Jul 02, 2021
Top tips - harvesting best practice
Jul 02, 2021
Getting harvest right can be the difference between a good and poor quality forage. In this chapter we discuss how to execute your maize, wholecrop or grass harvest to make the best quality and highly digestible forage as possible.
Considerations before harvest starts
- It’s important to think about the harvest workflow in advance. For example, when making grass silage there may be different people mowing, tedding, rowing-up and harvesting. Even when communications are good, it can be difficult to make sure all parts of the process are aligned and teams are working effectively and efficiently
- Farmers should consider who needs to be where and when, where the bottlenecks in workflows might be and how to work around them
- Line up your contractors well in advance and bring them into the planning process as early as possible to make sure you don’t miss out on crucial cutting times
- There’s often a compromise to make in order to harvest as much of the farm as possible at the optimum time for quality. Not all fields will reach the same quality level at the same time, farmers may need to be realistic and go with an average
Best practice for harvesting grass silage
There’s several important targets and timings to meet during harvesting itself.
- Stubble height should be 6-8cm. The field should still look slightly green, not brown
- Spreading/tedding should be done within the first two hours after cutting as optimum wilting occurs during this time
- Grass should be wilted until it reaches 30% dry matter (DM) content, which is the ideal target. At a dry matter above 28% it’s ok to harvest, however if it is below 28%, it’s better to leave it a little longer
- Grass should never be wilted for more than 24 hours as dry matter losses start to increase after that point as the protein is broken down and the grass continues to respire
Should I use an inoculant for grass silage?
Applying a crop and condition specific inoculant will help promote rapid fermentation and reduce aerobic spoilage at feedout. The enzymes in an inoculant will break bonds in the fibre bundles releasing sugars to fuel the fermentation process which can have a positive effect on fibre digestibility in the animal.
The Magniva range of grass silage inoculants have been specifically formulated for the various challenges that you may find. They contain a blend of specific patented bacteria and enzymes that have been proven to improve silage quality, palatability and reduce total dry matter losses of valuable crops.
Which inoculant do I need?
My grass has a high DM – 30% DM or more.
Use Magniva Platinum Grass Dry. High dry matter silage creates a higher risk of aerobic instability. Because you’re looking to retain the maximum amount of nutrients within the silage, then this inoculant is the best choice.
The weather isn’t great, what should I use to counteract this?
Use Magniva Platinum Grass Wet. It’s perfect for ensiling in challenging weather conditions or in crops that are known to be difficult to ensile, such as clover or lucerne.
- It has an acidifying effect that will be useful in this situation because the natural acid is diluted by the added water content.
- It acts to out compete the negative bacteria that like wet conditions and helps increase stability at feedout
- It can increase the sugar available for fermentation by breaking down chains of sugars found in fibre bundles, which is useful in situations where sunshine and photosynthesis has been limited
My crop has a low DM and is analysing at below 28%
Use Magniva Classic. It helps the crop ferment, minimising DM losses during fermentation.
Best practice for harvesting wholecrop forage
Wholecrop forage is an option well worth considering for dairy, beef and youngstock diets as it provides a highly digestible, fermentable starch energy source, reducing the need for energy to be brought in via purchased feeds.
Its high straw content can also help balance a highly digestible grass silage-based diet with physically effective fibre, providing valuable flexibility.
Wholecrop cereals can be harvested to suit your situation. The below table can help you to work out when to harvest your crop for specific feeding needs.
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Should I use an inoculant for wholecrop forage?
Why use a wholecrop specific inoculant
Like maize, using a crop specific inoculant is important as wholecrop has different ensiling challenges.
Choose an inoculant which also includes antifungal bacteria to inhibit yeast and mould during the fermentation process.
Our wholecrop silage inoculant, Magniva Platinum Wholecrop, provides a unique combination of:
- Antifungal bacteria L. hilgardii CNCM I-4785, L. buchneri NCIMB 40788
- Homofermentative bacteria called P. pentosaceus, designed to inhibit yeasts and moulds
Inoculants for crimped grains
Benefits of using a biological crimp-specific inoculant are:
- A crimp-specific inoculant delivers a higher dose of beneficial heterofermentative bacteria to make sure they dominate the wild bacteria that result in uncontrolled and inefficient fermentation
- The specific types of bacteria in Magniva Platinum Crimp (L. hilgardii CNCM I-4785 and L. buchneri NCIMB 40788) facilitate production of the important acetic and propionic acids, as well as lactic acid, leading to a much quicker heterofermentative process. This leads to an early reduction in spoilage organisms and nutrient loss, which is maintained through to feeding
- A biological solution for crimp preservation has a single application rate across the range of dry matters, unlike traditional acid treatments
- By treating crimp with a biological solution the harmful release of ammonia into the environment, which is seen in some urea-based preservatives, is avoided
Best practice for harvesting maize forage
Maize should be harvested at least 40 cm in height or above the second node of the plant. This is because nitrogen accumulates in the bottom third of the plant, and by harvesting this part there is an increased risk of ensiling problems and potential creation of silo gases.
The bottom third of the plant is also the most lignified, which is a type of fibre that cannot be broken down in the rumen. There is no benefit with cutting the crop lower as the lower you cut maize, the lower total energy you’ll have in your silage.
The lower parts of the plant are also contaminated with spoilage organisms from the soil which could damage the overall quality of the forage, increase fermentation losses and present a mycotoxin challenge when feeding.
Should I use an inoculant for maize forage?
Using a crop specific inoculant is important as each crop has different ensiling challenges.
Due to the plant’s high starch content, maize ferments more easily than grass. However, the natural bacteria present in maize is very variable meaning fermentation is less efficient without the use of an inoculant.
The biggest challenge when it comes to maize forage is aerobic stability. This is because the stem of the plant has a high amount of lignin, which gives the plant structural integrity, and the centre of the stem is very spongy.
Both factors make maize more difficult to compact, meaning there’s more potential for residual oxygen in the clamp, allowing yeast to stay active for longer during the start of the fermentation process. When the clamp is opened, oxygen will penetrate faster, re-activating the yeasts and leading to aerobic spoilage.
This is a big problem when the maize clamp is crossed slowly (buffer feeding situations or very large clamps). Only by using a stability enhancing inoculant will farmers be able to conserve the quality from the clamp to feedout.
Magniva Platinum Maize helps reduce DM losses, yeast and mould presence and lowers pH which all leads to an enhanced feedout value.