There is a more direct communication between the blood in the vulva and the uterus and ovary.
It is possible to capitalize on this when administering reproductive hormones and reduce the dose required to achieve the desired response.
Use a 21 gauge 5/8” needle (piglet iron injection needle).
Massage the side wall of the vulva concentrating on the area where the vulva meets the normal skin of the back of the sow.
Inject just above this junction – on the vulva side keeping the needle perpendicular to the skin.
Remove the needle and syringe
The injection may sting the sow/gilt who may even jump up.
Relieve the pain response by vigorous rubbing of the area and the pain response will quickly subside.
Use of this technique
By injecting intravulval the dose of some reproductive hormones can be halved. For example:
Prostaglandin – PGF2α – used to induce farrowing.
Instead of a 2ml dose use 1 ml 18 hours before expected farrowing date – and no sooner than 114 day of gestation.
Oxytocin- use 2.5 IU – this is 0.25ml if the concentration is 10 iu/ml. to assist farrowing
Oxytocin – use 5 IU – this is 0.5ml if the concentration is 10 iu/ml to assist milk let down and to assist cleaning the uterus (ecbolic).