Some of being "proven" is just as much art as science, TTB.
I don't mean to be evasive, but it will vary from breeder to breeder.
I like high accuracy, but if I can't get it, then I look back in the pedigree to evaluate how a couple generations have bred relative to their parental EPD. Are they breeding on like their pedigre, or are they changing? If they are changing, then it will put the other EPD that take longer to measure (DCE, Stay, Milk, HFR PRG, ME) out of whack relative to the pedigree.
In other words, if I like 5 or less for ME EPD, and I find a bull that is 80 for YW, then I suspect that he will either come up for ME or go down for YW as his daughters come into production. This business of guys talking about watching ME while rolling generations to still get more growth is BS. You must certainly know who I am refering to!
It takes TIME to build accuracy in the ME EPD. Really, there are not very many REALLY proven bulls for that trait, so art has to come into play. I will be a small breeder for a long time, and some of my bulls sure won't see heavy use, since I have no established reputation, therefore, I am forced to use art and other science (biological relationships), rather than EPD accuracy science. Some of that just gets down to not using bulls from folks that don't weigh mature cows. When you begin to set a few limits, you naturally gravitate towards others that think like you. It limits some genetics, but also acts like a ratchett to limit troubles, too.
Well, you can tell that ME is important to me. +5 is about the highest I will go. In establishing the variation I want to get started, I might use a couple higher bulls on some lower ME cows. For my country in MT, I like just a little above average WW and YW, but that is dangerous to use percentiles to breed with, as averages change over time. So, 35-40 WW 65-75 YW, below average BW, 15-20 milk. Pretty "vanilla" sort of stuff isn't it? But, with my background in FE the last 5 years, I intend to incorporate that, too.
Moderate frame, usable cattle with acceptable growth and carcass, with FE.
I'll probably outcross to some Black Angus cattle that are documented for FE, so I don't have to wait as long or spend as much money. It won't be the BA that are currently being usedfor outcrosses, although some of them are FE, and will be more FE than mine, at least to start with.
Yep, mom flew in from Rapid City last night for a visit. It was a hard enough frost there yesterday AM they slide in the ditch getting to the airport, but it warmed up. She land here and today we have about 8" of snow which is more than what we have had all year.
Take care.
Badlands