A solitary scientist's decades-long search for answers to a pervasive problem in animal health.
Imagine a scientist spending 35 years, undeterred by personal tragedy, poring over thousands of research articles to solve one of animal agriculture's most persistent problems—metabolic diseases. This was the life of John Armstrong Mills, a man whose revolutionary ideas about animal nutrition remained largely hidden from the world during his lifetime. His unpublished work, preserved only on a 1.3 GB memory stick, challenges conventional wisdom and offers a provocative perspective on why our livestock get sick 1 .
John Mills earned his degree in animal nutrition 1 .
Completed his Master's in range animal nutrition and a Doctor of Veterinary Medicine degree 1 .
A car accident confined him to a wheelchair for life, redirecting his career exclusively to research 1 .
Dedicated 35 years to research, living self-sufficiently in a Vancouver apartment 1 .
John Mills passed away, leaving behind his unpublished legacy 1 .
Mills developed a fundamental principle that guided all his research: "development of disease may be multifactorial, but cause is singular" 1 . He firmly believed that no specific disease has more than one cause, and only elimination of that specific cause would eradicate a disease 1 .
He defined metabolic disease as "an imbalance of rate of input of food nutrients to output of metabolites in the internal metabolism of the animal" 1 . This imbalance occurs despite genetics, nutrition, management and environmental requirements being thought to be provided at adequate levels 1 .
Mills theorized that while standard diets contained adequate nutrients for growth promotion and basic maintenance, they fell short for optimal physiological function 1 . He maintained that "growth pushed by artificial diets compromises subjects in their normal functions, especially at a young age" 1 .
Mills directly challenged the dosage recommendations provided by ARC/NRC (Agricultural Research Council/National Research Council) for animal feeds 1 . He interpreted their recommendations as being applicable to growth promotion but insufficient for meeting optimal requirements for physiological function 1 .
His calculations consistently indicated the need for higher dosages of his "Big Six" nutrients for poultry, horses, dogs, and pigs than what was officially recommended 1 . This position brought him into direct conflict with national regulations for commercial feeds and created significant barriers to testing and implementing his ideas.
While Mills' own experimental work remained limited, modern research provides insight into how his theories could be tested. A well-designed experiment to validate Mills' nutritional approach would require several key components 8 :
Despite his extensive theoretical work, Mills faced a significant challenge: he had no experimental or field data to support his theories 1 . He recognized this limitation and spent nearly 20 years relentlessly approaching large feed companies, hoping to find a partner that could help test his ideas 1 .
Unfortunately, Mills' search for cooperation was met with "refusal after refusal" 1 . His classmate noted that "he was not known for subtle communication skills," which may have hampered these efforts 1 . Without experimental validation, Mills' life work remained confined to electronic files rather than reaching scientific publication.
To test Mills' central premise, we might design a controlled experiment using the rabbit model of diet-induced metabolic syndrome, similar to approaches used in contemporary research 3 . The step-by-step procedure would include:
40 adult New Zealand White rabbits, divided into control and treatment groups
Control group: Standard diet meeting NRC recommendations. Treatment group: Standard diet supplemented with Mills' "Big Six" nutrients
28-week experimental period with careful monitoring
If Mills' theories were correct, we would anticipate significant differences in metabolic health outcomes between the control and treatment groups.
| Health Parameter | Control Group (NRC Standards) | Treatment Group (Mills' "Big Six") | Statistical Significance |
|---|---|---|---|
| Glucose Tolerance | Pre-diabetic pattern | Normal glucose clearance | P < 0.01 |
| Blood Pressure | Mild hypertension | Normal range | P < 0.05 |
| LDL Cholesterol | Elevated | Moderate levels | P < 0.01 |
| Triglycerides | High | Normal range | P < 0.05 |
Through his extensive research, Mills identified six crucial nutrients that he believed were consistently underprovided in conventional animal diets.
Essential for enzyme function, energy production, and muscle and nerve function.
MineralCrucial for fluid balance, nerve signals, and muscle contractions.
MineralImportant for vision, immune function, and reproduction.
VitaminPowerful antioxidant that supports immune function and collagen production.
VitaminAntioxidant that protects cell membranes from oxidative damage.
VitaminEssential for energy, cell structure, and hormone production.
LipidBased on his theories, Mills made specific claims about which diseases could be prevented through proper supplementation with his "Big Six" nutrients 1 :
He was particularly convinced of the role of appropriate nutrition not only for preventing metabolic diseases but also for its significant impact on animal welfare 1 .
While Mills' work remained unpublished during his lifetime, contemporary research has begun to validate the importance of the nutritional pathways he identified. Recent studies confirm that gut microbiome plays a pivotal role in nutrient metabolism, immune response, and overall wellbeing of animals 2 . The microbiome serves as a "theater of activity" where nutrients are processed and utilized, potentially explaining why Mills' focus on optimal rather than minimal nutrition was so crucial 2 .
Today, metabolic disorders in cattle continue to represent significant challenges, with conditions like ketosis, milk fever, and hepatic lipidosis causing substantial economic losses while compromising animal welfare . The transition period from late gestation to early lactation remains a critical window where nutritional interventions could have profound effects, exactly as Mills theorized .
Modern diagnostic companies now focus on developing precise tools for detecting metabolic disorders, emphasizing early identification of biomarkers that Mills intuitively understood were important 5 . The field has evolved to recognize that "early diagnosis and proactive management strategies are crucial to mitigating their impact on dairy cattle health and productivity" - a principle that aligns perfectly with Mills' preventive approach.
John Mills died in November 2012, leaving behind a vast repository of unpublished research 1 . His classmate, who helped share excerpts of this work, appropriately ended with two of Mills' favorite quotes that encapsulated his philosophical approach 1 :
"If you are a minority of one, the truth is still the truth" - Mahatma Gandhi
"A causative agent of a disease could be the absence of a factor or substance, rather than the presence of a causative agent" - Jack Mills
Though his theories challenged conventional wisdom and his communication style may have been direct, Mills' fundamental insight - that we must feed animals for optimal biological function rather than merely adequate growth - continues to resonate in nutritional science. His life's work stands as a testament to the power of sustained intellectual curiosity and serves as a reminder that important ideas sometimes emerge from unexpected places, developed in solitude rather than in research institutions.
As we continue to grapple with metabolic diseases in animal agriculture, Mills' unpublished legacy invites us to reconsider our fundamental assumptions about what constitutes proper nutrition and how we might better promote both animal health and welfare through more thoughtful dietary formulations.