Nutrition for endurance horses – PART 2

As a continuation of my notes taken at Dr. Steve Duren’s talk on feeding endurance horses properly at the January 2014 PNER annual conference. If you missed it, check out PART 1 of this discussion for more information of feeding an endurance horse during and after an endurance ride.

This later part of the talk dealt mainly with other niceties beyond what to feed during and after an endurance ride. In other words: what about the fiddly supplementation you can do with horses? Why do it, and what substances matter and why?

Other Supplementation in Endurance Horse Diets

There was some discussion about other supplements that are commonly fed to endurance horses, which was great to hear because some of these issues apply to Deli and I now even though we are just starting back into riding more vigorously!

Magnesium (Mg) is commonly fed because it helps muscle and nerve function. I actually feed Deli magnesium and chromium to help curb her anxiety (and yes, it helps). What I didn’t know is that feeding too much Mg can inhibit calcium absorption because Ca and Mg are absorbed through the same pathways. And yes, endurance horses do need that calcium (see discussion below). Dr. Steve Duran’s recommendation was to feed no more than 25g of magnesium daily to avoid issues with Ca absorption.

Calcium (Ca) supplementation can be helpful because calcium functions in muscle contractions. An easy way to get some more Ca in an endurance horse’s diet is to add a little alfalfa. Beet pulp is also higher in Ca than grass hays.

Beet pulp is a common feed in the world of endurance, and Dr. Duren had some things to say about it as  a forage source. In this discussion it was acknowledged that beet pulp is essentially a super fiber – it is 80% digestible compared to hay, which is normally around 50% digestible. In my nutrition classes in college beet pulp was always referred to as a soluble fiber for this reason. As far as this expert was concerned, it was a safe forage feed but without a lot of its own nutritive value beyond that it as a digestible fiber. Oh, and it really is a myth that if a horse eats un-soaked beet pulp it will swell and explode in their stomachs. You won’t believe how many boarding barns I have been at where the barn manager was under the impression beet pulp would lead to horses exploding left and right, so it as nice to hear this myth stomped on yet again by an expert.

Selenium (Se) is a mineral that is deficient in many Oregon soils where hay is grown, and so I supplement Deli with it as a matter of course. Both selenium and vitamin E are also antioxidants that help prevent the condition of tying up, so these minerals are a good thing to add to an endurance horse’s diet beyond the fact that they might not be getting what they need from the hay they are eating.

That's all for endurance horse nutrition! Next up will be my notes on lameness in endurance athletes at the ride, which includes some discussion on the function of endurance vets and what exactly they are looking for in those trot outs. It was a great panel for the endurance green bean in me to hear the vet talk about ride vet checks, and I hope my notes in the topic will be helpful for others as well.