Estimated reading time: 2 minutes
by Dr Rebel Skirving, Gambier Vets, Mt Gambier, SA
The main purpose of the block and tackle is to assist with delivering calves, but they’re also good for lifting the feet of lame cattle. The set-up is 16-millimetre marine grade rope in a block and tackle. For a calving, I attach chains to the calf’s legs, then attach these to the block and tackle.
What’s good about it
Once the block and tackle is attached to the calf and a stationary object behind the cow, I use the mechanical advantage to pull the calf. It supplies gradual force and saves a lot of hard work. It’s also a gentle way to deliver a calf as you get a good feel for how much pressure you can safely apply.
Earlier in my career, I routinely used a calving jack that had a lot of bits and pieces that had to be set up. You had to physically winch back and forth to pull out the calf and it was easy to put too much pressure on the cow or calf. It also gave the cow an opportunity to clout inattentive vets!
The block and tackle is smaller, lighter and easier. It’s gentle on the cow and calf, safer for the vet and it takes up much less space in the back of my car.
One of the reasons I buy ropes from the local boat shop is that they’re marine grade so they’re water-tolerant. I put them through the washing machine after each use and the metal pieces of the block are washed with water and detergent. They all scrub up beautifully.
What’s not so good
The only drawback is that you need an immovable anchor point behind the cow. Normally the cow is in a crush so it’s not a problem. If you happen to be out in a paddock, you need another vehicle to act as the anchor point. It’s also important to have high-tensile clips and attachments—such as D-shackles—because inferior quality ones will break under strain.
Where did you get it
Taylor Marine, Mt Gambier
The advantage of a calving jack is that it pulls one leg at a time which is very important in getting the shoulders or hips through the pelvis. Especially with a hip lock – pulling both legs together may cause PPP. Using a block and tackle will pull 2 legs together unless you pull one leg then reposition the pull force on the other leg. I would never attach a calf puller to a live calf. If I couldn’t pull it without aids then I would do a Caesar. I only used a calf puller on dead calves. Most farmers have a block and tackle and I can see them using their own equipment if you are using a block and tackle. I have seen many disasters with farmers using block and tackle. Teach farmers that it is important to pull one leg at a time.
Also I treated a $60,000 calf that had its front legs broken by using chains (it was done by another vet). Proper calving ropes are more gentler and safer on live calves. Chains are ok on dead calves.