By Laurens Devers, master student in Tropical Natural Resources Management of the Katholieke Universiteit Leuven, Belgium; Prof Theo Kleynhans, Department Agricultural Economics of the University of Stellenbosch and Prof E Mathijs, Head of the Division for Agricultural and Food Economics, Katholieke Universiteit Leuven, Belgium.
Given the growing awareness of the impact of intensive livestock production and the transportation of feed and meat in the local and global environments, the common life cycle assessment (LCA) method was used to compare environmental impact scenarios involving producing pork in the Western Cape, and exporting it to Antwerp in Flanders versus producing pork in Flanders for the Belgian market, and also delivering it to Antwerp. It was expected that the energy needed for heating pig houses in the Western Cape and for transporting the pork to the Flemish export market, together with the associated emissions, would be lower than the energy needed and resultant emissions to produce pork in the colder Flemish climate. If this could be proven, SAPPO could use this information to start developing an image of South African pork in the export markets as being produced in an environmentally friendly manner.
Life cycle assessment (LCA) is a methodology that takes into account all the environmental effects of the entire life cycle of a product: the extraction of raw materials, manufacturing, distribution, transportation, maintenance, recycling, emissions and final disposal. LCA emerged in the early 1970s to assess the material flows, energy efficiency, raw material consumption and to some extent the waste disposal of industrial companies. As LCA applications were often disappointing and led to false conclusions, ISO norms were set up to create some firm rules for its use. Life cycle thinking is currently one of the five key principles in the European Union’s Integrated Product Policy.
In order to take into account many different environmental impacts, the complete pig production chain (a cradle-to-gate life cycle) was covered by the LCAs done on the Western Cape and Flemish case studies, including (i) the feed provision activity, which included the production of raw materials and feed, (ii) the pig farming activity, (iii) the slaughter house activity and (iv) the slurry (treatment) activity. An additional (v) pork shipping activity was added in the case of the Western Cape pork chain.
The functional unit (FU) is the functional output of a product, to which the assessed environmental impacts are scaled (ISO 14040, 1997). The functional unit (FU) used in this study is defined as one kg of Western Cape or Flemish pork (carcass weight) delivered to a distribution centre in Antwerp. Carcass weight is chosen because the ratio of live weight to carcass weight differs between the two regions. The computer programme used in this study for calculating impacts was the GaBi 4 programme.
In Flanders, official confidentiality restrictions excluded access to the data of any particular pig farm. A model of a typical 223-sow unit was therefore constructed from data available in different databases and from coordinating institutes. As such databases do not exist in South Africa, a specific 700-sow unit as a fairly typical pig farm in the Western Cape was chosen as a case study. Both are closed piggeries where the piglets and weaners are raised as well as fattened.
The following environmental impact cate-gories were included in this study:
• Global warming potential (GWP): climate change
This reflects an increase in temperature due to emissions of greenhouse gasses (GHG) like carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The results are expressed in kg CO2 equivalents calculated over a time horison of 100 years.
• Eutrophication potential
The leaching, runoff, and volatilisation of increased concentrations of nitrates and phosphates into nearby ecosystems are generally the biggest contributors to eutrophication potential. The results are characterised in kg PO4 equivalents.
• Acidification potential
A sensitive (im-)balance between ecosystems’ internal and external H+ sources, and internal H+ sinks of different capacities and reaction rates is the main cause of acidification. The release of acidic gasses like SO2, NOX and NH3 has the most potential to react with water in the atmosphere and form acids like H2SO4 and HNO3. The results are expressed in kg SO2 equivalents.
• Energy use
Establishing the total energy use of the pork chain is a way of measuring its efficiency in using renewable and non-renewable power. The results are expressed in MJ equivalents.
Figure 1 shows total Global Warming Potential (GWP) values of 2.55 kg CO2-eq (FU)-1 for the Flemish pork chain and 4.5 kg CO2-eq (FU)-1 for the Western Cape chain (see Figure 4). The absolute difference in GWP between the Western Cape and Flanders is greatest for the feed provision activity (0.68 kg CO2-eq (FU)-1), second for the slaughterhouse activity (0.53 kg CO2-eq (FU)-1), third the pig farming activity (0.34 kg CO2-eq (FU)-1), fourth for the pig slurry treatment activity (0.23 kg CO2-eq (FU)-1) and last for the pork shipping activity (0.16 kg CO2-eq (FU)-1). Pork shipping only occurs from the Western Cape to Flanders.
In the Western Cape, more than 60 percent of pig feed is comprised of maize, while in Flanders, this ingredient represents only seven percent, with wheat and wheat co-products making up 50 percent of Flemish pig feed. In the case of the Western Cape, maize has to be transported some 1 200 km to the feed factory. Increasing the use of locally produced main feed ingredients can reduce impacts for all categories.
The main reason for the difference in GWP of the slaughterhouse activity lies in differences in diesel composition and the higher electricity use – 1.66 MJ (FU)-1 for the Western Cape compared with 0.28 MJ (FU)-1 for Flanders. This, added to the higher impact of electricity per MJ in the Western Cape due to the use of coal, gives a GWP ten times higher for the Western Cape than for Flanders. In addition, gas combustion plays a role in the higher GWP of the Western Cape slaughterhouse.
