Thanks. I'm wanting a good duel purpose breed and was pretty set on the Biels but now* after hearing about their heat intolerance I'm wondering if I shouldn't reconsider. I was very drawn to the auto sexing function, hence my questions regarding preserving auto sexing in crosses. I still have a Birl hen but I'm gonna do some research on a breed (eta:for a roo to cross with the Biel) that continues to auto sexing feature but maybe brings in a better tolerance to our extremely hot summers.
I hear you, the heat problem is giving me concern as well. Right now I'm looking into Cream Legbars which are also auto-sexed. While they don't lay a huge egg, it is a very pretty blue egg.
But then again, I see that Greenfire Farms is in Florida, of all places. Given that I've recently moved to NC from the Sunshine State, I can guarantee you that it is HOT and HUMID down there 11 months out of the year. And Omega Hills is in Alabama, also a pretty sultry state. So maybe their stock is becoming acclimated????
Heat can be a definite issue, as it has been this past summer here in AZ where temps of 105 were common, but it doesn't have to be a deal breaker. My Biels were fine with frozen bottles to lay against, lots of well-ventilated shade, and moist earth to stand and lay on when it was 95 degrees and 47% humidity, as long as it's not all day long. If your summers are not excessively hot then it should be fine.