More milk.
Fewer cows.
A lighter footprint.
Dairy's environmental impact is best measured per unit of milk, not per cow. Here is why a more productive cow lowers that number, and what published research says rbST adds.
Every cow pays a fixed cost just to stay alive.
A cow needs feed to keep her body running whether she gives a little milk or a lot. Scientists call this her maintenance requirement.
The more milk she produces, the more thinly that fixed cost is spread. Each unit of milk then carries a smaller share of her feed, her manure and her methane. Researchers call this the dilution of maintenance, and it is the mechanism behind the efficiency gain when rbST is used.¹
Illustration, not to scale.
Source: Capper et al. 2008¹
U.S. dairy already did this once.
Because each cow produced more, making the same amount of milk in 2007 took far fewer resources than in 1944.
2007 compared with 1944, for the same amount of milk. Source: Capper et al. 2009²
Less of everything, per unit of milk.
Researchers modeled a U.S. cow giving 28.9 kg (about 64 lb) of milk a day, responding to rbST with 4.5 kg (about 10 lb) more. Per unit of milk, the supplemented cow needed less feed and produced less waste.¹
Source: Capper et al. 2008¹
What one million cows would change in a year.
The same study scaled the result up: one million cows supplemented with rbST for a year, compared with producing the same milk from unsupplemented cows.¹
Supplementing 1 million cows for a year cuts greenhouse-gas emissions by as much as taking about 400,000 family cars off the road, or planting about 300 million trees.¹
The same facts, as an advantage.
More milk from every cow
In a full-lactation trial, first-lactation cows on Posilac® produced ≈ 9.90 lb more milk a day than untreated cows, and older cows 12.47 lb more, averaged over a 238-day treatment period.³
The same milk from fewer cows
Fewer cows for the same milk means fewer replacement heifers to raise, fewer dry cows to feed and less land to grow their feed on.¹
Less feed per unit of milk
Modeled total feed per unit of milk falls by 8.1% with rbST.¹
Posilac® is for use in healthy lactating dairy cows according to its label. Read the Important Safety Information
How to read these numbers
The environmental figures on this page come from published models, calculated per unit of milk. They describe what the research predicts across a production system, not a guaranteed result on any one farm, where herd, feed and management decide the outcome. One author of the 2008 study, who also co-wrote the 2009 study, was then a Monsanto employee and its project manager for Posilac; another consulted for Monsanto outside this area. The journal published both disclosures.
For the wider debate, see our science hub:
References
- ¹ Capper, J.L., Castañeda-Gutiérrez, E., Cady, R.A. & Bauman, D.E. 2008. The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production. Proceedings of the National Academy of Sciences 105(28):9668-9673. Open source ↗
- ² Capper, J.L., Cady, R.A. & Bauman, D.E. 2009. The environmental impact of dairy production: 1944 compared with 2007. Journal of Animal Science 87(6):2160-2167. Open source ↗
- ³ De Morais, J.P.G. et al. 2017. Lactation performance of Holstein cows treated with 2 formulations of recombinant bovine somatotropin in a large commercial dairy herd in Brazil. Journal of Dairy Science 100(7):5945-5956. Open source ↗