All Wrapped Up.
Published on Fri, 03/29/2019 - 8:31am
All Wrapped Up.
By Michael Cox for American Dairymen Magazine
Wrapped bales are often viewed as a last resort when making bales, or as a solution to poor dry-hay making weather conditions. But properly ensiled haylage or wrapped silage can offer producers bales with better feed quality and digestibility than traditional dry hay.
The flexibility offered by wraps can make conserving forages in humid weather and unpredictable rainfall events more manageable. Wraps can offer a more trustworthy option for farmers in conditions when dry hay is marginal and heating/spoiling hay is a possibility post-harvest.
Another advantage of wraps is the faster harvest time and reduced machinery usage compared to hay making. Silage wraps will typically need only one pass with a rake before baling, compared to hay which may need to be turned several times to dry evenly. All this mechanical work on the grass can beat the valuable leaf out of the hay and result in less feed value in the bale. University of Missouri research suggests that most types of grasses and legumes are best mowed at the boot stage, which will capture most leaf and as little stem as possible in the plant. The leaves contain roughly 2/3rd of the nutritional value of the plant at the boot stage. Their research also points out that wraps will not improve the quality of the grasses harvested, it is only an ensiling and storage method. Mowing grass in the early afternoon however can increase the sugar and nutritional content of the grass, while also improving the ensiling process, as desirable lactic acid fermentation will feed off high sugar levels and ferment the wraps quickly. 30% to 50% moisture content in the grass at baling will allow good fermentation to occur – too wet or too dry poses challenges to the fermentation process. The higher moisture content in silage means the harvest window is much greater as opposed to saving dry hay. Weather conditions are not as critical, although ideally, bales should be wrapped in dry weather so the plastic has best tackiness and eliminates oxygen by wrapping tightly to the bale.
Wrapping can be done with an in-line wrapper or with a trailed wrapping machine, which will wrap bales individually in the field. Most manufacturers recommend using at least 6 layers of wrap on the bales, while some farmers opt for 8 layers as it offers better ensiling and less wastage. Regardless of which type of wrapper is used, keeping the plastic intact, with no holes or damage is critical to eliminating wastage. Storing bales on rough surfaces or handling individual bales without care will puncture the plastic and allow oxygen into the bale. Oxygen will disrupt the anaerobic fermentation required to ensile and preserve the bale. Baling the grass as densely as possible can help keep oxygen out of the bale prior to the wrapping process. ‘Loose’, saggy bales can begin to heat up before being wrapped and are more difficult to preserve without wastage and rotting. Research from University of Arkansas has found that prompt wrapping within 24 hours of baling will limit bale heating and improve feed quality in the bale. Typically, producers will wilt grass for 24 hours to reduce the water content in the grass, and then aim to wrap within 24 hours after baling. Prompt wrapping is important, but the University of Arkansas research did show that there is a window of opportunity up to the 24 hour mark, which is good news for producers who can focus on baling high quality forages with the comfort of knowing they have a full 24 hour window to wrap the bales.
Wraps will certainly add costs to the harvesting process, with wrapping costing anywhere from $5 to $10 per bale more than dry hay expenses. But the flexibility around harvest times and weather conditions should help custom-contractors to greatly increase the number of bales harvested in a season compared to dry-hay. If harvested at the correct stage of growth, wraps will also offer greater feed quality compared to dry hay on most occasions.