Basic Forage Analysis Considerations (Hay Analysis.)
Dry matter (DM) should be evaluated, not the “as tested” or “total” value.
CP crude protein. Horses need 9-15% depending on life stage and work. Protein is also an indication of hay quality. A good grass hay should have 12% CP of the dry matter.
NSC = Non-structural carbs or Total carbohydrate. Horses with metabolic dz/laminitis need minimal sugars so look for NSC <12%.
WSC Water-soluble carbs or simple sugars plus fructans. Ranges from 2-30% in grass hay averaging 11-15%. Low sugar hay will have a WSC in the 2-8% range.
ESC Ethanol-soluble carbs or simple sugars. Range from 4-11% in grass hay. A low sugar hay will have <6% ESC.
WSC – ESC = fructan approximation. If you notice that WSC is soluble carbs + fructans, you can calculate fructans (which are the most dangerous sugars.) You want an absolute maximum of 6% for laminitis-prone horses.
ADF = acid detergent fiber and is a measure of digestibility. Aim for less than 31% for horses. If your hay is not as digestible, that is OK. You will just need to feed more or may need to supplement with more digestible forms of forage like alfalfa pellets or beet pulp in horses who can’t eat enough to make up the difference.
NDF = neutral detergent fiber is also a measure of digestibility. Aim for less than 41% for horses. Like ADF, if the number is high you may need to feed more or supplement forage.
TDN total digestible nutrients is a calculated value from ADF and NDF. TDN > 60 is very nice feed.
Ca:P Calcium to Phosphorus ratio. For horses want 2:1. Error on the high side. Horses do not tolerate much less than 2:1 but can easily tolerate 3:1 Ca:P.
Vitamins and minerals. Most hays have a copper in the 5-6 range here in Vt and we will need to supplement copper. We have almost no selenium and horses should, across the board, get 1 mg per day of selenium in their ration balancer unless the owner is paying close attention to selenium supplementation. Because stored feeds lose Vitamin E, it can be considered lacking although forage reports rarely measure Vitamin E. A high quality ration balancer will add essential amino acids, copper, selenium, Vitamin E, and all the other vitamins and minerals that our hays tend to lack.
Fats are rarely very high in forage, so if you want to use fats as part of your diet this will come from supplemental feedstuffs.