Choosing hay for horses.
In the previous edition we presented an example of forage testing of four types of hays and reviewed the results of the laboratory analysis.
In this last part of the series about choosing the right forage for your horse, we continue interpreting the analysis results and discussing which of the forage types would be suitable for different types of horses including performance breeding and growing horses, as well as those that are sugar-sensitive or have metabolic disorders such as laminitis, insulin resistance (IR), tying-up, Cushing’s disease or Equine Metabolic Syndrome (EMS).
If you have not followed this series, we suggest that you read the previous articles online for more detailed information about feed properties and nutrient analysis of forages.
Nutrient requirements of horses
Nutrition starts with evaluating the nutrient requirements of your horses. Too often we see horse owners who copy feeding regimes (including feed products and quantities) from other horse owners without reviewing their horses’ needs and resource availability. In addition, many owners tend to over- or underestimate the amount of exercise or the “performance” level of their horses.
The nutrient requirements of horses result from 50 years of research on equine nutrition and feeding. So far, the National Research Council (NRC) has published five editions of the Nutrient Requirement of Horses. The sixth edition was published in 2007 and contains not only information about requirements but also information on feed products, feed processing and the feeding behaviour of horses.
Horses play an important role in human society and are used for various types of work, such as recreational purposes, sport (e.g. racing, polo, Olympic events), exhibitions, breeding, farm work and even therapy. The type of use, age and physiological state all affects the nutrient requirements of horses. The NRC provides us with a breakdown of nutrients requirements for the different classes and guidelines for estimating the workload of exercising horses.
For example a non-working (mature) horse requires 2% of its body weight in total feed per day (dry matter basis), 13-15 MJ Digestible Energy per 100 kg body weight (BW), 110-145 g crude protein per 100 kg BW and between 5-6 g Lysine per 100 kg BW.
A horse that is exercised at a moderate level (3-5 hours per week; 30% walk, 55% trot, 10% canter and 5% skilled work) requires 2.25% of the body weight in total feed per day (dry matter basis), 19-21 MJ Digestible Energy per 100 kg BW, 145-155 g crude protein per 100 kg BW and between 6.5-7 g Lysine per 100 kg BW.
When we are dealing with breeding, lactating and growing animals, the requirements will significantly increase for growth and milk production.
For example: a broodmare at early lactation (1-3 months) will require 2.5-3% of body weight in total feed per day (dry matter basis), 25-29 MJ Digestible Energy per 100 kg BW, 280-310 g crude protein per 100 kg BW and between 16-17 g Lysine per 100 kg BW.
The nutrient requirements will determine which types of feeds will be appropriate to cover these nutritional needs.
Horses that are not working require less energy and protein and can receive lower quality products compared to those that do considerable exercise, are breeding, lactating, or growing.
Feed properties of forages
The next step is evaluating the nutrient composition of your feed products. In this case we are only focussing on forages, but it is the same procedure when selecting concentrates or other feed products for your horses.
If we look at the four forages we tested we can see that Lucerne is a product that is high in crude protein, lysine and calcium.
Lucerne hay or chaff is commonly fed to all classes of horses, but suits in particular those horses with higher energy, protein and lysine requirements such as performance, breeding, lactating and growing horses. It is also popular in areas where the prevalent pasture species contain high levels of oxalates that bind calcium.
Cereal chaff and hay such as barley, wheat and oaten are frequently added to the rations of horses to increase the “fibre” bulk or concentrate meals. Chaffs in particular are very popular here in Australia.
In our example the wheaten hay has a slightly higher energy and protein content than the grass hays. It is lower in Acid Detergent Fibre (ADF) and Neutral Detergent Fibre (NDF) compared to the grass hay samples we tested, but has the highest values in the digestible carbohydrates part – Ethanol Soluble Carbohydrates (EWS) and Water Soluble Carbohydrates (WSC). This means that this product wouldn’t be the best choice for sugar- sensitive horses, especially when fed in large quantities.
Grass hay is universally fed to horses and comes in a wide range of varieties. As you can understand, the properties of the hay will depend on the geographical location and pasture species that were harvested.
In our example we tested two types of grass hay harvested in the South East Queensland region; an improved tropical grass (C4) hay (containing 95% Gatton/Green Panic and 5% Rhodes) and a mixed native pasture hay.
