The aim of the current study was to describe the fate of ingested a-hexabromocyclododecane (alpha-HBCDD) in fast-growing (FG) and slow -growing (SG) broilers, through an exposure to a dietary concentration of 50 ng alpha-HBCDD g(-1) feed during 42 and 84 days, respectively. Depuration parameters were assessed in SG broilers successively exposed during 42 days and depurated during 42 days. At market age, SG broilers had ingested 42% more feed than FG broilers, while their body weight gain per g of feed ingested was 34% lower. No isomerization of alpha- to beta or gamma-HBCDD forms occurred, while OH-HBCDD was identified as a product of alpha-HBCDD metabolism. Irrespective of the strain, abdominal fat displayed the highest a-HBCDD concentration on a lipid weight basis, followed leg muscles and then breast muscle, liver and plasma. The accumulation ratios of alpha-HBCDD were slightly higher in SG (6.7, 2.1, 2.6 and 9.9 in leg muscles, breast muscle, liver and abdominal fat, respectively) than in FG broilers (5.2, 2.2, 1.1 and 8.4, respectively). The elimination half-lives in SG broilers were 20,12 and 19 din leg muscles, breast muscle and abdominal fat, respectively, to which dilution through growth contributed for around 50%. The overall assimilation efficiency of alpha-HBCDD was estimated at 58 and 50% in FG and SG broilers, respectively, while 22 and 17% of alpha-HBCDD ingested were estimated to be eliminated in excreta as metabolites. (C) 2017 Elsevier Ltd. All rights reserved