Here’s one for you, just in case you weren’t confused enough about which foods you should eat. The diary industry is known for its use of recombinant bovine somatotropin (rbST), a protein hormone that boosts milk production. You may have noticed it on your pint of Ben & Jerry’s Cherry Garcia: “No significant difference has been shown between milk derived from recombinant bovine growth hormone treated and non recombinant bovine growth hormone treated cows”. Its use is controversial, as are its potential human impacts. The product has one seller: Monsanto. It is banned in Canada, and parts of Europe and New Zealand. Several FDA scientists were pressured to leave or dismissed during the approval process in the United States. Monsanto sued an independent dairy over their use of a label that pledged not to use the hormone – and won (resulting in such labels mentioned above). Approximately 1/3 of the dairy cattle in the US are injected with rbST. Most recently, many grocers (including some big ones like Wal-Mart) have pledged not to sell rbST milk. Organic milk is the fatest growing sector in the organic food market.
So, here’s the rub. A recent paper in the Proceedings of the US National Academy of Sciences looked at the environmental inputs of dairy production with and without the use of rBST. Their results complicate your life. Cow’s methane-laden flatus is the source of ten percent of the global annual emissions of this greenhouse gas. From a diary farmer’s perspective, using rbST improved individual cow production, with reductions in nutrient input and waste output per unit of milk produced. From a industry perspective, rbST reduced feedstuff and water use, cropland area, N and P excretion, greenhouse gas emissions, and fossil fuel use compared with an equivalent milk production from unsupplemented cows. It’s a complicated world we live in.