A 2019 Journal of Animal Science article entitled “The effects of improved performance in the U.S. dairy cattle industry on environmental impacts between 2007 and 2017” provides a picture of increased productivity with more efficient use of resources contributing to a reduced environmental impact over that time period. The researchers doing the study, Judith Capper, a livestock sustainability consultant from the United Kingdom and Roger Cady, of Agricultural Sustainability Specialties in Missouri, used extensive modeling and analysis to measure the increased efficiency of the dairy cow over this time period.
In a time when, in certain media and social circles, livestock production is viewed as being detrimental to the environment and inefficient in use of resources, this study provides some positive and impressive good news. Results indicate the resources required to produce one million metric tons of energy corrected milk (ECM) in 2017 were significantly reduced compared to 2007 production systems. Some of the key findings include:
- Producing this quantity of milk in 2017 required 25.2% fewer cows than in 2007
- Required 17.3% less feedstuffs
- Used 20.8% less land base
- Needed 30.5% less water to achieve this production
In addition to increased efficiency of the inputs required to produce milk, there were also reductions in waste products. The study found that the 2017 dairy cow made these production gains while reducing manure volume by 20.6%. As the dairy ration has become more finely tuned, thanks to the work of dairy nutritionists, the amount of nitrogen excreted in manure has been reduced by 17.5% and phosphorus by 14.3% when comparing 2017 to 2007. The authors of the article point out that with increased attention on water quality and ecosystem health, a research focus should be on investigating other mechanisms that would allow for further reductions in nutrient excretion, following the lead of the swine industry in this respect. The authors postulate that significant future gains can be achieved by focusing on dairy cattle manure management.
Another environmental parameter addressed in the article is green house gas (GHG) emissions. A 2013 report by the Food and Agricultural Organization (FAO) of the United Nations estimated that global livestock production accounted for 14.5% of GHG emissions, with the dairy production portion estimated at 2.9% of GHG emissions. Regarding US dairy production, the authors state that the GHG emissions per one million metric ton of ECM milk produced in 2017 were 80.8% of the equivalent milk production in 2007. In terms of actual milk production, the total US ECM milk production increased by 24.9% between 2007 and 2017, yet because of that increased efficiency, the total GHG emissions increased by only one percent.
For those interested in reading the entire journal article, I can provide a hard copy. Contact the Wayne County Extension office at 330-264-8722.
Rory Lewandowski is an OSU Extension Agriculture & Natural Resources Educator and may be reached at 330-264-8722.
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