Evaluation of LH-RH stimulation of testosterone as an index of reproductive status in rams and its application in wild antelope.
In rams a positive correlation (P less than 0.001) existed between average testosterone levels from 30-min blood sampling for 18 h and average testosterone levels of samples taken 0, 1 and 2 h after injection of LH-RH administered 90 min after anaesthesia. Attempts were therefore made to assess testosterone status by LH-RH challenge and limited blood sampling in animals immobilized in their natural habitat. In impala (Aepyceros melampus) territorial males had higher plasma testosterone values than did bachelors after LH-RH challenge (8.1 compared with 2.6 ng/ml, P less than 0.05). In blesbok (Damaliscus dorcas), the relationship was less clear, but testicular volume was correlated with plasma testosterone concentration and with testicular responsiveness measured by testosterone produced per unit of LH (P less than 0.001 and P less than 0.05, respectively). The LH-RH challenge technique therefore has value as a measure of testicular function and permits study of ungulates in their natural environment.
D000828:Animal Population Groups / Q000502:physiology*; D000818:Animals; D000835:Animals, Wild / Q000502:physiology*; D000866:Antelopes / Q000502:physiology*; D001188:Artiodactyla / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D012098:Reproduction; D012756:Sheep; D012931:Social Environment; D013737:Testis / Q000502:physiology*; D013739:Testosterone / Q000097:blood*
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone