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Why Use a Teaser Ram? And How?

Why Use a Teaser Ram? And How?

Teaser rams are entire rams that have been vasectomised. They have both testes still so they are keen to do the job but the operation has rendered them infertile - permanently. They are used to encourage ewes to begin oestrus activity in autumn and if used correctly the teaser rams can get this oestrus activity very well synchronized. This has some big positives - read on.

Here is some data to show what happens with the teaser effect. This is real data from lambing 2009 on one farm.



 Not teased

Ram joining date

10 March

5 March

Due start of lambing

6 August

1 August


1 August

1 August

% lambed by due date



% lambed within 7 days of due date



% lambed by 13 August



So nearly all teased ewes lambed within a week of due date while the lambing beat for the earlier mated and unteased ewes went on for another couple of weeks.

For best results...

  • Use the right rams- they must be “horny” breeds that are very sexually active. These are preferably Poll Dorset, Finn or Suffolk. Not old retired sire rams, not hoggets and not traditional breeds.
  • Use good rams - we can surgically prepare some of your rams (at $70/ram it'd be cheap at twice the price) or you can buy some ready-to-go from a couple of local breeders.
  • Get the teasers prepared well in advance. They need time to recover from their operation.
  • Get the timing right. You need to talk to us to get this spot on. Get it wrong and you will lose more than you stood to gain!
  • Use them with your hogget ewes after they have been with the MA ewes. That is value for money. Timing is important here too.

Basically, if you follow the recipe it will work- a predictable start to lambing, more lambs born early, earlier docking (and less shedding), more lambs sold at weaning and more money. If you are terribly risk-averse you will not want to do this though- the single biggest reason given for not using teasers is the risk that one storm may kill too many lambs. But what is the chance of three southerlies in an extended lambing against one in a very short lambing?

Teasers have some significant benefits for ewes mated in February or March in HB and have similar benefits for any hogget mating programme. As a sheep farmer this is one of the cheapest animal husbandry techniques you can use in terms of real monetary payback. Give it a go - those farmers using teasers already can't be wrong!

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