Maize silage: Shredlage – a new trend from USA
For quite some time, the media have been reporting a lot about the new shredding strategy shredlage from the USA. The objective is to achieve an improved feed utilisation. But how can this technology be assessed from a silage making point of view? The AGRAVIS expert Dr Sabine Rahn answers questions on the topic of shredlage at silage management.
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What is hiding behind the name shredlage?
Dr Sabine Rahn: Shredlage means that the maize silage is shredded somewhat coarser. Depending on the dry mass (DM content), the length of cut amounts to 2-3 cm. In addition, the plant parts are frayed and the maize kernels ground, which creates an enlarged contact surface for the microorganisms in the rumen. This procedure aims at improving the structural effect and the digestibility of fibres and starch. In addition, the risk of selective eating is to be reduced.
What are the requirements on silage management?
Rahn: If the length of cut is increased, the requirements on compaction increase as well. This situation does not change, even if plant parts are specially frayed to produce shredlage. Experiences from the USA range from better, to comparable to worse results. The decisive factor in evaluating these results is to know what has been compared. For instance, farmers in the USA operate with different lengths of cut. The recommendation here is a theoretical length of cut (TLC) of 0.5-0.75 inch. That equals 1.25-2.00 cm (1 inch = 2.54 cm). If the DM content is > 38 % DS, the length of the shreds should be reduced to < 0.5 inch. If the material of these long shreds is now additionally frayed, it can be assumed that the compaction characteristics will improve. In Germany, this is completely different. Here the recommendation of a 4-8 mm theoretical length of cut ranges clearly below the American values. If we now also take into consideration that compaction is inadequate in more than two thirds of German enterprises and problems with post-heating accumulate especially during the summer months, spontaneously converting to shredlage must be urgently discouraged from a silage making point of view. This could further aggravate the already familiar problems.
Which requirements should be met for shredlage from a silage making point of view?
Rahn: If the shredlage process is to be used nevertheless, we recommend to clarify the following points beforehand:
- How is the maize silage compressed? Have the target values been achieved?
- Has there been post-heating/moulding in the maize silage? If yes, what has caused it?
- Does the use of shredlage make sense given the current composition of rations?
Especially during the first year of shredlage, very accurate attention must be paid to meeting all the silage making parameters. Thus: Rather shred a week earlier than planned. That will additionally facilitate compaction. It is also advisable to use BioCool to safeguard the aerobic stability.