Achieving superior silage quality is imperative for maximizing the feed efficiency of your herd during the winter season. However, understanding the fundamental elements that contribute to the production of excellent silage and determining the ideal cutting date are crucial factors to consider.
The timing of cutting plays a significant role as the maturing seed head, characterized by its higher fiber content in the stem, can diminish the quality of the silage. To ensure the production of high-quality silage with a metabolizable energy (ME) of 11.5 MJ/kg dry matter (DM) or higher, it is recommended to cut the silage well before 50% ear emergence.
Assessing the level of ear emergence is essential in determining the appropriate cutting date. By thoroughly inspecting the silage swards and carefully examining a grass plant, it is possible to split the sheath and accurately determine the position of the seed head on the stem. This knowledge enables precise planning of the cutting schedule.
As a general guideline, early heading perennials typically reach 50% ear emergence around May 10th, while mid-season varieties achieve this stage around May 20th. Late heading varieties, on the other hand, typically exhibit 50% ear emergence in the initial days of June. It is important to note that these timelines are influenced by weather conditions and may vary by a few days.
Every week of delay in cutting after 50% ear emergence leads to a decline of 0.4 MJ/kg DM in silage ME. Consequently, to achieve the same daily milk yield, an additional 1.2 kg of concentrates would be required. Therefore, prompt action following the appropriate cutting date is essential to maintain optimal silage quality.
Weather conditions significantly impact the production of high-quality silage. Favorable weather, characterized by bright sunshine, enhances the sugar content of the grass, thus facilitating a superior fermentation process. Additionally, sunshine promotes rapid wilting, which reduces the moisture content of the ensiled grass. Ideally, the grass should be mowed when dry to avoid extended wilting periods, which can result in nutrient loss and a subpar fermentation process.
It is crucial to consider the impact of unused fertilizers or slurry nitrogen on the fermentation process, as they can adversely affect silage quality. Typically, grass absorbs approximately 2.5 kg of nitrogen per hectare per day (or 2 units per acre per day). However, this uptake is subject to weather conditions and may be reduced during periods of cold, wet, or cloudy weather when grass growth is less active. The presence of unused nitrogen diminishes the sugar content of the grass and increases the concentration of ammonia in the silage. If concerns arise regarding grass preservation, it is advisable to conduct a grass ensilability test to assess its quality.
The primary objective of silage production is to preserve grass effectively, minimizing losses, maintaining its nutritional value, and facilitating optimal intake. This process involves various crucial phases that must be carefully executed:
Harvesting: The target for ensiling grass is achieving a moisture content of 30% dry matter (DM). The most effective approach to reach this level is through rapid wilting, where the freshly cut grass is evenly spread across the entire field immediately after mowing.
Rapid wilting minimizes losses of sugars and proteins and, under ideal weather conditions, can be accomplished within approximately eight hours. It is important to note that at 30% DM, a short chop length is beneficial for optimal consolidation in the clamp. However, the chop length should not be less than 25 mm to ensure an adequate fiber content for rumination in the winter diet. In wetter crops, it may be necessary to consider longer chop lengths, closer to 20% DM.
Developing a wilting plan is crucial. Begin by assessing the initial DM of the standing crop. Depending on the circumstances, the moisture content of the grass can range from 14% DM for lush, early crops to 23% DM for maturing, lighter crops in exceptionally dry weather.
Under average conditions, the DM of a grass crop can increase by approximately 1.0% per hour during daylight hours. However, early, lush crops may struggle to reach the desired 30% DM within a single day. Implementing rowing, which involves forming windrows, can significantly reduce or halt wilting. If a crop begins to over-dry, it should be immediately rowed up. Care should be taken to ensure that the rake is set correctly during this process.
Setting the machinery at an appropriate height is crucial during harvesting. Machines that are set too low may pull up debris and dead material from the lower portion of the sward, resulting in a reduction in metabolizable energy (ME) and potential contamination. Conversely, setting rakes too high can lead to significant losses in the field.
If uncertainties persist regarding the initial DM, it is advisable to conduct a microwave drying test to accurately assess the DM content.
By meticulously implementing these strategies and maintaining precise control over harvesting and clamp management, silage production can be optimized, ensuring superior quality and nutritional value for effective winter feeding programs.
Efficiently filling the clamp is a critical step in the silage production process. It is essential to distribute the grass evenly in shallow layers and continuously roll it to eliminate oxygen and initiate the fermentation process.
Special attention should be given to the shoulders of the pit, as they pose the highest risk for potential losses as the compaction is often harder to get right here. To create an airtight environment, the pit must be sealed immediately with an Oxygen Barrier film, protected by a good quality Cover and it is recommended to secure the cover with the use of tires or mats to provide adequate weight.
The fermentation stage is pivotal, as it is during this phase that microorganisms present in the grass produce lactic acid. Lactic acid plays a crucial role in lowering the pH, facilitating silage production, and ensuring its stability.
Undesirable microorganisms can dominate the fermentation process if the pH does not drop rapidly. This occurrence is more likely when dealing with grass that has lower dry matter (DM) content and contains high levels of residual nitrogen. Additional factors that can contribute to this situation include soil contamination and insufficient sealing.
To promote effective silage fermentation, it is beneficial to utilize silage additives. These additives come in various forms, such as bacterial inoculants, enzymes, acids, and sugar sources. They aid in enhancing the fermentation process by facilitating the production of lactic acid and promoting a favorable pH reduction.
However, it is important to emphasize that while silage additives can assist in achieving optimal fermentation, they should not be considered a substitute for sound silage-making techniques and proper management. Implementing best practices in all aspects of silage production remains paramount. The use of additives should be viewed as a supplementary measure to further improve an already well-executed silage production process.
By implementing meticulous clamp filling techniques and prioritizing an effective fermentation process, producers can elevate their silage production to achieve superior quality and nutritional value, ensuring the success of their feeding programs.