Environmental Impact Of Recombinant Bovine Somatotropin
The use of Recombinant Bovine Somatotropin (rbST) in the U.S. dairy herd would significantly reduce the carbon footprint of milk production, equivalent to removing 400,000 cars from the road or planting 300 million trees. The use of rbST would also likely result in a reduction in the number of dairy cows needed to meet future demand, as opposed to other systems.
The world’s population is anticipated to reach 9 billion people in the first half of the 21st century, and the amount of food required over the next 40 years will approximately equal the total amount of food produced throughout the history of humankind. Consequently, U.S. milk production will have to increase to 5.62 billion gallons by 2040 to meet U.S. Department of Agriculture dietary recommendations for three 8 oz. glasses of milk per person each day. According to this research, the most sustainable way to do that is to improve milk production per cow and assess the total population environmental impact per unit of milk produced.
Three models were used to predict the environmental impact of rbST: 1) Examining the impact of increased productive efficiency of individual cows in a herd 2) Examining industry-scale adoption of 1 million rbST-supplemented cows (15% of U.S. dairy herd) 3) Examining the environmental impact of future increases in U.S. milk supply required to meet projected population growth using conventional, conventional-plus-rbST, or organic production systems.
This research concluded that the increase of milk production efficiency using rbST results in a reduction in carbon footprint by:
- Diluting fixed maintenance feed requirements over more units of milk (i.e. less manure produced per unit of milk, so the amount of nitrogen and phosphorous that could potentially run off into waterways is reduced)
- Decreasing the energy needed from fossil fuels and electricity for crop and milk production
The total reduction in carbon footprint by using rbST in 1 million dairy cows would be equivalent to removing 400,000 family cars from the road or planting 300 million trees. In addition, researchers estimate that 8% fewer cows would be needed in an rbST-supplemented population to meet the dairy projection requirements, versus and organic system, which would require a 25% increase in cow population.
The research does not address the potential human health impacts that may result from consuming rBST-produced milk, nor does it directly address the welfare of dairy cows treated with rBST.