Carbon footprint of China's livestock system - a case study of farm survey in Sichuan province, China

Characterizing and quantifying the carbon footprint (CF) of livestock production would offer insights into how livestock production contributes to climate change and help to establish potential greenhouse gas (GHG) mitigation options. In Sichuan, one of the largest provinces for livestock production in China, a questionnaire farm survey was performed in 2012. CFs of livestock and poultry production were quantified using a dataset encompassing 20 farms for egg production, 25 farms for milk production, 20 farms for chicken production, and 32 farms for pork production, including both household and aggregated farms. The results revealed that over both farm types, emissions from manure treatment accounted for 70% and 74% of the total CFs in egg and chicken production, respectively. On average, 39% of the total CF in milk production was contributed by enteric fermentation; meanwhile, emissions by fodder production contributed on average 75% to the total CF of pork production. In general, egg, milk, chicken and pork production in Sichuan were associated with CFs of 3.70, 1.01, 20.02 and 5.42 kg CO2-eq/kg production for household farms, and 3.46, 1.13, 7.86 and 4.29 kg CO2-eq/kg for aggregated farm, respectively. Statistically, egg, chicken and pork production on household farms was characterized by higher CFs than that on aggregated farms. This study highlights that aggregated farm management could be an efficient option to mitigate the GHG emission in China's livestock production.