Thanks to Teresa's coverage today we have the answer:

Teresa Genaro ‏@BklynBckstretch 11h11 hours ago

Dr. Tim Parkin on Equine Injury Database: the earlier you start racing horses, the better for their bone health. Dismisses notion, based on research, that 2yo shouldn't race

Slide presentations from today's Racehorse Summit:  https://www.grayson-jockeyclub.org/WelfareSafety/default.asp?section=48

And the entire booklet in pdf format, starts with bios of the presenters:  https://www.grayson-jockeyclub.org/resources/wssvi_booklet_complete.pdf

I'm so glad they are continuing on with these studies.  They now have six years of data and can predict which horses are at risk and will begin using this data initially at 8 specific tracks, I believe that is I what I've read here.  I know that Finger Lakes already has a vet that has developed similar data and has been using predictors for the horses there.

The video presentation of today's summit will be available on July 9.

Ten Takeaways From The Welfare And Safety Summit

1. A lot of riders are not wearing ASTM (American Society for Testing and Materials) approved headgear, and it’s placing them at tremendous risk.

2. Those helmet manufacturers’ replacement guidelines might be more than a marketing ploy.

3. Female jockeys may have a higher incidence of some injuries than male riders.

4. Data continues to support the notion that synthetic surfaces are safer than dirt when it comes to catastrophic injuries.

5. The longer a horse is in the barn, the safer he is.   The risk for a horse who has been with a trainer for one month was 60 percent higher than for a horse who had been with his trainer four years.

6. Data continues to support the notion that starting a race career at two is better for horses than waiting until they are older.

7. Speed, unsurprisingly, can be more dangerous for horses than middle or long distances.

8. Racing is behind the eight ball on continuing education – but it’s working to catch up.

9. Two months may be the optimum vacation length for horses needing a freshener.

10. Got a horse with a bone bruise? Get him moving as soon as you can.

http://www.paulickreport.com/news/ray-s-paddock/ten-takeaways-from-the-welfare-and-safety-summit/

Wow Irish racing authorities are taking a very strong stance here, banning for life every horse given any prohibitive substance. 

BloodHorse.com

Irish Task Force Issues Anti-Doping Report

An anti-doping task force in Ireland has issued recommendations designed to combat use of illegal drugs in racing and breeding and strengthen testing programs. One recommendation in the report released Feb. 4 calls for a lifetime ban on any horse found to have been administered a prohibited substance, including anabolic steroids.

Read more from BloodHorse.com

It's too bad the USA can't get their act together and make a stand like this!

I agree!!