Ok ive been wondering about managing a horse on grass. I have two horses, (one is 4 turning 5, and the other is turning 11),and I have a barn has over 23 acres with beautiful pastures. But the grass is what concerns me.
I've done some research on how grass can effect a horses digestive tract, and how nutritional it is. Ive found out that hay has more nutritional value and a active horse has to eat almost 8 times as much to get the same value. But there is also the fact that grass is the best sorce of nutrients in its natural state (that is if you exclude vitamin E). Not to mention that grass is also an exellent sorce of protein. But then the values depend on:
1)the soil
2)growing conditions
3)the growth stage of the grasses
4)types of grass in the pasture

Ive also learned how simple and complex carbohydrates have come into play in a horses diet (w/ grass as their main diet). Early growths and regrowths are generally high in simple carbohydrates and calories, but they are low in nondigestable fiber. This grass is usually low in sugars thanks to photosynthesis (not enough sun).

Horses that generally not used to grass may over-indulge causing several problems that include: digestive upset, bloating, gass, diarrhea, and colic. Insulin resistant horses (IR horses) also may become lamenitic on low fiber, high sugar, and high starch grasses (even short term grazing can lead to laminitis). Pasture assosiated laminitis typically occurs in the spring but could also occur in fall regrowths.

As you can see all this information is making me debate about what to do with my horses. Does anyone have any opinions about this topic?? I need HELP!!!

Where are you from? Blackstone

How did you locate this forum? google

P.S: Dr. Getty I need an honest opinion about grass and its nutritional value.

Where are you from? Blackstone

How did you locate this forum? google

Hello Alli,

I can see that you have been doing your research. Let me simplify things for you a bit.

Non-digestible carbohydrates that you mention are the fibrous portion of grass and are digested in the hind gut by the bacterial flora that live there. Grass, being a roughage, is high in this type of carbohydrate and it provides calories for the horse for energy (to do work and keep vital organs functioning).

Non-structural carbohydrates, on the other hand, are the sugars, starchs, and fructans that you mentioned and they are digested in the foregut (small intestine), providing calories, as well. However, too much NSC can cause laminitis in some cases and can interfere with the insulin response in insulin-resistant horses.

The NSC content is highest in the afternoon once the grass has been exposed to sunlight. But, if your horses are healthy, and not overweight, there is no need to restrict their time on pasture.

Grass, being higher in water than hay, needs to be consumed at a larger rate to get the same amount of solids. It also is higher in many vitamins because hay is dried and exposed to the air for a long period of time (hence, vitamins are destroyed).

So, that's a summary in a nutshell. How this affects your particular horses, can vary depending on many factors. So, if you would like to discuss this further regarding your particular horses, please feel free to contact me for an appointment.

All the best,

Dr. Getty

Where are you from? Bayfield, CO