Silage Advisory Centre

Many farmers view silage made in bales as the poor relation to that made in clamps and often describe it not as silage but as something else beginning with ‘S’!  After reading this article maybe the sceptics amongst you may think otherwise and may even consider some baled silage next season.

The main ‘perceived’ problem with baled silage is the hassle of having small quantities of silage wrapped in film that requires extra handling; ironically this is one of their key advantages that could enhance forage utilization on many livestock farms.

Silage Quality

Firstly, let us examine the issue of silage quality.  On-farm there are a number of very real reasons why baled silage is never as good as that in silage clamps. 

First and foremost the grass ensiled in bales is often more mature and so less nutritious than clamp.  Once made, bales are often poorly managed, with wrapped bales being left in the field for a few days before being moved and often to a less than adequate storage site.  This leads to damage to the wrap, with oxygen entering the bale.  All of these factors lead to poor quality silage. 

However many studies, where the same crops have been ensiled in bales compared to clamps, and good management procedures have been followed, indicate that baled silage has performed as well, if not better, than the clamp silage. 

Studiesconducted at Greenmount College (Northern Ireland) and IGER (Wales) comparing bale versus clamp silage, indicate no difference between the two in terms of animal performance and fermentation characteristics whereas dry matter losses were significantly lower in bale compared to clamp silage (Table 1).

Table 1 - Chemical Composition and Animal Performance of Baled Compared to Clamped Grass Silages

Benefits of Bales

So if we now accept that bale silage quality should be as good as clamp then we need to consider which best fits into your system or is there a requirement to mix and match both ensiling methods to maximise forage utilisation on your farm.

Bale silage has some significant advantages over clamp:

• Helps maximize utilization of grazed grass
• Flexible management system: variable harvesting dates, economical harvesting of small areas, complete forage diet feeding
• Rapid sealing: reduces time before fermentation begins and in silo losses
• Allows small sealed units of silage, reducing the problem of aerobic spoilage

Complete Forage Feeding

The use of alternative forages has seen a big growth over the last year or so in particular the use of Red Clover to reduce fertilizer nitrogen requirements and increase production f home grown forage protein.

Whilst Red Clover will ensile equally well in a clamp or a bale, if you have considerable acreage of red clover it is worth considering the bale option.  This approach will enable better rationing of the high protein silage at feed-out.  For example, by keeping it for high yielding or early lactation cows that have higher protein requirements that can then be met from a home-grown forage. 

Results of a study conducted at IGER looking at the differences in silage quality of Red Clover ensiled either in bales or a clamp, indicate very few differences between the two ensiling methods with the exception that significantly more WSC was retained in the bale than the clamp (Table 2).

Table 2- Chemical Composition of Red Clover ensiled either in Bales or a Clamp

Costs Considerations

Hopefully it is now clear that quality is not compromised and that there can be significant advantages of bales compared to clamps. The ultimate question is therefore the costs of production.

At a first glance bales are often seen as more costly to make than clamp silage.  However, to obtain a true picture of costs we need to cost the systems in terms of tonnes of silage dry matter fed in relation to the tonnes of fresh matter harvested.  Table 3 shows the comparison of losses between harvesting and feed-out and the resultant costs of production from silage prepared either in bales or clamp.  The table shows that the greater losses between harvesting and feed-out in the clamp compared to bale system significantly shift the costs of production. 

As with all costing every farm can debate what is applicable to them, but this example shows that the cost of production of a tonne of feed-able silage DM in a bale or clamp are surprisingly similar.  In fact, in this example baled silage is actually cheaper than clamp.

Table 3 – Ensilage Dry Matter Losses and Ensilage Costs Comparing Clamps to Bales (example for a 3 cut grass system with 300 kg N applied per Ha)

Hopefully in future you will view baled silage as ‘Shillings’ in the bank not something else!!

Dr Dave Davies is Director of Silage Solutions and independent scientist for the Silage Advisory Centre (SilAC)