While filling up the hay barn with hay is a worthwhile and relatively easily achievable objective, filling the barn with top quality hay is much more difficult.
However, if it is achieved it confers considerable extra benefits, apart from the obvious one of quality always being superior. The greater flexibility offered by quality hay gives many more feeding options. Quality hay can be used profitably as a supplement for producing animals, but the possibility of doing so with mediocre hay is much more remote.
So how do you maximise hay quality?
The first and most important point is that the quality of hay or silage can never be better than that of the pasture from which it was made. There is a common belief that compared with hay, silage is a better milking feed, meaning better quality feed.
This is generally true, but the only reason is that silage is invariably made from a better quality pasture than hay.
If hay and silage were cut from the same pasture, and efforts to prevent nutrient losses in harvesting and storage met with identical success, the benefits in feeding them would also be identical. Good hay will always be a better quality feed than poor silage.
The first step in making quality hay is organising a quality pasture to make it from. This is probably where a common objective in the haymaking process takes its biggest hit. The temptation is always to leave the hay paddocks closed just that bit longer and go for the maximum yield.
While this may seem a good idea, the longer paddocks are left before cutting, the greater the proportion of stalk and seed head as a percentage of total drymatter (DM), and the lower the quality of the final product.
After harvesting an over-mature crop, the stubble will be open and leafless so recovery and regrowth will be slower, particularly if conditions become excessively dry.
The reduced DM production from these paddocks could outweigh any gains obtained from the heavier crop. This is definitely one case where biggest is not best.
Determining the best stage of growth for cutting hay will be a compromise between the higher yields of a mature crop and the higher quality of a shorter, leafy one, which is usually the early flowering stage for the ryegrasses.
However, when the crop is clover dominant, cutting can be delayed past this point as the nutritive value of clovers does not decline as rapidly after flowering as grasses.
Having cut the grass the next obvious step is to dry it, and the success of this process will also heavily influence the quality of the end product. Pasture for hay will generally be at 20-25% DM when cut and it will need to be dried down to 80-85% DM to maximise quality. Anything less than this will result in heating and mould formation in the barn, with a consequent severe drop in quality, not to mention fire risk from overheating.
The quicker the crop can be dried to the target 20-25% DM the better. This is because as soon as the crop is cut it will begin the respiration process, breaking down carbohydrates, and this will continue until the crop is completely dry. Apart from weather conditions, over which the farmer has no control, the rate of drying will be affected by the resistance to moisture loss, firstly by the swath, and secondly by the individual plants.
The dynamics of the swath is likely to be the most influential factor. The bulkier and denser this is, the slower the drying will be. This is another point in favour of lighter crops.
Most critical will be the aeration of the swath. The more air that can move through it the more efficient the drying will be, so tedding that fluffs up the crop evenly and teases it out to avoid lumps and ropiness should be aimed for.
The ideal is to get the bulk of the sward as far off the ground as possible and also, as much as possible, to ensure the swath is turned on to dry ground.
As far as moisture loss from the individual plant is concerned it has been established that in cut plants this occurs primarily through the leaves, and that water in the stems is largely lost after first being translocated to the leaves.
Consequently, overall drying rate decreases markedly during the final stages of stem drying and this is what will prolong the total drying period.
This is one reason why leaf loss from shattering in the drying crop should be minimised – the other one being that the greater the leaf content, the better the quality of the hay. In the early stages of drying the plants are still fairly robust, so that at this time, treatment can be frequent, rigorous, and intensive. It is only when moisture content is lowered to 30-35%, (65-70% DM) that leaf loss from shattering will become a distinct possibility.
Tedding should begin soon after cutting and be frequent until 30-35% moisture content is reached. After this stage further treatment should be as gentle as possible and should consist of putting the crop into a final windrow and then gently turning this once or twice before baling.
While this might slightly prolong the drying period in the latter stages, the payoff will come from having a better-quality crop. Indeed this applies to the whole programme as outlined above.
Generally for reasons of cost, convenience, and time, minimising the turning and conditioning operations applied to a hay crop is considered to be the main priority. If this was shifted to processing to ensure the maximum possible preservation of quality, the payoff should more than outweigh the extra effort and costs.
