Hay : most commonly used source of forage for horses

The nutrtional value of stored forage will always be lower than the corresponding fresh green forage. Numerous factors influence the quality of hay.

Composition of the pasture

The quality of forage depends particularly on the following :

• On the plant composition, depending on the different plant species present. The percentage of legumes has a direct influence on the protein content of the hay harvested.
• On the development stage of the plant when the hay is cut. Early ripening is variable depending on the species. Schematically speaking, the heading stage of the plant happens more or less late in the season, and influences the nutritional value of the plant. Therefore mono-specific pasture, is more difficult to manage than multi-species pastures with regard to harvesting at the optimal stage.
• On the season and the plant cycle stage when harvested.
• On the soil and climate.
• On fertilisation…

Hay harvested late in a production cycle is more fibrous and will have less nutrtional value than the same forage harvested  earlier on.

For example :

• Hay harvested from  permanent pasture land in Normandy around the 25th May, tossed in good weather and when in its first cycle will provide on average 0,62 HFU (horse forage unit)  and 68g of Digestible nitrogen matter (MADC in French)/ kg of dry matter (DM).
• When harvested in the same conditions around the 25th June, it will only provide 0,48 HFU (-20%) and 40g of MADC (-40%) per kg of DM..

Harvesting conditions

It is paramount to make sure that the harvest conditions are respected to maintain the nutritional value of the plant, and therefore the quality of the hay obtained. It is influenced by :

Weather conditions

Temperature and amount of sunshine influence the length of time necessary to dry the hay, and its quality. The loss in nutritional value of the plant is less if the hay dries quickly.

Tossing the hay (after cutting) is to obtain uniform drying, before pressing and baling. Tossing several times (necessary when it rains, or if the hay dries slowly) will break the fibers and leaves (the rich parts of the plant)….and even more so if the hay is tossed quickly when dry. The number of times and the way the hay is tossed will therefore have an influence on the quality of the hay.

Rain causes the nutritional elements and minerals to be washed out, and lengthens drying time. It also leads to the development of mould.

Organisation of the haymaking tasks

• Choice and use of the agricultural machinery : adjusting the rotation speed has an impact on the quality of the hay.
• The time of day when cutting or tossing also have an impact on the leaves. When it is hottest, the leaves are more brittle than in the morning after the dew has evaporated, or in the evening.

The quality of stored hay will lessen when the cutting, harvesting and storage are not carried out in favourable conditions.

Visual assessment

Estimating the quality of forage is important. It will give you an idea of how the hay was harvested and stored. The following should be observed :

• The colour which should be fairly green, not grey with potentially mouldy slabs. Or yellowish indicating that the hay was pressed while still damp, or that it was subject to rain or prolonged exposure to the sun. Hay will also have a tendancy to become yellow over time.
• Presence of leaves (the parts which have the highest digestible element content) and the state of the ears to gain an idea of the stage at which it was harvested. :
  • No or little inflorescence : hay cut early, or second crop
  • Few inflorescences, small and well formed : cut at the start of heading
  • Large numerous inflorescences : cut in the full heading stage
  • More or less damaged inflorescences : hay cut too late
• Smell : hay should smell of dried grass, this can be more or less marked depending on the type grass species, but it should not smell mouldy
• The presence of dust indicates that the grass was cut too close to the ground and contains soil or animal droppings, or that it contains mould, or that it was cut during heading (pollen)

Chemical analysis

The chemical analysis of forage carried out in a laboratory gives an accurate idea of the nutritional value of the forage. Therefore it is easier to establish the ration of supplements that needs to be provided in terms of nutrients and minerals. The results will usually be sent out within a week for a cost of approximately € 50 for an analysis entitled « nutritional value + 9 minerals ».

The INRA has established average nutritional values according to the species concerned, the dates and harvesting conditions, from a considerable number of samples analysed. This data is available in the book « Nutrition and feeding horses ».

Being extra careful about how hay is stored is essential to preserve its qualities. It is advisable to do the following :

• Store the hay when it is first dry. Take care however to avoid bringing it in while it is still hot to the touch in the heart of the bales. This release of heat is potentially intense for a few days after pressing and can cause fire in hay barns.
• Store on pallets so as to avoid moisture getting into the hay by capillarity from the soil as, this is a source of fungii and bacterial contamination.
• Organise the storage so as to use the hay in the same order as its production. This also allows you to be able to feed the hay with the best nutritional qualities to the animals needing it the most (brood marss, young foals, horses in intense work).

Freshly harvested hay should not be fed for the first month to six weeks after the harvest to limit risk of colic.

Stabled horses

The required daily quantity for each horse should be estimated with regard to the role it plays in the nutrition. It is advised to do the following :

• Give it in several fractions to avoid waste and to enhance the animal’s well-being.
• Give hay on the ground to promote a more natural feeding position, and near a supply of fresh water.

The dust content of forage, and particularly hay can be incriminated in recurrent respiratory complaints in horses. For the animals affected, the use of haylage is preferable to that of hay. Nevertheless, slightly dusty forage can be used if it is dampened just before feeding, this will limit the particles being in suspension and inhaled by the horse. Soaking, even though more efficient in reducing dust (-88 % by soaking for 30 minutes), produces the major drawback of reducing the mineral content of hay, and even its nutritional value, through the loss of seeds and leaves in the soaking water

In the field or paddock

Hay is used in this case to supplement grass when it is in insufficient quantity. The way it is distributed should follow these recommendations :

• Located to enable all animals to have access. Accidents and fights usually occur around feeding stations.
• Limit waste ( outdoor hay feeders or hay nets) and limit the risk of accidents.

Be careful of weeds (contained in the hay) which will seed the ground, more particularly the feeding points which are often trampled and where droppings acumulate. This problem can be managed by regularly moving around the feeding points.