With white sheep, as well as specks . Typically ,when they begin to mature ,they are done ,Genetics is everything. If they are least buy opened up at points of shoulder, neck set is not right, or least buy tucked up in flank, they do not hold well. They just mature faster. Particularly if they are more moderate framed to begin with.
Most of our winning specks,have been out of the Dorset rams we have used ,and Suffolk ewes. They will tend to last longer into the year, than hampy Dorset crosses.
The bf rams on white ewes, definitely mature faster ,in my observation. .
And a white or speck, will test your feeding ability. If you get them fat early, your facing a very hard battle.
The specks I have sold at Midwest Stud ram sale, all went to California. Last year's April class winner ,into a high profile flock, can't remember the year before. Last year's buyer, said that is the " newest rage" out There. Good luck. A "GOOD " speck is just as hard to make , as any other good one . And and harder to feed.IMO.