how long is the journey ?
The stress of travelling and arrival at the abatoir might well offset the testostorone
In short, I don't know, but there are a lot of factors; journey time, precocious of lamb, is the ewe in season, how long after arrival will they get seen to and will they be in the same pen ?
I can't see it being an issue, to be honest
What's happening to the meat ? If to a high end restaurant, it would be different to in your freezer ?