The 2014 hay crop

EXCELLENT grass growing conditions during last summer together with good drying conditions around hay-making time led to bumper yields of well saved hay. On many farms meadows that might traditionally have been conserved as baled silage were dried through to hay instead. Thus, the overall quantity of hay produced in 2014 was much larger than in previous years and, in most cases, it was saved with only modest field losses and was adequately dry going into haysheds.

Storage of hay

Hay in Ireland has to be stored under cover, which is different than on farms in some continental climates. Properly field-dried and cured hay can be stored almost indefinitely provided it is kept under suitably dry conditions. In some cases where high value hay is being produced, bales of partially field-dried herbage are then barn dried but this is not common in Ireland.

In contrast, it is quite dangerous to store damp hay in a shed. Besides the likelihood of resultant mould growth leading to a loss of feed value and the production of mould spores or toxins, there is a risk of severe heating of damp hay (which further reduces its feed value) and in some cases this can lead to spontaneous combustion that causes the destruction of the stack of hay, as well as the shed and its contents. Spontaneous combustion is a greater risk when damp hay is stored as tightly packed square bales rather than as looser fitting round bales.

Obvious as it may seem, gutters and drainpipes on haysheds need to be properly operational to prevent the outer layer of hay getting rain damaged.

Handling of haylage

Haylage is herbage that undergoes extensive but not complete field drying (it is typically 50-65% dry matter (DM)), and is then stored under genuinely air-free conditions. It exhibits characteristics intermediate between normally wilted silage (25-50%DM) and hay (85-90%DM). The air-free conditions are achieved by sealing the bales in plastic stretch-film (or vacuum packing in special plastic bags) and the maintenance of the integrity of this seal through to feedout is essential if the haylage is to be successfully conserved. This means that any handling of bales before wrapping must be done carefully to maintain the shape of the bale, as the success of the subsequent wrapping process requires densely packed geometrically shaped bales.

Once bales are wrapped they need to be handled extremely carefully so that no damage is inflicted on the plastic film. Greater amounts of loading and unloading increase this risk of damage. Transporting wrapped bales on trailers can be particularly challenging in this regard as their placement and securing on the trailer, vibration during transport and their removal from the trailer all present opportunities for damaging the plastic film. However, these problems can be avoided if sufficient care is exercised.

Storage of haylage

Haylage can be stored for as long as the plastic film keeps the herbage air-free, and with securely wrapped bales this can be for well in excess of a year. Stored haylage needs to be protected from rodents, cats and birds, as well as from livestock. If any damage occurs to the plastic film it needs to be immediately re-sealed with a patch of adhesive plastic tape so as to re-establish air-free conditions. Failure to re-seal the bale will likely lead to extensive damage from mould growth. .

Wastage at feedout

A frequently ignored source of loss with hay or haylage occurs during feeding. In the case of haylage there will be some physical loss of feed particles due to horses pulling it under their feet, etc., but with good management this should be kept to less than 5% of the available feed.

There will also be respiration losses if it takes more than a day or two to complete the feeding of a bale of haylage and these losses can become concerning where it takes several days to complete the feeding of a bale. This is because respiration (initially evident as heating) results in a decline in feed value and the progressive growth of mould.

In the case of hay, both the transport of the bale from the hayshed to the feeding location and particularly the circumstances in which the animal eats the hay can result in considerable physical losses. Most of the latter result from horses pulling hay under their feet and then not consuming it and in severe cases this can amount to over 40% of the hay offered to the animals.

The scale of impact of such losses is shown in Table 1 where a heavy yielding meadow with 8.87 tonnes grass DM/ha is mown, field-dried over a six-day period without rain and bales are stored securely in a shed for several months before feeding. All fixed and variable costs have been counted, including a land charge of €300/ha. Field losses during haymaking, etc., have also been included. The effects of altering the losses during feeding (i.e. wastage) from 5% to 45% have a considerable impact on the quantity of hay eaten and thus on the true cost of the hay. Clearly, there is a major incentive to apply management practices that minimise such losses.