What are Pre-Mating S-B STRAWs?
The pre-mating S-B STRAW is designed to be used in natural matings, or by farmers savvy in DIY artificial insemination (with valuable, but unsexed, semen in the LN2 tank), or by dairy cow breeders that rely on services by artificial insemination technicians.
All the pre-mating S-B STRAWS contain anti-male bispecific monoclonal antibodies (bsmAbs) that are conjugated to tiny micro-platelets resembling sperm, suspended in bull semen diluent. Sticking exclusively to sperm that have the Y chromosome for male calves, the bsmAbs prevent the sperm from fertilising eggs, resulting in >85% heifers among the calves.
Using Pre-Mating S-B STRAWs
For artificial insemination, technicians simply perform a double insemination with two separate straws, first with the antibodies containing pre-mating S-B STRAW, then with any un-sexed semen straw.
With the pre-mating S-B STRAW’s content in place, immediately after a positive heat detection, expose the cow to the bull there and then. Alternatively, artificial insemination should take place with a chosen un-sexed semen straw at the following milking. After nine months there will, in over 85% of cases, be a heifer calf.
Storing Pre-Mating S-B STRAWs
Pre-mating S-B STRAWs can be used at almost any time during a cow’s breeding cycle, from one week after the last heat to, at the latest, straight after a cow has been mated by a bull or by DIY artificial insemination.
The sealed pre-mating S-B STRAW can be stored in the LN2 tank, the farm fridge, or even an ordinary esky away from direct sunlight at around -4°C.