How is vasectomy surgery performed on a teaser ram?

The most commonly used methods for estrus detection in sheep are the external observation method and the ram teaser cloth method. However, their accuracy is poor and operation is inconvenient. This article introduces the method of using a ram with ligated vas deferens as a teaser.

1 Instruments, drugs and supplies

2% procaine hydrochloride, benzalkonium bromide, size 6 suture thread, suture needles, routine surgical instruments, razor holder (blade), towel, soap, gauze, 5% iodine tincture, 75% alcohol and normal saline.

2 Disinfection and restraint

Use right lateral recumbency restraint, pull the left hind limb forward and fix it to fully expose the surgical site. After clipping the hair at the surgical site, rinse first with clean water, then wash with 0.1% benzalkonium bromide and apply iodine tincture and 75% alcohol. Finally cover with a surgical drape. Disinfect the operator's arms with 0.1% benzalkonium bromide 2 times.

3 Anesthesia

Use intraspermatic cord nerve conduction anesthesia, injecting 2% procaine hydrochloride 6 mL into each spermatic cord.

4 Ligation of the vas deferens

Make an incision in the scrotal skin at the upper front midline of the ventral surface of the scrotum, with an incision of about 5 cm, bluntly separate the subcutaneous tissue and the scrotal sheath, insert the right index and middle fingers into the incision, locate one spermatic cord and pull it out of the incision, locate the vas deferens, incise the spermatic cord sheath, lift out the vas deferens with the knife handle, hook it with one finger of the left hand, and have an assistant tightly ligate together the two ends of the vas deferens at the dorsal edge of the finger, withdraw the finger, cut the vas deferens about 1 cm above the ligation site, apply 5% iodine tincture to the cut ends, then in the same incision locate the other spermatic cord and vas deferens by the same method, and ligate and cut the vas deferens. Apply oil-based penicillin 800,000 IU into the wound, close the skin incision with button sutures, and apply 5% iodine tincture to the incision.

5 Postoperative care and teasing

After surgery, apply 5% iodine tincture to the incision once daily, and remove the sutures at 7-10 d. A teaser ram that has undergone vas deferens ligation can be used for teasing at 20 d, and its libido shows no clinical difference compared with rams that have not undergone vas deferens ligation, and there are no abnormal changes in the morphology of the testes and scrotum. Under the condition of teasing 2 times daily, 1 teaser ram treated by this method can complete the teasing work for 30-40 ewes.