People have been enjoying dairy foods for millennia but scientists are only just now discovering that cows can give more than a vital source of nutrition. They could also be “eco-warriors”, according to some scientists from the USA (1).
Cows produce methane, a powerful greenhouse gas that contributes to climate change. But this downside may be outweighed by the benefits we may gain from the bovine.
The authors have reviewed the links between people, dairy, and the environment. According to them, dairy production has come on in leaps and bounds in recent decades, increasing milk yield while shrinking its environmental footprint.
Continuing these improvements in dairy production has a key role to play in a sustainable future. That’s especially so as our planet will soon to be inhabited by over 9 billion people, putting growing pressure on the environment and the capacity to feed the world.
Step in the cows. Ruminants can digest certain plant foods that people can’t and this can partly explain why dairy products can be part of sustainable diets. The cow helpfully converts plant fibre into calories we can readily use, in a form that most of us enjoy.
‘The ability of the ruminant to digest plant fiber makes them one of the green energy innovations available to humanity. ’ – Nguyen BT, et al, 2022
Keeping dairy cows healthy
Much of the gain in dairy production efficiency has been down to the improvement in how we look after our animals, say the authors. In the United States, today’s dairy cows are healthy and in an overall state of well-being thanks to the efforts of farmers, including :
- Providing cows with high-quality feed, water, air, light, rest, and space
- Keeping cows spick and span – improved hygiene
- Reducing use of antimicrobials in dairy farming, meaning better milk quality and food safety
- Giving cows a clean home with comfortable stalls and bedding,
Disinfecting teats before and after milking, better milking equipment and improved treatment have helped to reduce the risk of cows suffering from mastitis – infection and inflammation of the udder that’s both painful and impacts on milk yield and quality. The past 20 years has seen a dramatic improvement in somatic cells counts, a marker of udder health.
‘Dairy has and continues to make continuous improvements in animal care, environmental impact, and nutrition while contributing to strong communities across the US and the globe.’ – Nguyen BT, et al, 2022
Dairy farming should become more “eco-friendly”
The dairy industry produces about 2% of all total US greenhouse gas emissions (GHGE) (2). According to the authors, higher productivity – how efficiently the cow convert its food into milk – has meant that each serving of dairy that ends up on our plate has a smaller environmental footprint. More milk is being produced from fewer cows and fewer dairy farms, say the authors. And between 2007 and 2017 improved dairy efficiency in the USA has led to a:
- 19% fall in GHGE (3)
- 21% reduction in land footprint
- 17% reduced requirements for feed
- 30% less water used per gallon of milk
Cows also have a knack of being able to digest waste by-products from our own foods and commodities – including almonds, soy oil, sugar, and even cotton and to use them as energy to produce milk. If instead such by-products were put in landfill, they would cause a 50-fold increase in GHGE compared with ruminant digestion, the authors have calculated (1).
Dairy products are contributor to people’s health
Dairy is unmatched among food ingredients for its provision of nutrients and vitamins, say the authors. For example, today’s dairy industry in the USA provides enough milk to meet annual energy needs for 26%, protein requirements for 51%, and calcium requirements for 77% of the US population. It also provides 39% of the vitamin A, 47% of the riboflavin, 57% of the vitamin B12, and 29% of the choline available for human consumption in the USA.
Around the world, dairy is important for providing nutrition to the large swathes of the population who are undernourished, including children, the authors point out.
And dairy products are well known for playing a key role in healthy growth and development and preventing broken bones in young and old. Evidence also points to dairy having a protective effect against several common long-term diseases such as cardiovascular disease. More recently studies of obesity, eating habits, and satiety have suggested that full-fat milk can reduce cravings and help in weight management (4).
As well as an important source of nutrition, the dairy industry continues to provide a livelihood for millions of people. In the USA alone, dairy farms and associated industry employ more than double the number of Amazon employees in the world, the authors say (5,6).