Round up from the lameness Week of Webinars

The Week of Webinars is a series of talks organised by the Cattle Hoof Care Standards Board (CHSCB) and hosted by the British Cattle Veterinary Association (BCVA), delivered by researchers and experts working in the field of cattle foot health. Talks ran from 19 -22 October 2021 (trimmers are clearly sensible planning a 4-day week). This year we had over 1400 registrants and attendees from all over the world. If you missed the talks, recordings are available through BCVA. Dr Nick Bell rounds up the webinars below.

Sara Pedersen: What lies beneath: can we really predict sole depth? (Webinar 1, 19 October)

In this talk, Sara Pedersen presented the findings from a cadaver limb study of over 220 cow hindlimbs. This work was conducted as part of her PhD at University of Nottingham, funded by AHDB. Previous research had started the conversation about what is appropriate toe length, and focussed attention on whether the original wording of the Five Step method (“a good 7.5cm for a Friesian”) was still apt.  In her study, Sara assessed a variety of external dimensions (Figure 1) and cow factors, and related these to sole thickness at the tip of PIII.  The best predictor turned out to be the one most commonly used in the field– the dorsal wall toe length measured from where the wall goes palpably hard to the tip of the toe (measurement F). Cow parameters such as weight and age were not useful predictors and combinations of parameters did not enhance predictions significantly. Approximately half of the variation could not be explained, suggesting that whilst toe length is the appropriate measure to use to estimate sole thickness, we must apply caution by allowing for a margin of error.

Figure 1. External measures used to predict sole thickness.

Professor George Oikonomou: New research findings on lameness genetics and automatic lameness detection (Webinar 2, 20 October)

Research has shown foot lesions have a small but significant heritability. Consequently, for the last 15 years several European nations such as Sweden have gathered standardised foot lesion data through foot trimmers. This data is then used for bull selection (see week of webinars 2020). In 2018, AHDB launched two selection indices for lameness: Lameness Advantage and Digital Dermatitis Advantage. These indices were generated using lesion data collected at classification.  Professor George Oikonomou took lesion data from 2352 cows collected by a trained research student and compared the findings with the genetic predictions generated by Lameness Advantage. Heritability of sole haemorrhage, sole ulcer and white line lesion was 0.20, 0.29 and 0.06 respectively, much higher than previous estimates for sole haemorrhage and sole ulcers. These findings should increase our confidence in using Lameness Advantage to enhance foot health through better breeding and selection.

In the second part of his talk, Professor George Oikonomou reported an evaluation of the CattleEye automatic lameness detection system. CattleEye uses a simple camera located above the cows to capture cow walking behaviour, which is sent to the cloud for processing. Algorithms are used to identify the cow from its markings and shape, and to allocate a mobility score. In the validation study, the Liverpool team reported mobility scores comparable to two standardised, independent human scorers, with differences being of a similar magnitude as the difference between the two human scorers. Excitingly, the system was superior than the human scorers at discriminating between cows with and without major foot lesions.

Dr James Wilson: Targeted use of NSAIDS to reduce lameness: setting our heifers up to succeed (Webinar 3, 21 October)

Previous trials have shown newly lame dairy cows affected by claw horn lesions achieve a higher 5-week cure rate when NSAIDs are used. James reported the results of a randomised control trial, one of his University of Nottingham, AHDB funded PhD studies, in which he tested the use of NSAIDs on a dairy herd over a 3-year period. Cows were allocated to one of 4 treatment groups: 1. Trim only when lame (no NSAID) 2. Trim plus NSAID when lame 3. Trim plus NSAID when lame, plus NSAID at calving 4. NSAID only when lame. Cows given NSAID received 3 days of a ketoprofen product. The results were startling. Animals in Groups 2 & 3 were at a reduced risk of being culled throughout the study period. There was an absolute reduction in lameness prevalence of approximately 10% in the Group 3 animals in comparison to those in Group 1. The results of this trial have been recently submitted for peer-review, but estimates indicate the return on investment is around 2-to-1 for the proactive use of NSAID, with clearest benefits being for parity 1 (heifers).

Professor Martin Green: Strategic update from the Chair of the Dairy Cattle Mobility Steering group (Webinar 4, 22 October)

The Dairy Cattle Mobility Steering Group is a stakeholder group which meet twice a year to support AHDB with the development of the Healthy Feet Programme and other foot health activities. Since leaving the EU, the UK and devolved governments are setting out plans for the funding mechanisms to replace things like the single farm payment. Strategic meetings indicate foot health is a high priority to incentivise through the available funding mechanisms.

Dr Gerard Cramer: Vet and hoof trimmer communications: moving beyond arguing about techniques (Webinar 5, 22 October)

Gerard started his presentation looking at some of the data in a trial comparing the wide model (“Big model”) with a small model. The trial took place on US dairies using recycled sand (high abrasion levels). The results showed cows with the big model had fewer lesions, the effect being most obvious in first lactation animals.

Gerard then went on to challenge the audience to think about how we go about positive engagement in team discussions. By using survey responses and case study data, he showed the importance of getting past the small details about trim technique and onto the big questions about how to support a farmer in improving herd foot health. He showed the power of having good data and the importance of vets working with trimmers and vice versa (more on this research in the next section).

All the presentations were recorded and will be available through BCVA.