Ask the Vet

Thoughts on Timed AI Protocol

Going to a timed AI approach to breed early calvers is one way to keep a productive herd. (DTN/Progressive Farmer file photo by Boyd Kidwell)


For years I've used artificial insemination (AI) on early calvers to increase quality and genetic diversity in the cow herd. I used the CIDR Synch protocol, bred cows in head and had good success. My arthritis has gotten to the point, however, where I just cannot do it anymore. I am thinking about trying timed AI and hiring an AI technician to breed my cattle. What are your thoughts on time AI?


As you probably know there are more synchronization programs out there than you can shake a stick at as we say in the South, and many are timed AI (TAI) protocols.

There is a relatively new program we have had very good success with called the 7+7 Synch protocol. Cattle are given prostaglandin (Lutalyse, Estrumate, etc) on Day zero. On Day 7, cattle are given GnRH (Cystorealin, Factel, etc.) and have a CIDR implanted. On Day 14, the CIDR is removed, and a second prostaglandin injection is given. Then on Day 17 (or more precisely 66 hours) the cows are AIed and given a second injection of GnRH.

Most trials have demonstrated higher pregnancy rates with this protocol than other protocols. Some have reported 80% or better conception, but conception rates vary widely in real world operations based on many factors from nutrition and body condition to skill of the person doing the AI.

There are many good articles available discussing this protocol. I think it is worth a look for all producers, but it really may fit the bill for you.


Editor's Note:

Please contact your veterinarian with questions pertaining to the health of your herd or other animals. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.

Write Dr. Ken McMillan at Ask the Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email