[Attempts at control of parturition in swine with dexamethasone. 1. Effect of various treatment dates in late pregnancy on onset of labor, litter and rearing performance of the sows].

: Studies were conducted with 66 gilts with synchronised ovulation, all kept in five separate experimental groups (I-V). Each of the animals received 75 mg Dexamethason (DXMS) per die over three consecutive days of pregnancy. Treatment of Groups I through V was started in this order on the 101st, 103rd, 105th, 107th or 109th days of pregnancy. The average intervals that elapsed between the last DXMS injection and onset of parturition were, in the same order, 174, 167, 133, 94 or 74 hours. Births were concentrated on two consecutive days in Group V. DXMS had no significant effect on the average duration and course of parturitions. The lowest average litter and piglet birth weights were recorded from those DXMS groups with shortest pregnancy. No significant mean differences in piglet weight were any longer established between the groups on the tenth day of age.