Using maize silage to reduce risk

Using maize silage to reduce risk

Maize silage has become an important part of many farm systems throughout New Zealand. The value of maize silage as a feed came to the fore last summer when farmers with a stack of maize silage managed well despite the drought. Many farmers reported how grateful they were for having a maize crop growing on farm. Others who bought maize silage from a local grower said that purchasing maize worked well as it got them out of a terrible feed deficit.

With dry summers becoming more frequent and intense, there are three key reasons why most dairy farmers should consider integrating maize into their systems. These are as follows:

1. Grow more feed per hectare.

Typically yielding somewhere between 18-24 tonnes of dry matter per hectare (tDM/ha), maize silage is the ideal crop for increasing the total amount of feed grown on farm. Even in the extreme dry of last summer, farmers were reporting maize yields around double that of pasture. Research conducted the early 2000s, showed that maize silage and a subsequent winter crop (e.g. oats or Italian ryegrass) yielded more than 30 tDM/ha/year in an area that typically grew 15 tDM/ha/year of pasture.

Many farmers are using maize silage to renew parts of their farms that are under performing. Research has shown that there can be up to 100 percent difference in yield between the best performing and the worst performing paddocks on a farm2. Using maize to renew pasture results in greater total DM grown in the short term through cropping, and more pasture grown per hectare in the long term through the introduction of new pasture species.

2. Use maize to manage pasture.

Because it's a forage, maize silage can help farmers manage pasture. Many farmers have discovered three simple rules when using maize silage for pasture management.

Rule 1. If your post grazing residuals are falling below 1500-1600 kilograms of DM per hectare (kgDM/ha), feed more maize silage.

Rule 2. If your grazing residuals begin to lift above 1800kgDM/ha, feed less maize silage.

Rule 3. If you don't need it, don't feed it. Instead, keep it in the stack.

The positive substitution effect that happens when feeding a forage like maize silage can be used to great effect when pasture growth rates begin to slow down. Feeding maize silage leaves pasture behind which means you can both protect pasture from being over-grazed and build pasture cover, which results in more pasture growth. Also, at certain times of the year, it may be necessary to stand animals off pasture to reduce damage from pugging or overgrazing. In these circumstances, maize silage can feed animals on a feed pad or stand-off area.

3. Use a stack of maize silage as an insurance policy against the issues associated with drought.

Farms with a stack of maize silage seemed to fare better through this summer's dry than those that did not. Farmers without feed struggled to keep cows in milk while those who used palm kernel expeller (PKE) to fill the gap found themselves struggling to stay out of the C and D range of the FEI. As well as this, farmers without a stack of maize silage also found themselves having to buy extra feed on the spot market with many forced to pay 40-50 cents per kg of DM (c/kgDM).

Having a stack of silage on hand is a great risk management strategy to help cope with the dry. The beauty of maize silage is that if you get a summer where pasture growth is good, and you don't need to feed it, the maize silage can remain in the stack until it is needed. At current interest rates, storing maize silage for a year will only add about one c/kgDM to its cost, meaning 25c/kgDM maize silage now costs 26c/kgDM. It is certainly a lot cheaper to store maize silage for a season than to pay 40c/kgDM for supplements on the spot market.

It looks like contract maize silage may be in short supply this season.

Don't be caught out again by another dry summer. Talk to your local Farm Source TSR or Pioneer representative about growing another paddock of maize silage to provide feed to get you through.


1. Densley et al., 2006. Maize silage and winter cropping options to maximise DM and energy for NZ dairy systems. Proceedings of the NZ Grasslands Association 68:193-197
2. Clark et al., 2010. Inter-paddock annual DM yield variability from dairy farms in the Waikato Region of New Zealand. New Zealand Journal of Agricultural Research 53:187-191


Article supplied by Pioneer Brand Products