INSEMINATION WITH STALLION SEMEN FROZEN IN 0,5 ML STRAWS

An insemination trial using frozen semen is described. The freezing pr ocedure was slightly modified from the Hannover method. The inseminati on dose consisted of 7 medium straws containing approx 1 x 10(9) sperm atozoa. A total of 28 mares of the Norwegian Trotter breed were insemi nated during the 1991 season. During oestrus the mares were examined a t 12 hour intervals, and the insemination was carried out after detect ion of ovulation. The pregnancy rate was 43% after the first inseminat ion. increased to 68% after second and further to 75% after the third and last insemination. The foaling rate was 61.5%.