Maize silage analysis reveals significant variation

After a dry summer in 2026, the first analyses of maize silage have reached livestock farms in the Greater West region. These analyses show wide variations in the nutritional profiles of the maize, which require farmers to recalculate feed rations before adjusting forage amounts and concentrate types. While the 8 samples analyzed do not represent the entire harvest in the region, they highlight the discrepancies that could affect winter feeding strategies.

Starch content varies widely in 2026 maize

The first notable finding is the variation in starch content, which ranges from 17.2% to 38.1% of dry matter, with an average of 26.1%. Five of the eight samples contain less than 22% starch, while three exceed 33%. This is significantly lower than the 33% average reported in the 2025 national balance sheet from Arvalis. Despite this, the average energy value remains similar, suggesting that starch reduction is not universal across the 2026 harvest.

Drought affects maize differently at various growth stages

The lack of water during the summer had varying effects depending on the stage of the maize plant. Drought around the flowering stage can limit pollination and lead to grain loss, while later drought affects grain filling. However, some early-stressed maize plants still provide digestible stalks and leaves, which can contribute to the overall energy content of the forage. This means that lower starch levels do not necessarily equate to lower nutritional value, as other components can compensate.

Fiber content and digestibility are key factors

Crude cellulose levels in the analyzed samples range from 17.2% to 25.7% of dry matter, with the five starch-poor samples showing the highest levels. This indicates a higher proportion of vegetative parts, which contain more fiber. However, the quantity of fiber is not the same as its digestibility. Laboratory results must be combined with observations of the forage, the ration being fed, and the animals' performance to fully understand how the ration functions.

Adjusting rations based on starch content

A daily ration of 12 kg of dry matter from a maize with 20% starch provides 2.4 kg of starch, compared to 4.2 kg from a maize with 35% starch. This difference of 1.8 kg of starch per cow per day must be considered in the overall ration, but it does not automatically mean that cereals should be added. Other forages, sugars, and existing concentrates must also be taken into account, along with the production goals of the farm.

Energy concentration and forage quantity matter

While the nutritional value per kilogram of dry matter may be high, a lower harvest quantity can still result in a significant energy deficit. For example, a 12-ton dry matter harvest per hectare at 0.96 UFL/kg provides 11,520 UFL per hectare, whereas a 7-ton harvest provides only 6,720 UFL, a nearly 42% decrease. A good analysis does not replace the need to assess total forage availability, and these findings emphasize the importance of measuring stocks, updating analyses, and ensuring proper feed intake for a balanced ration.