areas, producers should be able to control calf scours,” Hansen says. “Calf scours is even more of a management problem than respiratory disease.”
- Nutritional deficiencies
“A respiratory condition can worsen if the calf is deficient in minerals, vitamins or energy,” he says. Nutritional deficiencies in the dam during late pregnancy can predispose the newborn calf to scours.
- Inclement weather
Producers can't control weather, but they can prepare for it. For instance, calf shelters or calf coats in severe winters can protect calves on open ground.
“Newborns up to three weeks of age are pretty susceptible to cold weather,” Hansen says.
- Biosecurity breaches
Commingling new calves in confinement can expose some calves to new disease strains.
“A prime example is bovine viral diarrhea (BVD) with persistently infected calves,” Bagley says. “Putting healthy calves in a backgrounding lot with calves shedding BVD virus can cause an outbreak among healthy calves.”
He recommends keeping calves separated by group at least three weeks in the backgrounding lot to minimize contact.
Tips for cows
In cows, reproductive disease challenges are more oriented to regions of the country. In the West, for example, trichomoniasis and vibriosis are two diseases producers tend to worry about the most. Most regions also manage for such diseases as brucellosis, infectious bovine rhinotracheitis, BVD and leptospirosis.
Hansen says heifer management should be a top priority in cow herds as poorly developed heifers are more subject to dystocia than well-developed heifers.
“You'll lose a significant number of calves, or they'll be born weak and way behind the rest of the herd in growth and development, if care isn't taken to develop heifers properly,” Hansen adds.