The healthy omegas in flaxseed are evident in coat shine and condition. If you google flax oil for human use you get far more info about their benefits. There are different kinds of flaxseeds out there that effect ruminants differently than single stomach creatures like humans and horses.
I buy my flaxseed from a feed mill in a 50lb bag. They are "feed" grade high fat flaxseed and aren't nearly as expensive as most flaxseed people get for themselves or animals.
In ruminants (which I have) unground/undigested seed isn't an issue since they have 4 stomach chambers and they chew cud, but I decided to give them to my horse whole anyway.
He is a slow eater who chews his food well without hoovering it down, and I have seen a difference in his coat since bringing him home and putting whole flaxseed directly into his feed. Because of how I buy my seed, if some don't get ground up and they pass through it's ok to me. The chickens will get them when scratching out the manure piles looking for other goodies.
Yes, the results in my ruminants are somewhat better than my horse so far, but I'm also the lazy sort who doesn't want to have to clean the blender or grinder each day.