Grain and sweet feed have too much starch/sugars. It's not good for them because they can have a hard time processing them which can lead to EPSM.
When it comes to calorie needs Dr. Beth has a pretty good table in her book. Depending on how much your horse weighs, maintenance diet for a 2000 pound horse is 22,500 calories; pleasure riding 28,125; farming/light logging 33,750; endurance riding/heavy logging/polo, driving 45,000. These are calories per day.
Feed calories per pound:
Timothy hay 800-900
Alfalfa pellets or hay 900-1000
Beet pulp 1000
Sweet feeds 1200-1400
Purina Strategy 1500
Rice bran 1550
Soybean meal 1600
Buckeye Ultimate Finish 1980
Vegetable oil 4000
Animal fat designed for horses or pigs 4000
So you can figure out how much your horse is getting calorie wise using the feed table and the calorie needs. The feed will increase decrease depending on the level of work.
As far as my horse he gets:
grass pasture turn out during the day
3-4 flakes of hay at dinner
1.5 lbs. of packer pellets (complete feed)
1.5 cups of Mazolla corn oil (only at night spread over the packer pellets)
2 scoops of MSM
He's not being worked much at all right now, but once he does start getting worked the corn oil amount increases to 2 cups.
The 'high fat' diet is a good preventative measure against EPSM. It may not keep the horse from getting it but per all the studies that have been done, it's showing excellent signs of working to keep them from getting it.
Not everyone believes you need to do it. But like I mentioned in the other thread, Dr. Beth indicates it's just a part of good draft horse management and I agree. Not a lot of people believe in her work but hey, it doesn't hurt the horse and it's extremely beneficial.
Not sure if you saw the thread where I listed all the benefits so I'll copy it here:
- Decreases body heat production with exercise
- Decreases risk of colic, founder and gastric ulcers
- Provides a ready source of energy that does not have to be chewed
- Provides high energy feed in a low volume
- Improves respiratory function in horses with chronic respiratory disease
- Enhances oxidative metabolism
- Controls or prevents EPSM
- Avoids OCD (a joint disease)
- Improves haircoat and skin
- Possibly protects from post-anesthetic muscle problems