We are lucky to have many fine hoof trimmers in the U.S. who do an outstanding job for their clients. Unfortunately, because the business of trimming is largely unregulated, there are trimmers who do not do a good job trimming our cows’ feet.
In fact, when I and fellow lameness experts are called to troubleshoot a herd with a lameness problem, we often find the hoof trimming on the farm is part of the problem – not part of the solution.
Hoof trimming serves to achieve two important goals: restore a more upright claw angle and balance the weight distribution between the inner and outer claw. If we can do this without removing too much horn, we will bring great benefit to the cow.
We also must understand that the benefits of this trimming do not last much more than four to six months for the average cow, which leads us to the standard recommendation of trimming each cow at least twice during lactation, usually around dry-off and a trim between 60 and 150 days in milk, timed to pre-empt the development of sole ulcers around peak yield.
So to evaluate trimming practices on a farm, we can ask two questions:
- Is there sufficient trimming to meet the stated goal for the herd?
- Is the trimming beneficial to the cow?
Is there sufficient trimming to meet the stated goal for the herd?
Let’s assume a 1,000-cow herd aims to trim each cow twice per lactation and have the trimmer see lame cows at an average rate of 45 cow cases per 100 cows per year. The expected number of trims would therefore be approximately:
(1,000 x 2) + (45 x 1,000/100) = 2,450 cow trims per year
For a single trimmer, I would expect no more than 50 cows to be trimmed each visit – they can reasonably do more with an assistant – which means 49 (2450 / 50) visits per year. That equates to a trimming day each week for the dairy.
Trimming records should be set up so we can confirm all cows are trimmed at the allotted time and the total number of trim events meets the stated goal. If not, the herd is not going to achieve what it has set out to do.
Is the trimming beneficial to the cow?
In simple terms, we can make two mistakes with trimming: We can over-trim, or we can under-trim. Over-trimming is by far the most common error we see, especially with the use of rotary grinders.
Over-trimming
Over-trimming is most commonly seen during routine trimming. The most common example of over-trimming is excessive removal of the outer wall of the claw (1).
You can see this even when the cow is standing. The wall is a weight-bearing surface, so when we remove it, we transfer weight to the sole and stress the white-line junction between the outer wall and the sole.
We also see trimmers using grinders between the toes, removing the weight-bearing inner wall of the claw. This practice is often associated with exposing the corium between the claws, and this can result in an abscess in this location (2).
Making the toes too short is also very common. For most dairy cattle, we expect the dorsal hoof wall, measured from the coronary band to the toe, to measure 3 inches. Trimmers will shorten the toe and then remove the overgrown sole in the toe region to restore a more upright claw angle, but they should not trim the toe to a point.
Instead, they should leave about a quarter-inch step at the toe. This will ensure we leave an adequate thickness of sole in the toe. Failure to do so will result in thin soles and toe ulcers with painful exposure of the corium.
Excess trimming of the heel of the inner claw of the rear feet is another problem (3).
Many cows live in high-wear environments on larger farms. If we trim the heel away, it will never grow back, and the cow will develop lower heels and lower claw angles. This is also a problem when we balance the heel of the outer claw to the inner claw.
If the inner heel is trimmed too low, we will end up removing too much outer claw horn, making the sole too thin.
Under-trimming
Under-trimming is most commonly observed when trimmers treat lame cows with lesions during curative trimming.
The goals of curative trimming are to remove any loose horn and expose the healthy corium beneath, and to transfer weight from the affected claw to the unaffected claw, often with the use of a hoof block.
Lack of weight transfer from the affected claw to the unaffected claw, and leaving loose horn attached on and around a lesion, will delay healing of ulcers and white-line abscesses. Loose horn should be removed with a knife, not a grinder, and correctly treating a lesion takes time. Trimmers who take shortcuts do not cure lame cows.
Hoof blocks must be placed on a correctly trimmed claw so the flat surface of the block is perpendicular to the limb and the affected claw is elevated from the floor when the cow bears weight. Failure to do this will result in further problems for the cow (4).
Occasionally, we see trimming where the toe is removed without removal of the excess sole horn, falsely creating the correct claw angle but providing little help to the cow (5).
One aspect of trimming where we still see a lot of debate is how we trim the sole: Should it be concave or flat? Proponents of concave trimming correctly state that this is how the natural shape of the claw is in grazing animals.
However, they forget that most of our cows live on concrete, where concave trimming results in separation of the claws when the cow bears weight, irritation of the interdigital skin and the creation of interdigital corns.
Confinement-housed cattle should be trimmed flat, but we still favor a large model of the medial region of the outer claw to remove pressure from the ulcer site and enhance drainage and hygiene between the claws (6).
We currently lack science to tell us exactly how we should trim cows. However, we do have a lot of experience to tell us what not to do. Armed with these tips, the producer should evaluate their trimming program and make sure it is beneficial to their cows. 
PHOTO 1: Excessive removal of outer and inner wall horn with excessive shortening of the toe
PHOTO 2: A trimmer-induced abscess between the claws
PHOTO 3: Poor hoof balance after trimming
PHOTO 4: Poorly located block with insufficient rest for the affected claw
PHOTO 5: Removal of the dorsal hoof wall without removal of the excess sole horn in the toe
PHOTO 6: Trimming the sole flat with a large model of the medial region of the outer claw of the rear foot. Photos provided by Nigel Cook.
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Nigel Cook
- Veterinarian
- University of Wisconsin – Madison’s School of Veterinary Medicine
