Looking into the future with maize

In the past few years there has been significant discussion around the future of New Zealand dairy farming and how systems can evolve to remain profitable and resilient in the face of changing climatic conditions and increasing regulatory requirements.

We asked the Pioneer Farm Systems Specialists – Wade Bell, Ian Williams and Matt Dalley to answer a number of questions about current challenges and potential future solutions. Here is what they said.

What are the key challenges facing the New Zealand dairy industry?

It is hard to summarise all the challenges facing local dairy farmers but some of the key ones are pasture yield, quality and persistence; rising input prices; increased environmental compliance specifically nitrogen leaching and greenhouse gas emissions and a widespread shortage of labour. Most farmers we talk to are concerned about one or more of these factors and researchers and farm systems experts are working alongside leading farmers to build future-proof systems which address these challenges.

What role will maize silage play in future farm systems?

We believe maize silage has an important role to play in future farm systems primarily because it is a locally grown forage that has a proven track record in New Zealand dairy farm systems and globally accepted environmental benefits. Farm systems which incorporate maize silage can help farmers resolve some of the issues they face. These include:

Pasture yield, quality and persistence

For some time, there has been evidence that on-farm pasture yields are stable or even decreasing and some farmers are having challenges with pasture persistence. As the climate becomes warmer C3 grasses like perennial ryegrass become less competitive whilst C4 grasses like maize, paspalum and kikuyu are likely to perform better.

Good feed budgeting is fundamental to successful dairy farming. But even farmers who monitor pasture cover levels and run an up-to-date feed budget can run short of feed. A key reason is that feed budgets use average pasture growth rates and around 50% of the time actual pasture growth rate will be below average! Growing a bit of extra maize (or buying it in), means you will have a stack on hand to feed when you need it. And the good thing about maize silage is that provided it is well compacted and sealed, it will hold its quality for several seasons. So, if you don’t need it, you don’t have to feed it.

Rising input costs

Farm input costs continue to rise with feed (28%), labour (20%) and repairs and maintenance (20%) being the biggest ticket items for owneroperators1 . The past 12 months have seen significant increases in the 3F’s – feed, fertiliser and fuel - as a consequence of the pandemic, Ukraine conflict and other global events.

The lift in global grain commodity prices has resulted in escalation and instability in the price of many imported supplementary feeds including palm kernel, soyhulls and other byproducts, grains, and protein meals such as soyabean and canola. Maize silage has become an attractive option particularly if at least a portion of farm requirements can be homegrown. The most cost-effective option of all is to grow maize silage in a dairy shed effluent paddock without the need for additional fertiliser. This provides a win-win in that the maize crop mines surplus nutrients, especially nitrogen which could otherwise be lost to groundwater whilst at the same time providing low cost supplementary feed which can be fed as required.

Increased environmental compliance

The proven environmental benefits of maize silage make it the crop for the future. Published New Zealand research showed the nitrogen leaching loss from maize silage followed by annual ryegrass in a cut-and-carry system, was less than 10 kg/ha/year2 . This is good news for dairy farmers wanting to decrease nutrient losses on their farms.

For most of the year the protein content of pasture is higher than cow requirements. Surplus dietary protein is excreted in the urine and is a major source of nitrogen in our waterways. Feeding maize, a low protein silage, decreases the amount of nitrogen in cow urine by more than 70%3 .

The agricultural sector makes up half of New Zealand’s greenhouse gas emissions with methane emitted from livestock being the main contributor. A recent study4 showed that average annual greenhouse gas losses from maize silage followed by winter crop, which was harvested, not grazed, were around 1.9 tonnes of carbon dioxide equivalents per hectare (tCO2 e/ha). For systems where the winter crop was grazed, the greenhouse gas lifted to 3.5 tCO2 e/ha. These losses were substantially lower than the average loss from a typical dairy farm system which is estimated to be about 9.6 tCO2 e/ha. Current studies are underway to determine whether reducing stocking rate and growing supplements like maize silage on-farm, rather than feeding imported supplements, can improve the profitability and sustainability of future dairy farm systems.

But what about workload, are maize silage systems labour friendly?

Silage systems are not typically viewed as being labour friendly, but they can be if they are set up properly with well-designed feeding facilities located close to silage storage areas. Timed gate latches can be used to release cows from the paddock allowing them to make their own way to the shed and this can offer significant time savings especially early in the morning.

A large amount of maize silage can be fed out quickly and farmers often comment that feeding maize silage is easier and less risky than managing the intake of some grazed forage crops.

A stack of maize silage also delivers significant peace-of-mind. Whether you are a farm owner, sharemilker, or herd manager, it is easier to sleep at night knowing you can fully feed your cows regardless of the weather conditions or how well the pasture grows. 

Do you need a feedpad to feed maize silage?

As Ian Williams often says in his Dairy News column “it depends”. There are many farmers who successfully feed 300-500 kgDM maize silage per cow in the paddock during drier months or on free draining soils, with minimal wastage. If your farm has heavier soils and/or you want to feed maize silage during the wetter parts of the year, a stand-off pad with feeding facilities could be a good investment. The benefits of being able to stand cows off pasture and feed them are signifcant to include:

• Less supplement wastage. While they are hard to quantify, the losses of paddock fed supplements are likely to be 10-20% higher than if the same supplement was fed in a feed bin.
• Less pasture damage. One of the biggest advantages of a stand-off pad with feeding facilities is that animals can be kept off pasture for extended periods reducing overgrazing and pugging. Everybody knows that it “takes grass to grow grass”. If you can keep average pasture cover levels above 2,000 kgDM/ha you will grow more drymatter. Pugging not only wastes feed, it reduces long term pasture yields and persistance.
• Less milk fever. Feeding high potassium pasture in the late dry period increases the risk of milk fever. Many farmers have been able to improve the health of their herds by limiting their access to pasture and feeding low potassium supplements like maize silage.
• Better animal welfare. In-shed feeding systems provide a convenient way to feed relatively small volumes of concentrates during the milking season. Their main limitations are that they cannot be used to fill major feed deficits caused by extreme weather events and they are less suitable for dry cows and youngstock. In contrast a feedpad can be used to feed forages (like pasture or maize silage) or a mix of forages and concentrates (including soyhulls or palm kernel). They can be used to feed milkers, dry cows or youngstock and the feeding rate can be as little or as much as you want.

The Pioneer Feedpad Calculator can help determine whether building a feedpad is an economic option for you. Visit Growing and harvesting cost calculator - Pioneer.