Back Maize silage buffer makes sense

Date: 12 December 2014

While most dairy farmers eagerly await the harvest of their next maize silage crop so they can start feeding it, a growing number are carrying a stack over from the previous season.

"Always having a stack of maize silage on hand makes a lot of sense" says Ian Williams, Forage and Farm System Specialist with Pioneer® brand products. "Farmers can grow longer maturity, higher yielding hybrids, their cows are not underfed while waiting for the next crop and maize silage which has been stored for 3-5 months usually has a higher feed value than a newly ensiled crop".

Longer maturity (higher Comparative Relative Maturity (CRM)) hybrids take longer to reach harvest maturity but generally produce higher drymatter yields than shorter maturity hybrids.

"Usually farmers will maximise yield and minimise the cost per kilogram of drymatter by planting longer maturity maize silage hybrids" says Williams. "However, it is important to ensure the maize crop is harvested early enough to allow timely regrassing, especially if the paddock is going back into permanent pasture rather than winter annuals".

Carrying a buffer of maize silage is also excellent insurance allowing farmers to feed cows well over the summer and into the autumn, regardless of how well pastures are growing.

"Cows milk well on maize silage, especially if it is coupled with a protein source such as leafy pasture, a brassica crop or palm kernel extract" says Williams. "Even when the interest cost of holding it in the stack for more than 12 months is taken into account, home-grown maize silage is a still a much cheaper option than most bought in supplements, particularly those purchased on the often price-inflated spot market".

Maize silage is a proven cow conditioner, with its energy being used 50% more efficiently for condition score gain than the energy in autumn pasture.

Carried over maize silage also delivers feed value gains.

"Recent research has shown ensiling time improves maize starch digestibility and the feed value of maize silage" says Williams. "The data shows freshly ensiled maize silage has an excellent feed value, but maize that has been in the stack for several months is even better".

As fermentation begins, proteases from silage bacteria degrade zein proteins that surround starch granules within the maize grain. The longer maize is ensiled, the greater the extent of zein protein degradation and the more accessible the starch is to rumen microorganisms. This results in improved starch digestion, and less starch being lost in the faeces.

"When compared to newly harvested maize silage, crops ensiled for 3 to 5 months increase 10-15 percentage units in starch digestibility" says Williams. "Farmers feeding older silage can expect to see less maize starch in the faeces and more milk in the vat".

Williams has some advice for farmers wanting to stack maize silage for long-term storage.

"Apply a quality silage inoculant like Pioneer® brand 11C33 to minimise fermentation and feed-out losses, compact the silage well and cover and seal it with a high quality cover" says Williams. "Place rat bait in bait stations around the stack, and check it on a regular basis to ensure there are no holes in the cover."


Raewyn Densley

Forage & Nutrition Specialist