Baled silage of legumes and lupins

Raymond Jones
Leader of Livestock Systems and Integrated Land Use, IGER, Aberystwyth, Wales

Research at the Institute of Grassland and Environmental Research (IGER) has shown the potential for a big bale silage system to conserve high value protein and energy crops.

The production of grass ensiled as big round or square bales has increased considerably and accounts for almost 30% of the total silage made in the UK. Concurrent with this change in harvesting system there has also been a need for UK farms to reduce their reliance on imported high cost protein concentrates and produce on-farm protein crops such as red clover, lucerne and lupins.

Tables 1 and 2 highlight the effectiveness of bale silage, using 6 wraps of quality film, to preserve legume and lupin silage crops, maintaining low protein degradation and high digestibility even when red clover and lucerne are wilted for up to 75 hours.

Table 1 - Effect of wilting on the chemical composition of red clover and lucerne baled silage (g/kg DM unless otherwise stated)

Crop	Chemical Composition	Wilting Time
Crop	Chemical Composition	27 h wilt	51 h wilt	75 h wilt
Red Clover	DM (g/kg)	263	420	521
	pH	4.12	4.24	4.65
	NH3-N (g/kg TN)	54	32	28
	CP	226	235	229
	DOMD	744	746	752

Lucerne	DM (g/kg)	402	594	625
	pH	4.42	4.70	5.13
	NH3-N (g/kg TN)	40	19	18
	CP	251	250	256
	DOMD	691	686	698

CP = Crude Protein
DOMD = Dry Organic Matter Digestibility

Table 2 - Chemical analysis of Lupin whole-crop baled silage (g/kg DM unless otherwise stated).

Chemical Composition	Whole-crop baled silage variety
Chemical Composition	Borweta	Bordako
DM (g/kg)	205	267
pH	3.92	4.08
NH3-N (g/kg TN)	76	49
CP	206	193
DOMD	700	660

Borweta and Bordako = Lupinus angustifolius (blue lupins)

There is a perception that big bale silage is an expensive process relative to clamp silage. However, this belief may be inaccurate if all costs are taken into account. Economic comparisons between baled and forage harvested silage systems in research establishments in Ireland and Wales have consistently shown little difference in the cost of producing grass silage (£/t DM) using either a clamp silo or a big bale system.

Attention to detail is imperative in order to maintain low costs for baled silage:

crops should be baled at optimum quality
bales need to be wrapped quickly after baling (within four hours)
for high protein (red clover, lucerne and lupins) and energy crops such as whole crop cereals:use 6 layers of film wrap and store in single layers where the stack can be protected from vermin and birds.

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Silage Insights

Baled silage of legumes and lupins