In this month's edition of Science Corner, we measure the impact of turnout time on a stabled horse's stress indicators and what genes are activated by what kind of exercise program. Plus, we explore whether there's a link between ulcer treatment use and incidence of EIPH, and how we can optimise jockey safety with better vest design.
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.
You can click the title of each paper to read it in full.
#1. Sixty minutes of turnout reduces stress indicators for stabled horses
What’s it about?
A team from the Department of Animal Science at the University of Nebraska-Lincoln put together this study to quantify the effects of solitary turnout on horses otherwise stabled, and if the length of the turnout session affected the results. Eleven horses were given 60 minutes, 15 minutes, or no daily turnout for 12 days at a time, and observations were made across each block.
Horse enjoying time in the paddock | Image courtesy of The Image Is Everything
Key findings:
Blood tests indicated lower immune stress in horses who had 60 minutes of turnout versus horses who experienced the other two options.
Heart rate variability was greater in horses with 60 minutes of turnout and that same group spent more time moving around the box by day 6. However there were no changes to stereotypic and aggressive behaviours.
What it means for you:
Turnout measurably matters for welfare! Even one hour of turnout made a scientifically significant difference to horses’ stress indicators. It is something to consider where possible for trainers looking to optimise their horses’ welfare, which obviously knocks on to performance.
#2. Long-term omeprazole use associated with higher rate of EIPH and epistaxis
What’s it about?
Omeprazole is commonly given to racehorse prophylactically to prevent ulcers, but what are the risks of long-term use? This retrospective cohort study completed with assistance from the Hong Kong Jockey Club Department of Veterinary Clinical Services analysed the records of nearly 3000 Hong Kong racehorses to uncover possible associations between omeprazole usage and common racetrack injuries/conditions.
Injectable Omeprazole | Image courtesy of V-Tech
Key findings:
There was effectively no association between cumulative omeprazole use and a risk of fracture or atrial fibrillation.
There was a slight increased risk of exercise-induced pulmonary hemorrhage (EIPH) and epistaxis associated with cumulative omeprazole use in the 30 days before a race.
What it means for you:
Omeprazole has its place in ulcer management, but this suggests that careful consideration should be given as to how long it is used for and how necessary it is, especially with horses at higher risk of EIPH. This study suggests further work should be done to better understand the connection.
#3. Genes react similarly whether a horse gets faster in its workout or starts faster and slows down
What’s it about?
This study led by the Equine Research Institute at the Japan Racing Association where different pacing patterns during high intensity exercise triggered different responses from the transcriptomes in equine muscles. Horses underwent two treadmill sessions in either a positive-pacing protocol (fast start) or negative-pacing protocol (slow start), then gene expression was measured four hours post exercise.
Key findings:
The positive-pacing protocol resulted in upregulation of 1989 genes and downregulation of 840 genes, while the negative-pacing protocol resulted in upregulation of 1710 genes and downregulation of 593 genes. However changes to most of the genes that react to exercise were shared by both protocols.
Four genes - RP1, MORN5, and two unannotated equine transcripts - were higher after the positive protocol than negative, while five genes - OLFML2B, POSTN, ANGPTL1, MAP1A, and ZNF554 - were expressed higher after the negative protocol.
What it means for you:
There isn’t a whole lot of measurable difference in gene expression between the two types of exercise protocol, when the workload is the same.
#4. Making smarter safety vests for safer jockeys
What’s it about?
Jockeys and trackwork riders undergo huge risks whenever they get in the saddle. The safety vest plays a huge role in their welfare, but are we optimising the design of those vests? This study from Monash University’s Lisa Giusti Gestri investigates the limitations of the current vest designs, and what opportunities there are to innovate PPE in the future.
Racelite jockey safety vest | Image courtesy of Racelite
Key findings:
Jockeys often criticised current designs for limiting movement during races, fitting their body shape poorly, and being hard to remove.
There was concern about who was setting and maintaining safety standards for vests, and jockeys felt they weren’t consulted enough in the process of designing something meant to protect them.
What it means for you:
There is a clear need for greater innovation in safety vest technology. This study highlights how the industry should include jockeys more in the process of designing new safety wear and consider whether smart materials and flexible sensors could be factored into the design. Data collected from ‘smart’ safety vests will help the development of the next generation of rider PPE.
#5. Just 1 million bacteria can cause placentitis
What’s it about?
Placentitis is one of the leading causes of late term pregnancy loss, so how can we best identify it, treat it, and prevent it from happening? This article brings together the most up to date information on the topic from some of the United States’ leading reproductive veterinarians.
Key findings:
Streptococcus equi subsp. zooepidemicus, E. coli, Klebsiella pneumoniae, and Pseudomonas are the most common bacteria to invade the uterus and cause infection. Just 1 million bacteria is enough to cause placentitis.
A vulva tilted just 20 degrees or more is at higher risk of leading to placentitis.
Progesterone metabolite 20α-DHP and eIL-1-β are currently being evaluated as potential biomarkers for placentitis, alongside more common laboratory tests like serum amyloid A and lactate.
What it means for you:
Identifying mares at higher risk of placentitis and carefully monitoring them is important to mitigating the number of placentitis cases and their severity. As Dr Joan Carrick reinforced in our recent article on her work on mid to late term pregnancy loss, knowledge is power and targeted treatments are the most efficient ways to keep on top of placentitis.
