The ideal grassland for bale silage production has a high proportion of valuable forage grasses such as Italian and perennial ryegrass.
Crop species suitable for grass silage are:
Alternative Crops for Ensiling1
Many crops other than grass can be used for ensiling. According to Dr. Phipps at the Centre for Dairy Research in the UK, almost all forages can be ensiled to some extent, although some are easier to ensile than others.
The quality of the silage depends on a number of factors, including harvest date, dry matter and sugar content and buffering capacity of the crop. Grass is the most commonly ensiled crop, then maize and whole-crop cereals, including wheat, barley, oats and occasionally triticale. However, legumes are also ensiled, particularly lucerne, red clover and peas. Kale is another option.
Some alternative crops are more difficult to ensile and may need an additive. The economics of alternative silages are the same as those for grass and depend on crop cost and yield, silage quality and any losses. An additional factor in some cases is eligibility for EU supports such as area/arable aid.
Maize for silage has developed steadily since the early 1970s, though its value was demonstrated in Europe more than 100 years ago. The popularity of forage maize has been boosted in northern areas by the continued development of earlier maturing varieties and more recently by the introduction of plastic mulches to accelerate the early development of the crop in cool spring weather.
In the right conditions, maize can be a relatively straightforward crop to grow and ensile, and provides good nutrition. It can be fed together with grass silage, and the likelihood is that it will increase in popularity.
Whole-crop cereals, usually wheat, are a feature of silage making in some countries of Europe, especially where rainfall in the growing season is low and where forage maize is not popular.
Whole-crop cereal silage is made from autumn or spring sown crops such as wheat, barley, oats or triticale (a hybrid of wheat and rye). It is harvested at a more mature growth stage than traditional arable silage and with dry matter concentrations between 35 and 60%. This helps ensure a good quality product without effluent.
Experiments carried out by Teagasc at Grange Research Centre with whole-crop barley silage fed to finishing beef heifers indicated that good rates of animal performance are attainable. UK trials have shown that whole-crop silage will maintain milk yields although quality is better with grass or maize silage.
Additional research in this area was recently conducted by the Swedish University of Agricultural Sciences:
The main forage legumes now grown in northern Europe include white clover (in mixtures with grass), red clover, lucerne (alfalfa), birdsfoot trefoil, sainfoin and goatsrue (Galega officinalis). Each of these has quite different characteristics, and there are particular niches (environment and management) to which each is suited, but lack of persistence of crops such as lucerne and red clover can be a disadvantage compared with a grass sward.
Research on the “Effect of ensiling method on the quality of red clover and Lucerne silage” was conducted by The Institute of Grassland and Environmental Research (IGER) in the UK.
Red clover can be incorporated as an alternative forage crop to reach better productivity and reduced costs. It is, amongst others, valued for its nitrogen fixation which increases soil fertility. Therefore, red clover brings important advantages for farmers in the livestock sector not only in terms of savings in fertiliser costs, but also nutritional and organic benefits and improved milk yields.
Research on this crop was conducted by IBERS (Institute of Biological, Environmental and Rural Sciences) for the Silage Advisory Center:
Pulses such as peas and beans can also be ensiled, but they usually require the application of high rates of preservative additives. Their protein is readily degraded in the rumen, which means that they will not be adequate as the sole supplementary protein sources used with grass silage-based diets without further processing. New varieties of lupins are being investigated by Teagasc, Oak Park Research Centre, and they show good prospects for supplying high concentrations of good quality protein.
Research at IGER in the UK has shown the potential for big bale silage system to conserve legumes and lupins.
BeetsThe roots, leaves or whole crop of fodder beet or sugar beet can be ensiled without great difficulty, producing very high quality feedstuffs. Because of their high nutritive value, these crops can benefit from the addition of an absorbent at ensiling; however, large volumes of effluent may be produced.