Why do I need a hay analysis?
Test your hay, have peace of mind.
The best way to evaluate your horse’s diet and know what to feed them is by knowing what is in your hay (1). A hay, pasture or forage analysis is the only sure way to know the exact nutritional content of your forage (2). Forage is the foundation of a horse’s diet and therefore plays the largest role in providing most of the nutrients for your horse (1,2). Knowing the nutrients in the forage you have provides valuable information and helps you ensure your horse stays happy and healthy. Forage nutritional composition varies greatly with plant maturity, climate, season, soil type and amount of fertilization. Hay from the same field can vary greatly from year to year depending on growing conditions, maturity, amount of rain, and even the natural variation of field plant composition that fluctuates each year. All hay is deficient in certain nutrients. If you buy your hay in 2 months supply or longer than it is worth testing your hay (3).
How is hay analysed?
Samples from around 20 bales spread across the field should be obtained for the best results (1,3). Hay is then analyzed in a lab using a variety of testing methods. There are chemical evaluations, in-vitro digestion systems, and near infrared reflectance (NIR) methods (1). NIR methods are quick and relatively inexpensive so are often used. NIR is a calculated assessment of the nutrition profile based on the near infrared light profile of the feed so there are occasionally some inaccuracies in certain results (such as sugar content). NIR is still a widely accepted and utilized method for forage analysis (1). Wet chemistry (chemical evaluations and in-vitro digestion) methods are typically more expensive and time consuming, but produce higher accuracy result compared to NIR methods (1). Many forage analysis packages will involve a combination of NIR and wet chemistry methods.
What is tested in an analysis?
There are many different types of analysis available. Most will cover the basics of water content in the hay, amount of energy, fibre, protein, calcium and phosphorus (1). Additional or more detailed analysis types can also include vitamins, essential amino acids, fats, minerals and sugars (1). Moisture, dry matter and digestible energy are generally included in most testing packages.
Protein levels are tested as crude protein or CP. CP is the total protein in the hay. While CP can tell you how much protein there is, it cannot tell you the protein quality or type (e.g. how much lysine is in the hay) (1). Proteins and amino acids make up more than just muscles and are involved in hormones, enzymes, and antibodies. Low protein levels can cause difficulties for your horse in building muscle, having a healthy immune system and even affect their hormones. There are also several essential amino acids, such a lysine, that need to be provided by your horse’s diet (1).
Carbohydrates come in two categories: fibre and non-fibre carbohydrates (1,3). Fibre carbohydrates are measured through a few different tests. There are many different types of fibre, some are easily digested by the horse and others cannot be digested by the horse. Total dietary fibre, or TDF, is a measure of all the fibre in the feed. Neutral detergent fibre (NDF, sometimes seen as aNDF), acid detergent fibres (ADF) and crude fibre (CF) are all measures of different fibre types in a feed or forage. The ADF, NDF, CF and TDF can overlap on different fibre types tested and so they are useful for calculating the content of other fibre types in the forage (1). For example, the NDF content minus the ADF content can tell you how much hemicellulose is in your hay.
Non-fibre carbohydrate content in hay is especially important for horses with Cushings (PPID), Equine Metabolic Syndrome (EMS), Polysaccharide Storage Myopathy (PSSM) and other conditions that require a reduced sugar content. There are four main measures to look at in a forage carbohydrate analysis: Non-structural carbohydrates (NSC), water-soluble carbohydrates (WSC), Ethanol soluble carbohydrates (ESC) and starch (1,2,3). It is important to know the amount of sugar in your hay as high sugar levels can cause issues in susceptible horses.
Crude fat (CF) can be measured in your hay. Fats play a roll as a source of caloric energy, they improve energy efficiency, enhance body condition, help with absorption of fat-soluble vitamins, and are involved in making hormones and other body structural functions (1).
Finally, minerals are often commonly tested in hay tests. Calcium and phosphorus ratios are important and generally included in basic analysis. More detailed analysis packages can include magnesium, potassium, sodium, iron, zinc, copper, manganese, molybdenum, cobalt, sulfur, and chloride (1,2,3). There are other tests that can be added on, such as molds, yeast, mycotoxins, and heavy metals. Testing packages vary by provider, though usually there are several levels from basic to advanced to accommodate most needs and budgets.
Final Thoughts
Hay is an incomplete forage meaning it is lacking in some nutrients. Even the highest quality hay will have some deficiencies in its nutrient profile. Knowing what is in your hay will help you pick the right supplements for your horse, and even eliminate some that aren't needed, saving you money. I recommend at a minimum having energy, protein, calcium, phosphorus, iron, copper, zinc, and manganese tested, along with ADF, NDF, starch, WSC, and ESC. Many labs only test forages for cows, so it is important to find a lab that tests for horses. Additionally a cow-only lab will not be able to accurately calculate the energy content in hay for horses. Select a laboratory for testing that is certified. Select a laboratory for testing that is certified. You can look here for a list of NFTA certified labs around the world. NFTA labs are sent blind samples every year and their test results must be within a certain percent of the actual results to be listed here. Many equine veterinary clinics also offer testing through them and some will rent out hay sampling equipment to aid in sample taking. Testing is also available through https://equi-analytical.com/.
Test your hay, have peace of mind, save money on supplements and know your horse is getting all that they need to be at their healthiest.
Learn more: Importance of equine nutrition, vitamin E loss in hay.
References
1. National Research Council (2007). “Nutrient requirements of horses” 6th edition. The National Academies Press; Washington, DC.
2. Getty, J. (2010). “Feed your horse like a horse”. Dog Ear Publishing; USA.
3. Thunes, C. (2016). A Short Guide to Horse Hay Analysis. Available at: https://thehorse.com/19037/a-short-guide-to-horse-hay-analysis/
