Just wondering because my Thoroughbred isn't putting weight on as quick as he should be and I was told tht Millrun works really well and you don ' t need much of it.

His teeth and worming are up to date so it's not a health issue. Just want to know about the feed.

Millrun is alright, but I've found that Copra and Full Fat Soy Bean Meal is so much better.
Prydes feeds like Easy Response and Bio Mare Cubes are also really good. I've head of people feeding Bio Mare to their stallions to help them keep up a good weight.
My horse gets a small scoop of Copra and a large scoop of Millrun twice a day and he's gaining weight quite well. He's hard to keep weight on as he's a young horse he runs around playing with my friends ponies all day so he's burning it off almost as fast as he puts it on.

I have never used Millrun, I've actually never hear of it . But I do own thoroughbreds and I know how putting weight on them is hard.
I've tried dozens of weight gaining supplements and I think Weight Builder is the best along with Fat Cat and Cool Calories.
Cool Calories is great for thoroughbreds because it wont make them "hot" like the others.
If Millrun is a grain then I would also look at Triple Crown Complete, its the best of the best, especially for TBs.

years of experience

i have all ways used millrun and find it to be ok but you could all way try bio mare cubes ( geldings can eat them to) it is also good for putting on weight and you don't need to feed a great deal of it, i am about to start my TB mare on it

Yes Millrun is good for weight gain.

I know a lady who uses it on her aged horses to help them keep weight on. Just mix it with water to make a mash.