| 摘要 |
A porcine intra-vaginal device of a shape and size adapted to be positionable in the vaginal tract across the hymenal ring of a target animal (e.g., a gilt) to extend to both sides of the hymenal ring of the animal. The device once inserted delivers progesterone from a progesterone impregnated matrix on either side of the hymenal ring, the progesterone releasing surface being at least 150 cm 2 in total area. Variable geometry means (preferably for vestibular engagement) ensures retention of the device (e.g., for at least 7 to 14 days) where, in the preferred device, the progesterone load of from 1.9 to 2.5 g within 1.2 mm of the release surface can, by maintaining a progesterone blood plasma level (equating to a progesterone blood plasma level in excess of 4 ng/mL measured in an ovariectomised animal), ensure or prompt the onset of oestrus within 3 to 5 days after device removal. |
