Could forage maize feed value be slipping through your fingers?
13 September 2016
With harvest just around the corner, a new survey suggests that while forage maize is an important silage, not all farmers are doing everything possible to preserve its feed value.
A massive 98% of farmers growing forage maize feel it is either extremely important (66% of respondents) or very important (32%) to maximise the amount of milk produced from forage, versus from bought-in feeds.
Moreover, 84% rate maize silage as either extremely important (50%) or very important (34%) in helping achieve to this.
Yet more than half of growers may be underestimating the scale of dry matter losses in maize silage. And many are not using all available methods to control their main challenge of aerobic spoilage.
Those were the key findings of a new survey of around 70 UK dairy farmers growing forage maize, just completed on behalf of Ecosyl.
In particular, despite 87% of respondents saying it will be either extremely or very important to preserve and maximise the number of tonnes of dry matter of their maize silage this season, most respondents (54%) underestimated the typical loss in dry matter tonnes that occurs in maize once in the clamp.
“Clearly, maize silage was viewed as a very important forage,” says Ecosyl silage microbiologist, Philip Jones. “But there was a clear underestimation of clamp dry matter losses. We know that typically these can be 20-30%, but fewer than a fifth of respondents (18%) put them in this sort of region. Most put them at between 0 - 20%, and nearly another fifth (19%) said they didn't know.
“With the importance of maximising milk from home-produced forage, understanding the scale of losses in maize is the first step to doing something about them.
To put losses into perspective, for a 1,000 tonne clamp of 30% DM maize silage, a loss of 20% is equivalent to losing over £6,500 if you assume a dry matter value of £110/t for maize silage.
"Few dairy farmers could afford to ignore that. In vulnerable parts of the clamp, such as the top and shoulders, dry matter losses can be as high as 50%.”
Back on the survey, when asked about the biggest challenge faced when preserving maize silage, over two thirds of respondents (71%) said preventing aerobic spoilage.
“This makes sense, because a high energy, higher dry matter silage such as maize is particularly prone to aerobic spoilage, caused by yeasts and moulds in the presence of air and characterised by heating”, Mr Jones notes.
However, while farmers had a pretty good understanding of the problems caused by aerobic spoilage – with more than two thirds (69%) saying losses in feed quality, and nearly two thirds (65%) saying risk of mycotoxins – once again, only around half of respondents (54%) recognised that it also leads to loss of dry matter tonnes, he points out.
“There seemed to be a real issue of whether maize growers were fully associating aerobic spoilage with loss of dry matter. In addition, you could argue that although around two thirds recognised that loss of feed quality is a problem of aerobic spoilage, there were still around a third who did not.
“Indeed, although some methods for tackling aerobic spoilage were used quite extensively by survey respondents, others were used to a much lesser extent.
“For example, although 75% said they used tight sealing to minimise aerobic spoilage and 60% said they used good consolidation, that still suggested a fair proportion weren’t fully utilising these methods. And we know that minimising air penetration into the clamp is crucial.
“Allied to this, only around a third used techniques such as fast filling (32%) or filling in thin layers (35%) – both of which are important ways of keeping air out.
“Similarly at feedout, methods such as using a block cutter or shear grab to keep the face tidy, and avoiding leaving the silage sheet over the face – to avoid conditions that encourage mould growth – are both important. As too is moving the face back quickly, since air can penetrate a metre beyond the face.
“Yet only 54% were using a block cutter or shear grab to keep the face tidy, with fewer than a third (28%) keeping the sheet off the silage face, and fewer than a third (31%) moving the face back quickly.
“These are all details but combating aerobic spoilage requires attention to detail in all areas,” he stresses.
Linked to this, Mr Jones says around half of survey respondents (54%) included use of an additive within their strategy to minimise maize aerobic spoilage.
Key reasons given for using an additive in maize included to reduce aerobic spoilage (61% of respondents), to better preserve feed quality / nutritional value (54%) and to aid fermentation (49%).
Once again, however, only a third (34%) said they used an additive to minimise loss of dry matter tonnes, Mr Jones notes.
It’s important to remember that dry matter losses can occur both during fermentation and as a result of aerobic spoilage. Although it’s true that the biggest dry matter losses are likely to come from aerobic spoilage, it’s still important to tackle both areas, and using an additive can help with both in a number of ways.
“For example, an additive containing a proven strain of Lactobacillus plantarum which brings about a more efficient initial fermentation, has been shown to almost halve fermentation dry matter losses.
“This can be combined in a product that also contains another beneficial bacterium which inhibits the activities of the yeasts and moulds that cause aerobic spoilage. We launched a new product, Ecocool, last year for precisely this reason. As another alternative, you can use one that combines Lactobacillus plantarum with a chemical preservative to tackle aerobic spoilage.
“Whichever you use, it’s important to understand the different types of additives so you can choose one appropriate to your silage and how it is fed.
“By combining good clamp management with a proven additive you can delay the onset of heating and have less extensive heating, less physical waste, less risk of mycotoxins, and higher energy feed.
“Indeed, when asked about preserving maize silage this season, 97% of respondents in the survey rated it as either extremely or very important to preserve and maximise its energy content,” Mr Jones concludes.
Forage Maize Studies by Ecosyl
Source: Ecosyl survey of UK dairy farmers growing forage maize
Source: Ecosyl survey of UK dairy farmers growing forage maize