In comparison with grasses, legumes have a higher energy, protein and calcium content. These plants can fix nitrogen through nitrogen-fixing bacteria in the root system, which results in a higher protein level in the plant.
Horses with a higher energy and protein requirement, such as growing horses, lactating mares or horses in work, will benefit when legumes are used as the base of the diet. Legumes are a high-quality and nutritious roughage. The two common legumes are lucerne and clover.
Lucerne/alfalfa (Medicago sativa)
Lucerne can be regarded as the king of all fodder because of the high nutritional value, high palatability and suitability for use with a wide range of animals. With regard to horse nutrition, lucerne can be included as a major source of fibre to the diet and also contributes to the daily nutrient requirements. It can be especially beneficial to horses needing a higher level of nutrients, such as broodmares in foal or lactating; growing young horses; or horses in hard work (racing or competing). During winter or pasture shortages, it can be used as a supplement to increase the roughage and nutrient intake.
Lucerne has a good leaf-to-stem ratio, and is a good source of energy, protein, vitamins and minerals. It should, however, not exceed 50 to 60% of the total daily roughage intake. It should be supplemented with another roughage such as teff or eragrostis to keep the digestive tract in healthy, working order.
Lucerne in South Africa is graded according to the nutritional value and fibre quality (age at cutting). The higher the grade (lower fibre content, higher digestibility), the higher the non-structural carbohydrate (NSC) value will be. However, the NSC of lucerne is in the form of pectin, which is a safe form of carbohydrate for sugar-sensitive horses. A later cut of lucerne (lower-grade quality) has a lower NSC value and sugar content and is therefore a safe hay to use for horses who require a low-NSC diet.
In multiple studies done, lucerne has shown that it can be effective in the reduction of the severity of gastric ulcers. It can reduce the occurrence of gastric ulcers because of the buffering capacity it provides, thus increasing the pH in the stomach and making it less acidic and harmful in comparison with other roughage.
Clover provides protein, energy and calcium at a higher level when compared with grasses. Clover hay is not common; however, clover is usually mixed in with pasture for grazing purposes.
Teff hay (Eragrostis teff)
Teff is a widely fed roughage in South Africa. A great concern with the use of teff is the variable qualities available, which have an influence on the nutrient quality and palatability. If managed correctly, teff can have a high protein level with adequate fibre digestibility and a higher energy value than other grasses used as roughage. Care must be taken when buying teff to make sure the quality is good and that it is not mouldy, which can cause problems when feeding to horses.
Weeping love grass/oulandsgras
Eragrostis has a lower protein value, lower fibre digestibility and a lower energy value when compared to teff. With good management, however, it can be as good quality as well-managed teff.
The quality of the two above-mentioned hays is greatly influenced by the following: stage of growth when cut, fertilisation and environmental factors. These factors must be taken into account when these hays are fed to horses at various levels of production/workloads.
Rhodes grass is a fairly new grass being used in South Africa as a roughage source for horses. The protein value can vary from 9 to 15%. With good management, Rhodes grass can be a moderate- to high-quality roughage source for horses. When cut at an early stage, it can have a fibre digestibility value of between 60 and 70%, making it a more useable and palatable roughage for the horse. Rhodes grass can be used as an alternative roughage for teff and eragrostis. It can be used as a roughage source to add variety to the diet.
Oat hay is a reasonable roughage choice for horses if teff and eragrostis are not readily available. The time of cut/stage of maturity will determine the quality of the hay. Later-cut oat hay will have fewer sugars in the stems (sugar stored in seed heads) and will therefore be safer to use for sensitive horses, but this can also lead to more wastage because the stems are not that palatable. An earlier-cut oat hay is a higher-quality and better-digestible energy source. Oat hay can make up a great proportion of the daily roughage intake for mature idle horses.
The full article appears in the October issue (127) of HQ > Shop now