Rarely is this adequately considered when budgeting for replacement female purchases. The additional requirements through the third pregnancy must be budgeted. Most other classes can be considered low except when purchased in a thin condition. Requirements in this situation may range from high to moderate depending upon time to next breeding. Cull rates are one of the most difficult numbers to estimate or project for use in budgeting options.
Most budgets grossly underestimate cull rate of purchased females.
This will include cows culled for not rebreeding, poor udders, structural unsoundness, health related problems, disposition, and any possible death loss. In some cases, cows which should have been sold for poor performance will be held for this second year which ultimately lowers weaning weights again. Again structure, udder and rebreeding will remove the bulk of these in the second year. Now, in the case of older purchased females, age becomes a factor. There is no easy answer to the question of what should be bought.