Commissioned Research

This project was one of the largest longitudinal studies of thoroughbreds in training ever undertaken and gained prominent equine veterinarian Dr Nigel Perkins his PhD. This was certainly the first such work undertaken on NZ thoroughbred horses. It followed the stables of 20 thoroughbred trainers at 5 venues in the Waikato and Central Districts for 34 months. 1571 horses completed 3333 training preparations producing data from 554745 study days and 287973 training days.

A huge amount of data was produced that summarized the way thoroughbred training was undertaken in these venues, the amount of time and the reasons horses were taken out of training, either permanently or to be spelled, and the equine contribution to racing of various age and gender groups.

In the section of this study concerned with evaluating predictors of various life events that could affect performance it was found that:

• During training risk of injury to the structures of the lower limb is increased in animals that are older [5 years or more] when compared with young horses [2-year-olds], and in those trained during the summer compared with any other season.

• If a horse remains uninjured through the first 20 weeks or so of training preparation they are considerably less likely to get injured after that period of time. It is believed that those horses that have reached the 20 week or more stage are fitter and healthier than those not reaching that stage.

• For horses that have already started in one trial or race there is a complex relationship between the risk of injury and the total distance raced by a horse the previous month; those racing very little the previous month are at moderate risk; those that race about 20 furlongs (4000m) the previous month are at low risk; and those that race 30 furlongs (6000m) or more are at a relatively high risk. This suggests there is a three level process of risk - when horses are initially getting to race fitness there are risks of injury because they are not quite fit enough to handle a race and/or minor injuries are being made worse by more exercise; horses getting through this period enter a phase where they can race well for a period of time with a low risk of injury; then, after a period of time which varies with each individual, the risk of injury rises if they continue to race presumably because of the stresses imposed on the musculoskeletal system. Finding the critical threshold as to how much racing a horse can stand before it should be spelled has yet to be determined.

The results of this study were reported to lay audiences at the 2005 Bomac Lectures and the proceedings from these are available on the NZERF website. As often happens, this research asked as many questions as it provided answers. It was intended that this research would be followed up with research that targeted specific types of injury to understand the interrelationships between multiple risk factors that might influence injury risk. Developing such tools as a standardized methodology for reporting track surface characteristics, injuries, etc. was needed. Unfortunately the cessation of NZRB funding of the NZERF meant we did not have funding to pursue this work in thoroughbreds let alone extend it to standardbreds and sportshorses.

Ancillary to this work was a second project aimed specifically at determining whether the newly installed “Matamata All Weather Training Track” had any influence on wastage during training when compared with other training tracks. In summary no evidence was found that could be attributed to the new Matamata track itself concerning any effect on wastage during training. While the author believed the finding is convincing he did sound a note of caution in that the information he had access to did have its limitations.

It is hoped that further work will follow to better understand the causes of thoroughbred wastage in New Zealand, especially as there has been real concern about the number of horses available to race. The NZERF is using the Australian Racing Incident Database (ARID) system to record race day injuries, which will provide valuable data for future studies.

"An economic analysis of the equine industries in New Zealand". The section on the Thoroughbred breeding and training sectors was completed and the following conclusion drawn: The Thoroughbred Breeding and Training sectors are vital components of the New Zealand Horse Industry and make very significant contributions to Gross Domestic Product. The estimated contribution of these two sectors in 2002/3 totalled to $774 million. It represented approximately 0.70 percent of New Zealand's GDP. Taking other sectors of Veterinary, Grain and Feed and Transport into consideration the total estimated contribution was $863.90 million. This represented approximately 0.79 percent of GDP. The Northern region is regarded as the hub of the Thoroughbred Industry, and the economic contribution was largest in this region. The Central and Southern regions followed respectively in their contributions. Because the Thoroughbred Breeding and Training sector's contribution has been substantial, it has also been very important as a provider of employment and for backward and forward linkages it has created with other sectors of the economy. They also contributed substantial multiplier effects with various businesses and provide economic benefits to a large number of communities in New Zealand.

Read more HERE on pages 60 - 61.

Commissioned research on "Prevalence of gastric ulceration in Standardbred and Thoroughbred racehorses in New Zealand".

While this problem has been suspected in NZ horses it is surprising, considering how different our husbandry systems are for managing horses in this country compared with most of those elsewhere, that the prevalence of gastric ulceration is so high [about 90%] and comparable with the prevalence described overseas. Further research is clearly required to identify potential risk factors for the horse and to explore the importance of the problem in respect to performance in affected animals.

The NZERF purchased the first veterinary gastroscope in NZ for Massey University. No breed/age differences were found and all horses at pasture had gastric ulceration whilst a few that were stabled did not.

Knowledge of the biology of the major roundworm (nematode) parasites of horses under New Zealand conditions is limited. This will impact severely on our ability to continue to successfully control horse parasites if, as has happened with cattle and sheep parasites, resistance to anthelmintic treatments becomes more prevalent.

A study was therefore undertaken to examine natural infections in 12 horses (in 3 groups of 4) of mixed ages - adult mares, yearlings and foals - kept at pasture for just over one year in the lower North Island (Manawatu). The major objective of the proposed research was to build an understanding of how infection patterns in a group of horses varied over the course of one year. To this end, every month, 4 of the horses were treated with anthelmintic and their faeces collected to allow the parasites acquired in the 3 months since they were last treated but now killed and expelled, to be counted and identified. The next month, the next group of horses would be due for treatment and so on.

The horses were treated with 2 doses of abamectin (600micrograms per kilogram - 3 times the normal dose rate), 2 days apart, and 5 daily doses of oxfendazole at the normal dose rate (10 milligrams per kilogram). Preliminary work had shown that this regimen would remove approximately 98% of the resident parasite population.

In addition to establishing the level of parasitism using worm count and faecal egg count data, a number of other parameters were also studied - these included various blood parameters - to examine their suitability as diagnostic markers for parasitism. A study of the ecology of the free-living stages of the parasites’ lifecycles was also attempted through studies of pasture larval populations and through plot studies.

One of the most interesting observations to emerge from this study was the marked difference in the levels of parasitism experienced by individual animals. Some animals appeared to be more resistant to parasites in comparison to others that appeared relatively more susceptible. Grazing the same pasture, some animals were allowing only negligible numbers of worms to establish whilst others were harbouring several hundred thousand.

Overall, worms were acquired in all seasons with no tendency evident statistically for more to be acquired at certain times, although this may have been the inevitable consequence of using small numbers of animals per group coupled with marked between-animal variation. Nevertheless, higher proportions of larval stages were present during winter and spring, suggesting that higher proportions of the worms acquired in the autumn and winter periods may have become inhibited in their development.

The 12 study animals were grazed for 14 months in one relatively small paddock and were treated with anthelmintics every 3 months. These conditions would not be much different from those experienced by many horses throughout NZ. Some of the study animals appeared to cope better with the study conditions staying largely free of infection, but others, in particular some of the younger animals, were consistently infected with substantial populations of nematodes. Thus it can be anticipated that individual anthelmintic requirements should also differ.

Acknowledgement

The study authors would like to express our sincere gratitude to the Equine Research Foundation for their generous funding of this work and their patience in awaiting its successful conclusion.

To download this article CLICK HERE.