You can be sure that what racecourses make does not go into any aspect of breeding, owning, training and related staff and costs. Why would it? A trainer makes his money out of owners and any other businesses, he doesn't pay a percentage to racecourses to help keep them going. Breeders get no help from anyone, apart from the slight EBF prize if something they've bred wins, and then only if it's by a sire standing in their own country. If they make a massive profit on a foal sale, they certainly don't have to divvy it up with any other aspect of racing.
All major sections of racing are standalones: the breeders, the trainers, the courses, the jockeys, the owners, and all of the periphery such as vets, grounds staff, officials, feed, transport, saddlery, farriery, you name it. Yet, without one or the other, it all falls apart. Thus 'racing' should be an umbrella term in a very broad sense, taking in all these assorted aspects.
Specifically, rather than generally, speaking, though, 'putting money back into racing' should mean - right now - boosting the prize money which the Levy Board is falling short of supplying. And it's falling short of supplying because of the rise of exchanges, which put nothing into the sport they parasitise, and offshore bookmakers likewise. Unless the British govt gets to grips with these issues, racecourses' prize money is only going to just meet the Tariff, and there will be a continuing and probably increasing reliance on sponsorship of races.
I don't have a problem with the Tote or bookmaking services being plugged if they're sponsoring significant amounts of racing - it's that they're not offering prize money in excess of bare Tariff levels (bar a few major races) that's cheapskating the sport. We see millions of pounds in profits accrue to the betting industry, while its payback to what gives it that money, sustains its little shops, its websites and its staff, is proportionally pathetic.
It's not in the betting industry's interest to see British racing wither and die, but as long as owners keep running their horses (all the bluster about boycotting has died without effect) and accepting the poxy prize monies on offer for standard levels of competition, it really won't give a XXXX about improving their lot.