A single blood sample is drawn after a horse is fasted for 12 hours and a resting serum insulin test is run. This is not a fool-proof test, but it is a good basic screening test.
This is the quote my friend wanted me to post in responce to this: "Horses should not be fasted before this testing but should not be fed anything but hay or pasture for at least 4 hours prior to the test. Free access to hay before testing is ideal. The horse also should not be exercised within 4 hours of the test and avoid shipping before testing if at all possible. Stress and exercise influence glucose and insulin dynamics. As we are evaluating the relation of Insulin and Glucose to each other, they need to be from the same blood draw."
This was from a yahoo group that she joined that another friend recommended since she has IR horses. Also in my opinion, it is not good at all to "fast" a horse for 12 hours...and impossible to do so at my barn, or her barn from what she has told me.
As for the hay, no matter what her horse needs a minimum of 1% of his body weight in forage per day to maintain good digestive health. So she needs to make sure that she isn't cutting too much hay out of his diet.
Oh he'd of course get at least this and probably more. What she said she wanted to do is if her vet doesn't think the round bales would be a good idea, is to feed him 3 times a day, and if her barn owner will, to spread the hay out so he has to find it.
She would be better off to have her horse put in a paddock seperate from the round bale and feed him a hay that has either been tested for non-structural carbohydrate levels or soaked for 30 minutes in cold water prior to feeding. She needs to concentrate on getting the NSC content of the diet down to 10-12%. Besides vitamins, she will also likely need to provide a protein supplement if she is feeding grass hays. Rather than a vitamin/mineral supplement, she should choose what is often called a ration balancer.
All the hay is tested at her barn..well all the different cuttings.
The supplement that her horse is getting is this: The Cheshire Horse - Keene, NH and Saratoga Springs, NY
What does NSC mean?
Daily exercise is also very important for these guys to help maintain good health. So, turnout and preferrably at least a bit of light work daily would be a good idea.
Her horse is outside 24/7, never in a stall. She comes up at least 2 times a week (her work schedule is very weird) to ride or play with her horse on the ground and she makes sure she works him a good ammount each time