This is just my opinion, ok? At today's prices, I would sell the hell out of any and all calves...bull or heifers. When you retain one...6 mos old at weaning, it will be 2 and 1/2 year before you wean the 1st calf off of her to sell. I watched 300 weight heifers bring plus or minus $3.35 a pound yesterday in several places across the country. 400 weights bring $2.80 - $3, and 500 weights bring over $2.50/lb. When good cows can be bought for $1k or loess, and calves are down at $1.50 a pound, it might be worth raising one ( not to me).
Most genetic defects in mammals are carried on recessive genes. Takes 2 copies of the gene to manifest. Think about it...if they were dominant instead of recessive, then most of a species would be affected. When inbreeding works out, it is the exception more so than the rule. You can have a cow with traits you like, but you don't have to breed her to her son to get other good calves. You can find a bull that is unrelated that also has the traits you desire. Same with a bull that throws calves you like. Don't have to breed him to his dam or daughters, to get other claves with the traits you like. There is a reason other than religious reasons, that incest was always taboo in most all human societies. Even in primitive societies, long before any science, much less genetics were present, that man had an instinctive aversion to it.
That being said, if one wants to retain heifers, there are several ways to avoid in-breeding. Two neighboring dairies back when I was growing up, would swap bulls to breed to their cows sired by their own bull. I knew several small beef cow-calf operators, that would go buy a 900 lb or so Angus bull at the sale barn....keep it a few months to breed their cows, then carry it to the sale. It had gained some weight, and would sell for what they paid for it....maybe a little more.. maybe a little less, and just buy another one the next year. They thought it ridiculous and a waste of money to fool with and feed a bull year round. Retaining heifers might be easier than trying to buy replacements for their cows. and selling a bull and finding another one, is easier than having to find multiple cows or heifers to buy. Many commercial operators with moderate to smaller sized cows, are going to sell the bull once he approaches a ton in weight anyhow. Or once he is 5 years old or so.
If you sold those 3 heifers at weaning, and took the money to buy a good cow or two, you'd be money ahead 30 months later, before you got the first calves out of those heifers. Those cows would have already given you 2 calf crops. If you are thinking of retaining those 3 because their mommas are about to age out, take them to the sale too, and you will make enough money to buy three absolutely bodacious, mac-daddy registered cows, and have some cash left over.
Another factor to consider is the quantity and quality of the cattle available to you in your area. And the distance to them. There is now less than 50% of the sale barns around here now than there were 20-25 years ago. And way less cattle operations here in north Ga, than there were at the turn of the century, But there is still a weekly sale barn 20 minutes from me, and several more within an hour or so. This may not be true for our Wyoming, Montana, Canadian etc, members. How about you?
Hope this helps. Ever how many CT forums members there are, is about how many different opinions and ideas about this subject you can get. Like many have said on various threads here on CT, there is more than one way to skin a cat.
Maybe there is a link to one groups culling practices vs the other that is causing the fear vs confidence.
