I'm not sure whether you were referring to Air Gator, or me with your question.
No targets. Just seeing the whys and the whats.
Having all low BW cattle is a way to get out of part of the bull market and to focus on one fraction. Folks with commercial cows that buy in cows do not want or need low BW, in general. I guess I am wondering on the "want" or "need" portion of low BW selection from anyone to comment.
1. The difference between CED epds and the calving ease star ratings ABS uses
No idea but I do know from experience when a young star bull flops there are no rebates for the folks who found out as paying customers. Sales enhancement, most likely.
2, a question of whether or not breeders had a "magic number" (whether it be CED or BW) for selecting bulls for heifers. I was not advocating for extreme low birth weight bulls, I was simply asking for feedback from experienced breeders.
The background of the heifers are as important as the bull. If her mama or sire was a high BW it will show back up. And you have to trust the breeders who have submitted the data. A couple of folks have told me over the years how to skew data for a few hundred $s. So it must happen if it is discussed around and about.
If you look at some large breeders and they have flushmate sisters (or brothers) it seems that they keep the lower birthweight calf (unless the other calf is exceptional).
It can also be an indicator that they NEED lower BW? Any corrector bull, extreme selection or different type brought into an established herd or program has been chosen to fix KNOWN problems by the breeder or else the ourchase is a political deal. Why do you or I go to the store to buy bandaides? We have a skint place! Same for folks with umpteen bulls and tanks full of semen. They are looking for a quick cure of known needs.
Connealy Confidence has a +20 CED and a -3.3 for birthweight. If I had a cow or heifer with a large birthweight herself, why wouldn't I want to moderate the birthweight by using a bull like Confidence?
I do not want a cow or heifer with high BW because it will not be gone in one generation.
Another thing to consider are the bulls who have a high CED epd as well as a high CEM epd.
If needed on CED and I do like to be sure that a source, line or herd is trending positive on CEM. If not, watch out.
The bull with these I think of most frequently that fits this is Sav Bismarck.
I've heard about offspring and don't plan to use him. But I never planned to use him anyway.
If breeders are "managing" cattle you are trying to get live calves and maintain the ability of heifers to calve without assistance. I like the idea of a a curve bender. A bull with a +10 CED and a YW epd of 100+. Not easy to find but why wouldn't you like a bull like that? (unless they are phenotypically a train wreck). I believe one of the reasons why you have so many breeds with black "purebred" animals (Limousin, Simmental, Gelbvieh, etc.) is because breeders were able to moderate Fullblood birthweights that had been unacceptable to bull buyers.
Whole difference of philosophy on breeding. Classic genetic pattern: BW tied to YW and such. Curvebenders defy normal genetic trends. My question: will the genes stay stable in a non-classic genetic linkage? I really doubt it. Same type thing for high BW bred to low BW to get moderate BW. That is first generation hope. Go to classic second generation diagram of possible gene pairs; aa, aA, AA and Aa. Where is the stability of genetics? The bell curve gets wider and shorter in the 2nd generation: more potential differences.
Not disagreeing, just writing. I have a bullseye and aim for the center and have the hope of it getting all of the arrows.