Question

I'm interested in using lecithin as a behavior modifier. I've done a lot of reading about using it in this way. I realize that more research needs to be done to form better conclusions, but I would like to try it on my four-year-old gelding. He is 15.1 hands and weighs approximately 1,100 lb (500 kg). He is used for trail riding only, not showing. He is very reactive to noises and sudden movements around him. I have not been able to find information anywhere as to the correct dosage for a horse. I appreciate your suggestions.

Answer

I find it interesting that you chose lecithin as a calming supplement over other popular options such as magnesium or thiamin. I have found only one study that investigated the effect of lecithin on the disposition of horses. Although the researchers discovered an effect with the use of lecithin, they were actually feeding quite a lot of it. In the end, the researchers also were not sure if the effect they saw was due mostly to the fat in the diet or whether the lecithin had played a role. 

In this study, the total diet of the horse was 10% fat (including the forage) and half of that fat was soy lecithin (either soy lecithin with corn oil or soy lecithin with soy oil). To give you an idea of how much lecithin that was, if a 1,100-lb (500-kg) horse is fed 2% of his body weight in feed each day, he would receive 22 lb (10 kg) of feed. If 10% of that is fat, it would be 2.2 lb (1 kg) of fat, and if half of that was lecithin, it would be 1.1 lb (0.5 kg). The horse would therefore consume over 1 lb (0.45 kg) of lecithin per day.

What the researchers do not say in the report was how difficult it was to get the horses to eat that much lecithin. In an earlier article published by the same research team, the scientists explained the strong preference of the horses for oil without lecithin over oil with lecithin. I was at the university when this research was being conducted and saw firsthand the difficulties involved in trying to keep horses on high-fat diets and trying to encourage the consumption of lecithin when pure corn oil tasted so much better.

There may be a solution to the dilemma of getting horses to eat lecithin. Lecithin used in the aforementioned research studies was derived from soybeans, but there is a significant amount of lecithin in flaxseed (linseed). It is much easier to get a horse to eat flax. Further, flax is rich in the omega-3 fatty acids that help moderate the inflammatory response in the horse.

There is no established recommendation for the amount of lecithin, but 0.5 to 1 lb  (0.25 to 0.45 kg) of flax seed per day should be adequate to test the premise that it will have an effect on the reactivity of the horse. Flax can be fed whole (horses can digest whole flax better than humans) or ground immediately before feeding. It is not a good idea to leave ground flax lying around because it oxidizes rapidly, destroying the beneficial fats. Stabilized ground flax is available and may be a convenient alternative.