Julie, I like the colors and the photoshop glow you added, the vignetting I can do without, in all th shots, but that's personal preference. I really like shot to stand on it's own without the addition of vignetting.
Those stud shots are nice too. As a rule, I dont like static shots of any animal (horses or elk ow whatever), it's one reason I dont like to shoot horses, at the barn, but I know what youre doing and what youre trying to achieve and you did great and youre making money doing what you love to do, that's fantastic!
I have one comment about the stud/barn shots (BTW, that's a rich joint youre shooting at - those studs have first class treatment) the first three stud shots look like they are off about .5 degrees or even less, but either your angle was off a bit making the ban and the ground look tilted, or you were not holding your camera level. Whatever the case, it's easy to fix. . .
As a horse owner, I like to look at horses. However, I dont like to photograph them because they do a lot of standing around, it's hard, because of their configuration to get good flowing crops, and mostly they always look tired, or board, unless your working them or getting their attention. So i'm always envious of people that can find energy in shooting lone horses. I like to shoot them in action like at a branding or at a rodeo, but not while they are standing, around.
I really like the stud portrait, you caught some emotion in that shot.
Again, nice job on the studs and i'm so glad that there are people like you out there that really love to shoot horses! Thanks.
Oh yea, BTW, flash with large animals (deer, elk etc) is tough, if you get the eye the flash will destroy the composition as their eyes are reflective . . .