Rice bran also comes in a heat stabilized form to prevent it's fat from becoming rancid. The heat treatment robs it of some the vitamins and is much more expensive. The horses love the rice bran. This makes it a logical additive to the fat feed and assists in the sales job as it is sometimes difficult so sell this fat feed program to your horse. A lot of commercial mixes tout their fat content in an impressive percentage but this is ONLY of their feed not total feed.
Total feed includes the roughage.
Rice bran, oil, oats and hay are probably a better choice better than any of the commercial fat feeds. A-D Vitamin shot may be in order, as the fat tends to wash out these vitamins from the system. If you feed the high fat diet you will need an active exercise program to burn all these calories. These value should be adjusted for each horses requirements. We have fed FAT PAK in recent years with excellent results.