Maize silage for effective dairy cow nutrition

Silage is preserved forage produced through fermentation under anaerobic (oxygen-free) conditions. Maize silage is produced by harvesting the entire maize plant at a specific growth stage using a silage harvester, finely chopping it, and storing it in airtight bunkers or silos. Here, lactic acid bacteria ferment plant sugars into organic acids, effectively preserving the forage while maintaining most of its nutritional value.

- By Pieter Brönn (Pr.Sci.Nat.), Feedtek

Maize silage is unique in that it provides energy (from starch in the grain) and digestible fibre (from the plant's leaves and stems). This combination supplies fermentable carbohydrates to rumen microbes, making maize silage a well-balanced roughage source for dairy cows.

Key considerations

Cultivar selection: High-quality silage starts with selecting a suitable maize cultivar. Choose high-yielding hybrids with proven silage performance, or those with a high starch content for greater energy value. Disease-resistant cultivars help minimise crop losses, while some varieties remain green for longer and maintain better leaf quality at maturity. For the best results, select cultivars that are well-adapted to the region's climate and growing conditions.

Optimal planting practices: Plant maize at the recommended density and row spacing suited to local soil type, moisture availability, and climate conditions, whether under dryland or irrigation systems.

Balanced fertilisation that includes especially nitrogen, phosphorus, and potassium is essential for achieving high biomass yields and quality. Regularly test soil pH and correct it before planting. Maize performs best in soils with a pH between 6 and 7,2 (pH water). A balanced pH boosts nutrient availability, particularly nitrogen, phosphorus, calcium, and magnesium, ensuring efficient uptake by plant roots.

Optimal harvest time: Harvest timing is the most critical decision in silage production. The ideal stage is when maize kernels are between the half and three- quarter milk line. A dry matter (DM) content of around 35% is ideal; the DM content should increase by roughly 0,5%/day. Harvesting too early leads to low starch levels and nutrient leaching, whereas harvesting too late causes poor compaction, slow fermentation, and reduced digestibility.