Agriculture accounts for 70% of the available freshwater supply and roughly 30% relates to the livestock sector (Hoekstra and Mekonnen, 2012). Similarly, around half the world’s agricultural area and 40% of all arable land is used for livestock feed production and grazing (Mottet et al., 2017). How these impacts on natural resources can be substantially reduced is still an open question, however alternative solutions in the field of animal nutrition are being proposed. Exploiting former foodstuff products (FFPs) as animal feed is an active and promising area of feed research, as FFP biomass is an attractive and abundant source of nutrients (Luciano et al., 2020; Pinotti and Dell’Orto, 2011). The SusFEED and ASSO projects were set up to tackle these issues in Italy and Lombardy, respectively. The aim is to assess the impact of substituting 30% of conventional cereals with FFPs in the diet of pigs, by estimating the nutritional effects, and thus the animal’s health, but also the potential positive environmental impacts. FFPs provide a way of transforming surpluses from the food industry into ingredients for the feed industry, thereby reducing overall food losses in the food chain. In terms of the environmental impacts, the amount of fertile land and fresh water related to the various ingredients in the swine diet are evaluated in order to quantify how many natural resources can be saved by promoting the recycling of food waste as animal feed. A spatially distributed and physically-based hydrological model is used to solve the vertical soil water balance equation, which computes the water associated with the growth of different crops, together with the biomass growth of the plant (Chiarelli et al., 2020). A comparison of the land and water demands for the two different diets (conventional and FFPs) shows how the pressure on the massive use of natural resources can be reduced, so much so that some countries may be able to meet their domestic feed demand without having to rely on imports. This would also have a positive effect on the global trade in water and virtual land. The results obtained show how food waste can be reduced not only by recycling, but also by enhancing the management of food left-overs, and also thus mitigating the environmental impacts.
How the environment can benefit by feeding pigs leftover pasta and biscuits
