[PMSG dosage precision in young and old sows in the course of biotechnical ovulation synchronization. 3. Fertility and litter effects].

One single PMSG batch, Pregmagon-Dessau, was compared with other PMSG doses on 2,126 adult sows and 1,700 gilts from five farms. Additional comparisons were made with other Pregmagon or Prolosan batches on 1,178 adult sows and 1,026 gilts. All experiments were made in the context of a programme for ovulation synchronisation and term-oriented insemination. Doses of 700, 800, 900, and 1,000 IU were tested on adult sows and 600, 800, and 1,00 on gilts, with the mean dose of 800IU being found to be sufficient or superior to other doses for fertility results. Doses for adult sows could be adjusted and related to present and previous litter numbers, with the dosage being between 700IU (treatment for third litter) and 700 to 800IU (treatment following average to high previous litter. The preferential dose for gilts was found to be 800IU. Higher PMSG doses (up to 1,000IU) should not be used in synchronisation of ovulation and term-oriented insemination unless extraordinary conditions were safely established.