This article explores the key issues associated with feeding dry maize silage to dairy cows and gives some ideas on how to work with dry silage.
The impact of dry silage:
1. Reduced palatability and intake: Dry maize silage is less palatable than properly fermented silage. As the dry matter (DM) content increases beyond 35-38%, cows may eat less due to the texture and lower moisture content. This reduced feed intake can lead to decreased energy availability and result in lower milk yields.
2. Poor fermentation and nutrient losses: Dry silage often undergoes poor fermentation. The lack of sufficient moisture inhibits the activity of beneficial silage bacteria. This results in less acid production and poor pH reduction. This weak fermentation not only compromises preservation but also increases the risk of mycotoxin development, which can harm cow health.
3. Increased risk of heating and spoilage: Dry maize silage is more prone to aerobic spoilage. Upon exposure to air during feed-out, dry silage heats up rapidly due to yeast and mold growth, leading to nutrient degradation. Heat-damaged silage loses valuable energy and protein, and cows may refuse to eat overheated, spoiled feed. We often see this when the face of the silage pit or bun is poorly managed.
4. Digestibility challenges: The starch in dry maize silage is often less available due to incomplete kernel processing. Fibre is often higher as the plant is generally more mature if cut late. This lowers the digestibility of the silage, resulting in less efficient rumen fermentation and reduced energy extraction.
5. Ration mixing and sorting issues: Cows may sort against the dry components, leading to imbalanced nutrient intake. This selective feeding disrupts rumen function and increases the risk of metabolic disorders such as subacute ruminal acidosis (SARA).
6. Handling and storage complications: Dry silage tends to have lower packing density, making it harder to exclude oxygen during ensiling. The more oxygen available, the higher the risk of spoilage and dry matter losses.
Key considerations before cutting silage to prevent dry maize silage issues
The following points should be considered before the silage crop is cut to minimize the issues associated with dry maize silage:
• Harvest at optimal moisture (30–35% DM) to promote good fermentation.
• Use effective kernel processing to enhance starch availability.
• Apply silage inoculants to improve fermentation in marginal conditions.
• Ensure proper packing and sealing to exclude oxygen.
The above measures are critical when making the silage, but sometimes dry silage is unavoidable. Once the
silage is made, there are still measures that can help reduce the negative aspects of the dry silage:
• Monitor face management at the silage bunker to minimize spoilage.
• Balance the ration with other forages or wet ingredients to adjust moisture and palatability.
Other raw materials on the farm or purchased can help improve the digestibility of the dry silage and can also help improve the rumen environment. Molasses is a readily fermentable sugar source that can significantly enhance digestion. Other products like yeast-based probiotics, prebiotics and other fibre-digesting enhancing products can be added to the diet. Mycotoxin binders can help reduce the negative effects toxins can have on animal health and support a healthy and high-producing dairy cow.
Conclusion
Maize silage is a valuable feed source; its value is heavily influenced by the moisture content at harvest and ensiling. Sometimes it cannot be helped or controlled, as farming has many challenges that are uncontrollable, such as the weather, and farmers are faced with the challenge of feeding dry maize silage. There are still some measures that can be taken, and they need to be considered seriously as the negative implications on cow health and performance can result in significant financial losses from lower production, higher cow health costs and lower fertility.
Make feeding dry maize silage easier, get practical tips and support from your local De Heus technical advisor to keep your cows healthy and productive. - https://www.deheus.co.za/meet-our-team/.
