Broiler meat production as affected by dietary supplemental hydroxy-selenomethionine

•Selenium supplementation improved body weight gain and feed conversion ratio of broilers.•Selenium from hydroxy-selenomethionine that optimized body weight gain was 0.48 ppm.•Effects of dietary selenium on carcass and meat quality of broilers were measured.•Selenium supplementation increased activity of glutathione peroxidase in erythrocytes. Selenium (Se) is essential and usually deficient in corn-soy feeds for broiler chickens. Hydroxy-selenomethionine (OH-SeMet) is a commercial organic source that has not been thoroughly evaluated as a single supplemental source of Se. The objective of this study was to evaluate the increasing dietary Se supplementation from OH-SeMet on broiler growth performance, meat yields, wooden breast (WB) and glutathione peroxidase responses in tissues. A total of 1,500 Cobb vs. Cobb 500 slow feathering one-day-old male chicks were allocated to five treatments with 12 replicates of 25 broilers each in a 3-phase feeding program from d 1 to 42 (0.0, 0.15, 0.30, 0.45 and 0.60 mg/kg of Se supplemented from OH-SeMet). Supplemental Se levels were chosen in order to provide a robust dose-response adjustment and were based on known deficient and excessive dietary contents for broiler chickens. The non-supplemented starter, grower, and finisher feeds had analyzed 0.03, 0.03, and 0.02 mg/kg Se, respectively. At 35 and 42 d of age, five broilers per pen were processed for meat evaluation and scored for WB. Samples from blood, liver, jejunum, and ileum as well as breast meat samples were taken at 42 d for evaluation of glutathione peroxidase (GSH-Px) activity and lipid oxidation (TBARS), whereas breast meat was also analyzed for cooking loss (CL) and water-holding capacity (WHC). Statistical analysis was conducted using the quadratic polynomial regression model. Increasing Se from OH-SeMet led to quadratic increases (P < 0.05) in BWG from d 1 to 42, with optimal concentration at 0.47 mg/kg Se as well as optimized estimations for FCR at 0.42 mg/kg Se. Dietary Se that maximized carcass and breast meat yields at 42 d were 0.41 and 0.48 mg/kg Se, respectively (P < 0.05). Dietary Se that maximized GSH-Px activity in erythrocytes was at 0.27 mg/kg (P < 0.05). No effects of Se were observed on WB scores at 35 and 42 d of age, CL and WHC as well as on TBARS in intestine, liver and breast muscle samples (P > 0.05). Supplementation of Se from OH-SeMet in corn-soy feeds improved broiler performance, carcass and breast yields. Average Se that optimized