Intensive dairy systems produce fewer emissions

Targeted attacks on large-scale intensive dairy systems for their contribution to greenhouse gas emissions are unfounded, according to farm business consultant, Graeme Surtees speaking at the 2010 British Cattle Breeders Conference, Telford.

“A recent study showed higher-yielding cows delivered a lower carbon footprint for each litre of milk than low yielders.” For example, a cow producing 5000 litres a year creates a total of 434kg carbon equivalent/litre compared with 290kg/litre for a cow producing 9000 litres a year.

And Cadbury recently stated the key to reducing the carbon footprint of milk was improving herd health and welfare to produce more milk and optimising yields by feeding a diet with less fibre and higher starch levels.

“In fact the diets associated with large scale intensive dairying produce less methane than less intensive pasture bases diets.”

Intensive feedlot systems in Wisconsin produce an average 1.38kg of carbon a litre compared with 1.62kg of carbon on New Zealand extensive grazing systems.

“Typically intensive feedlot dairies make good use of by-products such as brewers’ grains which would usually end up as land fill waste if they weren’t fed to livestock.”

The scale of operation also allows more efficient milking, cooling, feeding, milk collection and manure management.

In fact, through increased yields and scale, the dairy industry has made significant improvements to greenhouse gas emissions unconsciously, ahead of its time.

“In 1944 the US dairy industry was pasture-focused, used horse power and little or no fertiliser, suggesting it would provide low carbon milk production. However, in reality the story is completely different.”

In 2008 the US cow population was 64% smaller than in 1944, but milk production had increased by 62% and yield by 347%. “As a result, the carbon produced for each 1kg of milk had reduced by 64% from 6kg/kg milk to 2.2kg/kg milk.”

This means that producing 1m litres of milk today requires 59% less carbon. “Carbon footprint for each cow may be greater but, critically, not a litre.”