Virginia Tech’s School of Animal Sciences conducted a study to examine the relationship between the dairy and meat industries, human nutrition, and environmental impact. Previous research on the environmental impact of the global dairy industry often failed to consider its contribution to nutrition, focusing solely on milk weight or energy content. However, this study emphasized that removing livestock from US agriculture would only marginally improve GHG emissions while simultaneously reducing essential micronutrient supplies.
The objective of this research was to analyze the global contributions of fluid milk to human nutrient supplies and the environmental impacts of food production, specifically GHG emissions and water use. The researchers hypothesized that dairy cattle produce more nutrients than they consume as human-edible nutrient supply. Additionally, they expected milk to contain a unique nutrient profile, delivering high-quality vitamins and minerals with low energy content. It was predicted that milk production supplies in individual countries would strongly correlate with environmental impacts such as GHG emissions and water use.
To conduct this assessment, the researchers analyzed data collated by the United Nations and Food and Agriculture Organization, examining the environmental and nutritional contributions/impact of dairy on a global and continental scale, including North and South America, Europe, Africa, Asia, and Oceania. In terms of environmental impact, the study focused on the nutrient provision of milk, rather than weight or food energy as previous studies had done.
The results of the study demonstrated that milk provides sufficient calcium, phosphorus, riboflavin, B12, vitamin A, vitamin D, and choline to fulfill the needs of a significant portion of the global population. Milk also contributes more than 7% of the supplies of these essential nutrients. Analyses of the nutrient-to-calorie ratio revealed that milk is a concentrated source of many vital amino acids, riboflavin, phosphorus, and calcium. Notably, calcium was found to be inadequately consumed globally, despite agricultural systems supplying sufficient quantities of this micronutrient to meet nutritional requirements, except in Africa and Asia.
The study concluded that milk must be recognized as a primary source of calcium and other nutrients for human consumption due to its ability to provide concentrated nutrients, fulfill essential nutrient needs, and avoid excess energy consumption. Although the study did not establish a direct link between milk and water use, it was acknowledged that considerable water resources are necessary for milk production, representing an expected trade-off associated with food production.
The study also found a strong interconnectedness between meat and milk production. Reducing milk production to curb GHG emissions would lead to decreased nutrient supplies, including amino acids, vitamins, and minerals. Similar reductions would occur if meat production were limited. However, strategies such as animal diet manipulation and manure management have the potential to reduce emissions and enhance the utility of milk and ruminant products for human consumption.
In summary, this research underscores the importance of milk in the global agroecosystem. Despite the environmental trade-offs associated with its production, milk provides critical vitamins and minerals, particularly calcium. Global efforts to improve milk supplies and coordinate distribution among supply chains are vital for enhancing the availability of these essential nutrients in food systems worldwide.
Source:
Global contributions of milk to nutrient supplies and greenhouse gas emissions
R.R. White, C.B. Gleason
Published 29 March 2023
DOI: 10.3168/jds.2022-22508
