What To Feed A Weanling?

I just got a Paint weanling colt, and he is pretty underweight. He has just been in the pasture with his dam, so he wasn't being fed anything special. I would like to show him in open halter classes, and I am wondering what to feed him to help him bulk up. I don't need him super bulky like the halter-bred horses, just want to make him look more filled in, especially his neck. I usually feed my underweight horses rice bran and beet pulp, but this is my first weanling, so I want to make sure that I don't feed him something that wouldn't be good for his growth, etc. Also, is there any exercises or something I can do with him to help him build muscle, especially in the neck? It's so skinny, and it drives me crazy. Lol. Please help and thank you!

I have been raising foals for almost 10 years and have tried about every feed out there. IMO the best without a doubt is Purina EQuine Jr. Its a complete feed so has alfalfa and beet pulp already in it. We also feed good hay with it. Once they are used to it the best way to get weight on is to feed them free choice. I have 2 I just weaned and they have access to the Jr 24/7 and they look awesome.

Please do not excercise a weanling. They are just too young. Once his weight comes up he will play more and excercise himself

We keep show horses on equine jr until they are 2

If he needs a fast boost get some Equine Body Builder (liquid) and put him on that for a couple weeks. They love the taste of this and will come running when they see the syringe. This increases appetite and will put weight and muscle on very quickly. Really adds a nice bloom and shine to their coats.

Don't worry about exercising him, he is a baby. Muscle will come with age.

I agree, Purina Equine JR seems to be the best thing out there, that coupled with good hay, a salt block and water.