.....He'll be 2 in June. Gelded, and about 14.1hh now. I need to add some serious magic growing powder, and wondered what feed you have had youngster on. Grazing is quite good, and hay is top stuff.
My young man is the same age, I feed D&H Suregrow. Fab stuff!! I feed this with a bit of Dengie Hi-Fi and speedibeet. Though i strongly reccommend that you dont use hard feed to force growth, thats when things go wrong. Id leave him to grow at his own pace! Whats his breeding? What should he make? My boy is an appy and not a great doer, this is why i feed him because he wouldnt keep the weight on just with haylage, as we've no grass atm!! Once the grass comes through i'll drop his feed ration considerably!
To be honest, if your lad is doing well off good quality hay and grass, theres no real reason to feed hard feed. If you would prefer him to be getting all the necessary vits and mins then perhaps just feed a handful of chaff with a vit/min supplement in.
But i stress, dont feed him up to try and make him grow, it puts all kinds of unneccesary stress on joints and if he ended up with OCD youd never forgive yourself!
Mine is 2 in May and is looking really well have not changed his feed all winter even in the snow. I'm just giving him chaff and vit/min supplement and he looks great oh and hay. But i also secong D&H suregrow is really good too.