Energy requirements of dairy cows updated based on research data
During spring 2026, the energy requirements of dairy cows were updated based on a large data set with 960 observations collected from respiration chamber experiments. The meta-analysis revealed that the maintenance requirement of the cows was higher, but that for milk production lower than in the earlier requirements. The update increases the energy requirements of non-lactating cows.
Nutrient requirements of farm animals and feed values form the basis of feed ration formulations that fulfil the nutritional requirements of the animals in the most economically efficient way. Natural Resources Institute Finland (Luke) is responsible of the feed evaluation work in Finland based on a mandate from the Ministry of Agriculture and Forestry.
New ME requirement
The new requirement of metabolizable energy for maintenance is: 0.63 MJ/kg × live weight0.75kg; and for milk production: 5.0 MJ/kg energy corrected milk (ECM) × ECM, kg/day.
The higher maintenance energy requirement is likely caused by the increased proportion of metabolically active organs such as liver and the intestines with increasing level of milk production. In addition, the previous requirements were based on experiments conducted at fasting level of metabolism.
ME-intake discount refined
At the same time, the amounts of urine and methane energy were included in the ME intake discount equation. These losses decrease as the level of intake increase, so that the correction term decreased compared to the previous version. The new ME-intake correction equation is:
-34.5 + 4.94 × MEm + 1.59 × DM intake – 0.43 × CP + 0.0011 × CP² – 0.6 × DM intake,
where MEm (MJ/kg DM) is the diet’s uncorrected ME content at maintenance level, DM intake is expressed as kg DM/day, and CP is the crude protein content of the diet (g/kg DM).
The updated requirements provide a more accurate assessment of the energy needs of dairy cows and improve ration optimisation. From practical point of view, the updates mainly compensate for each other. However, it is important that both the energy requirements and energy intake calculation models are as correct as possible. This is particularly important in developing feed efficiency by animal breeding.
