Trimming cow’s feet using a grinder

Step-by-step instructions on using a grinder for cattle foot trimming.

Grinders are widely used to make foot trimming quicker and more efficient.

In the right hands, they can improve trimming technique. However, without the right training, grinders can be dangerous for both the trimmer and the cow.

It also increases the risk of over-trimming because the grinder makes it easy to trim the walls and soles. Only use a grinder if you’re trained in trimming and abrasive wheel use.

Rotary power tools are more dangerous than using knives alone. City & Guilds Land Based Services (formerly NPTC) offers a qualification in abrasive wheel operation.

Follow these safety rules when using a grinder:

• Only use a grinder if you’re competent in cattle hoof trimming and trained to use it safely
• Make sure the cow and foot are well restrained
• Always wear the appropriate personal protective clothing (PPE), including:
  • Level 5 anti-cut gloves
  • Eye and face protection
  • Wrist guards
• Always keep both hands on the grinder:
  • One hand on the side handle
  • One hand on the grinder barrel
• Never use a complete set of new blades. New blades are too sharp and remove too much horn. Dulling new blades on a piece of timber is recommended
• Keep the grinders, blades and cables well maintained. Ideally use battery-operated grinders

Several grinder attachments are available, each designed for different tasks.

Figure 1. Twisted wire brush (M14 attachment) 

Use this attachment for cleaning the sole before applying a block/glue.

Figure 2. Abrasive metal disc (tungsten carbide)

This attachment can be used to clean and prepare the sole for block/glue application and carry out light trimming work. Be aware that these discs can be noisy and generate dust.

Rotary cutting blades are available in two main designs.

Figure 3. Closed disc rotary blade

A closed disc only cuts with the face of the disc. This reduces the risk of injury from the disc edge.

Figure 4. Open rotary cutting blade

The open disc allows trimming with the edge of the disc, but it carries more risk of operator injury.

Steps 1, 2 and 3 are functional trimming steps and should be used for all cattle.

Steps 4 and 5 are therapeutic trimming steps and should be used when there’s a problem with the claw.

The trimming steps are the same with a grinder as they are for the knives.

Toe length cannot be reliably assessed by looking at the sole alone.

Some trimmers prefer to cut toe length precisely with nippers. If the trimmer is confident about judging toe length, then the grinder can be rotated to face forward by twisting the arms.  

Figure 5. Using a grinder to correct hoof shape

If excess sole thickness is detected, then sole depth can be removed very carefully with a grinder.

Take extra care not to remove too much. Only remove sole if there is excess sole thickness. If toe length is correct, move on to the next step.

Figure 6. Excess sole depth is removed with a grinder

Many claws will be naturally well balanced. Avoid the temptation to clean the sole with the grinder or lower a claw just in case it’s overloaded.

Sole modelling needs to be done with a sharp knife.

While it’s possible to remove some of the overgrown sole with the edge of an open cutting disc, this requires a high level of skill and experience.

There’s a significant risk of trimming too deeply or damaging the wall, heel or toe. A hoof knife is always needed to get the correct depth and shape of model.

Figure 7. Using a hoof knife to get the correct sole depth and shape

If a block is being applied, prepare the sole with a wire brush or abrasive metal wheel.

Only remove a light skim of sole. Do not use cutting blades for this, as they can remove too much sole.

Loose horn needs to be carefully removed with a sharp hoof knife.

Where lesions are deep, abrasive or cutting discs can be used to thin the surrounding horn to make the final knifework easier.

Sometimes trimmers find that separating the claws with a used glue tip reduces the risk of catching the opposite claw while trimming.

However, if the grinder technique is right, this is completely unnecessary.

If glue tips are used, disinfect them between cows to minimise the risk of cross-infection with digital dermatitis.