There has been some discussion on ECIR about the effects of steaming on the s/s content of hay and Joan did an article about hay steamers in The Horse's Mouth. Because our IR horse (Robin) is also COPD and my non-IR horse (Obi) seemed to be "clearing the cobwebs" more as he started work after we got this year's hay, I decided to research steamers. This hay is not visibly dusty or moldy, but I still suspect a bit of mold since it was a very difficult haying season (wet). In short, there's essentially no scientific data about lowering s/s, although tons of anecdotal reports on good results with COPD. We had no more options to help Robin's breathing since he was already on spirulina, chondroitin, flax, etc. with minerals balanced to hay + hay soaked for 1/2 hr. in hot water. Since he's IR, steroids are not possible. Frustrating, since because he's IR, work is critical to controlling his insulin.

So I tested the steamed hay. This was VT 2nd cut mixed grass hay. I sent one sample to Equi-Analytical that was just pulled handfuls of hay that had been steamed (HayGain suggested this, saying the results would be different than the cored sample.) The second sample I sent was cored and steamed. The baseline is simply cored.

These are the results:

Baseline: Not steamed, cored sugar (ESC, simple sugars) + starch total: 10.4%

Steamed, cored ESC + starch: 10.2%

Steamed, pulled handfuls ESC + starch: 9.9%

The effect of steaming on this hay's minerals was insignificant. (No fun soaking AND steaming this winter!) But there was a significant improvement in both Robin's and Obi's breathing while in work; neither has breathing issues at rest. 

As Lavinia says, this is a "one rat test," but hopefully it will be of some help to someone else in a similar situation.

Donna Coughlin, Duke, Obi and Robin

CT 2009