Each month, we break down five recently published scientific studies that could affect the way we breed, train, and race Thoroughbreds. We explain what the research found and what it means for you.
In this month's Science Corner, we look at a range of topics associated with welfare outcomes for the Thoroughbred. From how their dams care for them at the beginning of life, to getting off to a good start in pre-training and keeping them sound, we have spotlighted research with promising real world applications in the future.
You can click the title of each paper to read it in full.
#1. A gene that predicts maternal behaviour
What’s it about?
This study, prepared by a team at University College Dublin, examined the heritable aspects of how mares behave with their newborn foals. Observing the behaviour of Thoroughbred mares, the team established high and low maternal care styles (MCS), and then examined the DNA of those mares to find areas of crossover.
Key findings:
Thirteen regions of interest were identified in mares' DNA containing candidate genes with functions involving stress, anxiety, and depression.
The C-allele for the top identified genomic variant occurred at a frequency of 79.2% in low MCS mares as opposed to 42% in high MCS mares. There were a number of other regions of interest that occurred more often in low MCS mares.
What it means for you:
While environmental factors will also play a role in a mare's maternal behaviour, this could lay the base for a future test to identify mares who are likely to be less maternal. If such a test was developed, it could help breeders proactively identify mares who might need extra support or attention with their newborns.
Mare and newborn foal | Image courtesy of Silverdale Farm
#2. Unshod hooves encourage positive changes to the foot
What’s it about?
No hoof, no horse - British farrier Gavin Moody understands this and he leads the team in this study, where they looked at what changes happened to hoof morphology in Thoroughbred racehorses during a 90-day period without shoes on.
Key findings:
Trimming (without shoeing) improved the dorsal hoof wall angle (DHWA), heel angle (HA), and the DHWA-HA difference, and altered solear morphometrics.
At the end of the 90 days, the DHWA angle was stable in the unshod horses, the heel angle improved, and the difference between the two decreased. In the shod control group, there was no significant change.
What it means for you:
The group recognises this would be more robust with a bigger sample size, but this research supports what all good farriers know, that stimulation of the frog and digital cushion (by contacting the ground) helps with hoof remodelling, and that an extended period with no shoes aids healthy hoof growth. It is a factor to consider when attempting to maximise healthy hoof shape and growth in order to minimise injury.
#3. Blood test for osteocalcin shows promise as lameness predictor
What’s it about?
Researchers from Charles Sturt University, TeleVet, and the School of Veterinary Nursing collaborated on this research that looked at whether two simple blood tests looking for osteocalcin and C-terminal telopeptide type I collagen could help assess soundness risk in Thoroughbred racehorses in active training.
Key findings:
Looking at blood samples taken from 1359 race-fit horses, levels of osteocalcin, a marker linked with new bone formation, was higher in horses who were lame when sampled and was associated with short term (7-28 days) lameness.
There was too much variation with C-terminal telopeptide type I collagen levels to draw much of a conclusion.
What it means for you:
This shows the promise of testing for osteocalcin as a predictive marker for lameness that is worthy of more research. Blood tests are already commonplace in many trainers' pre-raceday routines so this could turn into a valuable part of the testing package they order.
#4. Uphill tracks are associated with less fractures than flat tracks
What’s it about?
Something very much on theme, given our recent discussions about training methods for juveniles - particularly in Japan - this study prepared by the Japan Racing Association analysed 15 years' worth of training data to quantity the incidence and location of fractures on different training surfaces at the JRA’s Miho and Ritto Training Centers.
Key findings:
The uphill woodchip tracks were associated with a lower incidence of both forelimb and hindquarter fractures compared to flat woodchip tracks.
There was in general a lower incidence of fractures on the uphill tracks.
What it means for you:
Given we train most commonly on a circle on the flat, it is interesting to see that the uphill tracks generally had a lower incidence of training injury than the same surface on the flat. Something to ponder when considering the construction of new training facilities in this country.
Interior view of the uphill indoor training track | Image courtesy of Northern Farm
#5. Pretraining influences changes in behaviour
What’s it about?
In this study led by the University of Berlin, researchers examined behavioural changes before and after a 12-week stint in pretraining. Horses were observed in the stable, as well as in novel object tests, to see how their responses changed.
Key findings:
After pretraining, horses moved around more and faster during novel object tests, but they also interacted more with the objects, touching it more often during less approaches.
Behaviour during 24-hour observation in a stable correlated with behaviour during the novel object test. Also, the variation between individuals increased after pretraining.
What it means for you:
This study draws a neutral conclusion on pretraining, but it is important to recognise that horses will react differently to the pressures of pretraining. A good trainer will always observe how a horse changes with work and adjust the routine and environment accordingly.
