Maize silage is proven

Extensive research and development programmes have resulted in increased maize yields, improved pest and disease resistance and a reduction in the time from planting to harvest. There has been more worldwide research into growing, harvesting, storing and feeding maize for silage than there has been for any other crop or supplement.

Local research (conducted at both the Waimate West Demonstration Farm in Taranaki and the Resource Efficient Dairying (RED) Trial in the Waikato) has helped farmers understand the principles behind the successful integration of maize silage into New Zealand pasture-based dairy farm systems.

As the following data shows, the Waimate West Trial, feeding maize silage in the autumn to keep the herd milking (rather than drying them off) gave an exceptional milksolids response of 179 gMS/kgDM maize silage fed. Feeding maize silage in the spring to support earlier calving and increased lactation length gave a milksolids response of 157 gMS/kgDM maize silage fed.

In the RED Trial, maize silage was used to support an increased stocking rate, lifting pasture harvested and milksolids per hectare.

Maize silage has also been proven on a large number of top New Zealand commercial dairy farms. For example, in the period 2001-2005, in those areas where maize can be grown (i.e. north of Dunedin), 19 of the 23 (83%) regional winners in the Fonterra Westpac Dairy Excellence Awards were using maize silage.

 Maize silage is profitable

A paper presented at the 2006 Dairy3 Conference identified five principal pasture-based dairy farm systems in the Waikato region and described key factors for high performance and financial returns for each system at a $4.00/kgMS payout. Note that these were best-practice farm systems with a high pasture yield (19 tDM/ha) and were feeding economically priced supplements.

As Table 3 shows, System 5 farms were the most profitable because they milked more cows per hectare, produced more milk, grew and harvested more pasture and had a higher milk response to feed. They also had longer lactation lengths and better labour efficiency (more milksolids per person).

 Maize silage allows farmers to reduce feed costs

Many New Zealand farmers can grow crops of maize silage that yield 18-26 tDM/ha for 15 - 21 c/kgDM (in the stack). No other New Zealand crop can deliver the same amount of harvestable high quality feed at such a low cost.

Recent DairyNZ research has shown the best yielding pasture paddocks on a dairy farm produce double the annual drymatter yield of the worst paddocks⁴. This pasture yield variation is due to a number of factors, including soil fertility, drainage and weed pressure as well as pasture species. The on-farm cost per kgDM of maize silage is the lowest when a high-yielding maize crop is grown in a paddock that was not producing much pasture. For this to occur, any weed, drainage or fertility issues that were impacting pasture yields must be addressed prior to maize establishment.

Growing maize silage on-farm allows farmers the opportunity to conduct contour and drainage work, incorporate capital dressing of fertiliser and get rid of hard-to-kill weeds. It is an excellent part of a pasture renewal programme and produces large amounts of low cost, quality feed. While many farmers are growing at least a proportion of their maize silage requirement themselves, a significant portion are also buying in maize silage.

Although it will often cost a little more, bought in maize silage has a number of advantages including convenience and the ability to bring in more feed than could be grown on the milking platform. Buying in maize silage also brings nutrients onto the milking platform. In fact there is a fertiliser value of up to 3 c/kgDM associated with every kgDM of bought in maize silage.

The cost per unit of energy of even bought in maize silage is lower than many other commonly available forages (including baleage, hay and straw) and concentrates (including meal and molasses).

 Maize silage allows farmers to harvest more pasture

One of the key reasons maize silage systems are profitable is that they allow farmers to lift stocking rates and maximise pasture harvested. With a stack of maize silage on hand to fill feed deficits, farmers can confidently milk more cows per hectare increasing grazing pressure. This makes it easier to maintain pasture quality throughout the season and pasture drymatter and energy yields are increased.

In many dairy systems pasture management is a compromise between what is best for the pasture and for the cows. Because it is a forage, maize silage can be used as a tool to constantly keep pasture in its most efficient growth phase.

