animals Hypothesis The Root towards More Circularized Animal Production Systems: From Animal to Territorial Metabolism Marcello De Rosa 1 , Jorgelina Di Pasquale 2, * and Felice Adinolfi 3   Citation: De Rosa, M.; Di Pasquale, J.; Adinolfi, F. The Root towards More Circularized Animal Production Systems: From Animal to Territorial Metabolism. Animals 2021, 11, 1540. https://doi.org/10.3390/ani11061540 Academic Editor: Phillip Sponenberg Received: 8 April 2021 Accepted: 20 May 2021 Published: 25 May 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department of Economics and Law, University of Cassino and Southern Lazio, 03043 Cassino, Italy; mderosa@unicas.it 2 Faculty of Veterinary Medicine,University of Teramo, 64100 Teramo, Italy 3 Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, Ozzano Emilia, 40064 Bologna, Italy; felice.adinolfi@unibo.it * Correspondence: jdipasquale@unite.it Simple Summary: The relationship between the rates of world population growth and the consump- tion of natural resources is a subject of strong debate in the political and academic areas. Since the 1960s, technological progress has made it possible to achieve extraordinary increases in agricultural productivity, which was at the basis of the so-called green revolution. However, this happened at the expense of environmental sustainability. Agricultural activities impact natural resources such as water, air, biodiversity, which are crucial for future generations. The livestock sector is particularly sensitive to the problem, being responsible for an important part of the global greenhouse gas emis- sions. To make livestock production more sustainable, a radical rethinking of livestock production models is required. In the face of these needs, the circular economy provides a sound basis for a sustainable transition. Therefore, it is necessary to identify the crucial factors for a transition towards more “circularized” animal production systems. More precisely, our work aims to identify economic, social, and environmental factors that can boost transition, by framing it within a circular vision of livestock farming. Abstract: This paper deals with a relevant topic in the literature on sustainable management of animal farms, concerning the transition towards circular methods of animal production. The paper aims to put forward an original analytical multilevel perspective overlapping different dimensions at either micro, meso, and macro level. Starting from the Malthusian analysis on depletion of natural resources, with risks of the fragility of the natural and economic systems, the paper points out the importance of moving away from intensive methods of production, by adopting more circularized approaches based on resources efficiency. The application of circular economy approaches to animal production is theorized through the concept of territorial metabolism involving not only internal resources (at the animal farm level) but also territorial resources. The paper underlines the critical points of the transition, which is labeled as a socio-technical transition in that it involves not only technical issues but also social aspects. Critical points are addressed through consumers’ acceptance of products drawn on circular approaches and political support to transition, through political tools which are boosted in recent documents of the European Union, like the Green Deal and Farm to Fork strategy. Keywords: circular economy; sustainability; circular livestock management; agricultural policy; consumers’ acceptance 1. Introduction Concerns about the sustainability of economic growth have fueled scientific and political debate for over two centuries. Thomas Malthus in 1798 published his work “An Essay on the Principle of Population” [1], in which he theorized the progressive Animals 2021, 11, 1540. https://doi.org/10.3390/ani11061540 https://www.mdpi.com/journal/animals