May has been tricky. For me, it remained too wet to fertilise our larger grazing fields and with our large bale haylage supply coming to an end, the horses had to be turned out. Subsequently, they have of course made a bit more of a dent in the ground and grass than we would have liked.

The pregnant mares are still in the maternity barn and happily getting through some excellent quality extortionately priced small baled haylage. We’d had that tested at the Irish Equine Centre, and it thankfully proved to be top quality which eases the pocket pain a little. I heard a friend recently paid €110 for a round bale of straw, so I wasn’t looking forward to the chat with our local fodder supplier to try to get some big bales to top up the mares in the grass-short field.

The upshot with him was that he only had hay a couple of years old left to sell, far from ideal. That, plus having just had the bill for next winter’s haylage (pay on cutting first week of June at £35 per bale), it got me thinking about hay and haylage quality and what we need to look for from our fodder suppliers. I turned to the experts at Teagasc to give an overview of what we should consider when it comes to buying haylage or hay.

What should I look for in good hay?

A. The main requirements from hay are that it provides horses with an appropriate supply of energy and fibre, protein, minerals and vitamins, and that it is relatively free of dust and any harmful plants, moulds (spores or toxins), dirt or other unwanted substances.

Hay is most frequently assessed subjectively by its appearance, smell and feel. Obviously, hay should always feel (and sound) dry. Hay with a lot of leafy grass and some clover will have a much higher available energy, protein and mineral content than hay composed of very stemmy herbage that has many well developed seed heads. Stemmy herbage will also feel much rougher and stiffer.

Dead herbage at the base of stems indicates further reduced feed value. It is a disadvantage to have weeds such as thistles, docks and buttercups in hay, while plants such as ragwort should never be present. Hay with a greener colour has normally been cut before it became too mature, and has been dried quickly with little or no rain damage. Pale coloured hay may have been relatively mature when cut (in which case it will be quite stemmy and have mature seed heads) or suffered some rain damage during slower field drying.

Heavy mature crops mown after an extended duration of wet weather, or that lay on the ground during several days’ rain after mowing, generally have a very dull and sometimes dark appearance. Dark brown hay in the centre of a bale usually indicates heating during storage. If hay contains visible mould it should not be fed to horses. Hay should always look ‘clean’ and certainly not dusty (shake the hay to see this). Always pull hay out of a bale to see it properly, as the outer layer of a bale can often look quite different from the inner parts of the bale. Good quality hay certainly shows no signs of soil or manure contamination.

When hay is properly made from ‘healthy’ grass under good drying conditions it will have a characteristic good smell. In contrast, a musty or bad smell indicates poorly saved hay that suffered losses in the field or, more often, during storage. Any caramel or tobacco-type smell indicates considerable heating of damp herbage during storage and a reduced feed value. Hay can be assessed objectively based on a feed analysis undertaken by a competent laboratory. It is really important that if a sample of hay is going to be chemically analysed that it is genuinely representative of what will be fed to the animals.

What exactly is haylage?

A. Haylage is herbage that undergoes extensive but not complete field drying, and is then stored under genuinely air-free conditions. It undergoes a much less extensive fermentation than conventional silage, and exhibits characteristics intermediate between normally wilted silage and hay. Air-free conditions are achieved by sealing beneath plastic sheeting – in the case of baled haylage, this normally involves wrapping in six or more layers of stretch-film. The integrity of this film must never be damaged between wrapping and the time when the bales are being fed. Haylage is typically 50-65% dry matter (DM) i.e. 35-50% moisture.

What should I look for in good haylage?

A. Most features are the same as for hay. The quality of haylage will be set by the growth stage of the herbage at harvest (i.e. leaf vs. stem) and by the presence or absence of unwanted weeds, dead herbage or mould. It should have a pleasant fermented smell. Typical pH values are 4.5-5.5 depending on the DM content of the haylage, and both butyric acid and ammonia concentrations should be very low.

What are the advantages and disadvantages of hay?

A. In most years prevailing weather permits only a single crop of hay to be produced from a meadow in Ireland. The extended period of field drying required and the general need to allow some field curing of the bales before storing them under cover, means that hay-making is hugely dependent on prolonged dry weather. Most frequently, some rain damage occurs and occasionally this is severe.

Once hay is adequately dry and is safely stored under cover, then it is a very flexible feed – durable, transportable, tradable, and easy to handle. However, if the drying process has not been successful then mould and dustiness, as well as reduced feed value, are likely.

What are the advantages and disadvantages of haylage?

A. Because of the shorter duration of field wilting, haylage is somewhat less dependent on weather conditions. This increases the opportunity to save more than one harvest from a meadow in a year. It does not need to be stored indoors and is usually not dusty. However, any damage to the integrity of the quite delicate plastic film in which it is wrapped will results in extensive damage due to mould growth. Furthermore, bales of haylage usually need to be consumed within a few days of removing the plastic wrap, as mould can start to grow if exposure to air is prolonged. This can be a limitation where only a small number of animals are being fed.

It is particularly important to remove stale and visibly deteriorated haylage from the feeding area. Similarly as for hay, mouldy haylage (or otherwise ‘bad’ haylage) should not be offered to horses. It is important if rationing or budgeting haylage instead of hay for horses, that an allowance is made for the higher moisture content of haylage. For example, it would take 12.8kg haylage (assuming 55% DM) to provide the same quantity of feed dry matter as 8kg hay (assuming 88% DM).

Which is better, hay or haylage?

A. If a meadow is mown during dry sunny weather and alternate windrows are baled and wrapped for haylage production after two-or three-days’ wilting, or baled for hay production after five days’ drying, and each is then stored properly, the nutritive value of both feeds might be expected to be relatively similar.

However, the shorter wilting duration in the field will likely give a small advantage to the haylage. Where inclement weather prolongs the hay-making process and damages hay quality, then the advantage in favour of haylage can widen considerably. If haylage production allows two crops be harvested from a meadow rather than a single crop for hay, then the less mature grass used for haylage production will result in a higher nutritive value.