Tuesday, January 8, 2013

Wednesday, January 2, 2013

Are Your Cows and Heifers Good Candidates for Fixed-Time A.I.?

            One of the most common questions that I get from producers is, “How can I get the most out of my synchronization program.”  Synchronization and A.I. can add value to your bred females, but it also involves an investment of time and money, and you want to make sure you are getting the most bang for your buck. At the recent Applied Reproductive Strategies in Beef Cattle Conference in Sioux Falls, SD; Dr. Michael Smith from the University of Missouri addressed the issue of ensuring that your females are good candidates for a timed synchronization program and A.I.   

Here are Dr. Smith’s tips for a successful estrus synchronization and A.I. program:

Things to do before fixed-time artificial insemination
  • Keep accurate calving, breeding and pregnancy records.
  • Animal identification should be clear and easily readable.
  • Ensure herd health and disease prevention with a well designed prebreeding vaccination protocol.  Females should be vaccinated at least 30 days before the breeding season begins.
  • Decide which estrus synchronization protocol best fits your breeding program, facilities and personnel.
  • Ensure all products are purchased and on-hand prior to initiation of the protocol.
  • Prepare the calendar of actions to ensure protocol compliance.

Dr. Smith stressed that the females to be bred via fixed-time A.I. should meet a minimum criteria before enrolling them in the protocol:

Heifer criteria
  • Heifers should weigh 65% of their mature body weight by the start of breeding.
  • At least 50% of heifers should have a reproductive tract score (RTS) greater than or equal to 4 by two weeks prior to the start of synchronization or 6 to 8 weeks prior to the breeding season.
Cow criteria
  • Synchronize and inseminate only cows with a body condition score (BCS) at calving of  greater than or equal to 5.
  • The average days postpartum of the group of cows to be synchronized should be greater than or equal to 40 by the start of estrus and synchronization and have experienced a minimum of dystocia.
There are several factors that can contribute to favorable pregnancy rates with fixed-time A.I.  Following these tips for herd health, preplanning, and criteria for breeding females can help put you on the tract to success!  

Written By:  Sarah Thorson
Beef Education Manager