Checklist for a Successful Estrus Synchronization and AI Program

By Sandy Johnson

Friday, May 1, 2026

Sandy Johnson, extension beef specialist, Colby

Achieving a high proportion of cows calving early in the calving season has a big impact on total weaning weight and subsequent rebreeding performance. Use of estrus synchronization, with or without AI, can help move herds in that direction. Paying attention to details year-round will help achieve the best possible results from an estrus synchronization and AI program. The following checklist is designed to help evaluate key aspects.

Herd Management

  • Pregnancy rate history after 60-day breeding season > 90% for mature cows, > 85% for first calf heifers
  • Body condition at calving ≥ 5 cows, 5.5-6 first-calf heifers
  • Body condition at breeding ≥ 5 cows, 5.5 – 6 first calf heifers, 5-6 yearling heifers (fatter is not better)
  • Majority of herd > 40 days postpartum at start of breeding, 20 days postpartum earliest time to insert CIDR in 5 to 7-day CIDR protocols.
  • Steady to increasing plane of nutrition before and during breeding season
  • Nutrient analysis of forages used to balance rations
  • Scale used to monitor body weight and allocate feed resources
  • When grazing, appropriate stocking rate for available forage
  • Dry feed/forage available when grazing lush forages
  • Appropriate mineral supplementation for water and feed resources
  • No modified live vaccinations < 30 days before breeding (45-60 days better)
  • Functional facilities for sorting, treatment administration, and AI. Skilled labor that minimizes handling stress.
  • Transportation and nutritional stress minimized day 5 to 45 post breeding
  • Complete and accurate records to assist with troubleshooting

Synchronization

  • Synchronization system implemented according to Beef Reproduction Task Force recommendations, as shown in all major sire catalogs
  • GnRH and PG products administered using correct dose, proper technique, day, and time
  • Uniform daily MGA consumption
  • Dedicate sufficient time and skill to heat detection when used

Semen

  • Breeding soundness exam performed before semen collection
  • Semen received from CSS certified lab
  • Minimal and correct semen handling at all times
  • Straws not above frost line more than 8 seconds during handling
  • Semen inventory system in place
  • Appropriate type of sheaths on hand for AI gun
  • Clean AI gun, scissors, thaw unit and other equipment
  • Use clean thaw water, temperature monitored (94-98⁰ F)
  • Thaw semen according to provider’s instructions or not less than 45 seconds and not more than 10 to 15 minutes
  • Avoid temperature shock and exposure to UV rays when moving straws from the liquid nitrogen tank to the cow

Insemination

  • No contaminants introduced during insemination
  • Deposit semen slowly in the uterine body; push plunger forward and don’t pull the gun back