Milk production from family agro-industries in São Paulo state: Carbon balance accounting

Abstract

Purpose The objective of this work was to evaluate the environmental profile of milk production from family agro-industries in the State of São Paulo Brazil, in order to characterize them and identify opportunities to reduce their environmental footprint. Given the complexity, variability in the form of calculations and the importance of carbon balance accounting, this article discusses only this impact category.

Methods The data used in this project were collected through visits to 14 dairy farms. The life cycle assessment tool was used considering the stages of production of feed and maintenance of the cattle, considering heifer, lactating and non-lactating cows, the milking process, and milk cooling. A model to estimate the emissions resulting from enteric fermentation from the composition of the feed given to the animals was used. The inclusion and exclusion of carbon capturated during photosynthesis, as well as the biophysical allocation of part of the impacts to livestock co-production, were considered.

Results and discussion The simple average carbon footprints of the 14 farms were 2408 and 2189 kg CO2 eq. per 1000 kg FPCM, without and with, respectively, biophysical allocation of inputs and emissions between milk and cattle. The step with the greatest contribution to these emissions is that of enteric fermentation, which represented 60% of greenhouse gas emissions. The amount of feed offered varied greatly from 1118 to 2484 kg of DM (dry matter)/1000 kg FPCM. For cattle obtained from this herd, the calculated impact of climate change was 15,117 kg CO2 eq. per 1000 kg live weight of animals, using the same methodological approach. The carbon capturated during the photosynthesis process occurred in the production of feed was 1677 kg CO2 eq. per 1000 kg FPCM for milk and 15,003 kg CO2 eq. per 1000 kg live weight of animals, values that represent 76% and 99% of the calculated carbon footprint.

Conclusions Production units that combine smaller amounts of feed offered (in dry mass) by the functional unit, with little dependence on its external acquisition and good milk yield, tend to generate more environmentally efficient units. The authors consider that the carbon balance, including carbon captured during photosynthesis, is of great importance and should be accounted for and disclosed together with traditional calculations. Recent studies show that agriculture, which is part of this chain, when carried out with good cultivation practices, can be one of the most efficient ways of stocking carbon.