Effects of HCG with oestradiol benzoate on the luteal function in gilts.

Human chorionic gonadotrophin (HCG) combined with oestradiol benzoate was tested for induction and synchronization of heat in gilts. Judging from the progesterone levels in the blood, several of the gilts were already exhibiting spontaneous oestrous cyclicity on the day of treatment. Only gilts with low blood progesterone levels on the day of treatment showed standing oestrus within the expected time. On the basis of the results a second trial was carried out to elucidate the influence of the hormone compound on the ovarian activity in gilts during the luteal phase.