Programas de fixed-time artificial insemination de alta fertilidad con semen sexado

For years, researchers have been seeking to manipulate sex before conception. Although the use of sexed semen has been of great interest in the past 20 years to inseminate dairy heifers, the massive use of sexed semen was somewhat limited because fertility was compromised and could not be solved by increasing the number of sperm per inseminating dose. However, new simplified and less traumatic procedures for sperm have recently been developed that have significantly improved pregnancy rates obtained with sexed semen. However, for the massive use of this technology it is necessary to develop fixed-time Artificial Insemination (FTAI) programs for sexed semen. Therefore, a series of experiments were carried out on heifers in cows with calf on foot. In all cases the animals were synchronized with the help of paint at the base of the tail to detect the presentation of jealousy and optimize the IATF schedules. Although pregnancy rates were generally higher for conventional semen than for sexed semen, pregnancy rates with sexed semen were 45 to 50%. Therefore, the results of the experiments carried out show that IATF protocols can be adapted for the use of sexed semen and thus enable the massive use of this technology.