How Each Wrapping Method Works Inside the Baler

The 8-Factor Head-to-Head Comparison

Net wrap wins 6 of 8 factors. Twine wins on upfront cost per bale and on environmental disposal (sisal twine only — plastic twine has the same disposal problem as net wrap). But the storage-loss factor alone overwhelms the cost advantage. A $60 round bale wrapped in twine that loses 30 percent in outdoor storage delivers $42 of usable feed. The same bale wrapped in net wrap that loses 12 percent delivers $52.80 of usable feed. The $10.80 per bale difference dwarfs the $1.00 to $1.50 per bale wrap-cost premium. On 200 bales stored outdoors through winter, net wrap preserves $1,860 to $2,160 more feed value than twine after subtracting the additional wrapping cost. That net savings pays for the net wrap roll and then some.

The Storage Loss Factor: Why Net Wrap Pays for Itself in the First Rain

The 12-percentage-point gap in outdoor storage loss (12 percent for net wrap versus 30 percent for twine on bare ground over 12 months) is the single number that settles the debate for any producer who stores round bales outdoors. The physics are straightforward: rain falls on the curved top surface of the round bale. On a net-wrapped bale, the continuous polyethylene mesh deflects the water outward and downward off the edges of the bale, similar to an umbrella. On a twine-wrapped bale, the water flows between the twine strings and directly into the exposed hay surface, where it is absorbed by capillary action into the interior. Each rain event drives moisture 1 to 3 inches deeper into a twine-wrapped bale. Over a 6-month storage period with 30 to 50 rain events, the cumulative water infiltration creates a spoilage layer 4 to 8 inches deep on the curved surface and 6 to 12 inches deep on the bottom where ground moisture compounds the rain damage.

This spoilage layer is not just cosmetic. The moldy, rain-damaged outer inches are refused by cattle and wasted during feeding. The dry matter that remains in the interior is nutritionally intact but represents only 60 to 75 percent of the original bale mass. The producer paid full production cost for a 1,000 lb bale but delivers only 600 to 750 lb of usable feed to the animal. That 250 to 400 lb of lost feed per bale, multiplied by 200 bales, totals 25 to 40 tons of hay that was 刈り取った, 熊手でかき集めた, and baled but never consumed — a $3,250 to $7,200 annual loss at $130 to $180 per ton that net wrap reduces by 60 to 75 percent.

The Speed Advantage: 30 Percent More Bales Per Hour

Net wrap applies in 2.5 to 3.5 bale rotations, which takes 6 to 10 seconds at standard PTO speed. Twine applies in 15 to 25 bale rotations (the twine arm must shuttle back and forth multiple times to cover the full bale width), which takes 25 to 40 seconds. The 15 to 30 second difference per bale accumulates across a full day of baling into a significant throughput advantage.

On a 200-bale day, net wrap saves 50 to 100 minutes of wrapping time — nearly 1 to 2 hours that the round baler spends stationary in the field waiting for the twine cycle to complete. Those 1 to 2 hours of saved cycle time allow the operator to bale 30 to 50 additional bales per day or, more commonly, finish the same number of bales 1 to 2 hours earlier, reducing the risk of running into the evening humidity window that raises windrow moisture back above the baling threshold. In tight weather windows where every hour counts, the speed advantage of net wrap can be the difference between finishing the field before rain arrives and leaving 30 unbaled windrows to be rained on overnight.

Leaf Retention: The Hidden Quality Advantage of Fewer Bale Rotations

Every rotation the bale makes inside the chamber tumbles the forage against the belts or rollers, and each tumble dislodges dried leaf particles from the stems. With net wrap at 2.5 to 3.5 rotations, the leaf exposure to mechanical abrasion is brief. With twine at 15 to 25 rotations, the leaves endure 5 to 8 times more tumbling, which shatters and removes a measurable portion of the leaf mass before the bale is even ejected from the chamber. University of Kentucky research measured 2 to 4 percent higher crude protein in net-wrapped alfalfa bales compared to twine-wrapped bales from the same windrow, attributable entirely to the leaf retention difference. On Premium-grade alfalfa where each CP percentage point is worth $8 to $15 per ton, the 2 to 4 point advantage of net wrap adds $16 to $60 per ton of quality value — on top of the storage-loss savings.

The Third Option: Stretch Film From a Silage Baler

The net-wrap-versus-twine debate assumes the product is dry hay. When the product is baleage, a third wrapping option enters the comparison: 6 to 8 layers of 1-mil stretch polyethylene film applied by a bale wrapper after the サイレージベーラー ejects the bale. Stretch film provides a complete, airtight barrier that eliminates rain infiltration, UV exposure, and oxygen contact entirely — something neither net wrap nor twine can achieve. The 12-month dry matter loss for stretch-film-wrapped baleage is 3 to 8 percent, compared to 8 to 15 percent for net-wrapped dry hay and 20 to 35 percent for twine-wrapped dry hay.

