The pattern of luteinizing hormone secretion during pregnancy in goats

The concentrations of luteinizing hormone (LH) in plasma were determined over 24 h in samples taken every 15 min from goats at 25, 60, 90 and 120 days of gestation, and from non-pregnant goats on days 10–14 of the oestrous cycle. The concentrations of LH were low throughout pregnancy with an overall mean of 0.9 ng LH/ml plasma, significantly different from a mean of 1.4 ng LH/ml found on days 10–14 of the oestrous cycle. A cyclic change in concentration of LH could be demonstrated throughout pregnancy in most animals, was of small amplitude and had a periodicity of 4–5 h.