Circularity in livestock farming: an Emerging Research Topic or Established Concept?

The world’s population is constantly increasing, while natural resources are becoming limited. In intensive livestock farming is relying more and more on external inputs in order to meet the growing demand for food, with a negative impact environmental sustainability and resilience to volatility of markets. The purpose of this study is to examine the literature focused on the theme of circularity. A database of 403 articles extracted from the 'Web of Science' platform was constructed using keywords: circularity, dairy, cows, sustainability, self-sufficiency, by-products, nutrients stocks and environment. SAS® 9.4 software was used to calculate descriptive statistics and to perform correlation and multiple correspondence analysis. Articles specifically focused on circularity area accounted for only 3.72% of the database, indicating the novelty of the topic. The remaining articles were related to by-products (52.8%), nutrient stock (29.3%), self-sufficiency (14.1%). Into the database studies from Europe were 111, followed by North America (n=102), South America (n=70), Asia (n=58) and others (n=50) (not specified n=12). In North America, the interest in these topics was considerable already before 2010 (43.1%). Conversely, in Europe, the largest number of articles on these topics have been published since 2017 (41.4%). Regarding the keywords circularity and self-sufficiency, appeared respectively for 60% and 76.4% in European articles. Multivariate analysis showed that articles from 2017 focus on issues related to self-sufficiency and environment issues, for which the livestock sector is often criticised. Despite not yet being a widespread field of research, circularity is essential for the survival of farms and fundamental for achieving sustainable livestock farming system production. The authors acknowledge the financial support through the Dairymix project, funded by the Joint Call of the Cofund ERA-Nets SusCrop (Grant N° 771134), FACCE ERA-GAS (Grant N° 696356), ICT-AGRI-FOOD (Grant N° 862665) and SusAn (Grant N° 696231).”