🌍 1. Climate Motivation

• Denmark aims for 70% GHG reduction by 2030 and climate-neutral dairy by 2050.
• Agriculture is a major emitter:
  • Methane = 35% of agri GHGs; 75% from cows 🐮.
  • Methane is 28× stronger than CO₂.
• Hence, researchers seek “lab milk”—a sustainable, cow-free alternative.

🥛 2. Dairy Alternatives Overview

Three main directions:

1. Plant-based drinks 🌾 (soy, oat, almond, etc.)
2. Precision fermentation 🧬 (microbes produce milk proteins)
3. Cell-based milk 🧫 (cultured mammary cells)
4. Hybrid products combining the above.

🌱 3. Plant-Based Drinks

Pros: Easy to make, climate-friendly. Cons: Nutritionally limited.

• Low in protein, missing essential amino acids, and vitamins/minerals.
• Example: MSc Nora Stachel-Braum tested 12 plant drinks vs. 2 cow milks.
• Soy, oat, rice, spelt, almond, pea, coconut tested.

Key results:

• Cow’s milk: rich in bioactives (EGF, IGF, TGF-β) stimulating or inhibiting cell growth.
• Spelt drink: phenolics, vitamin E, and fibers—stimulate cells.
• Soy drink: phytoestrogens and omega-3—inhibit growth.
• Oat drinks: effects depend on variety, processing, and dosage (hormesis).

Conclusion: Plant-based ≠ Milk nutritionally. Some act like soda (high sugar). Even Danish Veterinary & Food Administration says: “Not an alternative.”

⚗️ 4. Precision Fermentation

Microorganisms (usually yeast) are genetically modified to produce milk proteins like casein and whey.

Companies worldwide:

• 🇺🇸 Perfect Day, BetterLand, Tomorrow Farms, New Culture
• 🇮🇱 Remilk, Imagine Dairy
• 🇧🇪 Those Vegan Cowboys
• 🇩🇪 Formo
• 🇬🇧 BetterDairy
• 🇨🇱 NotCo

Perfect Day example:

• Uses engineered yeast 🧫
• Produces real milk proteins (casein & whey)
• Mixed with plant ingredients → lactose-free, allergen-free, long shelf life.

But: Milk isn’t just protein — it contains >2000 components: lipids, carbs, growth factors, vitamins, hormones, and immune compounds vital for infant and gut health. → Synthetic proteins ≠ complete milk.

🧬 5. Cell-Based Milk: “Milk Without Cows”

How can cells make milk?

Mammary Physiology

• Heifers reach puberty (9–11 mo, 250–280 kg), inseminated (13–16 mo), calve at ~2 yrs.
• Mammary gland grows under estrogen + growth hormone stimulation.
• Contains alveoli (milk-making sacs) lined with epithelial cells that secrete milk into ducts and cisterns.

Growth Factors

Key regulators: IGFs, EGF, FGFs, TGF-α/β, amphiregulin, PDGF, MDGI, etc. They coordinate cell proliferation and differentiation during lactation.

Milk Synthesis

Mammary cells use:

• Glucose → lactose
• Amino acids → proteins
• Acetate, fatty acids → milk fat
• Nutrients transported from blood into cells and secreted.

🧫 6. Culturing Milk-Producing Cells

Step 1: Isolate mammary cells from tissue or milk. Step 2: Grow and differentiate in vitro. Step 3: Induce secretion using lactogenic hormones (prolactin). Step 4: Harvest secreted milk proteins (“secretome”). Step 5: Analyze with proteomics.

• Tools: xCELLigence for real-time growth tracking, 3D culture matrices, and bioreactors.
• Fetal calf serum (FCS) often replaced by plant/yeast-based alternatives (pea, cotton, etc.).
• Milk-derived or milk-isolated cells can both produce secretomes!

🧪 7. Results from Cellular Milk Studies

• Secreted milk-like fluid contains ~56 proteins, including albumin, osteopontin, fibronectin, clusterin, etc.
• But total protein yield = 0.2 ng/cell, vs. real milk ≈ 0.5 ng/cell.
• Only ~1% of major milk proteins appear — most are minor secreted proteins. → Still far from real milk composition.

Single Cells vs. Organoids

• Mammary organoids (mini 3D glands) produce more complex secretions.
• Cultured in Matrigel or MammoCult, mimicking natural extracellular matrix.
• Visualized by X-ray tomography.

🌐 8. Global Cell-Based Milk Startups

• 🇺🇸 BioMilq – human milk
• 🇮🇱 Wilk – human & bovine
• 🇨🇦 Opalia – bovine
• 🇸🇬 TurtleTree Labs – human & bovine, precision-fermented lactoferrin
• 🇮🇳/🇺🇸 BrownFoods – bovine
• 🇦🇺 Me& – human
• 🇩🇪 Senara – bovine
• 🇫🇷 Numi – human Investments range $1M–80M+, most aiming for market within 5–7 years.

🔬 9. Challenges & Potentials

Challenges:

• Replace animal-derived FCS 🧫
• Create plant-based growth media 🌱
• Control growth, differentiation, and long-term viability
• Upscaling in bioreactors (e.g., hollow-fiber systems)
• Recreate complex milk composition

Potentials:

• Tailored “designer milks” for infants, elderly, or special diets
• Hypoallergenic or disease-targeted formulas
• Sustainable, ethical, and climate-friendly production
• Could even produce human milk substitutes for infant formula.

🧯 10. Bioreactors & Upscaling

• Hollow fiber bioreactors mimic capillary networks, providing nutrients & waste exchange.
• Used by TurtleTree Labs and FiberCell Systems.
• Goal: continuous milk secretion from cultured mammary cells.

📆 11. Cellular Agriculture Timeline

The presentation ends with a timeline of ongoing cellular milk projects, research teams (Stig Purup’s Cellular Milk Group, AU-FOOD), and their interdisciplinary collaboration between animal science, biotechnology, and food innovation.

🧠 Key Takeaway

Lab-grown milk aims to merge biology and sustainability:

• 🌱 Plant-based drinks = climate-friendly but nutritionally weak.
• 🧬 Precision fermentation = real proteins, incomplete milk.
• 🧫 Cell-based milk = biologically authentic but technically hard.

The future “milk” of 2030 might come not from cows, but from cultured cells, smart microbes, and innovative bioreactors — with scientists bridging biology and food tech to make it happen.