A Guide To Forage Analysis

Forage should supply the basis of every horse’s ration, with a minimum of 1.5% bodyweight of forage being supplied per day. Despite contributing a large amount to the diet as a whole, only a small percentage of horse owners routinely test their horses source of forage. Forage analysis is the only way to truly know the nutritional quality of your forage and allows nutritionists to make more informed decisions when devising a ration.

How important is forage analysis?

Even when good quality forage such as fresh spring pasture, or low maturity soft hay is provided, forage alone will not supply enough essential vitamins and minerals to support normal body functions. For good-doers or horses at greater risk of metabolic conditions, it is important to monitor the digestible energy and sugar content of the forage, so that extra measures, such as soaking your hay, can be implemented if these come back high. Alternatively, forage testing can provide an insight as to why a poor doer may not be responding to their ration as expected, allowing us to increase their calorie intake with feed and forage replacements. Performance horses and breeding stock have elevated nutrient requirements, so by testing their forage, we can ensure that these requirements are being met through the whole diet.

How and when should a forage analysis be taken?

Anytime that you are concerned about the nutritional or hygienic quality of your horse’s forage, or when the supply of forage is changed is a suitable time to have a forage analysis performed.

For hay and haylage, it is recommended to send a representative sample for analysis when a new batch arrives. The ideal method of obtaining representative hay or haylage samples is to use a corer or hay probe on the bale ends. Where these tools are not available, hand grabs should be taken from different bales and different depths within the bales at random. To obtain a representative sample, we recommend taking 10-20 sub-samples. These sub-samples should be mixed thoroughly in a clean dry bucket to create a composite sample, before putting it into your sealable sample bag for transport to the lab. This method ensures that the composite sample you have sent for analysis is as representative as possible of the whole batch of hay, rather than just one bale. The larger the number of sub-samples, the better the analysis can account for variation between bales.

Although this is the recommended method for forage sampling, we can appreciate that this may not be as applicable to haylage bales, due to haylage being enclosed in a plastic wrap. Where it is unlikely that a large number of haylage bales will be open at one given time, sub-samples should still be taken from various areas and depths of as many bales as possible to make up your composite sample.

Pasture samples are beneficial to determine the contribution of grass to the diet. Due to the large seasonal variations in grass nutritional quality, it is recommended to send a pasture sample for analysis as we come into each season, or if specific concerns arise. Similarly to hay, it is recommended to take 20 sub-samples per field, to account for differences across the field. One way to obtain this is to walk in a spiral pattern from the outside to inside of the field and take a sample every 10-15 paces. Pasture samples should be cut with scissors at the height in which the horses are grazing. Be sure to avoid any soil or roots in the sample.

WHAT TYPE OF FORAGE ANALYSIS SHOULD BE Carried out?

We offer three options for forage analysis. The most basic analysis, but the test we recommend most often, to get a general idea of the forage nutritional quality, is Near Infrared Reflectance (NIR). This test provides a basic analysis and will include Dry Matter, Crude Protein, Oil, Ash, NDF, ADF, Sugar, and Digestible Energy.

• Dry matter represents everything in the forage sample other than water including protein, fibre, fat, minerals, etc. Horses consume the forage they are eating to meet their DM needs, because it is the dry matter that contains all the nutrients. Wetter forages (such as haylage) need to be provided in higher quantities to ensure that enough fibre is being provided. It is recommended that no less than 1.5% of the horse’s bodyweight is fed in forage on a dry matter basis.

• Protein of forage is naturally variable and influenced by species of grass.

• Ash reflects total mineral content of the forage.

• ADF and NDF are measures of the fibrous components of forage and used as indicators of forage quality. NDF represents the total fibre content of the plant. Forages with an NDF of greater than 65% are likely to have a poor intake and are not considered suitable for horses. ADF is an indicator of digestibility. Forages with a lower ADF value are easier to digest. Forages with an ADF value of less than 40% are suitable for horses.

• Sugar reflects total natural sugars found in the forage.

• DE (Digestible Energy) is the unit of measure for the energy or calorific value the forage contains.

A further test that can be carried out is Dietary Minerals. This test provides information about the mineral content of the forage and will include Dry Matter, Phosphorus, Magnesium, Calcium, Sodium, Potassium, Chloride as well as CAB and Macro Mineral Analysis. We recommend this test if owners have any concerns about certain deficiencies, or if Ash comes back as low on the NIR test. This test allows us to ensure that all essential mineral requirements are being met through the whole diet.

The third test indicates the water-soluble carbohydrate (WSC) level of the forage, which includes fructans, and the simple sugars sucrose, glucose, and fructose. This test is recommended to determine whether a forage batch is suitable for horses with or at greater risk of metabolic issues such as laminitis.

How does forage analysis affect a concentrate recommendation?

When we receive forage analysis results, a member of the nutrition team will look at these values against the “typical ranges” for that type of forage. If a ration is working well for a horse, and their forage falls within the typical range, it is unlikely that the current diet will be changed, as the ration will have been based on what we consider “average forage”. If any of the values lie outside of the typical range, at this stage we can then look further into the contribution of the forage to the whole diet. In most cases, if the horse is receiving the recommended rate of a fully fortified feed or ration balancer, they will still be meeting their nutrient requirements, even on a low-quality hay. When forage is harvested early under optimal conditions, it is likely to have a higher digestible energy. For horses with high energy requirements this is excellent. However, if your horse has too much energy or is overweight, we would then be looking at reducing the energy intake from the feed.

For the majority of yards, once a forage sample has been sent for analysis, the owner or yard will have already purchased their forage and will have to use it regardless of the forage analysis results. Therefore, if any key components come back as low on the forage report, it is our job to recommend suitable feeds or supplements to ensure that nutrient requirements are met.