When Dr. Todd Gunderson demonstrated cattle restraint at AABP, he didn’t bring a model animal on stage. He tied a rope around his own foot.
The Kansas State University production medicine veterinarian was demonstrating a simple point: when working with a 1,000-pound cow or a much larger bull, you aren’t going to win a contest of strength. The better approach is to use rope, leverage, positioning and physics to make the restraint system do the work.
For much of his career, Gunderson worked as an ambulatory veterinarian, often without access to a clinic or specialized equipment. Knowing how to rope and restrain cattle allowed him to perform procedures in the field that otherwise might not have been possible.
“You are not going to physically force them to pick up their foot with a rope, just by pulling on the end of a rope,” he says.
Instead, Gunderson recommends putting physics to work for you.
Start With the Right Knot
Two knots are particularly useful to have in your cattle handling toolbox:
- Bowline: A versatile, foundational knot that can be used in a variety of restraint situations.
- Timber hitch: Particularly useful for securing a rope to a cow or bull’s foot. It holds securely when the rope is under tension, yet releases easily when tension is removed.
That combination is especially useful when working around a hind foot, where minimizing the time spent close to the animal is critical.
“You want to be able to get that knot on and off quickly, easily, and with as little time spent down there with your hands and your face next to that cow’s foot,” Gunderson says.
Gunderson prefers a thick cotton rope because it is supple, strong and less abrasive. He also likes the way it behaves when used with other knots, including a double half-hitch casting technique.
Change the Direction of Force
Once a rope is secured to the animal’s foot, the next question is where to anchor it.
Rather than trying to lift a hind foot directly, Gunderson routes the rope over an elevated anchor point, such as a crossbar. That changes the direction of the pull, allowing you to pull downward and use your body weight rather than relying solely on arm strength.
The arrangement also creates mechanical advantage. By adding pulley points or additional loops in the system, you can increase the amount of force applied to the animal relative to the force they are exerting.
“If I can rig up some kind of a pulley system, every time I loop that rope over something above me I increase my mechanical advantage,” Gunderson explains.
That can make a significant difference when trying to elevate a foot on a strong animal.
A Small Angle Can Make a Big Difference
Gunderson’s favorite part of the restraint system is the mathy, physics bit.
When a rope is anchored to a pulley system and the animal’s foot, applying a small lateral force to a taut rope can generate a much larger force within the rope. The effect is particularly pronounced at small angles.
The practical application is more important than the equation. Gunderson isn’t trying to use that force to move the animal’s foot a long way. Instead, he uses it to encourage the animal to make the initial movement.
“At very small angles I can generate enormous amounts of force on that cow’s foot,” he says. “It’s just meant to give them a little bit of a budge, get them to pick their foot up.”
Once the animal picks up the foot, you can quickly remove the slack and bring the foot into position.
Positioning is Part of Restraint
The rope system is only one part of safe restraint. Where you stand can be just as important.
Gunderson recommends slowing down and thinking about where the animal can move before beginning any procedure. When working directly behind a cow to restrain a hind foot, he recommends a staggered stance rather than standing squarely behind the animal. This can reduce the chance of taking a kick directly to the leg.
He also emphasizes awareness of the back bar in a squeeze chute. Be sure to never position yourself in a way where you can get stuck if an animal suddenly backs into the bar.
Most importantly, he recommends having an exit strategy before something goes wrong.
Gunderson also speaks candidly about the mistakes that can come with experience. Earlier in his career, he says, some decisions were influenced more than they should have been by “testosterone and ego.”
The lesson is simple: confidence should come from good technique, not from believing you can overpower an animal.
Let the Restraint System Do the Work
For Gunderson, the physics isn’t just an interesting calculation. It provides a framework for thinking differently about cattle restraint.
You don’t necessarily need more strength. You need an understanding of how leverage, tension, friction, rope angle and positioning affect the restraint system. The goal is to arrange the system so the animal’s strength works against the animal rather than against you.
The strongest restraint system may not be the one that applies the most force. It may be the one that uses physics to make force unnecessary.
To hear more from Dr. Gunderson, along with other veterinary experts, on the newest technique and technology advancements in bovine health, tune into the latest episode of The Bovine Vet Podcast:
