Vasectomy in the ram is a management technique used principally to increase conception rates in a compacted lambing period. The ewe flock is isolated for at least 1 month from sight, smell and sound of rams or wethers, after which a vasectomised ram is put with the flock for a period of 12 days. The vasectomised ram is then removed and replaced by normal rams. Provided the ewes were on the point of cycling, this results in a close compacted lambing, usually in two peak periods some six to eight days apart.
Rams chosen for vasectomy should be strong and healthy, with good incisor teeth occlusion, sound feet and no signs of any arthritic condition, head or brisket sores. Young rams are preferable to older failed stud animals because they are relatively easy to operate on and there is less risk of them having previously acquired transmissible disease. The chosen rams should have had some sexual experience and have well developed genitalia. The penis and prepuce should be normal, and it should be ensured that the testicles are free of any palpable lesions from Brucellosis.
The ram is sedated, and local anaesthetic is injected into the operation site. The procedure takes about 20 minutes per ram and there should be no complications post operatively. Antibiotics and anti-inflammatories are given after surgery. Vasectomised rams may pass sperm for several days after surgery and we generally advise to wait four to six weeks after surgery before using these rams. Remember this operation is not 100% guaranteed! There can be recanalization of the spermatic cord, but this is rare. The vasectomised rams should be joined with the ewes at a ratio of 1 ram to 200 ewes and left with them for 12 days. Vasectomised rams can injure themselves and tire just as easily as ordinary rams, so if you plan to use them over a period of time with different mobs, keep to this ratio, to give some of them a rest. Vasectomised rams will last for a good number of years but should be palpated each year for Brucellosis. The cost of the surgery and drugs is around $100 (excl. GST), which is an inexpensive way to increase conception rates and compact your lambing period.
As they are needed prior to the mating season, and do have a recovery period after surgery, now is the time to think about selecting some rams for surgery so that they are recovered and available for this coming mating season.