soaked alfalfa cubes help them put on weight so quickly.
i have a thoroughbred as well!! we used alfalfa cubes for a while along with his grain and he loved them!
Cocosoya works wonders on my thoroughbred
I use hay pellets and weight builder on my hard keeper to gain and keep weight but it made her a little hot but it works wonders.
Instead of hay use hayledge x
I had a similar situation. A skinny thoroughbred. I used Tribute feed to help him gain. He is on a mixture of there Kalm Ultra and Kalm N Eazy. This has worked for him. He gained 58lbs in 4 weeks while in work. My trainer also recommend that if that wasn't showing a lot of improvement I could try cool calories.