[Clinical study results of the embryonic development in gilts and brooding performance of gilts and sows after HCG treatment on the 11th day of pregnancy].

Forty-four pregnant gilts were slaughtered on the 32nd and 33rd days of pregnancy, after 30 of them had received 100 or 400 IU of HCG on the eleventh day of pregnancy. Both doses had resulted in higher number of living embryos. Embryo survival rates of treated sows were up to 14.9 percent higher than those of untreated animals. Higher numbers of embryos had no adverse effect on their mass development. Fertility was measured of 77 HCG-treated and untreated gilts as well as of 54 adult sows. The number of non-pregnant sows which returned to oestrus was higher in the group of gilts and adult sows which had received treatment. The number of pregnant animals in the treated adult sow group was seven percent higher than that in the control group. Increased litter sizes were additionally recordable from those gilts and adult sows that had received HCG injections. Yet, those higher litter sizes were associated with lower weight of live-born piglets. In further studies more attention should be given to possible stimulation of LH secretion in early gravidity.