Sergei Volkov, Valery Lototsky, lecturers, Bilotserkivskiy NAU

One of the most important scientific and practical achievements of the past century was the invention, development and widespread introduction of long-term storage of semen and artificial insemination.

However, the introduction of artificial insemination is accompanied by the need to address a number of issues, including choosing the best time of introduction of semen. Natural insemination (mating) is possible only during females sexual hunt when it admits coitus with a male, which ensures the convergence of sperm and egg in the optimal place and time and promotes fertility. Artificial insemination involves the same choice of point in females’ life when certain signs or their complex indicate the presence of sexual hunt. All signs, except positive sexual response of females to males is only probable, and therefore artificial introduction of semen may be early (before the onset of sexual hunt), late (during or after ovulation). In addition it is possible that this procedure may expose animals beyond the stage of sexual arousal cycle or already pregnant.

It is known that the stage of sexual arousal cycle in cows lasts 3-5 days and is characterized by consistent expression of four phenomena: estrus, sexual arousal or general reaction, sexual hunting and ovulation.

The main signs of estrus are: moderate swelling of the labia, redness of the mucous membrane of the vagina and discharge from the genital slit mucus. At the beginning of estrus mucus is transparent and is released in small quantities. It is clearly seen at the end of the tail or on the floor, when the animal is in the stall. In the middle period of oestrus mucus becomes glassy, transparent and cords secreted from the genital tract. At the end of oestrus mucus decreases, it becomes sticky and muddy.

More you can read in «Milk and Farm» magazine #4 (11), August 2012.