Yaghobfar A - Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
Javaheri Barfourooshi H - Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
Hamedi S - Department of Basic Sciences, Faculty of Veterinary Medicine, Islamic Azad University, Karaj Branch, Karaj, Iran

This study conducted to determine the effect of guanidino acetic acid consumption and management methods on the enhancement of aged rooster s reproduction. A total of 486 broiler breeders (Ross 308) were used in a 3 × 3 factorial experiment from week 41 to 62. Three levels as 0, 1200, and 1600 (mg/kg) of guanidino acetic acid, as a precursor of creatine (CreAmino) in combination with three management methods (no-management, spiking, and, intra-spiking methods) were evaluated. Quantitative and qualitative characteristics of sperm were determined every other week. At the end of the experiment, three roosters from each treatment were slaughtered and their testicles were evaluated for morphological and histological characteristics. The volume of sperm was a significant reduction in CreAmino (1200 mg/kg) + spiking. Sperm progressive motility reduced in CreAmino (1200 mg/kg) + nomanagement and CreAmino (1600 mg/kg) + intra-spiking. Also, CreAmino (1200 mg/kg) +no-management, increased the weight of the testicles. CreAmino (1600 mg/kg) + spiking showed the highest number of spermatozoa. The results showed that using 1600 mg CreAmino in combination with management methods, spiking and intra-spiking, can reduce and delay the occurrence of signs of aging in roosters. So, with using this level of CreAmino it is expected fertility in broiler breeder flock improved.

Spiking, Fertility, Creatine, Intra-spiking, Elderly rooster