Type of indicator

Qualitative

Relative dimension and aggregated criteria

Environmental sustainability: Herd management practices: Unproductive cattle

Description

This indicator refers to an LCA midpoint impact category. The LCA midpoint method explores environmental impacts at an early stage of natural biochemical processes in the cause-effect chain. In this case, it evaluates the direct impact of excess N and phosphorus (P) inputs on water quality. This measure is given in kg of phosphate (PO4-3) equivalent (eq) per Functional Unit (i.e., quantitative amount that represents the function delivered by the system). In this study, the selected functional unit is 1kg of fat-protein-corrected milk (FPCM). Please refer to Guinée et al. (2002) for the detailed method.

Indicator calculation

𝐸𝑃 = (∑ 𝑒𝑖 ∗ 𝐶𝐹𝑖 ) / FPCM

Where:

ei= the emission of substance i and

CFi = associated characterization factor

𝐹𝑃𝐶𝑀 = Total FPCM produced in kg, calculated by the following equation (International Dairy Federation, 2015):
𝐹𝑃𝐶𝑀=𝑇𝑜𝑡𝑎𝑙 𝑚𝑖𝑙𝑘 𝑝𝑟𝑜𝑑𝑢𝑐𝑒𝑑∗𝑀𝑖𝑙𝑘 𝑑𝑒𝑛𝑠𝑖𝑡𝑦∗(0.1226∗𝐹𝑎𝑡%+0.0776∗𝑃𝑟𝑜𝑡𝑒𝑖𝑛%+0.2534)
𝑇𝑜𝑡𝑎𝑙 𝑚𝑖𝑙𝑘 𝑝𝑟𝑜𝑑𝑢𝑐𝑒𝑑 = Total milk produced in L
𝑀𝑖𝑙𝑘 𝑑𝑒𝑛𝑠𝑖𝑡𝑦= = 1.032 kg/L
𝐹𝑎𝑡% = Fat content of the milk produced in %
𝑃𝑟𝑜𝑡𝑒𝑖𝑛% = Protein content of the milk produced in %

Unit

Kg PO4-3 eq / kg FPCM

Indicator interpretation

Higher values indicate larger negative impacts on the environment.

Scale definition

Reference values Scales Dexi

interpretation

 References
0.0027 kg PO4-3

/kg               (New

Zealand) Average of 3 scenarios

 < 0.003 Low + (Basset-Mens                 et                   al., 2009)
0.0061 kg PO4-3

/kg                     in

conventional (Sweden)

 [0.003;

0.005]

 Medium    to low (Cederberg and Mattsson, 2000)
0.0066 kg PO4-3

/kg    in     organic (Sweden)

 [0.005;

0.007]

 Medium    to High
0.011 kg PO4-3 /kg in         conventional

(Netherlands)

 > 0.007 High – (Thomassen                         et                 al., 2008b)
0.007 kg PO4-3 /kg in              organic

(Netherlands)

 (Thomassen                         et                 al., 2008b)

Check with other LCA studies covering a good diversity of system:

(Brizga et al., 2021) : from 0.0019-0.0039 kg PO43- /kg

From 0.0029-0.0075 kg P eq/kg (CML eutrophication) in dairy system (De Vries and de Boer, 2010)

References

Emission calculation: Koch, P., Salou, T., 2016.