Secretory pattern of LH in castrated, hemicastrated and intact pubescent male goat kids

Abstract

The mean and baseline concentrations, pulse frequency and pulse magnitude of LH were measured in jugular vein blood samples in two pairs of pubescent goats after hemicastration (Group B) or castration (Group A) at 8 weeks of age. Contemporaneous measurements were made in a matched pair that remained intact (Group C). All animals were studied for a 16 week period, from the time of castration, until they were 24 weeks of age. Weekly mean LH concentrations were highest in Group A and lowest in Group C. In three 6 h periods when blood samples were collected every 15 min via an indwelling jugular vein catheter, all four LH parameters were highest in Group A and lowest in Group C; the hemicastrated kids (Group B) were intermediate. As in other species, this study demonstrates the rapid response of the hypothalamic-pituitary axis of the pubescent goat kid to the removal of gonadal inhibition at a very young age.