The terms tend to be interchangeable but as a general rule cereal silage relates to oats, wheat and barley, whereas wholecrop silage refers to triticale, a cross of wheat and rye. Cereal silage can be used as a generic term to describe all.
Compared with good-quality pasture silage, which tends to be high in protein and low in starch, cereal silage is the opposite, with high starch levels and low protein.
Good levels of protein are required in lactating ruminants. The energy content isn’t as high as pasture or maize (corn) silage either and for this reason it isn’t recommended as a valuable feed supplement to milking cows.
Despite this it is widely used in dairying systems, particularly on the shoulders of milking season, ie: just before drying off and during calving.
Not always, but often, it is ensiled with pasture to assist with better compacting of the silage stacks. The mix of cereal and pasture also balances out the protein levels – see Ensiling stacks up below.
The big benefit of growing cereal silage is it grows well in cooler climates not normally suited to growing maize. It also fits well as a reasonably quick-growing cash crop.
The accuracy of the test to measure metabolisable energy (ME) levels is questionable when used on cereal silage, or any feed other than pasture. Cereal silage is often stated around 9-10 MJ/kg drymatter DM but it could be significantly higher.
Recently retired pasture expert Dr Tom Fraser said all ME tests were calibrated for pasture and therefore if feeding cereal silage, or any feed, it was important to monitor animals to get a better gauge of feed value.
Under-sowing with permanent pasture is a reasonably common practice but it can be hit and miss.
Semi-retired farmer and consultant Keith Milne is a cereal silage pioneer in Southland and still has a share-farming interest in growing it. He said under-sowing grass with the likes of barley or oats did work but he could recall his own father saying you tended to get a really good grass paddock and a light cereal crop or vice-versa.
KEY POINTS
• Select cereal type to fit paddock rotation time frames and harvesting constraints
• Identify soil pH and nitrogen levels
• Avoid growing to sell on the spot market. Have a contract to buy-sell in place before sowing
• Pre-plan fungicide treatments and their withholding restrictions
• Good communication with buyer and harvesting contractor is vital, and
• Monitor, monitor, monitor.
If keen to under-sow with pasture, Milne suggests a slightly lower seeding rate of barley or oats, which means you get less yield but the grass makes up for this.
Although the grass will establish, the clover doesn’t like the shade so you would have to broadcast this on as soon as the crop is harvested.
Some would be good at it but at times it was difficult and for a really good pasture paddock you had to do it right, he said.
Southern dairy farmers John and Val Ellis like cereal silage and grew it themselves the first year, under-sown with permanent pasture, but they weren’t happy with how the pasture lasted. In hindsight they would have been best to regrass.
The experience also proved they were better off to buy the cereal silage in because otherwise the paddock was out of rotation too long for their dairying system.
From the second year onwards they had sheep farmers grow the crop for them and cut and carried.
Normally it would be fed out to cows on pasture late in autumn, then if any remained it would be given on the feed pad over calving in the spring. It would be mixed with grass silage if it was available and cows were milked off it.
The key message with sowing, growing and selling cereal silage is to leave nothing to chance. Cows did well on it as long as it was made and processed at the exact right time, Val Ellis said.
Select a cereal type to suit your system. Consultant Keith Milne said barley and oats could be cheaper to grow and oats could be grown without a lot of fungicide.
“Normally triticale, barley, and wheat would need one fungicide as a bare minimum.”
Cereal silage features high starch levels and low protein.
Barley did have a small harvesting window compared with other cereals.
Technical field officer with Farmlands(Central Southland), Allister Gibson, said barley seemed to be the most popular cereal type grown in his area. This was because it provided good yields in a short growing time.
Most of the barley Gibson sees grown for silage is planted at the end of October through to early November in paddocks that have run out or been used as sacrifice paddocks over winter or had winter crop in them.
Once the cereal is harvested, normally 110-120 days, these paddocks are then sown into young grass.
Milne is an advocate for triticale and has been growing it since early in the 1990s, using it for dairy heifers and also beef steers on a feed pad. He recommends barley, oats or triticale as good options and said wheat wasn’t as popular because it could be slightly harder to grow.
Cereals can be sown March to May in Southland if paddocks are available, but most is sown in spring when ground conditions are suitable. Barley doesn’t like cold damp conditions and can sulk, so can be sown later in spring unless the ground is free-draining.
Milne likes to sow his triticale in September but conditions will often push sowing into October. Ideal harvest time is usually March but at times it has been April.
Milne said specific chemicals had to be used on cereals and many had long withholding periods, so this needed to be planned for in advance.
He suggests spraying at the early ear emergence stage as a preventive because otherwise it can be too close to harvest.
“Disease can take the flag leaf off or severely affect the top leaves of the plants and these are the ones that feed the grain.”
Soil fertility is important because cereals like a high pH. Nitrogen may need to be applied, especially if the paddock has been in winter crop or the ground is wetter. Soil testing is recommended.
Barley doesn’t like cold damp conditions and can sulk, so can be sown later in spring unless the ground is free-draining.
Harvest timing is vital and Milne recommends using the Plant & Food Research harvest predictor model as a tool guide.
Many farmers noted ear emergence or flowering to give the contractor a rough idea of harvest date, he said.
“Contractors mostly understand it is critical. Some will even monitor [the crop]. Seed reps and consultants will help monitor it, too.”
Most of the cereal for silage grown by sheep and beef farmers in Southland is for the dairy industry and is either milled or sold under contract or verbal agreement. Having a contract or agreement in place before sowing is vital, although at times these have been known to fall over.
John Ellis likes to have a contract in place before sowing with a rough figure agreed on, which allows for market changes. Building a relationship with the grower is important to him and he also likes to be involved in monitoring the crop near harvesting, which he would rather see done slightly early than left too late.
Harvest timing also brings a lot of pressure and having a good relationship with the contractor is also important.
Tom Fraser said starch levels could sit about 20% kg DM but could be higher if left to mature because more grain was produced – but the digestibility of the straw/forage declined, which was a Catch 22 situation.
The driving force behind which cereal type to grow often came down to how harvesting would be done. Those with their own gear had more flexibility so could harvest in a tighter window, but for everyone else it came down to having a good relationship with the contractor.
Like hay and any silage, be it maize, pasture or cereal, the quality of it would depend on how it was cut and made.
Ensiling stacks up
When ensiling, consultant Keith Milne aims for a stack that is half to two-thirds cereal on the bottom, then pasture at one-third to half on top. The pasture is to help with compaction and he also recommends using inoculant.
Farmlands’ Allister Gibson is also an advocate for ensiling with pasture on top of the stack for compaction.
“Straw is the enemy.”
Although cattle showed preference for the cereal silage, they had to eat the grass silage to get at it, Milne said.
The pasture component also aided the balance of protein, particularly if the pasture had been boosted with nitrogen. Many dairy farmers were doing straight cereal silage and the low protein did not seem to be an issue.
