[Synchronization of estrus in heifers using Chlorsuperlutin (CSL) vaginal tampons].

A pilot experiment with heifer heat synchronization with chlorsuperlutin-soked intravaginal tampons was conducted with 254 heifers in six herds in the North Moravian region. The rubber-foam tampons, cylindrical in shape (diameter 70 mm, height 70-90 mm), were introduced into the cranial part of the vagina, using an applicator and a vaginal speculum. Sixteen days after introduction, the tampons were removed by pulling the silon thread with which the tampons were cross-stitched. The heifers were inseminated on the second to fifth day after the removal of the tampons. The average performance in the application of the tampons was 38.5 tampons per hour, and in their removal 20.7 tampons per hour. The retention rate of the tampons was 97.6%; out of this, 79.8% of the tampons were pulled out by the silon thread. The signs of heat were good, 87.9% of the heifers could be inseminated intrauterinally. All the heifers with retained tampons were inseminated. The conception rate after the first insemination was 32.7%, after the second insemination 56.4%, and after two inseminations 68.1%. Out of the synchronized heifers, 8.1% were culled for slaughter. The drawbacks of this treatment include the low conception rate of the synchronized heifers, a high requirement for repeated insemination in the synchronized oestrus, and, consequently, a high sperm consumption.