[Control of labor in swine with dexamethasone of various injection frequencies on the onset of labor and other selected parameters in farrowing sows and piglets].

Included in experiments with 185 sows with synchronised oestrus and ovulation were 52 untreated animals (K), while the others received intramuscular injections of daily doses of 75 mg of dexamethasone (DXMS), between the 109th and 111th days of pregnancy (V1) or 200 mg on the 110th day (V2) or on the 111th day (V3). While DXMS failed to have any substantive effect on mean pregnancy time or duration of labour, the variance of farrowing dates was reduced with significance. The average intervals which passed from the injections to delivery were 58.

[Experimental application of steroids to sows in early gravidity to increase litter size. 2. Effects of repeated administration of progesterone alone or in combination with estradiol benzoate during 2 to 5 consecutive days].

Two mutually adjusted experiments were applied to 607 inseminated gilts and sows on the premises of two farms to test the effects on both pregnancy rate and litter size of repeated treatment, using progesterone in isolation or in combination with 0.5 mg oestradiol benzoate during the phase of implantation. The steroids were applied on the 14th and 16th or 15th and 16th days of pregnancy or between the 13th and 17th or 14th and 18th days following first insemination.

[Biotechnical increase of litter size in early pregnant sows using steroid application. 1. The effect of a single application of hydroxyprogesterone capronate on fertility response in ovulation-synchronized gilts and old sows].

One single intramuscular injection of hydropyrogesteroncapronate was given in an experiment to 199 gilts and 239 old sows on the 13th or 15th or 17th day after insemination to test various fertility performance parameters. Doses were 50 mg, 75 mg or 100 mg. Positive effects on litter size were established from the majority of nine compared experimental variants.