Soil testing is a valuable process for long term soil treatment but it's very limited in terms of helping to determine what to feed and supplement to correct imbalances/ deficiencies and excesses in a horse's intake.
Balanced Equine is all about knowing the amounts of nutrients your horses receive when they eat grass or hay. Soil tests will not tell you this. Soil tests will only indicate what is in the soil, not in your pasture. Plants differ from uptake of minerals based on species, growth stage, soil pH, moisture, oxygen and nitrogen levels.
Even if your soil test results say your soils are excellent, this does not mean that the grass species will be providing a balanced diet. Of course, these soils will be better than highly acidic or alkaline soils. It's always interesting to compare the results of a soil test to the results of a pasture test and it's nice to know the soil pH, as it can be very helpful to explain pasture test results. Levels of minerals in soil can be to a degree fairly insoluble or unavailable for uptake in plant roots, depending on soil pH and other factors.
Nutrient availability and microbial activity as affected by soil pH; the wider the band, the greater the availability or activity.
(Adapted from Truog, USDA Yearbook of Agriculture 1943-1947 - http://www.newwaveagriculture.com.au/articles/liming-soils)
Hair testing for nutrient levels and balance in the diet isn't going to help. Read more about hair testing...
Pasture or hay testing
The best way to find out what your horse needs is to find out what nutrients he is getting already from the main source of fibre, also known as roughage. Pasture or chaff/hay is the foundation of the diet. The horse's digestive system evolved over a very long time to a design that is geared to extract available calories from high fibre foods by hindgut fermentation. The base of the diet for EVERY class of horse should be pasture or chaff/hay.
Grass or hay (preferably grass unless the horse is insulin resistant) is the best food for horses as this is what their digestive systems evolved to eat. Grass contains so many nutrients that horses need and is very high in fibre. This includes protein, carbohydrates, fat, minerals and vitamins. You may be surprised to read that there is fat in grass. In fact, if your horse did not have access to grass and was mostly on hay instead then the horse would need supplementing with omega-3 fatty acids essential for the immune system. These cannot be manufactured by the horse, they have to come from the diet. Read more...
Many pastures contain grasses, especially pasture improved species like Kikuyu that are high in protein and energy. Some may think you always need to supplement protein for horses, but the pasture may be supplying 2-3 times their protein requirements or even higher.
To be able to know for sure what amounts of each nutrient/mineral your horse is getting it is best to have a sample of your pasture tested in a laboratory. If only a small amount of hay is in the diet then Balanced Equine can use average figures for your preferred type of hay but the most accurate way is to test a representative sample. Of course, some horse owners buy small amounts of hay from different sources so testing in this situation is not realistic.
Testing is not costly, especially if viewed as a way to find out what just how nutritious your forage is rather than guessing. Looking at photos of pasture cannot tell us what the nutrient levels are. The reason is that nutrient levels can vary so much. An explanation of what a test provides is in the Understanding test results article.
I have chosen a laboratory that provides a most comprehensive test for nutrients and will also measure the energy in terms of a horse (rather than cattle which have a rumen) and is the cheapest. A pasture test costs about $40, a hay test can cost as little as $30.
Frequently Asked Questions (FAQ)
Q. My pasture is diverse with different species of grass. It isn't one grass that never changes.
A. This doesn't take anything away from the value of a pasture test. First you need to get to know what grasses your horses eat and which ones they ignore. observing your horses as they eat is part of managing your paddocks. When you sample a paddock like this, you need to collect a sample of grass that as closely as possible will reflect the diversity of your grasses. If you have 40% of species A, 35% of species B and 25% of a bunch of different grasses then the idea would be collect in those proportions for your sample. The results from the laboratory would be a good indicator of what your horses are getting in nutrients. If you don't test you won't know.
Q. If I test my pasture now won't it change by summer and then in winter? Wouldn't you have to keep testing many times a year?
A. Trace minerals and especially the ratios do not change much over the seasons but digestible energy and protein will. Potassium can be a bit higher and magnesium lower in new shoots of grass. A pasture test will indicate the amounts of minerals that need to be supplemented to make up deficiencies and correct inbalances and this can be used year round. As the seasons change, the digestible energy will go up and down and that is where the art of feeding comes in. If there is less energy value in the grass then you will need to feed more so that your horse can maintain a good body condition score. On the other hand, with the flush of feed in spring you will need to feed less but the custom mineral mix can stay the same.
Q. I use my horse for eventing and I was told to use a high protein feed. Is that the right thing to do?
A. If your horse needs the additional protein then yes but you may be surprised to find that the pasture or hay that your horse has for forage is already very high in protein and therefore it would be totally unnecessary to add more to his diet. If the protein is excess to his needs then your horse will have to excrete the excess protein.
Managing factors that limit plant growth
NSW DPI Understanding soil pH
Soil pH Modification