Soaking Hay to Reduce NSC Content?

Soaking hay is a popular topic in equine nutrition. There are many reasons a horse owner may choose to soak their horse’s hay. Some examples include laminitis, poor dentition, digestion concerns, metabolic disorders, as well as respiratory problems. Today’s blog post will discuss what the research tells us about soaking hay to reduce non-structural carbohydrate (NSC) content. Non-structural carbohydrates include glucose, fructose, starch, and lactose.

Soaking hay for a horse that has a metabolic disorder or suffers from laminitis is done to reduce the NSC content. When a horse develops laminitis, it can be disastrous. When this occurs many horse owners resort to soaking hay. However, when you look at the research there are large discrepancies. Some studies tell us that soaking hay for 12-16 hours causes significant decreases in sugar content, while other studies tell us this can be achieved after 30 minutes of soaking. Additionally, it has been well reported that the initial non-structural carbohydrate content of the forage does not influence the rate of disappearance with soaking. To highlight the variation – studies have reported NSC losses of 12-45% after 60 minutes of soaking and 30-48% after 12 hours of soaking.

Although soaking hay does reduce NSC content, there are some drawbacks to the practice. When hay is soaked there is a significant loss of dry matter as well as other important nutrients. Additionally, in Canada it is not practical in the winter. This is why I personally prefer when this is only used as a short-term solution.

There is no guarantee that soaking hay brings the NSC content down to a safe level for horses with metabolic struggles. It is much more ideal to get your hay tested prior to feeding it to your horse so you are equipped with the information.  If you do not have any information on your forage, soaking for longer is safer when your horse is having a laminitic episode. However, a horse being deficient in nutrients and not consuming adequate dry matter amounts will further complicate the situation if soaking hay for prolonged periods persists

Imagine your horse develops laminitis…

You call the veterinarian, and they begin to rule out causes. You may begin to soak hay as a precaution until you can find a nutritionist to come and take core samples of your hay bales. But then you must wait for the results. During this time, you have increased labour for feeding your horse, you may be soaking for many hours out of caution and your horse may be missing valuable nutrients. To get a nutritionist to your farm and wait on lab results for the hay analysis could take a few weeks!

Wouldn’t it be better to include a hay analysis in your regular yearly routine?

This past summer a friend’s horse developed laminitis. When they called the veterinarian, they were able to provide them with the NSC content of that horse’s diet since they had worked with a nutritionist. They didn’t have to soak hay since they already knew that the sugar level was less than 10% NSC. Having this information on hand was able to give this horse owner peace of mind as well as allow her to provide the veterinarian with valuable information quickly. From there they could focus on other potential causes.

Simply scheduling a regular hay analysis when you get a new batch of hay can save a lot of worry and concern if any issues do arise. It is peace of mind to have this information in your back pocket. Knowledge is power, so why not know what your horse is eating!

If you have any questions or concerns about your horse’s nutrition email Madeline at: balancedbaynutrition@gmail.com 

References:

Longland, A. C., Barfoot, C., & Harris, P. A. (2011). Effects of soaking on the water‐soluble carbohydrate and crude protein content of hay. Veterinary Record, 168(23), 618-618.

Longland, A. C., Barfoot, C., & Harris, P. A. (2014). Effect of period, water temperature and agitation on loss of water‐soluble carbohydrates and protein from grass hay: implications for equine feeding management. Veterinary Record, 174(3), 68-68.

Moore-Colyer, M. J. S., Lumbis, K., Longland, A., & Harris, P. (2014). The effect of five different wetting treatments on the nutrient content and microbial concentration in hay for horses. PLoS One, 9(11), e114079.

Müller, C. E., Nostell, K., & Bröjer, J. (2016). Methods for reduction of water-soluble carbohydrate content in grass forages for horses. Livestock Science, 186, 46-52.