we keep moderately sized feminine heifers. we make a couple cuts. when fields are weaned, steers are for the most part shipped as bawlers and a large first cut of the heifers are too. the dinks and jumbos that dont fit anything are then sorted off the heifers. if my goal is to keep say 400 heifers, i may start the process with 500-600 "potential replacements" wean them let them all grow up over the summer in the case of California. after a few months, we will sort again and sell or send to feed 1-2 loads of what typically winds up being very attractive feeder heifers we have sorted off what we viewed as the bottom cut of the replacements. in recent years, many times those heifers have gone on to be made into cows by other operators. also the last few years, we have sorted some front end type cows into pasture groups and bred them to sets of full brothers that we felt had an opportunity to help build a nice replacement with an eye on keeping a greater % of those heifer calves than other fields. as our California cow herd has grown to a greater percentage of angus we have been doing this with hereford bulls to a greater extent with and eye on making more baldy and brockle face heifers with a higher degree of heterosis. we do very much the same thing with our Nevada heifers but due to the demands of the harsh country, even more importance is placed on a moderate heifer that will grow up to be an efficient mother cow. I'm sure there is no "set" way or answer but after some trial and error over the years, this fits us pretty good. i know some other large operations keep more heifers as a percentage of their calf crop and sell their cows younger, as they feel the revenue from selling bred cows makes this lucrative and for them it very well may be. we've always had the view that those middle age to older cows dont lose enough ground in terms of pounds of beef weaned to outstrip what they bring to the table knowing the country and how to get the job done. infact, for about 12-15 years now we have sorted about 100 head of our oldest cows into one field where they can be babied a bit if need be and with little to no increase in the care/feed/supplement, they wean calves right along with all their younger peers. it does bear mentioning though, that at preg check, all cows are mouthed and any smooth mouth cows are sent to town along with the opens in our California program and the next rung younger (1-2 teeth) would most of the time go too in Nevada due to the big tough country they run in.