Thanks to the partnership originally initiated by France Embryo with the english selection program Cogent, Genes Diffusion offers since July 1st, 2007, a whole range of bulls with sexed semen available.
In our offer, you will find bulls tested through the Gènes Diffusion program as well as bulls from COGENT (UK) and SEMENZOO (IT).
Whatever their origin, the bulls which we propose in our catalog had their semen sexed at COGENT, according to the XY method (flow cytometry). The expected rate of females averages 90 %. We draw however your attention on the fact that the sexing of the semen tends to lower somewhat the fertility. It is something to take into account when doing the matings. The use on heifers should be privileged.
Flow cytometry : the reference in semen sexing
Developed by the American company XY Inc. which detains the patent, the XY technology is based on the fact that the female (X bearing chromosome) contains 4% more DNA than the male (Y bearing chromosome).
After dilution with a fluorescent marker, the spermatic cells are conveyed at high speed and an electric charge is applied to the droplets. It is this difference in fluorescence related to the DNA content that is detected by the sensors when the sperm cells pass by a laser beam, one at a time in a fluid stream. Subsequently the cells are deflected into two groups, one with the spermatic cells desired (X) and one with the Y cells or those not having been characterized. At the end, only the female semen is packaged and the rest is rejected.