Protein is one of the key elements determining milk prices. Yet its level is subject to high variations due to genetics and environmental factors. It is often difficult to maximise protein content in milk relying solely on the farm’s own resources. How can one increase the revenue derived from milk solids?
Protein in dairy milk is currently worth 6€/1000l. Therefore, increasing milk solids is an effective way to maximise the revenue derived from milk production.
What are the factors affecting milk protein levels?
Natural variations in milk protein content have several causes. One of the most important of the non-feed related factors behind variations is genetics.
Milk protein levels not only vary between different breeds but also between animals who belong to the same breed.
The overall milk yield of a herd also changes with the seasons. The longer daylight hours of summer result in increased milk production but a reduced protein level due to dilution.
Milk protein also fluctuates throughout lactation. Protein content drops sharply during the first weeks of lactation. Then its level stabilizes and gradually rises as milk production decreases.
Milk protein synthesis also depends on factors specific to animal metabolism, such as the amount of energy and protein ingested by a cow.
Dairy proteins are synthesised from amino acids derived from the digestion of microbial and by-pass proteins.
Milk synthesis takes place in the cow’s udder. To trigger this process, the cow must draw a considerable amount of energy from her reserves.
How to increase milk protein levels
Increasing the amount of energy sources and providing cows with additional protein are the main levers for increasing milk protein content.
- Energy supply
Dairy cows’ milk protein is impacted by limits in the supply of energy. In other words, when cows do not have enough energy, their milk has almost no protein.
Adding 1700 kcal /dairy cow/day to the usual recommendation allows for a 0.6 g increase in milk protein per kg. It is therefore advised to maximise forage utilisation as these make up a high source of energy for cows.
In addition, the use of concentrates based on quick starch triggers the release of propionic acid (C3) contributing to increasing the overall milk protein level.
Degradable energy is also useful for helping the protein synthesis triggered by rumen bacteria. During digestion, these proteins end up being divided into amino acids that will later be used for milk protein synthesis.
- Supply of proteins in quantity and quality
The supply of protein resulting from protein synthesis is not sufficient to cover all the requirements of high-yield dairy cows. Adding by-pass proteins will increase the total amount of digestible proteins, thus meeting the cows’ requirements.
- Metdi /Lysdi ratio
Synthesis of milk proteins also depends on the profile of amino acids available for the udder. Methionine is often the first limiting amino acid with respect to protein content, particularly in diets or rations based on corn silage. One should also take account of the Metdi/Lysdi ratio in each of the raw materials making up the feed and aim for a Metdi / Lysdi ratio of 0.33.DLysDi and MetDi profile for various raw materials
Many other strategies, such as adhering to certain nutritional levels, or the use of customised raw materials, can also allow you to improve the protein content of your milk. Our experts are here to help you find out the most appropriate methods for your livestock. So do not hesitate to contact them.
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