I was helping a colleague do a horse nutrition training seminar the other day and the question came up “Is it okay to supplement a commercial feed?” Specifically, this person was feeding half oats and half SafeChoice to her horse. My colleague had a great answer for this. He picked up a half full glass of Coke – “Pretend this is SafeChoice. Balanced perfectly to provide just the right things in the right amounts.” Then he picked up a pitcher of water – “Now pretend this is the oats. Not nutritionally balanced, low in protein and high in starch.” He started pouring the water into the glass until the mixture reached the top. The result was a watered down, light brown mess that looked unappealing and I am sure tasted the same way. The message here is simple – commercial feeds are formulated to be complete in their vitamin/mineral content, protein level, energy and fat levels. When fed at the recommended amounts per day based on work level you are meeting your horses’ nutritional requirements and delivering a specific and targeted amount of nutrients. There is no need to add/substitute/mix anything else. If you take that same feed and mix it (with things like straight grains, sweet cob, etc) – the result is an unbalanced feed that does not meet the needs of the horse. The protein gets lowered, the vitamin and mineral contents become diluted and things like calcium and phosphorous and copper and zinc can get out of balance. What you get is a diluted mess that is only doing half the job. To get the full benefit of a commercial balanced feed, use it according to tag directions and resist the urge to dilute it with anything else!