A BBC documentary has examined the environmental impact of livestock farming and found poultry to be the most green meat, but recommended consumers cut back on their total meat consumption.
The 'Horizon' show, hosted by Dr Michael Mosley, first examined the impact of meat consumption on human health, before turning attention to the environmental consequences of producing livestock.
Dr Mosley's journey took him to America where pasture-raised beef was compared with the feed lot system that has become endemic in the country.
Following this, a visit was paid to Norfolk broiler farmer Nigel Joice to tour his site and a 58,000 bird shed. Dr Mosley said he was "surprised" at the lack of smell and how "settled and contented" the birds were.
Joice replied: "People expect them to be running up the walls, but it's part and parcel of our job to keep them in a calm and relaxed state."
He concluded that, in terms of environmental impact, poultry was the best protein.
The programme then asked a lifecycle expert, Dr Tara Garnett of Oxford University about the cost to the environment of rearing different types of livestock, when accounting for every energy input. Dr Garnett suggested poultry was "the greenest meat you can buy", and added that indoor-reared birds had a lower footprint than their free-range counterparts.
She did suggest, however, that the growth of livestock production was "inherently unsustainable" in its current form.
Ultimately, poultry meat lost out to mussels as the most efficient protein on the programme, the only input in their growth being the rope hung in the sea for three years for them to live on and the boat fuel required to fetch them.
Source: Poultry World