The document discusses key factors to consider when selecting breeding bulls and females for a grass-based cattle system. It is important to choose breeds suited to the local environment that can efficiently convert grass. Genetic information like EPDs should be examined, focusing on optimal growth and moderate milk production. Phenotypic traits like sound feet and legs, and proper udder and teat size are essential. Health records and the cattle's past performance history provide valuable insights. Purchasing replacements from one's own herd provides familiarity, but their success still needs to be evaluated. The overall recommendation is to do thorough evaluations of soundness, records, and genetics to find cattle well-suited to the operation's goals and management.