How can the energy supply of high-performing dairy cows be improved without placing additional strain on rumen function? Besides the amount of energy supplied, it is essential to consider how efficiently the nutrients in the ration are digested and utilised by the animal. Rumen-stable fats and functional additives such as lecithin and emulsifiers offer promising approaches.
High energy requirements during early lactation
Genetic selection has significantly increased the milk yield of dairy cows. However, feed intake has not increased to the same extent. Particularly during the first third of lactation, this can lead to a negative energy balance (NEB). Rumen-stable fats help increase the energy density of the ration without adversely affecting microbial digestion in the rumen. They are digested in the small intestine.
Fatty acids and metabolism
Not all fats have the same effect on metabolism. Palmitic acid (C16:0) and stearic acid (C18:0) are particularly relevant. Palmitic acid is primarily used for the synthesis of milk fat and body fat. Stearic acid can play an important role in energy metabolism, particularly around calving and during early lactation. The appropriate fatty acid composition depends, among other factors, on the stage of lactation and performance level.
What role does lecithin play?
Lecithin contains phospholipids, including phosphatidylcholine, which is involved in important processes of liver metabolism. Due to its fat-loving and water-loving properties, lecithin can also act as an emulsifier. BEWITAL agri has been using rapeseed lecithin in the spray cooling of hydrogenated vegetable fats for many years. This process produces finely structured, free-flowing and storage-stable fat powders.
Figure 1: Structure of the lecithin molecule.
Practical trial: +1.6 kg of energy-corrected milk
In a practical trial with a high-performing Holstein herd, rumen-stable fat powders without and with 8% rapeseed lecithin were compared. Under otherwise identical conditions, energy-corrected milk yield (ECM) increased from 39.6 to 41.2 kg per cow per day. Milk fat and milk protein content were also higher in the lecithin group.
The results demonstrate the benefit of the combination of rumen-stable fat and rapeseed lecithin investigated in this practical trial.
Table 1: Effect of adding rapeseed lecithin to rumen-protected fat in high-yielding cows.
Emulsifiers can support fat digestion
At very high feed intake levels, the retention time of feed in the digestive tract is reduced. This can limit fat digestion. Emulsifiers with a high HLB value can help support fat digestion. Scientific studies have shown positive effects on fat digestibility and milk fat production.
New at EuroTier 2026: BEWI®-SPRAY LeciBoost
BEWI®-SPRAY LeciBoost combines rumen-stable fat with natural rapeseed lecithin and an emulsifier with a high HLB value. The product range is designed to increase the energy density of rations for high-performing dairy cows. Variants based on hydrogenated palm oil or hydrogenated rapeseed oil of European origin are available.
DOWNLOAD THE FULL ARTICLE
All background information, scientific explanations, and figures can be found in the technical article “A New Approach to Rumen-Stable Fat – Interaction between Energy, Lecithin, and Emulsifiers” by Dr Michael Hovenjürgen.
Published in: FeedMagazine/Kraftfutter 9–10/2026
