I increase my horses' grain after a workout.
I don't feed extra before cause I never know if something is going to come up
that will abort the riding plans. I also feed my own mixture that I worked
out with my vet over 20 years ago. At a ride, I give extra grain at each
vet check, not a whole lot but extra. I do have about 20 acres of pasture
though which helps with keeping the horses moving. I almost tied up a mare
from feeding too much grain at a ride. I worked her out of it but it was
not a nice experience. After that, I kept the grain at a minimum before
the ride started, then fed the extra after the ride or during the ride. My
mare tends to gain weight during the season too and I don't increase her grain
input during the season either. But then each horse is different and one
does what will work for that horse. Jeanie