Ask the Vet

Implants May Decrease Heifer Fertility

Before implanting heifers that will be bred, consult with a veterinarian to be sure fertility won't be affected. (DTN/Progressive Farmer photo by Becky Mills)

Question: We always implant bulls and steers, but we have never implanted heifers. My neighbor told me he implants everything and I'm wasting money by not doing the same. What do you think?

Answer: I don't recommend implanting heifers that you know you want to breed. Others will disagree with that statement.

The data is far from consistent and conclusive on the best course. Some of the confusion is due to the multitude of variables involved. There are many different implants with different mixes of hormones. Some implants are more likely to decrease fertility.

Timing can also be important. Studies have shown heifers implanted with Ralgro at birth had a 35% decrease in pregnancy rates. Results from other studies when the same implant was given after 1 month of age have been all over the board. Some showed improved conception, others decreased conception and others no effect. Most of the studies showing decreased fertility were with heifers at low nutritional level, but when heifers were fed to gain at least 1.1 pounds per day to reach breeding weights, the implant had little to no effect on fertility.

Studies where heifers were implanted more than once have been equally mixed, but several have shown significant decreases in fertility. I am even more wary of this practice.

If you're considering implanting your heifers, the best advice I can give is to consult with your veterinarian. Be sure to read the label on the implant you plan to use. Administer the right implant at the right time for your operation. Your veterinarian can be helpful in this decision process.