effect of guanidino acetic acid consumption and management methods on the reproductive potential of elderly cockerel broiler breeders

This study conducted to determine the effect of guanidino acetic acidconsumption and management methods on the enhancement of aged rooster'sreproduction. a total of 486 broiler breeders (ross 308) were used in a 3 × 3factorial 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) incombination with three management methods (no-management, spiking, and,intra-spiking methods) were evaluated. quantitative and qualitativecharacteristics of sperm were determined every other week. at the end of theexperiment, three roosters from each treatment were slaughtered and theirtesticles were evaluated for morphological and histological characteristics. thevolume of sperm was a significant reduction in creamino (1200 mg/kg) +spiking. sperm progressive motility reduced in creamino (1200 mg/kg) + nomanagementand 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 withmanagement methods, spiking and intra-spiking, can reduce and delay theoccurrence of signs of aging in roosters. so, with using this level of creaminoit is expected fertility in broiler breeder flock improved.