Ask a swine producer about the role of biosecurity and herd health on the average hog farm, and a protocol and 20-minute lecture are surely to follow. Ask a cow-calf producer, and you'd likely get a much less detailed response.
No doubt beef producers enjoy an inherent advantage when it comes to herd health. For most of the year, our cows are spread out among many acres of nature. Conversely, modern swine units have animals in much closer proximity; since exposure enhances disease transmission, swine farms require strict preventive practices to produce healthy animals.
Of course, this doesn't mean that an abundance of space and fresh air makes biosecurity and herd health any less important for our cow-calf operations. Understanding why and how cattle get ill can help avoid sickness in your herd.
Know your herd
Before you buy animals from another producer, know what diseases have been diagnosed in your herd. This will help to know which, if any, vaccines are absolutely necessary before the animal enters your herd. An example would be Clostridium chauveoi (Blackleg), which is easily prevented with vaccination.
What does a negative test mean?
We have some very reliable tests for detection of some diseases; meanwhile, others lack the sensitivity and/or specificity to detect disease in individual animals. If you want high confidence that you're not buying an animal with Johne's disease, for instance, you should purchase from a herd where all adult cows and bulls have been tested negative for numerous years. A single blood test on a yearling bull means almost nothing.
Young animals are nearly always more susceptible to disease than adults. While environmental stresses like a cold rain, subzero wind chills or high heat and humidity negatively affect adult animals, they can mean increased sickness, even death, to neonates.
We can't prevent these conditions, but we can avoid calving during severe weather stress. If you consistently lose calves due to temperature extremes, stop fighting nature and move your calving season.
When to purchase
The best time to purchase new animals is in times of little to no stress. Avoiding purchases during weather extremes (noted above) would be a wise decision.
Also, avoiding purchase of animals during calving season is a must. I've seen absolute disasters when new animals are purchased and brought onto the farm or ranch when cows are calving. This reemphasizes the fact that neonates are incubators of disease and very susceptible to disease. Bringing in any new animals, especially cow-calf pairs, during calving season is a disaster waiting to happen.
Quarantine new purchases
New animals should be kept separate from the existing herd for at least 30 days. If new animals need to be tested for disease, vaccinated or dewormed before joining the herd, this gives ample time for benefit before commingling with your cattle.
Also, don't forget to keep cattle purchased for other purposes away from your cowherd. One of the classic instigators for an abortion storm is newly purchased feeder cattle in fence-line contact with a cowherd; bovine viral diarrhea doesn't respect fences. Shared water tanks are also a great way to spread Salmonella. You can get away with these practices for a few years, but sooner or later the piper will get paid.
Where to purchase
The unfortunate fact is most people pay very good money for disease. That bull purchased just before the breeding season without a thorough health check, that group of young cows with calves that seemed like such a bargain during calving season, or that calf you bought to put on a cow that lost hers can all be disease carriers that devastate your herd.
Before you buy
Prior to a purchase ask the seller if your veterinarian can call his veterinarian to ask about herd health. Every seller of healthy animals should give their herd-health veterinarian permission to discuss the herd's health status with potential buyers and their veterinarians. In fact, the seller should welcome this communication.
Be sure to purchase animals raised in an environment similar to yours. You don't want to buy a ‘cream puff’ bull raised in a cushy environment to turn out into an extremely harsh environment.
Disease doesn't generally sneak into a herd like a skillful burglar; it walks boldly onto the farm or ranch through the front pasture gate. Take some time to plan ahead to prevent disease through the use of proven biosecurity and herd-health practices. For optimum results, involve your herd-health veterinarian in these disease-prevention strategies.
W. Mark Hilton, DVM, is a clinical associate professor of beef production medicine at Purdue University in West Lafayette, IN.