The cost of stretch film is $3.50 to $5.50 per bale — higher than both net wrap and twine. However, the baleage product inside the film is worth $15 to $30 more per bale than the equivalent dry hay because the fermentation preserves higher crude protein, higher energy, and higher palatability. The net economics favor stretch film for any bale that will be stored outdoors for more than 3 months or any bale destined for the dairy market where the fermentation premium applies. A 飼料ベーラー that uses net wrap inside the chamber (for bale shape during transport from field to wrapper) and then passes through a stretch-film wrapper gets the best of both technologies: net wrap for structural integrity and stretch film for airtight preservation.

For operations that produce both dry hay and baleage from the same fields across different cuttings, the round baler should be equipped with net wrap as the standard wrapping method for dry-hay bales. The silage-grade configuration adds stretch-film wrapping through the downstream bale wrapper for baleage bales. This dual-product approach uses net wrap for the dry-hay inventory and stretch film for the baleage inventory, optimizing the wrapping economics for each product type independently.

When Twine Still Makes Sense: 3 Narrow Scenarios

1. Bales fed within 2 weeks of baling. If every bale goes directly from the field to the feeder with no outdoor storage period, the storage-loss advantage of net wrap never materializes and the $1.00 to $1.50 per bale savings from twine is real and uncontested. This scenario applies to operations that bale and feed in a continuous cycle during the grazing season rather than building an inventory for winter.
2. Bales stored entirely indoors. Barn-stored bales are protected from rain regardless of wrapping method. The storage-loss difference between net wrap and twine indoors is only 1 to 3 percentage points (from UV and air exposure through the twine gaps), which may not justify the wrapping cost premium for operations with ample barn space.
3. Biodegradability is a priority. Sisal twine biodegrades completely in 6 to 18 months after disposal. Net wrap and plastic twine persist in the environment for decades and must be collected, baled, and transported to a recycling facility — a logistics step that many small operations skip, leading to net wrap accumulation in field corners and fence rows. For producers committed to zero-plastic operations, sisal twine is the only fully biodegradable wrapping option for dry round bales.

Outside these 3 scenarios, net wrap is the superior choice for every dry-hay round bale, and stretch film from a サイレージベーラー and wrapper is the superior choice for every baleage bale. The wrapping decision made at the round baler determines whether 85 to 92 percent or only 60 to 75 percent of the forage you produced reaches the animal’s mouth — a gap too large to justify the $1.00 per bale savings that twine offers.

Switching From Twine to Net Wrap: What It Costs and What It Requires

If your current round baler is twine-only, switching to net wrap requires either a net wrap retrofit kit ($1,200 to $3,500 installed, available for most major baler brands manufactured after 2000) or purchasing a baler that comes with net wrap standard. Most new round balers from every manufacturer — including America Ever-Power’s fixed-chamber models — ship with net wrap as the standard wrapping system, with twine available as an option or a field-switchable dual system that can run either wrap type depending on the operator’s preference for that particular cutting.

The retrofit investment of $1,200 to $3,500 pays for itself in the first season on any operation that stores 100 or more bales outdoors. At a net savings of $9 to $11 per bale (storage loss reduction minus wrapping cost premium), 100 bales generate $900 to $1,100 of net savings in Year 1 — recovering 25 to 90 percent of the retrofit cost. By Year 2, the retrofit is fully paid and the annual savings continue for the remaining life of the baler. For operations purchasing a new round baler, the net wrap system adds $0 to $1,500 to the purchase price depending on the manufacturer and model — a trivial premium on a $15,000 to $35,000 machine that delivers $1,800 to $2,200 of annual value on 200 bales.

The Number That Matters: Cost Per Ton of Usable Feed Delivered to the Animal

The most useful way to compare wrapping methods is not cost per bale at the time of baling but cost per ton of usable feed that actually reaches the animal’s mouth after storage. This metric captures both the wrapping cost and the storage loss in a single number that reveals the true economics.

The bottom row is the number that settles the argument. Twine saves $2.41 per ton in wrapping cost but wastes $40.48 more per ton in feed value loss compared to net wrap. The total cost of wrapping plus waste is $61.71 per ton for twine versus $23.64 per ton for net wrap — twine costs the producer nearly 3 times as much when the full picture is measured. Stretch film from a forage baler has the highest wrapping cost but the lowest feed-value loss, making it the most economical option per ton of usable DM delivered for any bale stored 6 months or longer.

編集者: Cxm