How does this work? When supplements are fed to cows grazing pasture, the animals will eat the supplement and reduce the amount of pasture they eat. This is called substitution, because the supplement is substituted for the pasture. The extent to which substitution occurs varies depending on a number of factors including the stage of lactation, the amount of pasture being fed and the type of supplement that is fed. Concentrates (e.g. grain, molasses, tapioca, palm kernel extract) have lower substitution rates than forages (e.g. maize silage, pasture silage or hay).

Every farmer knows it takes grass to grow grass. In periods when pasture growth rates are low compared to cow demand, maize silage intake can be lifted, increasing pasture substitution, boosting pasture cover levels and encouraging faster regrowth. When pasture growth is higher than cow demand, maize silage feeding can be reduced allowing greater grazing pressure.

The use of a feed pad that doubles as a stand off pad to feed maize silage reduces the significant loss of pasture growth potential associated with pugging. Feed pads also reduce maize silage wastage and effluent can be captured and applied to pasture or crops providing a valuable source of nutrients.

 Maize silage allows farmers to harvest more dry matter

On-farm
On many farms, pasture yield appears to have reached a plateau. Maize allows farmers to maximise the return from their high value dairy land by harvesting more drymatter from every hectare. A replicated, two-year forage production trial conducted in the Waikato showed maize silage followed by a winter crop could produce an annual drymatter yield of over 38 tDM/ha (Figure 1). Even on farms harvesting more than 15 tDM/ha of pasture each year, planting 20% of the farm area in maize silage can lift the overall farm drymatter yield by more than 15%.

Figure 1: Total annual drymatter yields for maize and a range of winter crop options (two-year average data)⁵

Run-off
Many dairy farm run-offs are not farmed to their full potential. In a paper presented at Dairy3 in 2007, Scott Ridsdale (DairyNZ) provided an example (Table 4) which showed a partially cropped run-off could harvest 86% more drymatter than a traditional run-off. The partially cropped run-off provided an 83% higher return on assets for the farmer that owned it.

Dedicated cropping area
A dedicated cropping area, either on-farm or a run-off, not only increases drymatter yields, it also provides an excellent sink for dairy shed and feed pad effluent. In fact, recent research has shown maize crops grown in paddocks with a history of dairy effluent application may not require any additional fertiliser⁷ although it is still recommended that a soil test is taken.

 Maize silage reduces the risk associated with feed shortages

The weather has a huge impact on the quantity and quality of pasture grown. Adverse weather events (such as drought, flood and record snowfalls) negatively impact milk production levels, cow reproductive performance and farm profitability.

Of all mankind’s cultivated crops, the hybrid maize plant is the most efficient converter of sunlight, water and nutrients into economically valuable plant drymatter. Modern maize hybrids have excellent yield stability allowing them to produce consistently high yields even under challenging growing conditions. Maize as a plant, has had a greater investment in its plant breeding and development over the past fifty years than all other crops in history combined. Having a stack of maize silage on-hand allows dairy farmers to weatherproof their feed supply, giving stable production, improved reproduction and greater peace of mind.

Maize silage that is well-covered and sealed will maintain its quality for several seasons, providing quality feed when pasture growth rates are low.

* The price of bought in maize silage varies between regions and seasons. For up-to-date information on the price of bought in maize silage, contact your local maize silage supplier.

 Maize silage is an excellent cow conditioner

Many New Zealand cows are dried off early because their body condition is too low. Reduced body condition score (CS) at calving affects milk production, as well as reproduction and animal health.

DairyNZ information shows a cow calving at CS 4.0 will take 8-10 days longer to start cycling than if she calved at CS 5.0. This will result in a later calving date and up to 15-20 kgMS less the following lactation.

Starch-based feeds such as maize grain or silage are readily converted to bodyweight gain. Feeding maize silage in the autumn is a cost-effective way of increasing cow condition while, at the same time, extending lactation and lifting pasture cover levels.

 Maize silage is simple and easy to use

Recently, there has been increasing attention paid to helping farmers achieve their lifestyle goals. Well-managed farm systems use maize silage and the latest technology to simplify management and reduce workload.

