There are many products out there. Not all are created with the health of your horse in mind. Simple is always better. In my practice I encourage your horse to be fed not supplemented. My standard recommendations are the Original Performance Formula or Cool Formula feeds that are grown, produced and manufactured right here in Alberta by Wilson Feeds. Aloe Vera juice and Flax oil. 

All other supplementation should be short term. 
I also recommend Equine Choice generation 2 pre probiotics. 

I have have also found the Rambo Ionic blankets and products to be very beneficial, especially for those hormonal mares. It works in a do no harm way by converting molecules to negative ions which allows natural positive charge which helps bring oxygen to the muscles. 

I am am happy to book you an appointment to help find you the most efficient and cost effective natural program for your horse.