Possibly a numpty question about racehorses

[Boxers]

Are all male racehorses stallions?

If they are geldings and are really good, then surely by gelding them you have missed out on progeny (sp?).

Were any of today's Grand National runners mares?

 

[Fools Motto]

All geldings today I think.
Rare to see NH stallions racing.

Not sure why some aren't kept as stallions, maybe too tricky to keep or maybe by the time they are 3/4 they are gelded before they reach their potential?
Flat horses tend to be kept entire for a while longer - just in case. And obviously flat bred horses tend to be of a higher value than NH.
Just my thought.

 

[Slinkyunicorn]

Mainly gelding I think - certainly Kauto Star, Denman etc are as were Desert Orchid and Red Rum

 

[glenruby]

Essex a few years ago was a notable nh horse who was still entire. However he was a fairly decent flat horse too beforehand.