Use an implant approved for use in heifer replacements. Identify implanted heifers with a different color ear tag. Consider that buyers of replacements may discriminate against implanted heifers. If replacement heifers are not selected before implanting and the major goal is to maximize weaning weights of all calves, implant all heifers. Do not re-implant replacement heifers since this could reduce their fertility.
Insure nutrition is adequate to support target growth rates.
Never implant breeding bulls. This can cause permanent damage to their testicles. By keeping a clear management objective in mind, you can reach a rational decision about use of implants in the brood cow herd. Read the instructions for each delivery device before using it. Also, carefully read the label before using any implant.