Scientific Research Supports Scoping Results at Sales

The preliminary findings of a comprehensive study of endoscopy results from the New Zealand auction sales has provided conclusive evidence to support current post-sale endoscopy gradings.

The seven-year study, lead by Dr Jonathan Hope, Convenor of the New Zealand Equine Veterinary Association (NZEVA) Endoscopy Committee, confirms that there is no difference in the future performance of horses with Grades 1 & 2 post-sale scoping results as those with a Grade 3.

Hope says the study was undertaken out of a necessity to identify whether there was any evidence to support Grade 3s being regarded as scoping failures.

"It is now firmly accepted by buyers and vendors that Grade 1 & 2 endoscopy results are a pass, and Grades 4 & 5 are a fail. However, there is a perception from some clients that Grade 3 horses may not perform as well, and consequently earn less in stakes, than Grades 1 & 2.

"It was my intention that this study should reveal one way or the other whether Grade 3 horses should be treated as a pass or a fail, judging by their future performance compared with Grades 1 & 2.

"We are thrilled to see that our preliminary findings demonstrate no statistical significance between the two groups of horses. This means we now have scientific evidence to support the robustness of the current grading procedures adopted at the New Zealand sales."

New Zealand Bloodstock Co-Managing Director Petrea Vela says the company is extremely heartened by the results of the research.

"We are very grateful to the NZEVA endoscopy committee, the team at Massey University, and particularly to Jonathan Hope, for their considerable hard work to undertake this analysis over many years. There was always a risk in a study like this that the results wouldn't fall in our favour, but with mounting pressure from buyers looking for ways to reduce their purchasing risk it was a study that needed to be performed and we supported it wholeheartedly.

"It is very heartening to see that the evidence supports the procedures already in place at Karaka. We have confidence from these findings that we have a robust system for the protection of our buyers and vendors, and therefore see no need to review our scoping or grading system at the present time."

In 1995, post-sale endoscopic examination of yearlings and racehorses (older than one year) was introduced in New Zealand. A New Zealand Equine Veterinary Association (NZEVA) endoscopy subcommittee of Drs Brian Goulden, Brian Anderson and Jonathan Hope established the current convention applied at all auction sales in New Zealand. With regard to laryngeal hemiplegia (roarers) the English grading system using a 1-5 scale was adopted. Grades 1, 2 & 3 a pass, and Grades 4 & 5 a fail.

Since 2003, data on the laryngeal function of yearlings and two-year-olds at the point of sale has been collected by a team headed by Jonathan Hope. In August 2010 Massey University assisted Hope with the analysis of the data, comparing it with the race performance of each crop of sale horses (using the number of starts, the number of wins and the amount of earnings to date).

The aim was to determine what difference in performance, if any, there is between yearlings and Ready to Run Sale two-year-olds with Grade 1 & 2 function and those with Grade 3 function.

A total of 3867 yearlings and 908 two-year-olds were examined. For this analysis, a Grade 1 or 2 horse was randomly selected as a corresponding control for every Grade 3, providing both horses had been examined in the same year, and both had raced[1].

The results of the study showed no statistical significance[2] between the two groups in either case. There was no statistical difference in the number of starts, wins or stakes earned between the Grade 3 and control horses, demonstrating unequivocally that a Grade 3 should be regarded as a 'pass'.

In the study, the results were the same for both yearlings and two-year-olds, as well as for both age groups combined.

The findings confirm that there is no scientific support for buyers to reject Grade 3 horses as there is no difference in their performance when compared to Grade 1 or 2 horses.

A separate analysis was conducted on horses that did not race, comparing them to both the Grade 3 group and the control group (Grades 1 & 2). Similarly there was no statistical significance for the proportion of horses that didn't race.

Hope says that buyers to New Zealand can take confidence from these findings.

"The post-sale endoscopy system in place in New Zealand has its limitations here as it does all over the world. The endoscopic examination of horses is not an exact science although the panel of vets at the Karaka Sales has developed a uniformity that provides the highest level of consistency that it's possible to attain under the circumstances.

"These results go a step further to endorse the grading system we already have in place as being scientifically sound. This can give both vets and buyers confidence that every horse passed by the panel, whatever its grade, has the same statistical probability of remaining sound in the wind as any other horse that passes inspection."

The 2011 Endoscopy Report will be finalised in the coming weeks and the full report published later in the year.

Footnotes:

[1] The Wilcoxin Signed Rank Test was used to test for difference in time horses have had to race. Inflation of earnings was also taken into account.
[2] A p-value of <0.05 was considered significant for all analyses

For news and sales information from New Zealand Bloodstock visit www.nzb.co.nz.� Don't miss Karaka 2011, starting Monday 31 January at 11am at Karaka.