Oldie at our yard gets it as he has no teeth left... he has a huge tubtrug full at night, as much as he can eat really, he's only a little lad. And then he has another half tub for lunch.
I use Just Grass (Dodson & Horrell) and it comes in a big sack. My mare has about 5 handfuls twice a day whilst shes on box rest mixed with a bit of water. The bag would probably last around 2 wks using at this rate.
I feed Graze On, which is the same thing, but £5 a bag cheaper.
I use it as a partial hay replacer for my fussy oldie. She's 16hh and I feed 5 stubbs scoops in the evening and 1 in the morning. I think this is approx 1.5kg, so a bag lasts me 10 days.
I use grass pellets, bags are cheaper and last longer. I prefer the smell of readigrass but horsey prefers the pellets...think other is too spiky for his mouth.