Abstract
Genetic selection based on the high growth rate and consequently high slaughter weight in broiler chickens has caused many problems in broiler breeders. A negative correlation between growth and reproductive traits has declined semen quality and fertility in roosters. The present study aimed to evaluate the effects of camphor levels on some reproductive parameters included semen parameters, antioxidant status, and testicular development in broiler breeder roosters. Thirty-five ROSS 308 broiler breeder roosters were divided into 5 groups to receive camphor (C) levels: C0, C50, C250, C750, and C1000 ppm for 12 consecutive weeks (31-43 wk). Body weight, seminal volume, sperm concentration, and percentage of live and morphologically normal sperm were not affected by diets (P > 0.05), however, significantly were changed by bird age over the experiment (P < 0.05). Semen quality factor (SQF) significantly was affected by both diets and age (P < 0.05). Mitochondrial activity, apoptotic-like changes, and DNA fragmentation were improved in the groups fed camphor levels compared to the control group (P < 0.05). Testes weight (left, right, and combined weights) and gonadosomatic index were increased linearly by the camphor supplementation (P < 0.05). The serum activity of glutathione peroxidase (GPX) was not affected by treatments, however, superoxide dismutase (SOD) activity, ferric ion reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were significantly higher in C50, C250, and C750, respectively (P < 0.05). The lower malondialdehyde (MDA) content in the testes and liver samples was observed in C750 (P < 0.05). Excluding the number of Sertoli cells and blood vessels, other histomorphological traits of testes showed one of the linear or quadratic responses to the camphor levels (P < 0.05). It can be concluded that camphor as an antioxidant source may improve reproduction performance in roosters.