I havn't done this yet, I am going to Austailia this year though on a Working Holiday Visa. I have done so much research on it and spoke to people who have done this before.
It is realistic to work and live off the money you make, or you could work hard for a few months, maybe take on two jobs, save up the money and then travel around and live it up that way. I guess it depends how good you are with your money aswell. There are temp jobs out there, you can basically do any job you want. Admin jobs pay good money but harvest work is more hours (working 12 hour days and more).
I'm sorry i did get it wrong on my post further up, you can work a maximum of 6 months with one employer and work as many months as you want out of the 12. If you do 3 months harvest work you can apply to stay for another 12 months. Hope this helps.
The OP asked about horse racing but I don't know about that sorry.