From Simple Start to Nutritional Science
Over 100 years of research transforming how we raise dairy calves
For over a hundred years, the Journal of Dairy Science has been the leading source for research on raising dairy calves, tracking our journey from basic observations to sophisticated nutritional science. This century-long evolution has fundamentally transformed how we care for calves, turning what was once a simple task into a complex science that recognizes the profound impact of early-life nutrition on an animal's entire productive life 1 2 . From understanding the vital role of colostrum to unraveling the mysteries of rumen development and epigenetics, the journey of calf research is a story of continuous refinement and discovery.
The science of calf rearing has undergone dramatic shifts, driven by research that has continually challenged and refined best practices.
The first calf research paper, published in the May 1919 issue of Journal of Dairy Science, was a simple study on factors affecting a calf's birth weight 1 6 . In these early days, experiments were often observational, used very few calves, and lacked the statistical analysis we consider essential today 1 . Despite these limitations, this period established fundamental concepts in digestion, rumen development, and milk replacer formulation 1 . A key driver of early research was the practical goal of conserving milk by developing effective early weaning strategies 1 .
This period marked a surge in calf research, with nearly 150 papers published on a wide array of topics 1 . It became the "golden era of calf rumen development studies," which spurred parallel investigations into calf starter rations and ingredients 1 . The use of antibiotic growth promoters in calf diets was first evaluated during the 1950s 1 . This era also saw a major shift towards the metric system and a growing emphasis on developing management systems that balanced calf growth and health with reduced labor and feed costs 1 .
From 1977 to 1996, more than 400 calf-related articles were published 1 . The growing research interest led to the first call for standardized procedures for conducting and reporting calf experiment data, improving the quality and reliability of studies 1 . A major area of focus was colostrum, with over 60 research articles published on its quality, feeding methods, and preservation 1 . The overarching goal of most research during this time was determining how to successfully wean healthy, well-grown calves at an early age, typically under 30 days 1 .
Number of calf-related articles published in Journal of Dairy Science over time 1
While the historical context shows broad progress, it is the detailed, rigorous experiments that have truly advanced the field. A landmark study exemplifies this modern approach, meticulously examining how the protein content in milk replacer affects a calf's growth and body composition.
This study was designed to pinpoint the exact relationship between dietary protein and growth in pre-weaned calves 5 . The researchers took several meticulous steps to ensure accurate results.
| Dietary Crude Protein (%) | Average Daily Gain (kg/d) | Gain:Feed Ratio | Retained Nitrogen (g/d) |
|---|---|---|---|
| 16.1 | 0.38 | 0.51 | 7.6 |
| 18.5 | 0.45 | 0.59 | 9.0 |
| 22.9 | 0.56 | 0.71 | 13.2 |
| 25.8 | 0.62 | 0.78 | 15.6 |
| Dietary Crude Protein (%) | Water (%) | Protein (%) | Fat (%) |
|---|---|---|---|
| 16.1 | 68.2 | 19.6 | 7.2 |
| 18.5 | 69.1 | 20.0 | 6.2 |
| 22.9 | 70.2 | 20.0 | 5.5 |
| 25.8 | 70.5 | 20.2 | 5.2 |
Base diet for experiments; macronutrient content (protein, fat) is manipulated to test specific hypotheses 5 .
A high-quality, highly digestible protein source commonly used in milk replacer formulations for nutritional studies 5 .
The first milk; research focuses on its quality, immunoglobulin concentration, feeding timing, and preservation 1 .
A dry feed used to stimulate rumen development; studies evaluate ingredients, palatability, and nutrient composition 1 .
Today's calf researchers and farmers have access to tools and knowledge that were unimaginable a century ago.
Nutrition models, like the Calf Toolkit, allow for precise evaluation of calf performance under different conditions. These tools, based on National Research Council requirements, can estimate growth, feed efficiency, and nutrient needs, accounting for variables like environmental temperature, which is critical for cold-weather feeding plans 3 . More sophisticated models are continually being developed to better predict the forage intake and growth of suckling calves, further refining nutritional strategies 7 .
The most recent 20-year period has seen an explosion of research, with over 580 articles published in the Journal of Dairy Science alone 1 . A revolutionary new area is the study of how the maternal environment and nutrition affect the long-term health, growth, and future milk production of the calf 1 6 . From a mechanistic standpoint, the field of epigenetics is poised to explain these phenomena, revealing how early-life experiences can program an animal's biology for life 1 .
How early nutrition programs lifelong biology
Gut health and its impact on development
AI and sensors for individualized nutrition
The past century of research has transformed calf rearing from a matter of basic survival to a science of optimizing life-long potential. We have moved from observing a handful of calves to understanding the molecular underpinnings of development. The key takeaways are that early-life nutrition is not just about weight gain, but about building a healthy, productive animal through high-quality colostrum, strategic protein feeding, and managed rumen development. As we look to the future, the field promises even greater precision, guided by advanced modeling and a deeper understanding of the biological programming that begins the moment a calf is born.
From simple observations to sophisticated nutritional science, calf research continues to evolve, ensuring healthier animals and more sustainable dairy production.