Figure 2From: A preliminary study on the induction of dioestrous ovulation in the mare – a possible method for inducing prolonged luteal phaseProgesterone levels after saline treatment in two control mares. Mare Me developed a spontaneously prolonged luteal phase. Dashed lines show the cut-off levels for progesterone samples taken twice weekly (3 nmol/l) or once weekly (10 nmol/l)Back to article page