By Debbie James

Top quality silage will keep cows productive and healthy. With attention to detail it is within every farmer’s capability to produce good forage.

With variants ranging from the growing season to clamp preparation and management silage can be a challenging crop, but making the time and effort to get it right will benefit cow rumen health and lead to improved feed intakes and productivity.

Independent grassland specialist Chris Duller cites good quality silage as an important factor in feed conversion efficiency.

By improving it from 1.2 litres/kg DM to 1.3 litres/kg DM, the milk production of an 8,000-litre cow can be increased by 8.5% – or the amount of feed needed to support this yield can be reduced by over 1 kg DM per day.

“It’s all about attention to detail, from start to finish,’’ says Mr Duller.

Storing and managing silage correctly is key. Silage quality is often compromised by aerobic spoilage and mould but with foresight and management this damage can easily be avoided.

From selecting the right site for a clamp and the materials used to cover it through to feeding the silage correctly, there are many factors farmers should consider.

SITING A CLAMP

The most important consideration when siting a clamp should be access – both for ease and speed when filling and feeding silage out.

Ideally the clamp should be under cover to protect the exposed face from weather and to prevent rain from pooling on the top. It will also mean that less water will enter the slurry store. All water falling on an outside pit is classed as dirty water and therefore needs to be collected. One of the downsides of an indoor clamp is that the sides are frequently poorly rolled as the eaves of the shed prevent the tractor on the pit from getting tight to the edges.

PREVENTING THE CLAMP FROM HEATING

Taking the time to compact silage as it comes in will keep air out and prevent it from heating. Rolling a nine-inch wedge each time is the ideal.

“The man on the clamp must not be rushed,’’ Mr Duller insists. “The contractors are only interested in getting to the next job but if it means paying them extra to slow down the loads or paying to have another tractor on the clamp then it is a sound investment.’’

Depending on the size of the clamp, there should be at least two tractors rolling, each fitted with narrow wheels.

By rolling in the shape of a saucer, it will keep the edges firm and prevent them from heating.

Chop length is also important and the dry matter content of silage should dictate the length. If the silage is wet and it is cut short it will compact too tightly; if it is dry and too long it will be difficult to consolidate.

Mr Duller recommends cutting grass with a 25-27% dry matter content at one inch, longer if it is wetter.

PREVENTING SPOILAGE

Producing high quality silage relies on encouraging a healthy population of beneficial bacteria, predominantly lactic acid bacteria, to multiply and use up oxygen in the clamp to transform grass sugars into lactic acid.

Bad bacteria such as coliforms and clostridia will disrupt the fermentation, raising the pH and reducing the nutritional quality and intake potential of silage.

Inoculants are designed to help dominate the fermentation with the beneficial bacteria and to drive down the pH.

“If the silage is wet and contaminated with soil then an inoculant is unlikely to improve the fermentation but using an acid will stabilise the silage and at least make it edible,’’ says Mr Duller.

COVERING THE CLAMP

Speed is the most important factor when it comes to covering the clamp and should ideally be done immediately.

Mr Duller favours keeping the clamp airtight with a layer of cling film topped with silage wrap.

Alternatively, he recommends two layers of silage wrap, weighted with tyres or a suitable alternative.