title: Prevalence rates of health and welfare conditions in broiler chickens change with weather in a temperate climate.
abstract: Climate change impact assessment and adaptation research in agriculture has focused primarily on crop production, with less known about the potential impacts on livestock. We investigated how the prevalence of health and welfare conditions in broiler (meat) chickens changes with weather (temperature, rainfall, air frost) in a temperate climate. Cases of 16 conditions were recorded at approved slaughterhouses in Great Britain. National prevalence rates and distribution mapping were based on data from more than 2.4 billion individuals, collected between January 2011 and December 2013. Analysis of temporal distribution and associations with national weather were based on monthly data from more than 6.8 billion individuals, collected between January 2003 and December 2013. Ascites, bruising/fractures, hepatitis and abnormal colour/fever were most common, at annual average rates of 29.95, 28.00, 23.76 and 22.29 per 10 000, respectively. Ascites and abnormal colour/fever demonstrated clear annual cycles, with higher rates in winter than in summer. Ascites prevalence correlated strongly with maximum temperature at 0 and -1 month lags. Abnormal colour/fever correlated strongly with temperature at 0 lag. Maximum temperatures of approximately 8°C and approximately 19°C marked the turning points of curve in a U-shaped relationship with mortality during transportation and lairage. Future climate change research on broilers should focus on preslaughter mortality.
authors.affiliation: School of Biological Sciences , Queen's University Belfast , Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL , UK.
authors.forename: Chérie E
authors.identifier: 0000-0002-3281-1671
authors.initials: CE
authors.lastname: Part
authors.affiliation: Department of Population Health , London School of Hygiene and Tropical Medicine , Keppel Street, London WC1E 7HT , UK.
authors.forename: Phil
authors.initials: P
authors.lastname: Edwards
authors.affiliation: Department of Social and Environmental Health Research , London School of Hygiene and Tropical Medicine , 15-17 Tavistock Place, London WC1H 9SH , UK.
authors.forename: Shakoor
authors.initials: S
authors.lastname: Hajat
authors.affiliation: School of Life Sciences , University of Lincoln , Brayford Pool, Lincoln LN6 7TS , UK.
authors.forename: Lisa M
authors.identifier: 0000-0002-8596-5498
authors.initials: LM
authors.lastname: Collins
keywords: animal health; animal welfare; broiler chicken; climate; epidemiology; temperature