Why Test Hay?

There is no perfect hay or pasture

Most hays are low in copper and zinc, two very important trace minerals. Many hays are high in iron or manganese. Often what is found in a hay analysis is an over-abundance of one or two minerals and a shortage in one or two. By over-abundance I mean that the hay provides substantially more of the mineral than is required in the equine diet. By low I mean that mineral quantity in the hay does not satisfy the NRC minimum requirement for the horse or it is just at minimum. What happens when a supplement or feed is added is that more of the mineral(s) that are in over-abundance are added along with the minerals there is a shortage of. What results are minerals out of balance. In this case, the term 'balance' is referring to minerals occurring in the NRC recommended ratios.

For example, you may have heard that Calcium:Phosphorous ratio should be 2:1. If your hay has a ratio of 3:1 and your feed has the correct ratio of 2:1 you'd have to feed an enormous amount of feed and a very limited amount of hay (something you would absolutely not want to do) to get the overall ratio close to where is should be. If the calcium need is met by the hay, all that is needed is to add the Phosphorous to get the ratio where it should be.

Mineral Ratios: Why They are Important?

The nutrients your horse takes in are absorbed in the digestive track. There are both active and passive transport in the digestive track to absorb the minerals. Let's say for example there are 100 receptors that actively absorb both iron and copper. Say there are 2000 iron 100 copper units in the digestive track. Odds are not in favor of much copper being absorbed. Even if the 100 units of copper exceeds the minimum requirement for the horse, the horse will not get the benefit of that amount because the absorption pathways are being taken up by the high iron concentration. To remedy this, we could either reduce the iron and/or increase the copper to the correct ratio of 4:1, thus improving the concentration of copper which will result in more being taken up by the body.