I got my colt foal Isaac at 6 months old, he had lived on a hill with his mum until then, was quite poor and FULL of worms, I had never seen such a burden being dropped once I started worming him. He is a traditional Black and White Cob and a good stamp of one too, I had him DNA tested to see if he was Homozygous, he is Heterozygous so I had an easier decision in getting him gelded.
Considering his poor start in life he is now the picture of health, very happy, VERY cheeky and growing nicely, he's 3 now.
If I was to ever breed from my mare, I wouldnt be too bothered what sex it was as it would be kept and brought on for a riding horse, probably for my partner, I wouldnt breed indescriminately and definitely wouldnt disregard a colt just because he was a colt.
I also wouldnt send any of my horses to the ring, I would want to know where they were going and hopefully keep intouch with the new owner, saying that, I wouldnt sell any of mine, a horse is for life, not just for the summer!