Has anyone fed either of these feeds and did you like or dislike them? I have a senior mare currently on BlueBonnet Senior but she has quit eating it. I have recently had her vetted and teeth checked at Outlaw about a month ago and she didn't have any major issues so I'm thinking she may just be burnt out on her current feed. 

Most horse feeds today are "least cost formulated". This means that every production run uses different ingredients to try to get the same Protein, Fat, Fiber and Ash gurantee for the least amount of money.  Many horses are sensitive to changes in the diet and will quit eating a feed that has changed too much. This is likley what happened to yours. Least cost formulated feeds have a sewn on tag that shows ingredients. This is easy to change when the actual formulation changes from production run to the next production run. This is why the feed often looks different every time that you buy it.

A fixed formulated feed uses exactly the same ingredients every time. There is no need for a sewn on tag for these products since it is made the same with the exact same ingredients every time. Fixed Formulated feeds have the ingredients actually printed on the bag itself since they never change.

If your feed has a sewn on tag it is least cost formulated. The only thing the same every time that you buy it is the outside bag itself, not the feed inside.

There are a few companies that still fixed formulate. Try some Renew Gold. Not the only one out there. Just remember to look for the ingredients printed on the bag, not on a sewn on tag.