Shifting Consumer Preferences in Dairy: The Higher Demand for High-Protein Milk in the GLP-1 Era

Author: Valentina Mayorga and Inge Heinzl, EW Nutrition

Today, the dairy market is undergoing a remarkable transformation. Demand is no longer focused solely on volume or fat content, but rather on a specific component: protein. But why is protein suddenly at the center of consumer attention? Recent estimates indicate that approximately one in eight adults (12%) in the United States is currently using a GLP-1 medication such as Ozempic or Wegovy for weight loss or chronic disease management (Lacsamana, 2025). By significantly reducing appetite and overall caloric intake, these medications may increase the risk of muscle mass loss in the absence of adequate nutritional planning, particularly when protein intake is insufficient.

Humans and animals compete for high-protein products

For this reason, consumers are increasingly seeking high-quality protein sources, particularly those rich in whey protein, known for its high biological value and rapid digestibility. However, this shift in consumer demand also creates a new challenge for the feed industry. Whey protein, traditionally used by feed mills as a highly digestible ingredient for young animals, is increasingly being diverted to human nutrition markets, creating direct competition for this valuable protein source. Either way, dairy consumption is growing, but not uniformly across all categories. The increase is concentrated in products with lower fat content and higher protein density, such as cottage cheese, premium Greek yogurt, and whey-protein-enriched milk beverages. The protein market is accelerating, and in an industry that rewards adaptation, standing still is simply another way of moving backward.

Increase milk protein with higher energy intake

Milk protein synthesis is primarily driven by energy intake, particularly fermentable energy. When cows consume more metabolizable energy (ME), rumen microbial activity increases, leading to greater microbial protein synthesis. Since microbial protein represents the main source of metabolizable amino acids absorbed in the small intestine, improving rumen efficiency directly supports higher milk protein production. Research has shown that increasing concentrate intake is associated with increases in milk protein concentration, with a response of approximately +0.06 percentage units per additional 10 MJ of ME intake per day. This response occurs because higher energy intake increases dry matter intake, improves nitrogen utilization, enhances microbial growth, and ultimately increases the supply of metabolizable protein to the mammary gland. Importantly, the source of energy matters. Energy derived from fermentable carbohydrates, particularly starch and sugars, is far more effective at stimulating microbial protein synthesis than energy derived from fat.

Starch plays a crucial role

Among fermentable carbohydrates, starch plays a central role in increasing milk protein concentration. When starch in the diet increases, rumen fermentation produces more propionate. Propionate is absorbed and converted in the liver into glucose through gluconeogenesis. Glucose is essential for lactose synthesis in the mammary gland, and lactose regulates milk volume through osmotic pressure. At the same time, improved energy status enhances microbial protein synthesis, increasing the availability of amino acids for casein production. This makes increasing dietary starch one of the most influential nutritional strategies for enhancing milk protein concentration.

Replacing grass silage with forages higher in starch and sugars, such as maize silage or fodder beet, can increase total energy intake, milk yield, and milk protein concentration. However, starch must be carefully balanced with adequate fiber. Excessively low fiber levels can reduce rumen pH, leading to acidosis, decreased feed intake, milk fat depression, and compromised animal health. Therefore, the objective is not simply high starch inclusion but rather high fermentable energy within a stable rumen environment, supported by sufficient physically effective fiber.

Effective protein strategies coordinate the supply of fermentable energy and degradable protein

Feeding more crude protein alone does not increase milk protein concentration. If degradable protein exceeds the availability of fermentable energy, excess nitrogen is converted into urea, reducing nitrogen efficiency and increasing milk urea nitrogen (MUN) without improving milk protein yield. Instead, effective protein strategies involve synchronizing rumen-degradable protein (RDP) with fermentable carbohydrates to maximize microbial growth, while also providing adequate rumen-undegradable protein (RUP) to supply metabolizable amino acids directly to the intestine. Precision supplementation of limiting amino acids, particularly methionine between 2.4-2.5% and lysine between 7.2-7.5% of metabolizable protein (MP), ensures a crucial 3:1 ratio, supporting casein synthesis in the mammary gland and improving true milk protein yield.

Feeding is one thing, genetics is another

Higher protein production is possible…up to a certain degree

High-starch diets often increase milk protein while potentially lowering milk fat percentage. This occurs because increased propionate production is associated with reduced acetate formation, and acetate is the primary precursor for milk fat synthesis. For consumers seeking dairy products with higher protein and lower fat content (particularly individuals aiming to preserve muscle mass while reducing caloric intake), this shift in milk composition may align with emerging market demands. However, excessive starch without adequate fiber can negatively impact rumen health, emphasizing the importance of nutritional balance.

References

Chamberlain, A. T., and J. M. Wilkinson. Feeding the dairy cow. Mountwood House: Chalcombe Publications, 2011.

Hunt, Andrew. “The GLP-1 Gold Rush: Why Dairy Protein Is Pharma’s New Best Friend.” The Bullvine | The Dairy Information You Want To Know When You Need It, August 12, 2025. https://www.thebullvine.com/news/the-glp-1-gold-rush-why-dairy-protein-is-pharmas-new-best-friend/

Lacsamana, Rain. “Poll: 1 in 8 Adults Say They Are Currently Taking a GLP-1 Drug for Weight Loss, Diabetes or Another Condition, Even as Half Say the Drugs Are Difficult to Afford.” KFF, November 14, 2025. https://www.kff.org/public-opinion/poll-1-in-8-adults-say-they-are-currently-taking-a-glp-1-drug-for-weight-loss-diabetes-or-another-condition-even-as-half-say-the-drugs-are-difficult-to-afford/