Many producers purchase rather than raise their replacement females for several different reasons. While initial cost is often the main "selection" criterion used, it's not the only consideration and not necessarily the most important. Many other factors should be considered.
The most common sources are herd dispersals, special replacement sales or local auction barns. Often, little to nothing is known about these prospective females in terms of genetics, health and previous management. Still, with planning and effort, replacements can be found and chosen that have a good chance of maintaining herd productivity. Once a producer is sure the cow size, breed type and limited calving season are appropriate for his goals, resources and management, he should define a set of criteria to use when considering replacement females for purchase.
Additions should match the existing herd's mature size, breed type and stage of reproduction, preferably the early part of the calving season. The 2000 National Beef Quality Audit identifies the top quality concern facing our industry as "low overall uniformity and consistency of cattle, carcasses and cuts." Whether you produce 25 or 2,500 calves, and market at weaning or post-harvest, uniformity and consistency are important to you and the industry. According to work done by Oklahoma State University, the advantages of uniformity are paying out every day at local and terminal auctions to the tune of a $7.50 to 9.00/cwt advantage for uniform calves in lot sizes greater than five head.*
Visual inspection should always be a part of the equation. Soundness is any physical trait that enables a female to wean a calf every 365 days ability to travel, feet, legs, and udder, eyes, etc. Disposition should also be appraised at this time.
Almost never consider replacement females that are in a body condition score (BCS) of 4 or below. As a cow drops below a BCS 4, she will begin to mobilize muscle tissue in order to meet her nutritional needs, negatively affecting your ability to appraise muscling characteristics. Also, a stressed cow is susceptible to a host of other problems that may not be evident yet. On the other end of the scale, you may want to avoid overly fat animals of BCS 8 or greater.
Your herd's health program, developed with your veterinarian, should include a protocol for new purchases. He may recommend a quarantine period of 30 to 60 days and testing for specific diseases, such as Johne's and persistent infection of bovine viral diarrhea, before moving new females to the main herd.
Define your selection/purchase criteria and expected price range, but don't necessarily etch them in stone. Just be aware that any departure from your criteria probably comes with added costs of some kind. Value (discount) perceived "bargains" fairly when you're comparing.
*Oklahoma Cooperative Extension Service Publication E-955.