Wednesday, 15 October 2008 23:23

Have you made silage or compost?

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If you don’t take care when making or storing silage - you could end up with compost. Good silage should have a feeding value close to the crop it was made from, if the job was done right.

The ensiling process is ancient and basically it “pickles” pasture. A good “pickle” comes from a quality crop high in sugars, that has been wilted to reduce moisture, and with rapid removal of air. A sweet-smelling lactic acid fermentation should result producing silage of around 25% Dry Matter (DM). Once the acidity level (pH) reaches 3.8-4.3, it stabilises and the silage will keep for years.

If the crop is too wet, sufficient heat is not generated so a foul-smelling butyric acid fermentation will result and the feeding value will be very low. If the crop is too dry, the silage will heat up quickly to very high temperatures and the end product will be like tobacco with white mould through it. Never feed this to stock as this truly is compost and a danger to stock health.

Good quality acetic silage should be yellow or brown-green, with a sweet acid smell and firm texture. Poor butyric silage is olive green, has a putrid smell and is soft and slimy. Putrid silage is green to black with a terrible smell and is wet and slimy. Only feed and purchase the very best silage.

Wrapped baled silage has been a great advance, provided you can feed them out without damage to pastures and human life. Silage bales can weigh 500-700kg and are lethal when they fall from raised front-end loaders.

Silage cannot be any better than the crop that went in, so for top quality feed, you should cut and condition the crop (done by the one machine) when there are no more than 10-15% of seed heads showing. Do this on a sunny day and spread it widely for rapid wilting. Keep a daily watch on the seed heads as they can change rapidly.

Beyond this stage a crop is only fit for “haylage” or “balage” with around 40% DM, or hay at 85% DM. Be careful when buying so-called balage as it could be hay that got wet or silage that was too dry.

Don’t try to save money on wrapping - use plenty and make sure handling is done carefully as this will prevent punctures of the bales. Limit a stack to two high and fence them off from stock. They provide good winter shelter at the side of the paddock. Watch for damage by rats, possums and magpies.

Dr Clive Dalton

Clive did a Ph.D. in sheep breeding at the University of North Wales at Bangor. After lecturing at Leeds University, he came to New Zealand to do research with MAF. Because of his communication skills, he moved to the Ruakura Agricultural Research Centre to be fully involved in interpreting science for practical application by farmers.

After 14 years he moved to teach at the Waikato Polytechnic where he taught young future farmers. He won the 1993 Landcorp Communicator of the Year award and the 1999 Sir Arthur Ward award for agricultural communication.