Conception rate of goats inseminated with semen cooled in egg yolk diluent at 5°C, for 12 or 24 hours

The fertilizing capacity of goat semen cooled in egg yolk diluent at 5 degrees C, for 12 or 24 hours was evaluated. Sixty-two Toggenburg does and two sexually mature Toggenburg bucks were used in a fatorial treatment combination (two bucks and two storage periods). The semen was diluted in 2.5% Tris-frutose-egg yolk; envased in 0.25mL plastic straws, with 150x10(6) mobile spermatozoa; and cooled at 5 degrees C for 12 or 24 hours. The females received two doses of 22.5 mu g of prostaglandine F2 alpha, at each 10-day intervals in order to synchronize the estrous. From the first PGF2 alpha injection, estrous occurrence was monitored three times per day. Only one insemination was used, using the cervix fixation method, 12 hours after the estrous onset. The means of motility and strength, 12 (TI) and 24 hours (TII) after semen cooling at 5 degrees C, were 66.14 +/- 0.11% and 62.50 +/- 0.05%, and 3.46 +/- 0.61 and 3.27 +/- 0.50, respectively. Neither the sire nor the period of semen influenced (P>0.05) the conception rate of the does, which was 49.1%.