[Induced preovulatory discharge of LH during the seasonal anoestrus of the goat (author's transl)].

Preovulatory LH surges were induced and synchronized in 12 Alpine goats during the anoestrus season using a progestagen-PMSG treatment. Onsets of oestrus, plasma LH levels and numbers of ovulations were recorded. During the preovulatory surge, frequencies of blood sampling were such (1 per hour in 8 goats and 1 each 4 min. in 4 other goats) as to allow for the first time a precise description of this biological event in the goat. Results may be summarized as follows: (1) Plasma LH levels were low (less than 1 ng/ml) and constant during the hours preceding the surge, (2) the onset of LH surge preceded by 2 hrs, on the average, that of oestrus behaviour, (3) preovulatory surges presented a definite pulsatility when maximum levels were reached, (4) no positive relationship was found between the magnitude of the surge and the corresponding number of ovulation, (5) in two animals, the LH surge was definitely biphasic, each peak presenting serveral pulses of secretion.