Procedures that support reproductive management of replacement beef heifers

Abstract

Selection and management of replacement beef heifers involve decisions that affect future productivity of an entire cowherd. The decision to breed heifers as yearlings involves careful consideration of the economics of production and the reproductive status, breed type, or genetic make-up of the heifers involved. Reproductive competence is established as a consequence of a specific program of developmental events leading to organization of functionally competent reproductive tissues and organs. The timing of puberty is critical in determining whether a heifer remains in the herd and the extent to which lifetime productivity is achieved. Because most components of fertility that influence calving and subsequent reproductive performance are not highly heritable, it is logical to assume that the majority of factors related to reproductive performance in cattle are influenced almost entirely by management. Utilization of various prebreeding management technologies enables producers to improve breeding performance of heifers during the first breeding season and during the subsequent calving and rebreeding period as 2-yr-olds. These practices help to ensure that heifers entering the herd as raised or purchased replacements will contribute to the general performance and productivity of an entire cowherd immediately, and cumulatively long-term. This review examines the relative merits of these various practices and provides an assessment of the adoption rate of specific reproductive management procedures for replacement beef heifers.