Batt-Latch automatic gate release timers release the cows from the paddock and they make their own way to the feed pad prior to milking. This saves significant time that is usually spent getting the cows in each morning and afternoon. Large amounts of maize silage are fed quickly into feed bins. The use of Pioneer^® brand 11C33 maize silage aerobic stability inoculant means the feed bins can even be filled the day before.

Maize silage is highly palatable and, because its energy comes from a combination of starch and digestible fibre, it is safe to feed.

 Maize silage is the perfect partner for pasture

No single feed can meet the changing nutrient requirements of high-producing dairy cows. For most of the year, New Zealand pastures have high levels of crude protein but carbohydrate levels are below cow requirements. Maize silage is the perfect partner for pasture because it is a high carbohydrate, lower protein feed.

Maize starch delivers an excellent source of rumen-available carbohydrates which allows the rumen microbes to convert more of the pasture protein into milk, increasing rumen efficiency and decreasing the amount of nitrogen excreted by the cow (Table 6).

*Based on 1 tDM/cow.

 Growing and feeding maize silage is positive for the environment

There has been much publicity in recent years about the effects of dairy intensification on the environment.

While some imported by-products have a significant adverse environmental impact on the countries that produce them, maize silage is an environmentally sustainable, locally produced crop which reduces some of the environmental concerns associated with the intensification of dairying. Maize silage dilutes cow nitrogen outputs (Table 6) and increases the efficiency of nitrogen and water uptake and usage.

Because maize is a highly efficient, rapidly growing C4 plant, its extensive rooting system allows it to capture nitrogen and water at depths two to three times greater than most C3 grasses such as ryegrass (Table 7). This means maize can utilise both nitrogen and water that has fallen out of the root-zone of pasture. In addition, maize is more than twice as responsive as pasture to both nitrogen and water.

The superior water use efficiency of maize over pasture species is an important consideration over summer, especially as the cost to pump water rises and there is increasing pressure on New Zealand’s water resources for irrigation, power generation and recreation.

When fed out on a feed pad that doubles as a stand-off pad, maize silage can reduce the emissions of nitrous oxide, a powerful greenhouse gas.

Maize silage is the perfect partner for pasture, it is a proven, reliable feed that delivers increased production, profit and environmental benefits as well as lifestyle choices.

To find out more information on how commercial dairy farms are successfully using Pioneer^® brand maize silage read the farm profiles here.

• ¹Deane, T. 1999. The profitable use of supplementary feeds in pasture based systems. Proceedings of the Ruakura Farmers Conference 51:64-77.
• ²Glassey, C.; Clark, D. 2008. Milksolids Production Per Ha ≠ Profit Per Ha, DairyNZ, Hamilton.
• ³Hedley, P.; Kolver, E.; Glassey, C.; Thorrold, B.; van Bysterveldt, A.; Roche, J.; Macdonald, K. 2006. Achieving farm performance from a range of farm systems. Proceedings of the 4th Dairy3 Conference 4:147.
• ⁴Romera, A.; Clark C.E.F.; Clark, D.A. Paddock to paddock pasture yield variation on dairy farms in the Waikato region of New Zealand. XXI International Grasslands Congress. Hohhot, China. 272.
• ⁵Densley, R. J.; Austin, G. M.; Williams, I. D.; Tsimba, R.; Edmeades, G. O. 2006. Maize silage and winter crop options to maximise drymatter and energy for NZ dairy systems. Proceedings of the New Zealand Grassland Association 68:193-197.
• ⁶Ridsdale, S. 2007. Are you getting the best out of your run-off? Proceedings of the 5th Dairy3 Conference 5:177.
• ⁷FAR 2008.
• ⁸Ledgard, S. 2006. Nitrogen management - Why is it important and what can we do about it? Proceedings of the 2006 Dairy3 Conference 4:23-31.
• ⁹Neal, J. S.; Greenwood K. L.; de Ruiter J. M.; Martin R. J. 2007. Water use efficiency, productivity and profitability - How do forages compare? p. 240-255. In: Proc. Australasian Dairy Science Symposium. p 240-255.