Figure 5: Experiments 1 and 2 The short term changes in the plasma concentrations of LH and oestradiol in ewes of ewes between -4 and 8 hours after the introduction of rams with (i) a LH surge (? and grey bars), (ii) ewes without a LH surge and no increase in the concentration of progesterone following the introduction of rams (? and open bars) and (iii) ewes without a LH surge but with an increase in the concentration of progesterone following the introduction of rams (? and black bars). Experiment 1 on the left; LH surge (n=5), no LH surge (n=14) and Atypical (n=9) and experiment 2 on the right LH surge (n=13), no LH surge (n=39) and Atypical (n=8). For the LH data, and for the oestradiol data values with different superscripts are significantly different (P <0.05).