The native hay was a blend of temperate (C3) and tropical (C4) grass species and consisted of 60-70% native species such as Queensland blue grass, windmill grass and slender rats tail or native Parramatta grass, with 30-40% improved pasture species such as Gatton/Green panic, Rhodes grass and ryegrass.
The laboratory tests showed that our grass hays have higher values for NDF and ADF (the less digestible structural carbohydrates or fibre in the forage) which results in a lower digestible energy value compared to the other forages.
We also know that these grasses were cut at a mature stage and, with maturing, more stem is developed, which means a higher ADF value. When the grass is harvested at an earlier stage (before seeding) you would expect to obtain a hay with less fibre and higher feed quality.
The native hay shows the lowest values for the digestible carbohydrates (EWS and WSC), although there is not much difference between it and the Gatton/Green Panic hay. When grasses mature the digestible carbohydrate content reduces.
When comparing other nutrients, it shows that the mixed native hay has slightly higher values for some minerals and trace minerals.
Feeding performance, breeding and growing horses
These types of horses have higher nutrient requirements – energy, protein, lysine, vitamins and minerals, so we need to select forages that could cover these needs.
During the breeding season (spring and summer) there will be more pasture availability (growing season) – so benefiting from your fresh grass is very important. Fresh grass in the growing season will be higher in nutrients compared to conserved forages and could provide all the necessary nutrients for these types of horses.
If however, performance, breeding, lactating and growing horses cannot be fully maintained in good condition on pasture alone, additional feed needs to be supplied.
Pasture availability will depend on a number of factors, such as stock density, pasture management, season and weather, so reduced availability is very common. This is why many horse owners rely periodically or all-year round on hand feeding. In this case, conserved forages such as lucerne, cereal and grass hay could all be offered to these classes of horses.
As mentioned earlier, lucerne and/or other legume forages (clover, pinto peanut etc.) can provide quality protein and lysine, and are very suitable for performance, breeding, and growing horses.
It is, however, advisable to provide a variety of forages, because feeds that are too rich (high in nitrogen) can bring on satiation and can also cause digestive problems. In nature horses will seek and eat a large variety of vegetation, so it is healthier and safer to offer more than one option.
Feeding sugar-sensitive horses
Selecting appropriate forages and feeds for horses that are sugar-sensitive or have metabolic disorders such as laminitis, insulin resistance, tying up and obesity can be quite difficult. It get’s even more complex when these horses also perform at a considerable level.
Managing these horses on pasture can be tricky due to variability of digestible carbohydrate content of grasses. It requires integrated pasture and horse management.
Usually we see horses being restricted to pasture for certain times of the day or fully maintained in sacrifice areas and/or stabled. This means that there is a heavy reliance on hand feeding.
For this group of horses it is essential to analyse your forages to make sure you get a complete picture of the carbohydrate composition. You also need to review the feed labels of additional products you may be using so you can evaluate the carbohydrates in the total ration.
In general, cereal hay/chaff would not be the best choice for sugar-sensitive horses as they can contain high levels of digestible carbohydrates. Lucerne would be a better choice because it is lower in digestible carbohydrates compared to cereal hay/chaff – but care should be taken that you are not overfeeding your horse.
Generally a combination with grass hay (cut at a mature stage) could be a good option. In particular, combining with mixed hays that have a higher percentage of native grass species (as our example). Native grasses and mature grasses are typically lower in digestible carbohydrates. However, there are many factors that will influence this, so even though you have native grasses or bought native grass hay – analyse your forages to be sure.
If horses fully rely on hand feeding, you may have to add some other products to increase the fibre intake. There are a number of alternative (low GI) fibre products that can be incorporated in the diet of sugar-sensitive horses such as beet pulp, copra meal, legume/seed hulls and tree/shrub fodder. Always review the labels or take a sample for analysis.
The wrap up
It is important to take into account both the nutrient requirements of your horse and the nutrient composition of forages when selecting roughage sources.
Other factors will also influence your choice, for example the availability of these roughages in your region, the price, your budget, and the palatability of the feed.
We also need to take into account that the nutrient composition in plants is influenced by environmental conditions and so the time when forages are cut is essential.
Whether you are buying hay or making your own, you will benefit from testing your forages for better feed efficiency and to safeguard the health of your horses.
An equine nutritionist is qualified to help you review the analysis and your horse’s diet as a whole, and assist you in the decision-making process when it comes to selecting forages and alternative products that could be incorporated in the diet to meet the individual needs of all your horses.