Electricity is also the key GWP determinant for the pig farming activity. Electricity used at pig farms in Western Cape is almost double that used in Flanders, the main reason for this difference being that in the Western Cape, the weaners are heated by heat bulbs. Central heating, more specifically floor heating, is used in Flanders.
The emissions caused by the slurry and the slurry treatment activity are more or less the same for the Western Cape and for Flanders. Factors influencing the GWP of this activity are (i) the feed conversion ratio (2.97 for Flanders and 3.45 for the Western Cape), (ii) the live weight at slaughter (112.5 kg for Flanders and 90-100 kg for the Western Cape), (iii) the difference in feed composition influencing emissions and (iv) the slurry treatment. The added impact of the first two factors results in the Western Cape producing 14.28 kg of slurry (FU)-1 compared with the 14.01 kg of slurry (FU)-1 produced in Flanders. Attention needs to be paid to new techniques like anaerobic digestion, since they show promising results for reducing the impacts of generating pig slurry and treating it in South Africa.
The total eutrophication potential of the Flemish pork production chain is 0.022 kg PO4-eq (FU)-1. For the Western Cape it is 0.034 kg PO4-eq (FU)-1, 50% more than that of Flanders (see Figure 2). The main contributor to eutrophication is leaching of N and phosphate from pig excretions, and to a lesser extent, ammonia emissions to the atmosphere. The eutrophication impact of pig slurry treatment is 0.0078 kg PO4-eq (FU)-1 more in the Western Cape, and for the feed provision activity, it is 0.0023 kg PO4-eq (FU)-1 more in the Western Cape than in Flanders. The high impact of eutrophication potential in the Western Cape feed provision activity relative to that of Flanders, is mainly caused by the maize component of Western Cape pig feed. Maize contributes almost half of the eutrophication potential of the Western Cape. The eutrophication impact of the slaughterhouse-, pig farm- and pork shipping activities are negligible.
The total contributions of acidification potential in the Flemish and Western Cape pork production chains are 0.039 kg SO2-eq (FU)-1 and 0.063 kg SO2-eq (FU)-1 respectively (see Figure 3). The absolute difference in total acidification potential between the Western Cape and Flanders is greatest for the pig slurry treatment activity (0.0067 kg SO2-eq (FU)-1), followed by the slaughterhouse activity, the pork shipping activity, the pig farming activity and the feed provision activity (0.0057, 0.0052, 0.0043 and 0.0024 kg SO2-eq (FU)-1 respectively). The differences in acidification potential in the slaughterhouse and pig farming activity between the Western Cape and Flanders can be explained in terms of the much higher electricity use of the Western Cape.
Total energy use for the pork production chain is 18.3 MJ (FU)-1 in Flanders and 30.7 MJ (FU)-1 in the Western Cape (see Figure 4). The absolute difference in total energy use between the Western Cape and Flanders is greatest for the slaughterhouse activity (6.07 MJ (FU)-1), second for the feed provision activity (2.5 MJ (FU)-1), third the pork shipping activity (2.1 MJ (FU)-1), and last for the pig farming activity (1.72 MJ (FU)-1). The energy use of the slurry treatment activity is included in the energy use of the pig farming activity, since the energy for separating the slurry comes from the pig farm; also, trucks exporting the slurry are incorporated in the pig farming activity.
The significant difference in the impacts of electricity use between the two regions is due to the higher electricity usage per functional unit in Western Cape, and the different sources of power in the regions. In Flanders electricity is generated mainly by nuclear power, while in South Africa it is generated mainly by coal combustion.
The identification and quantification of the main environmental impacts of the pork life cycle chain revealed the contributions of the various pork production activities to the various impact categories. The feed provision activity, which includes the cultivation and production of raw materials, has been shown to have the largest impact on energy use and GWP, while manure (treatment) has the largest impact on eutrophication and acidification potential.
In all impact categories, the Western Cape province of South Africa scores lower than Flanders when a FU of one kg of pork meat is used as the basis of comparison, signalling environmentally less friendly pork production in the Western Cape. Furthermore, one kg of pork is more expensive in the Western Cape than in Flanders. The price per FU on leaving the slaughterhouse in Flanders is 1.55 euro (ZAR13.95), while in the Western Cape, it is 1.805 euro (ZAR16.245) per FU (ZAR9=1euro).
The choice of one kg of pork as the functional unit in this study favours the Flemish pork chain. If the eutrophication and acidification potentials were measured in terms of an area unit, the outcome would be more favourable for the Western Cape, as this region is in a far better position to accommodate the local impact of pig slurry than Flanders.
See the complete report with references to relevant literature sources on SAPPO’s website.
The authors wish to thank SAPPO (the South African Pork Producers’ Organisation) for the financial support for this study and for providing access to the data, specifically to Stefan Guizot and Mike Herambs for providing data on a typical Western Cape pig farm; and to Toon De Keukelaere of Boerenbond Vlaanderen, who supported the collection of data on the average Flemish pig farm.