Amazing Maize!

Maize – What is it really worth?

Maize is becoming an ever more common crop, grown across all types of sites. As dairy businesses grow and farms specialise, maize is fast becoming the crop of choice to grow on contract, sell on or the best way of utilising extra ground and for good reason.

With huge advancements in seed breeding, the crop can be established on most sites and indeed good yields can be achieved from April through to October, fitting well within a crop rotation. The reliance on home grown forage has never been as important as it is now, to drive milk, maximise output per hectare and utilise high value land as much as possible.

With such high fresh weight yields, the crop’s insatiable appetite for manure and for the ease of crop management, maize is the best option on many farms.

For £500/ac or £30/t and you can have as much as you desire with farmers willing to grow it, and dairymen glad of the extra forage to increase production over fixed costs. Everyone is a winner.

Well, until you get a season like 2015, of course.

It is unfavourable growing seasons like we have just had that changes things. Suddenly, the reliable, easy to grow crop, becomes less and less viable. But what went wrong? Complacency? After some of the best growing years for decades, did growers got carried away with the where maize can be grown, remember, maize has only been viable to grow under UK conditions for 30 years.

The importance of seedbed preparation and correct agronomy cannot be understated. Doing an average job would be fine in a year like 2014, but 2015 was different. Why? Sunlight. Maize is the sunshine crop after all, and if the sun doesn’t shine, maize won’t mature. Sunlight levels in a couple of months, have a huge influence on crop viability, crucially in July and August, sunlight levels and heat units have a huge influence on crop viability, plant maturity and starch yield.

Many farmers however, grew brilliant crops, with average or good yields, providing an economic feed for milk production over the next year. So it can be done, year after year.

Was 2015 an exception? A one off?

Sunlight Hours Shawbury
Figure 1: Hours of sunlight per month in Shropshire from April to October, from 2009 to 2015. Source: Met Office

As the graph below shows, there is a large variation year on year in sunlight levels and 2015 was one of the worst. None the less, maize management must be robust enough to grow a viable crop in a poor year, but utilise the advantages of a good year.

The graph below is only over a 7 year period, in which crop growing technology and breeding has changed little. As the graph shows, these challenging years, or indeed very good years, are not 1 in 10 occurrences, they are one in every three or four years.

Many fresh weight yields I have heard anecdotally are similar to other years. Many have sampled up to standard, but many have not. There is a large variation in maize samples and there are obvious factors like altitude and location for some, but even within a small graphical area there has been a huge range in feed value of maize.

From a nutritional point of view, these sub-standard samples present challenges like acidotic conditions, poorer cow performance and lower dry matter intakes (See ‘Rationing poor quality maize’ by Stuart Miles for more info on this topic).

But very dry, high starch maize samples have lower starch degradability, are more susceptible to moulds and can be high in indigestible fibre. There is a significant cost saving to be made by growing optimal maize compared to sub optimal maize. Sub optimal samples are hard to justify, they are unlikely to cost significantly less to grow, but their value differs immensely.

What is the value in that difference? Is what you lose in starch and dry matter yield, made up in fresh weight?

Wynnstay Maize Samples
Figure 2: Starch and Dry Matter (DM) values for samples taken by Wynnstay for 2015 maize crops

Is the extra investment in a power harrow pass, a more expensive variety or even growing under plastic worth the cost?

With such low wheat prices, is it viable to invest to get more energy from maize crops?

It all comes down to value. We need to look at the value of the feed produced first, not the cost of production. This then puts into perspective the investment in production costs.

The nature of maize starch means it is a superior form of starch when compared to wheat. Being both slower to degrade with more bypass starch available, it means acid loading is far less.

The amount of Metabolisable Energy (ME) in the feed is equally as significant, as plant stem and leaves contribute significantly to whole plant ME. Cobbs on sticks are for combining, not forage maize.

Palatability of maize is like no other forage and moving away from it will reduce forage intakes, especially if there is no longer a mix of forages fed. A well grown, mature crop of maize is one of the best, most cost effective feeds, but if quality is not up to scratch, then it soon becomes less viable to feed.

Below is a table looking at a selection of maize samples, all collected from the west midlands, grown on a range of soils, altitudes and with varying management practices (some under plastic).

All are being fed to dairy cows, intending to get the most amount of milk from their investment into the maize crop. By putting a value to buying in 1gram of starch, ME and protein in the best alternative – cracked maize for starch and ME, urea for protein, we can compare to a ‘typical’ 30%DM 30%starch 11.5ME, 8.3% crude protein (CP) maize.

When adding starch, ME will rise and when adding ME in the form of cracked maize, starch will rise, so a compromise figure has been used to avoid double counting.

Sample 1 2 3 4 5 6 7 8 9 Base
DM (g/KG) 287 259 327 260 355 271 232 425 293 300
ME (Mj/KgDM) 11.5 11.3 11.8 11.7 11 11.3 11.3 10.9 11.7 11.5
Starch (g/Kg) 244 217 309 318 328 255 264 364 315 300
Protein (g/Kg) 76 80 84 80 78 83 89 76 80 83
pH 4 3.8 3.9 3.8 4.1 3.9 3.8 4.4 3.9 3.9
NDF (g/Kg) 410 489 348 406 353 432 467 407 375 425
Shortfall in ME/ T 0 200 -300 -200 500 200 200 600 -200 0
Kg starch/T fresh 70 56 101 83 116 69 61 155 92 90
Financial diff/T fresh -£22.56 -£33.60 £9.67 £8.49 -£3.48 -£19.24 -£13.66 £2.82 £7.70 £0.00

Figure 3. A comparison of maize values from 9 samples taken autumn 2015. Based on prices-Cracked maize -£150/t, Urea-£400/T

This does not consider fresh weight yield, NDF levels, intake potential, acid loading, risk of moulds or crop production costs, but it highlights the nutrient value of maize.

Figure 3 shows the financial value of 1 tonne of maize in terms of its nutrients, can vary hugely. The best maize samples are with no extremes, but good all round levels of starch, ME and DM, with reasonable protein levels.

Based on the calculations, samples 3, 4 and 9 are the most valuable, being good in all areas. The two driest samples, 5 and 8, have the highest starch levels, but with ME of 11 and 10.9, overall value is reduced. Samples 1, 2, 6 and 7 are worth considerably less, with low DM and starch, with only average ME levels.

These calculations do not show the whole picture. There are many other factors to consider when assessing the value and efficiency of your maize production. But looking at the nutritional value and its worth purely as a feed, puts perspective on how important getting a quality maize feed is. Forage plays the most important role in every ruminant ration. We cannot isolate forages as different to any other feed, accepting variations, maize is a feed like any other.

How many farmers would accept such variation in bought in moist and concentrate feeds?

As margins are put under more pressure, land value increasing and availability of land becoming a real constraint to business growth, we must fully utilise the potential in forages. We must view forage production as feed production to produce a premium dairy feed, not just fill the pit for as little cost as possible.

Seasons vary, feed prices vary, but the demand for quality forages in dairy rations will remain constant.

Get it right, every time.

Written by Mark Price  – Dairy Specialist
Follow @m_priceo
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