A breeding ewe, unless of a breed like Dorset Down, is likely to have lambs only every 12 months.
However, any ewe lambs may be impregnated by the tup before they are old enough and fit enough to be getting pregnant.
Also, any ewe which loses her lambs (aborts) may then take to the tup at an odd time of year, and you may not then know when to be watching her closely and be in a position to help if she needs it.
The usual solutions for a very small flock are
- Do not keep a tup at all. Borrow or hire a tup or a tup lamb for 3-5 weeks each year.
- Buy a tup lamb each year, use him and then eat him.
- Have your own tup, but run him with a local farmer's tups (for a fee, of course) when not needed for work
- Send your ewes to a local farm for tupping
- Don't breed. Buy store lambs to fatten each year.
Note that in the first 3 cases, you will still need to keep your ewe lambs separate when the tup is working. So if you don't have 2 fields, you have a problem. (Even if you think you will always have all your lambs off to the abattoir before 7 months old, you will get a year when one was ill and wasn't fit at 7 months, or some other curve ball.)