Haylage and silage

Methods for making haylage and silage both use bacterial fermentation, without oxygen, of the sugars in forage. The bacteria contribute to the production of lactic acid, which inhibits the development of other bacteria and ensures the preservation of the forage.

Silage is based on transforming the forage into a silo of green, finely chopped forage (grass, corn, whole plants).

Haylage consists in surrounding the bale of harvested grass with between four and six layers of plastic film (usually round bales, sometimes big cubic bales).

Harvested at the beginning of May, silage is a green forage presented in the form of fine blades. The difference with haylage is that the blades of grass are chopped finer, and the pH is lower. The dry matter (DM) content should be above 25 %.  However, silage which is too humid (below 30 % DM) is not consumed very well by horses. Two types of silage can therefore be used, silage which has been pre-tossed, and corn silage. Silage exclusively from legumes should be avoided as it is not well consumed, and can cause disorders in the large intestine. The two types are :

• Pre-tossed silage, which is put into the silo 24-48 hours after cutting, so that the DM content > or = to 30 %. The forage obtained is well balanced, and well consued by horses.
• Corn silage, whole plant : it is rich in starch and soluble sugar, therefore is a good energetic feed. However the nitrogen matter, mineral and vitamin content are low.

Depending on the stage the plant was harvested at, and the origin of the forage, the nutrtional value of silages are variable.

Haylage can be made from any forage. It is however advisable not to go over 50 % legumes (natural meadow or sown with white clover, purple clover, alfalfa…) compared to grasses (Orchard grass, English ryegrass, Italian ryegrass, tall fescue…) in the harvested forage so as not to increase the nitrogen matter content in the ration. 

Haylage is a palatable forage which has very good nutritional qualities. It can therefore be distributed ad lib instead of hay.

• Energy values usually vary between an average of 0,6 and 0,8 horse forage units/Kg of DM.
• Digestible Nitrogen matter is subject to higher variations : from 30 to 160 g MADC/Kg of DM depending on the percentage of legumes and the stage it was harvested at.

Quality

Poor quality haylage or silage can be a risk for your horse’s health. Harmful bacteria can develop and produce toxins which cause digestive diorders (colic). These problems are mainly related to bad storage or baling. One should therefore make sure that fermentation occurs in the best possible way.

When harvesting, take care not to collect mould, droppings or soil by cutting too close to the ground (or when the ground is too wet). In these situations forage can contain spores which could cause botulism.

Dry matter

It also needs to be harvested with athe proper dry matter content. A DM content which is too low (too wet) at harvest, reduces the horse’s consumption, and also causes the forage to be too acid, which does not enable the intestine to function correctly. On the other hand, a DM content which is too high reduces the interest in choosing this method, which is more ewpensive than the production of hay. Moreover, when the fibres are too dry, they may pierce the plastic film and be damaging for preservation.

Appreciating the DM content by touch

• Liquid flows when pressed = 20 % DM
• Liquid flows when wrung = 25 % DM
• A few drops when wrung = 30 % DM
• Traces of damp on the hand when wrung = 35 % DM
• No traces of damp when wrung = 50 % DM
• Feels like hay to the touch = 65 % DM
• A few brittle fibers = 75 % DM
• All the fibers are brittle = 85 % DM

between 50 and 65 % DM : optimum stage of pressing

Procedure for haylage

Preservation

Subsequently, during storage, it is important not to expose the forage to air until it is consumed, otherwise it will deteriorate. Silage or haylage where the plastic film has been pierced can be dangerous if eaten by your horses. The storage area should therefore be protected from birds or rodents.
So that the bale is not pierced during handling, a tractor with a « bale hugger » should be used.

Usage

Before distribution, check that the forage has been preserved correctly, by making sure that there are no suspicious smells or presence of mould. If the mouldy areas are small, the mouldy forage can be removed from the bale.

Distribution

A transition period  over a fortnight should be observed when changing from a diet based on hay, to a haylage or silage diet.

Avoid giving the haylage or silage before the hay when both are used, as horses may tend to reject the ration of hay.

Using silage for horses requires sufficient numbers of animals, as the leading edge of the silo should go back by at least 10 cms a day to avoid any fermentation or mould setting in.

When using haylage, an opened bale should be consumed within 5 days.

Consumption

For a same forage, these different methods of preservation, when carried out in optimum conditions, give an increased nutritional value for the animals than with hay, with the same level of hard feed.

Corn silage is interesting to use as a basic ration for warmbloods and draft horses on a breeding stud. They can consume up to 6-7 kg of DM/day (20kg gross). For example :

• Warmblood mare: 15 kg gross (5kg of DM/day)
• Draft mare : 30 kg gross (9kg of DM/day)

The quantity will vary with age, weight and physiological state of the animals. It can be fed without adding hay. On the other hand it cannot be given ad lib, as the starch content would be too high.

Haylage or silage from pre-tossed grass are forage feeds which can be given without adding hay, and ad lib. Between 4 and 8kg  DM/day/ horse (i.e. 6 to 12 kg gross weight) is the recommended ration. In any case, the haylage or silage needs to be analysed so as to adapt mineral and nitrogen supplementation in the ration.

All these forage types can be given instead of hay in these conditions. However, overfeeding  can lead to the horse becoming overweight, but especially to an excess of carbohydrates (starch in corn silage) and protein (for haylage and grass silage) excesses which can cause serious disorders in horses.

Making several types of forage on a farm enables a more flexible management of the different surfaces.

• Affecting certain areas to the production of silage or haylage gives an earlier regrowth than after hay. At this time of year the soil is still damp and it is not too hot. This means that the animals can be put back out to graze around the 10th June, on an area that has been harvested. These techniques therefore allow you to optimize the available farming surfaces.
• Cutting dates are staggered out from the beginning of May for silage to the end of June for hay which allows:
  • Staggering the work load
  • To benefit from regrowth also staggered over time (three weeks approximately after cutting depending on the weather) which helps in rotational grazing of the animals at optimum grass height.
• Making silage or haylage takes less time than hay (reduced drying time), therefore it is easier to schedule, particularly with regard to weather conditions. In the same way, making haylage from an area that was planned as hay when rain is forecast before complete drying can sometimes help to « save » a harvest.
• Providing there is a flat area which will not deteriorate the plastic, haylage does not need a barn and can be stored outside in several different places to facilitate handling when feding the animals. This advantage should however be weighed up in terms of cost/profit : saving on the building for hay storage is counter balanced by a production cost which is about 1,8 times higher than for hay (cost of the wrapping plastic and specific handling material to move the bales around without piercing the plastic) even more so for haylage using monobaling techniques. Additionally, as the DM (dry matter) content of haylage is lower than hay, there is therefore a larger volume to handle and store for a same amount of dry matter.