I am totally new to boarding a horse as I've always kept them at my house and even boarded horses myself at our last home... I am boarding at a farm now that I LOVE and horses seem well cared for but whenver I go to ride my horse.. he always seems super hungry and cranky.. they don't give free choice hay and are fed in the morning and at night.. I usually go there an hour or two before (or what I belive to be) he gets fed.. He is more on the skinny side (came that way) so I want him to have plenty to eat but I don't know my rights.. am I allowed to request that he have more hay? Do I offer to pay more? should I have to? We always fed our horses round bales or kept them on pasture so they can eat whenver they want to.. I've considered feeding grain but I think through the winter, hay to keep him warm would be better. I don't want to create a bad relationship with the barn manager telling her my horse isn't getting enough to eat... 

Side note: the horses at this farm all LOOK great, most are more on the fat side.. so I'm unsure why my horse stays skinny and is always hungry.. I did deworm him and had a fecal done.. turned out fine.. he is appendix bred so more a lanky horse than the beefy quarter horses. 

I would ask for more hay to be fed to my horse, and if offer to pay for it. 

My guess is that boarding  facilities probably factor in feed and hay costs....and that anything additional would need to be paid by the boarder. 

can you provide a slow feed hay net or two for them to rotate in and out?  it would be a little more work but maybe he is just eating it up all really fast and then standing board and hungry the rest of the day?

So all he gets is hay and nothing else? Is he staying in a stall or a turn out?

I think you have the right to sit down with the barn owner or whomever is in charge and discuss your thoughts.  Years ago I was in the boarding business.  I had several owners that were serious combined event competetors (english) and they had some concerns.  We sat down, discussed their need(s) and what I was able to accomadate.  We came up with a plan that worked for us all.  One person wanted hay in front of her horse all the time (stalled) and a special diet.  I worked with her in the feeding and she provided the pre-prepped feedings (3x/dy).  Since I was there full time it wasn't and issue to do a noon feeding.  I think if you will just ask to have a conversation, share your concerns and discuss any issues you see or the barn mgr. is having / sees you will easily come to a workable solution.  

That's what I was wondering.  I've never fed a horse hay only.  They get grain twice a day.  

Not all horses need grain though. Many many many do just fine on good quality hay free choice. 

Yes I understand that, in fact my horses in the back pasture only get hay also along with pasture grass but this summer we didnt get the rain we needed so upped their hay with pelleted feed, but when winter rolls around I start giving them a little extra pelleted feed with hay cubes along with their hay. And I dont ride these horses. 

But since OP says her horse is on the thin side and getting limited hay and the horse is riden and seems hungry all the time, I think this horse needs more hay then what its getting with help as in getting some good pelleted feed for added fat.I would not want my horse being hungry when I rode him, just not fair. Being riden and just getting limited hay only and on the thin side, thats a big NO for me I want my horse to feel and look good.  When he gets some extra pounds I think good guality hay would be just fine. So waiting for OP to tell us how this horse is being fed. Sounds like to me its not getting enough and being riden poor fella. 

I am boarding a horse for the first time as well - i drive there & grain my horse once a day plus I bought a Hay  Chix  hay net & i feed a few flakes of grass hay every day - I see others doing the same - The barn feeds twice a day so my hay bag is to hopefully add weight as well.   

You have every right to discuss the possibility of adding more hay. But if you aren't there for feedings I would ask how well he eats and how much alfalfa he's getting and how much grass? If he's eating every morsel and looking thin then he clearly needs more hay. If he starts wasting hay and not staying fat then he clearly needs some sort of grain. 

Also my last appendix was a picky eater! Which in return made him a hard keeper. Even after teeth were done yearly and monthly chiro etc. 

I own and run a boarding facility. We have most all horses on pasture, some that are in shared 2ac pastures with 2 horses we try and keep round bales out pending if we have them available. Our 1ac pastures with 1 horse per pasture get thrown flakes of hay. This is how we do it, they get their grain and hay, we feed the reccomended amout of hay for that horses body weight or a little more. When its cold I normally throw one flake extra. Some horses eat every bit of it up twice a day and within an hour and look at me like they are starving, but are getting fed 10-15lbs of hay 2x a day. Some it takes all day to eat that much. If you are concerned about how much hay your horse is getting I would talk to the barn manager, if they are feeding the reccomened amount based on your horses weight then I would offer to pay extra to have them feed more. We dont make a lot of profit, so think about that as well. Im lucky I have a feed nutritionist I work with, they test our hay, come out and we look at the horses and if I have one we are having weight issues with we come up with a plan for them. What is the horses feed program, also maybe needs gastric support. 

He is in a turnout with one other senior horse. We are going to start graining them this week. When my friend had him though, before she brought him here for me. She said he would chow down a ton of hay.. he only have him a few days but said he ate a lot. We had a fecal count done and showed just fine. 

Thank you! Yeah, he isn't wasting any and not a picky eater.. he eats every last bit and always wants more! 

I would definately talk to the facility but from the sounds of his body type he might the horse that owner just has to buck up and pay for more. If after talking to the facility they can not get him more hay. I would buy some good alfalfa and some slow feed hay nets. And keep them full and just ask them to hang them in his stall so that he has extra good quality hay on top of what they are feeding. Its amazing what just a flake or 2 of good alfalfa will do for a horse. If he is a new horse to you I would also treat him for ulcers. But some extra good hay might be all he needs. The big thing is making sure they are willing to hang the bag if your not there every day. and they realize they hay you are buying and feeding is extra.... like a supplement.... and not to reduce the farm hay he is getting. Most places want the horses to look good so its just a matter of figuring out what works for him I am sure.

Also if you are there most days. He will finish up a couple flakes of good alfalfa in very little time. You can toss it to him and groom on him while he eats it then ride him with a full belly. That would be ideal.