By Lorna MacPherson, dairy consultant SAC Consulting

Over the last year, consultants from SAC Consulting, part of Scotland’s Rural College, have been monitoring lameness prevalence and mobility scoring results on several dairy farms in the South West of Scotland.

The aim of the project was to encourage more farmers to adopt regular mobility scoring in order to reduce lameness and improve cow welfare. The 12 herds involved in the study included six that were using the CowAlert System from IceRobotics Ltd., for lameness detection and automated mobility scoring. The other six were mobility scoring their cows on a quarterly basis, which was required by their milk buyer.

All farms were taking a pro-active approach using the mobility score information to promptly deal with lame cows to try to reduce lameness in their herds.

While many studies have put the average lameness prevalence in the UK at around 30%, lameness in these herds was quite low. A lame cow was classed as having a mobility score of either two or three using the AHDB Dairy Mobility Scoring System.

In the manual scoring herds, quarterly scores were provided and in the CowAlert herds, a mobility score was taken on a monthly basis between February and November 2020.

Lorna MacPherson, dairy consultant SAC Consulting

Lorna MacPherson, dairy consultant SAC Consulting

The average incidence of lameness ranged from 3.1% to 23.9% across the 12 herds, with some performing consistently below 10% throughout the recording period.

The average days in milk of lame cows did vary between herds but generally lameness tended to be more prevalent in mid to late lactation, with lame cows in some herds being on average well over 200 days in milk.

In almost half of the herds the average milk yield of lame cows was greater than the herd average milk yield. This is perhaps not surprising as higher yielding cows are likely to lose more condition in early lactation, which also causes thinning of the digital cushion and increases the risk of them being lame from claw horn lesions. These higher yielding cows may also have a higher dry matter intake and spend more time standing at the feed fence compared to lower yielding cows. Therefore, nutritional management of high yielding cows should focus on minimising body condition loss in early lactation to protect the digital cushion from excessive thinning and risk of claw horn lesions.

Lameness in CowAlert herds

Lameness in CowAlert herds

Lameness in manual scoring herds

Lameness in manual scoring herds

The average lactation number of lame cows ranged from 2.75 to 4.3, with very little lameness in first lactation animals (generally less than 10% of lame cows were in first lactation), which was good to see as lameness in the first lactation doubles the risk of that animal being lame in her second lactation.

There are many factors that influence lameness. Some of the causes that farmers felt were having an influence in their herds were long standing times, poor cow tracks in grazing herds, overstocking and bringing in problems with purchased stock.

Digital dermatitis and sole ulcers were the main forms of lameness. Herds that foot bathed regularly (i.e. 5-7 times per week) indicated that sole ulcers were the main type of lameness, having got on top of digital dermatitis through regular foot bathing. However, on the farms where digital dermatitis was more prevalent, the incidence of foot bathing was much lower and these herds would benefit from increasing the frequency.

Many farmers agreed that quarterly scoring was not regular enough to pick up early cases of lameness and SRUC vets advocate scoring on at least a monthly basis, if not fortnightly, with follow-up trimming. Although this can initially seem like a daunting task, a preventative trim is much quicker than trimming a severely lame cow’s foot and more regular scoring and reactive trimming is proven to work very well in reducing lameness in herds. Other barriers mentioned included having to upgrade housing or improve cow tracks, which would require investment.

It is important to make the job as easy as possible for the farm staff and ensure crush facilities are easily accessible, safe and easy to use. While using a professional hoof trimmer is a cost, it frees up time and can be a cost-effective solution.

NADIS estimates that the average cost of a lame cow is equivalent to the cost of a professional hoof trimmer treating 18 cows. Frequency of routine trimming is also important, and research has shown that cows foot trimmed twice during lactation (e.g. at drying off and in early lactation) as opposed to just once at drying off are 70% less likely to be lame.

Reducing lame cows may also benefit herd fertility as lame cows tend to have a longer interval from calving to first service and therefore conception and also require more services per conception.

Summary of main findings:

• These dairy herds are all very proactive in mobility scoring and have a lower-than-average herd lameness figure – between 3.1% and 23.9%.

• The average lactation number of lame cows ranged from 2.75 to 4.3, with very little lameness in first lactation animals.

• Many farmers agreed that quarterly scoring was not regular enough to pick up early cases of lameness.

• Frequency of routine trimming is important to get on top of lameness and is cost-effective to help prevent severely lame animals.

This work was supported by the Universities Innovation Fund from the Scottish Funding Council.

References:

Griffiths, B.E., Grove White, D. and Oikonomou G. 2018. A cross-sectional study into the prevalence of dairy cattle lameness and associated herd-level risk factors in England and Wales. Frontiers in Veterinary Science, April vol 5, article 65.

Huxley, J. 2013. Impact of lameness and claw horn lesions in cows on health and production. Livestock Science, 156: 64-70.

Manske, T., Hultgren, J. and Bergsten, C. 2002. The effect of claw trimming on the hoof health of Swedish dairy cattle. Preventative Veterinary Medicine, 54: 113-129.

Randall, L.V., Green, M.J., Chagunda, M.G.G., Mason, C., Archer, S.C., Green, L.E. and Huxley, J.N. 2015. Low body condition predisposes cattle to lameness:

An 8-year study of one dairy herd. Journal of Dairy Science, 98: 1-12.

Randall, L.V., Thomas, H.J., Remnant, J.G., Bollard, N.J. and Huxley, J.N. 2019. Lameness prevalence in a random sample of UK dairy herds. Vet Record, 184: 350.