Tackling Lameness on Dairy Farms
23 November 2020
Lameness accounts for the third largest loss of income on dairy farms, after mastitis and infertility.
Sole ulcers and white line disease are the two main non-infectious causes. Peak incidence of lameness typically occurs 2-4 months after calving and is often the result of a ‘trauma’, around calving; hence, transition cow management is critically important.
A sole ulcer is caused by bruising of the sole corium (the layer of tissue which produces sole horn), leading to horn growth ceasing. The bruising is caused by the sharp rear edge of the pedal bone nipping on the sole corium. Refer to Figure 1. for hoof anatomy.
Causes of corium bruising leading to sole ulcers:
1. Weakening suspensory apparatus (ligaments holding the pedal bone in position) allowing the pedal bone to nip down on the corium causing bruising. The weakening is believed to be due to:
a) Natural hormonal changes that occur around calving.
b) Release of toxins due to infectious diseases (e.g. mastitis, metritis), acidosis or abrupt dietary changes.
2. Overgrown hooves resulting in more weight on the rear of hoof.
3. Thin digital cushion. This is the layer of fat acting as a shock absorber between the pedal bone and corium. Cows in negative energy balance mobilise fat including the fat pad in the foot. Therefore, thin cows, particularly at calving are at greater risk of sole ulcers.
4. Increased standing time on hard surfaces.
5. Thin soles. Increased wear combined with the decreased growth that commonly occurs at calving will lead to thinning of the sole.
White line disease (WLD)
WLD occurs due to foreign material penetrating the white line. Foreign material is gradually pushed deeper, infection starts and causes an abscess. Prior weakening of the horn or white line increases the risk of penetration.
Weak horn results from
- Inflammation of the corium (laminitis) due to infectious diseases, acidosis, abrupt dietary changes etc.
- Stress on the white line due to increased pressure on the hoof wall from laminitis, sinking pedal bone (described above) and twisting and turning on unyielding surfaces.
As the causes of sole ulcers and WLD are very similar, preventative measures for both can be applied:
- Avoid thin cows at calving. Target body condition score (BCS) at calving of 3.0 – 3.25.
- Prevent metabolic disorders (e.g. milk fever, ketosis) at calving.
- Reduce negative energy balance in early lactation.
- Minimise infections such as mastitis and metritis.
- Reduce the risk of acidosis.
- Decrease standing time e.g. at milking. Ensure adequate feed space, correct number of cubicles per cow, correct cubicle dimensions and comfortable cubicle beds.
- Avoid abrupt dietary changes – e.g. introduce new forages gradually over 2 weeks.
- Regular hoof trimming – ideally routine hoof checks at drying-off and again 3 months after calving.
- Avoid sharp turning points – use of rubber flooring on turning points.
- Mixing heifers with dry cows prior to calving helps to establish social hierarchy before calving and minimize stress and standing time in heifers post-calving. Keeping heifers in a separate group for the first lactation is also effective.
- Supplementation of a good mineral pack including highly bioavailable minerals such as IntelliBond Zinc and Biotin helps improve hoof strength.
The obvious causes of lameness such as excessive standing are easily identified; however other causes require good record keeping to link lameness to a possible trauma. This allows the correct action to be taken to minimise future lameness. Good records to keep include BCS of cows at calving, metabolic issues, and dates of any dietary and group changes.
by Claire Beckett, Dairy Technical Support Coordinator