Environmental impacts of a dairy cheese chain including whey feeding: an Italian case study.

The dairy industry is associated with the production of wastewaters and effluents that could have a significant environmental impact because of their pollutant characteristics. Cheese whey is an important source of pollution that needs an appropriate treatment because of several environmental burdens. Thanks to its nutritional value, liquid whey can be successfully recycled in animal nutrition. Following the LCA methodology, this study aims to contribute to the literature on the environmental sustainability of cheese production in a traditional dairy chain, based on an Italian case study and on liquid whey usage. The environmental assessment considers both the milk and the mozzarella cheese production. Three dairy chains and cow diets were assessed and compared: the A diet, with traditional feeding hay and no liquid whey; the B diet, with silages but no liquid whey; the C diet, including both silages and liquid whey. A physical allocation method was used to share the environmental burden between milk and meat at farm level, while the environmental burden of the mozzarella cheese production was totally allocated to curd. A sensitivity analysis based on the cereal unit allocation method was performed. A further sensitivity analysis was performed to compare what the effect would have been considering the variability of milk yield observed in the three diets. Results showed that raw milk production was the most impactful phase along the considered supply chain. Compared with other dairy chains, the C chain with liquid whey recycling did not result the lowest impacting solution at a global environmental perspective, showing best performances on some impacts, but not on others. However, sensitivity analysis testing for the observed yield variability showed that the C diet with whey usage could represent the best option among the different diets.