Is it Okay to Mix Horse Supplements? (Mineral Interactions)

Updated August 16, 2024 | By: Dr. Lydia Gray

"Is there any problem with nutrients interacting with each other if they are stored together for a long time? Do any minerals “eat up” others?"

- Stacy

Dear Stacy,

Great minds think alike! SmartPak has long wondered this too, so first we consulted a variety of experts in the medical, nutritional and basic science (chemistry, biology, etc.) fields to try and find the answer.

Turns out there are issues not only with nutrients interacting with each other but also with nutrients degrading due to light, heat, moisture and air. The scientists we spoke to also explained how nutrients like vitamins, fatty acids and amino acids have the most tendency to degrade. In fact, one laboratory told us that Vitamin C levels in a particular liquid human supplement were nearly undetectable the very next day after they opened the container!

Some examples of things not to mix together before feeding are inorganic minerals with fats, Vitamin E with copper, antioxidants with fats, and so on.

Study on Storage and Nutrient Potency

Based on this information, we designed a study and sent product to an independent laboratory for testing. Since measuring the degradation of vitamins and some other nutrients can be tricky because current testing methods have a wide margin of error, we chose to measure the potency of fatty acids over time in two separate systems. Basically the study protocol was this:

• A sealed bucket of a supplement from a major, nationally recognized supplement company and SmartPaks containing the same supplement from the same lot were sent to a third party for analysis.
• The sealed bucket and SmartPaks were stored in ambient conditions (77°F and 60% relative humidity) under 12 hours of light and 12 hours of dark. This was the best we could to try and recreate the average barn environment.
• The bucket was opened one time per week to simulate preparation of baggies or plastic containers then resealed. The bucket was only stirred for the Day 0 (baseline) sample.
• The bucket and SmartPaks were tested throughout the study for levels of Omega 3 and Omega 6 fatty acids.

We’re confident in the integrity of the SmartPak system and so were pretty sure that the study would show some loss of fatty acids from the bucket, but we were not prepared for the actual difference seen in levels between the bucket and SmartPaks. After just two weeks—and with only two lid openings–both Omega 3 and Omega 6 levels began to decline in the bucket. The amounts of these two fatty acids in the bucket continued to steadily decline throughout the course of the study which we had set to end at Day 84 (7 weeks).

In stark contrast, Omega 3 and Omega 6 levels were maintained in SmartPaks (which were replaced every 28 days, just like in real life). To share actual data, levels went from 1.4% in the bucket on Day 0 to 1.3% by Day 28, and down to 1.1% by day 84. Put in other terms, Omega 3 and Omega 6 degraded to 90% of their original potency after four weeks and to less than 80% potency after 7 weeks.

I’m guessing we’ll perform more of these types of potency studies–on different nutrients stored in different ways–but for now the take-home message is if you want to guarantee that your horse is getting 100% of the active ingredients you paid for, either buy a fresh bucket every month or switch to SmartPaks.

Mixing Supplements Before Feeding

Mixing supplements, feeds, etc. right before feeding is fine. It’s storing them that’s a problem, sometimes even for just a few days.

As an example, here’s some research I found on Vitamin E: Dove, C R, and R C Ewan. “Effect of trace minerals on the stability of vitamin E in swine grower diets.” Journal of animal science vol. 69,5 (1991): 1994-2000. doi:10.2527/1991.6951994x

The purpose of this study was to determine the stability of different forms of Vitamin E in the diets of growing pigs during prolonged storage in the presence of high levels of copper, iron, zinc or manganese. While all of these trace minerals led to increased Vitamin E degradation, copper had the greatest destructive effect on tocopherols (Vitamin E).

In fact, the study showed a reduction to less than 10% of the initial concentration of Vitamin E after only 10 days of storage.

Key Takeaways on Mixing and Storing Horse Supplements

The take-home message from this particular experiment is that certain trace minerals (especially copper) when stored with Vitamin E cause it to breakdown faster than normal. Therefore the feed or supplement no longer contains the full amount of Vitamin E that was originally in the product. So instead of Vitamin E being available for the animal to use as an antioxidant inside its own body, to fight the damaging effects of oxidative stress on tissues, the nutrient was oxidized (used up) during storage.

For the most part, interactions like these between nutrients don’t create harmful substances, they just destroy the nutrients that you paid for and that you or your veterinarian wanted your horse to have. I know chemistry can be challenging, but I hope this clarifies things a little!