Round bale handling and transport
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Round bales can weigh a ton or more and are well-suited for modern large scale farming operations. However, due to their size and weight, they require specialized moving equipment.
The most important tool for round bale handling is the bale spear or spike. It is either attached to the three-point hitch of a tractor for short-range transport or bolted to moving arms on the front of a farm machine for loading onto a trailer. The prongs are inserted into the approximate center of the bale, lifted, and the bale is hauled away. Once at the destination, the round bale is set down and the spear pulled out.
Alternatively, a grapple fork may be used to lift and transport round bales. The grapple fork is a hydraulically driven implement attached to the end of a tractor's bucket loader. When the hydraulic cylinder is extended the fork clamps downwards towards the bucket, much like a closing hand. To move a round bale the tractor approaches the bale from the side and places the bucket underneath the bale. The fork is then clamped down across the top of the bale, and the bucket lifted with the bale in tow.
Round bales can be directly used for feeding animals by placing it in a feeding area, tipping it over, removing the bale wrap, and placing a protective ring (a ring feeder) around the outside so that animals don't walk on hay that has been peeled off the outer perimeter of the bale. The baler's forming and compaction process can assist in unrolling a round bale, as it is often possible to unroll a round bale in a continuous flat strip for feeding in the open, or through a feeding barrier.
Silage or haylage bales
editA recent[when?] innovation in hay storage has been the development of the silage or haylage bale, which is a high-moisture bale wrapped in plastic film. These are baled much wetter than hay bales, and are usually smaller than hay bales because the greater moisture content makes them heavier and harder to handle. These bales begin to ferment almost immediately, and the metal bale spear stabbed into the core becomes very warm to the touch from the fermentation process.
Silage or haylage bales may be wrapped by placing them on a rotating bale spear mounted on the rear of a tractor. As the bale spins, a layer of plastic cling film is applied to the exterior of the bale. This roll of plastic is mounted in a sliding shuttle on a steel arm and can move parallel to the bale axis, so that the operator does not need to hold up the heavy roll of plastic themselves. The plastic layer extends over the ends of the bale to form a ring of plastic approximately 12 inches (30 cm) wide on the ends, with hay exposed in the center.
In order to stretch the cling-wrap plastic tightly over the bale, the tension is actively adjusted with a knob on the end of the roll which squeezes the ends of the roll in the shuttle. In this example wrapping video, the operator is attempting to use high tension to get a flat, smooth seal on the right end. However the tension increases too much and the plastic tears off. The operator recovers by quickly loosening the tension and allows the plastic to feed out halfway around the bale before reapplying the tension to the sheeting.
These bales are placed in a long continuous row, with each wrapped bale pressed firmly up against all the other bales in the row before being set down onto the ground. The plastic wrap on the ends of each bale sticks together to seal out air and moisture, protecting the hay from the elements. The end-bales are hand-sealed with strips of cling plastic across the hay opening.
The airtight seal between each bale permits the row of round bales to ferment as if they were in a silo bag, but they are easier to handle than a silo bag, as they are more robust and compact. The plastic usage is relatively high and there is no way to reuse the hay-contaminated plastic sheeting, although it can be recycled or used as a fuel source via incineration. The wrapping cost is approximately US$5 per bale.
An alternative form of wrapping sees the same type of bale placed on a bale wrapper, consisting of pair of rollers on a turntable mounted on the three-point linkage of a tractor. It is then spun about two axes while being wrapped in several layers of cling-wrap plastic film. This covers the ends and sides of the bale in one operation, thus sealing it separately from other bales. The bales are then moved or stacked using a special pincer attachment on the front loader of a tractor, which does not damage the film seal. They can also be moved using a standard bale spike, but this punctures the airtight seal, and the hole in the film must be repaired after each move.
Plastic-wrapped bales must be unwrapped before being fed to livestock to prevent accidental ingestion of the plastic. Like round hay bales, silage bales are usually fed using a ring feeder.