I bought some shetland shearling ewes off a farm who had the ram lambs away each year by 12 months, weighing 40ish kilo
But I knew a farm who had a smaller less "commercial" type who had them away at 14-18 months.
I have two types of shetland ewes, short and wide or tall and lanky, I havnt had pure shetland lambs before, only crossed them, these crosses can be finished at 6 months on grass alone, 40ish kilo
Im guessing if I have any pure shetland rams, they may take 12-14 months to finish pure as I have lots of overwintering ryegrass from a dairy farm.
However the shetland ram covered all my big ewes and the commercial ram covered my first timers (well I think so anyway) but would have to wait and see who pops out what!
Commercial ram is a Hampshire down cross Charollais and really shouldnt have gone onto first time shetlands who are rather short (but wide)
I find the rams dont get aggressive as they dont have any competition? as I dont feed them at all and just look at them really, dont handle them much either
I have a shetland ram whom I havnt touched since october 13 and I caught him last week and was walking him around on a halter (for the first time ever) he is a big boy and has a lovely wide back
So I dont know about aggressiveness!!