Horse’s odd odor on SBM?

[Doc-t]

I have not heard of a bad odor from feeding SBM to any horse.

Usually, an odor comes from bacteria on the skin that has overgrown, such as excessive sweat. But the real culprit is the body’s microbiome, which is not “normal” for the area. The most common cause of body dysbiosis is excessive cleaning with antibacterial soap (or any kind of soap). Coupled with poor nutrition, skin with dysbiosis can stink when a change in diet or stress is added.

How SBM is affecting this horse is curious to me. I would need to ask questions about the grooming/bathing and a timeline of the feeding changes. I am certainly interested in the results of removing the SBM and how long it took to resolve. However, it would be important not to change anything else, such as increasing the bathing to clear up the smell.

Remember that bedding can affect some horses. Was there a change in this? Are other horses fed SBM at this barn and starting to smell, or are they unaffected? This case needs a detective or at least a lot of questions asked. Remember, correlation is not causation, so we can’t make assumptions, especially when something seems to be a one-off.

Keep me posted about the removal of SBM results.

[Kathy]

“Definitely no over cleaning- he’s only had two bathes with soap in the last month. I’m pretty judicious about using soap on my guys.

Diet is the same as all of mine (hay, alfalfa, SBM, Himalayan salt block).

I did add a probiotic to the diet, I’ll stop and just withdraw SBM.

Bedding doesn’t make a difference- he’s on straw now but was on shavings with same result.

Smell is definitely decreased now. (I.e. He doesn’t reek with being off SBM for three days. Very faint smell now.)

Thoughts I had- excessive protein? He is a hair underweight so is getting really high test alfalfa.

His urine/manure doesn’t have a strong smell though.

He had a medically resolved impaction and seemed to start stinking around that time so I was thinking gut biome or ulcers…but haven’t had one….stink. He smells sour 😰

Will keep y’all updated 😜“

[Doc-t]

Thanks for this update. It is hard to give excess protein in the diet (at least in humans). 1 pound of SBM raises the total protein to just the minimum, so I don’t believe it is excess protein.

If you bathe the horse, does the odor go away? If not, then where is the smell coming from? If it resolves with bathing, the microbiome (skin?) is affected somehow. It would be interesting to test the SBM/odor without the probiotic.

Other than doing a thorough elimination test, I can offer no advice on this. I have never heard of an odor from consuming protein or, specifically, SBM in horses. It forces me into a genetic explanation, which I don’t like to do. Please let us know what you find as you progress through your investigation as well as with the seasonal changes or if you choose another protein source (pes, whey, hemp, man-made amino acids).