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Avoid using regional silage analysis results for nutrition decisions 

Avoid using regional silage analysis results for nutrition decisions 

Sizeable variability in first cut silage results across the UK means farmers are being urged to conduct their own silage analysis, rather than relying on regional averages, to guide effective nutrition decisions.  

Lientjie Colahan, forage technical support at Lallemand Animal Nutrition, explains the inconsistent silage quality, even at a local level, is a result of variable spring weather conditions.

She says: “Met Office reports show certain areas across the UK saw up to 170% of the average rainfall for spring which meant it was too wet for farmers to travel fields to fertilise. However, other areas within the same region were drier than average.

“We’ve seen this reflected in the huge range of dry matter (DM) results, which vary from as high as 44% on some farms to just 22% on others – sometimes even on neighbouring farms.  

“This equates to double the amount of material that can offer nutritional value to a cow, per kilogram of fresh silage.” 

These DM extremes affect the silage fermentation, negatively reducing nutrient retention, she notes, advising farmers to aim for 28-33% DM for optimal fermentation and metabolisable energy (ME) levels. 

“For example, a farmer in the Peak District following the Opticut silage system managed to catch the weather just right, and produce a high quality first cut with 31.4% dry matter (DM) and an ME of 11.5 MJ/kg DM, which will have a positive knock-on effect for livestock intakes. 

“However, if silage is too wet or too dry, as we’ve seen with a lot of first cut results, there will be a significant drop in silage quality overall.” 

When analysing forage, she explains wet silage may appear to have high metabolisable energy (ME), but can suffer from a limited intake capacity. 

“When the fresh forage has a low DM, the excess moisture will dilute lactic acid as it is produced by the bacteria. This means it takes longer for the forage to reach a desirable pH of 4.5 or lower, and more nutrients are lost during fermentation. 

“Low DM forages also run the risk of becoming over-acidified because the excess moisture allows microbes to remain highly active for longer. This will limit the inclusion of the silage and can affect palatability,” she says. 

If a forage analysis shows your silage is of low feed value, you can take action to get the most out of it.  

“Incorporating a proven rumen modifier into the ration, like the live yeast Levucell SC, will improve rumen function and increase fibre and overall diet digestion,” she explains.   

“This helps the cow to get more out of the ration, increasing milk yield from the same quantity of feed.” 

She concludes: “To take the right steps to achieve the optimum feeding regime for cattle, individual silage analysis is critical to understand forage quality. 

“If you rely on regional averages, you could be misled when making forage management decisions and end up with an energy shortfall in your feed. 

“It’s important to work closely with your nutritionist to formulate a ration that gets the most out of the nutrients you have available in the clamp.” 

Published Aug 7, 2024 | Updated Aug 11, 2024

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