Equine Nutrition: Fixed versus Variable Formulas

Download PDF In the world of horse feed manufacturing, companies use one of two different methods for formulating horse feeds, fixed formulas or formulas in which the ingredient mix changes on a regular basis. This last method is most often referred to as “Least Cost Formulating”. This article is designed to explain the differences between the two.

In fixed formula diets, the formulas are set by the nutritionist and never change until the formula or ingredients are updated to meet the latest information on nutrient requirements. This rarely happens more than once or twice per year. So how can you tell if the feed you are using is a fixed formula? Some ways to tell if feeds are fixed formulated are if the ingredients are listed specifically, if the guarantees are relatively extensive, or if the feed company expressly states that they are fixed. For instance, Triple Crown has changed our formulas in the past by adding an organic form of selenium and flaxseed to the ingredients and made some alterations to the vitamin and mineral guarantees. The alterations did not affect the basic ingredients or appearance of any of the diets. We also extended the guaranteed analysis, which is unrelated to any formula changes. Our changes have made our fixed formula better than ever!

Least cost formulating takes the feed ingredient market into account and changes the basic ingredients to produce a feed using the cheapest combination of ingredients. The changes are usually made weekly, but some price sensitive formulas may actually change daily. The guarantees on the tag don’t change, but the ingredient combination to meet those guarantees does. Obviously, no feed company will admit to least cost formulating, they will refer to the practice under various guises. One of the most recent spins is that each load of ingredients is tested for nutrient value and the formulas are adjusted accordingly. In reality, the nutrient content of basic ingredients varies little and the cost of analyzing millions of pounds of incoming ingredients on a daily basis is cost prohibitive. The feed you’re using may be least cost formulated, if the tag lists ingredients in general terms such as “processed grain products”, providing the required minimum or a very limited amount of guarantees on the tag, and if the actual color of the product fluctuates. One of the basic rules of proper horse management is to make changes in your horse’s diet very gradually.

However, if your feed supplier is changing the basic ingredients in the formulas on a regular basis, you are no longer in control of your feeding program. If you really want the “true” nutrition in your diet consistent from week to week, then fixed formulas are best way to go. Because a fixed formula matters, we encourage you to compare your horse feed brand to Triple Crown with our new Comparison website!