A calf puller (also called an OB jack or calving jack) is a mechanical device that helps deliver a calf when natural delivery isn't progressing. For cow-calf operations, a calf puller is one of the few pieces of equipment that absolutely must work on the first try — the cow and calf may not survive a malfunction.
Here's how to pick the right calf puller, use it correctly, and maintain it between calving seasons.
What is a calf puller?
A calf puller consists of three main components:
- The breech plate — a curved metal piece that rests against the cow's rump and serves as the brace point
- The pulling rod or shaft — a long steel rod with a ratchet mechanism
- OB chains and handles — chains that attach to the calf's legs, connected to the ratchet
The operator places the breech plate against the cow, attaches OB chains to the calf's feet through the birth canal, and ratchets the chains slowly. The ratcheting motion delivers controlled pulling force — much steadier than manual pulling.
When you need a calf puller
You don't use a calf puller for normal deliveries. You use it when:
- Labor stalls after the calf's feet appear
- The calf is malpositioned (after manual correction)
- The heifer is too small for the calf's size (dystocia)
- The calf is exceptionally large for the cow
- You need controlled delivery speed to prevent injury
If you have to pull more than 5–10% of your calves, that's a sign of bigger management issues — bull selection, heifer size, or cow nutrition. The calf puller is for the exceptional case, not the routine.
Choosing a calf puller
Frame type
- Standard rod puller: One straight steel rod with ratchet. Cheapest and most reliable. $130–$180.
- Telescoping puller: Adjustable length. Useful if you work in tight spaces.
- Double-ratchet puller: Two independent ratchet handles for finer control. Used by professional operations.
OB chain length
30-inch chains are standard for cattle. You'll want two chains per puller. Cheap chains break at the worst possible time — spend the extra dollars on quality.
Quality indicators
- Hardened steel rod, not plated
- Smooth ratchet mechanism that doesn't bind
- Replaceable parts (handles, chains)
- Carry bag included
How to use a calf puller correctly
- Confirm proper presentation. Both front feet plus head, or both back feet (for breech) presented. If position is wrong, correct manually first.
- Use lubrication. Inject OB lube generously around the calf before pulling.
- Attach chains above the fetlock joint. A second half-hitch above the joint distributes pull force and prevents broken legs.
- Position the puller. Breech plate firmly against the cow's rump, just above the vulva.
- Pull during contractions. Alternate pull with the cow's natural pushing.
- Pull down and back. Not straight back. The natural birth canal curves downward as the calf exits.
- Go slow. Aggressive pulling causes calf injury (broken ribs, hip dislocation) and cow injury (torn tissues).
- If progress stops, call the vet. Pulling harder isn't the answer when something's wrong.
Common calf puller mistakes
- Pulling without checking position. Forcing a malpositioned calf can kill both cow and calf.
- Skipping lubricant. Friction causes injury. Use it liberally.
- Chains too tight on the leg. Can break the leg or strip the hoof.
- Pulling between contractions. Work with the cow, not against her.
- Aggressive ratcheting. Slow and steady prevents injury.
- Wrong angle. Down and back as the calf delivers, not straight back.
Maintenance and care
- After every use, wipe down with a disinfectant and dry thoroughly
- Replace worn OB chains every 2–3 years even if they look fine
- Apply light oil to the ratchet mechanism annually
- Inspect the breech plate for cracks at the start of each calving season
- Store in a clean, dry place, in the carry bag
What we'd buy
For most cow-calf operations: a standard rod calf puller with 30-inch chains, OB handles, and carry bag. In the $130–$180 range. Stock a spare set of chains.
If you regularly assist with calving on a commercial operation, consider a double-ratchet puller for finer control. $250–$350.
Pre-calving prep
Don't wait until you need it to find out your calf puller is rusty or the chains are missing. See our Calving Equipment Checklist for the complete pre-season kit.