title: The industrialization of farming may be driving virulence evolution.
abstract: Farming practices have changed dramatically over the years. The industrialization of farming has provided parasites with an abundance of hosts and is thought to have influenced parasite evolution. For example, the parasite that causes the highly contagious poultry disease, Marek's disease, has evolved over the past 60 years into a highly virulent pathogen. It is assumed that the industrialization of the industry and vaccination have selected for more virulent strains of the virus. Here, with the use of an impulsive differential equation model, we investigate how modern broiler farm practices could independently lead to virulence evolution. Our model suggests that longer cohort durations and more densely stocked barns both select for less virulent strains of the virus. Our model also suggests that if intensive cleaning between cohorts does not rid the barn of disease, it may drive evolution and cause the disease to become more virulent.
authors.affiliation: Department of Mathematics and Statistics Queen's University Kingston ON Canada.
authors.forename: Carly
authors.initials: C
authors.lastname: Rozins
authors.affiliation: Department of Mathematics and Statistics Queen's University Kingston ON Canada.
authors.forename: Troy
authors.initials: T
authors.lastname: Day
keywords: all‐in‐all‐out; impulsive differential equation; infectious disease; livestock production; mutation; poultry; virulence