The dairy industry was addressing global warming long before that was cool. We're producing 59% more milk with 64% fewer cows than in 1944. We use 77% less feed, 65% less water, 90% less land, produce 76% less manure and have a 63% smaller carbon footprint per gallon of milk produced than we did 66 years ago.
We did it by improving production efficiency, which encompasses all inputs and outputs of a production system. One part of that is feed efficiency, defined as pounds of milk produced per pound of dry matter consumed.
What influences feed efficiency (FE)?
- More digestible forages increase FE.
- Rumen acidosis reduces FE; a stable rumen environment promotes higher FE.
- Heat and cold stress use more energy and reduce FE.
- Feed additives, ionophores and buffers improve FE.
- BST improves FE.
- Cow comfort, walking distances and pen or pasture conditions.
- Days in milk, age and growth.
The numerator in the equation, milk production, has the biggest influence. The higher the production in most cases, the greater the FE. All the listed items affect milk production.
Optimizing feed intake results in more milk. That's what a properly balanced and mixed total mixed ration does—it optimizes the nutrients used for milk production.
Depending on age and stage of lactation, an FE of 1.4 to 1.8 is a good benchmark. First-lactation animals may be less efficient because they're still growing, and very fresh and late-lactation cows will have lower FEs.
Papers presented at the 2009 Cornell Nutrition Conference and 2010 Florida Ruminant Nutrition Conference do a great job of defending the dairy industry and dispelling the often quoted and highly inflated figures on the livestock industry's contribution to greenhouse gas emissions.
The U.N. Food and Agriculture Organization reports that livestock are responsible for 18% of global greenhouse gas emissions. But 48% of this is attributed to cutting down forests to grow feed. We don't do that here in the U.S. Our forestlands are actually increasing. The EPA's estimate for the U.S. in 2009 was that 3.4% (not 18%) of emissions were attributable to all livestock. That's not bad—and we're improving.
Efficiency of Dairy Production and its Carbon Footprint
Demystifying The Environmental Sustainability of Food Production