Characterization of the degree distribution of the animal trade network of 23 Brazilian states

• Grant number: 14/24223-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2015
• End date: December 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: José Henrique de Hildebrand e Grisi Filho
• Grantee: Gabriel Gomes Lima
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The analysis of complex networks is an important tool that allows the study of relationships between pairs of premises, allowing the recognition and quantification of the animal trade between farms. Scale-free networks are the most common kind of networks when it comes to networks of animal movements. In this case, many institutions are responsible for few transactions and few of them are responsible for many transactions, and the frequency of these links follows a Power-Law distribution, which implies in very peculiar structural and dynamic characteristics. It is very likely that different Brazilian states have different concentration levels of transactions, due to the differences in the production systems. It is important to know the distribution of movements and the level of heterogeneity of different Brazilian states, regarding the movements of cattle, seeking to find similarities and differences in the structure of different production systems. In this study we will analyze the networks of cattle movements from 23 Brazilian states, with the aim of understanding how the trade between premises is organized. The intensity of marketing of each farm will be calculated using the parameters: number of neighbors; number of animals moved; and number of transactions carried out. For each parameter, the distribution will be adjusted to a Power-Law distribution, which will reveal the heterogeneity and concentration degree of the animal trade of each production system.