Why Bale Density Matters, and How To Get It Right

Properly compacted bales last longer, keeping livestock feed fresh and nutritious, and are often more cost-effective. This blog discusses why bale density is important, how to tell if your bales are dense enough, and considerations for different crop types.

Benefits of bales packed at the correct density:

• Easier to transport and more stable with less risk of collapsing
• More weather and pest-resistant when stored outside
• For silage bales, the correct density limits oxygen permeation, ensuring anaerobic fermentation and preventing spoilage
• Densely packed straw and hay bales keep their shape (though they need to “breathe” and dry properly to prevent moulds)
• Proper bale density keeps the feed nutritious for longer
• Denser bales equal lower storage, transport, and bale wrap (or twine) costs per tonne

The best bale density also depends on other choices you make during baling. Ensure the chop length is correct, harvest and bale at your crop’s optimum moisture content, and choose the right baler pressure setting.

The best pressure settings depend on the specific baler. Structural limits and “ideal” pressure settings vary by model, but general guidelines are:

• For silage, denser is better to exclude as much oxygen as possible
• Straw bale density and hay bale density depend on your crop and conditions – bales should be firm enough to hold their shape when stacked.

There’s a tradeoff between compaction and the wear and tear on your baler components. It’s tempting to go “as dense as possible”, but at higher pressures, you tend to get diminishing returns on kilograms of material you’re adding, while putting more wear on your baler.  Also, keep in mind the ease of moving and plan the stacking (single layer or multi-layer) of heavy bales.

You can approximate good bale density by:

• Checking weight – this AHDB guide gives the weight by size of a typical bale.
• The physical feel of the bale – a properly dense hay or straw bale should feel solid when hit. If the bale depresses and doesn’t spring back, it’s too loose.