Have any of y'all tried Purina's Supersport? It's a muscle building/recovery and energy supplement. 

https://www.purinamills.com/horse-feed/products/detail/purina-supersport-amino-acid-supplement 

I'm thinking about adding it to my barrel mare for adding energy and keeping her topline and muscles (she's fine, just want to keep it like that).

Never tried it but I love Purina feeds.  

I have used it for quite a while now. Mine looks great. Great toplines on everyone on it. I really feel like having it in my program helps them bouse back day to day at barrel races. I went to a weekend barrel race and my gelding did great. Found something to go to on the way home (because why not I won some cash) and he was just as strong and fresh as he was Friday when I put him on the trailer. 

Great to hear!

I really like that it helps with recovery/bouncing back, even though I have never tooken her to a back to back race (she just started competeing this year).

How much do you feed of it?

Anyone else? Very curious about the product

I've been using it on my gelding for about 8 months. He looks great & feels great on it. Good stuff.

I feed a cup in the evening every day. When I'm at a race or they had a hard workout, I feed a cup twice a day for 2-3 days to help them bounce back. 

Thanks for the inputs! I'll try to get a bag next time I head to the feed store. 

Just curious, but how long did you feed it until you noticed a difference?

Almost all high protein supplements are made with soy as the number one ingredient. Soy is the cheapest source of protein in the feed industry, so this is to be expected. A significant number of horses have a negative reaction to soy in their diet. Many have no problem with it. If you feed a protein supplement like this and see a allergic reaction, hives, or respiratory issues that were not there before, soy could be the problem. As I said, a lot of horses eat feeds with soy with no issues, but it is something to be aware of. I never use soy in a horse or dog formula for this reason. 

Thanks for the input Win!

I've never had a horse with an allergic reaction to soy, so it hopefully won't be an issue. Is there anything else I must know?

Soy provides fairly good quality protein considering the low price. Most horses can tolerate soy in the diet. Mares seem to be more sensitive to soy as it can be high in estrogen. It is the foundation for most horse feeds due to the low price and the fact that most horse feed manufacturers don't ride horses.