title: Average testosterone levels in bulls after GnRH stimulation at breeder bull rearing stations and A. I. stations.
abstract: Base average testosterone levels and testosterone levels in 60 and 90 min after GnRH administration were determined in bulls at five breeder bull rearing stations at their age of 13 months and at nine A. I. stations at their age of 17-34 months. Significant increases in testosterone levels in 60 and 90 min after GnRH administration were the responses of all groups of bulls. There were differences between the average testosterone levels typical of the various BRSs and AISs. Highly significant correlation coefficients 0.344 for base levels and 0.583 for induced levels were calculated from a comparison of the testosterone levels determined at BRSs at the bull's age of 13 months and of those recorded after a six-month stay of the same bulls at AISs. A decrease in testosterone levels was also observed.
authors: Veterinary Research Institute, Brno.
authors: A
authors: A
authors: Kozdera
authors: Z
authors: Z
authors: Vĕzník
authors: L
authors: L
authors: Rysavá
mesh_terms: D000818:Animals; D001947:Breeding; D002417:Cattle / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage* / Q000494:pharmacology; D007275:Injections, Intravenous; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D013739:Testosterone / Q000097:blood*
chemical_list: D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone