What happened to the bodies of the dead Aintree horses

just that there were a lot of fresh pies in the local Aintree butchers.
Joking aside what did happen to them. Burial,cremation or slaughterhouse.It seems that the latter is the fate of thousands of racehorses once they have finished racing or in some cases have never run.

https://www.bbc.co.uk/news/uk-57881979