Ovsynch & Heat Synchronization Protocol Builder
Every injection, on the right day and hour.
Choose a synchronization protocol and a start time. Get the full timeline of GnRH, PGF2α and CIDR steps, the timed AI or heat-watch window, a printout for the farm team, and reminders for your phone calendar.
Synchronization Timeline
Steps keep your start time, so an 08:00 start means 08:00 injections.
Timeline
Doses depend on the product. Always use the dose on your product label and follow your veterinarian's advice.
Timed AI vs. Heat-Detection Protocols
Synchronization protocols use GnRH, PGF2α and progesterone to control when animals ovulate.
Timed AI protocols (Ovsynch, CO-Synch, Presynch-Ovsynch, Double Ovsynch, G6G and the CIDR protocols) time ovulation closely enough that every animal is inseminated at a set hour, with no heat detection. The intervals matter: in Ovsynch, the second GnRH comes 56 hours after PGF2α and AI 16 hours after that.
Heat-detection protocols (single or double PGF2α and Select Synch) bring animals into heat within a few days. You still need to watch for standing heat and inseminate about 12 hours after it is seen.
Presynch-Ovsynch, Double Ovsynch and G6G are presynchronization programs designed for the first service of lactating dairy cows. Ask your veterinarian which protocol suits your herd, your heifers and your buffaloes.
How to use this calculator
- Pick a protocol. The list is split into timed AI and heat-detection programs, and the blue box under the form shows which animals the protocol is meant for and its published source.
- Set the start date (day 0) and the time of the first injection. Choose a time your team can keep for every visit.
- Choose cows or heifers. In the 7-day CO-Synch + CIDR protocol this changes the time of the final GnRH and AI.
- Choose a PGF2α product to see its usual label dose, or leave "Dose as per product label". Add a group label, such as a pen name, if you run more than one group.
- Print the timeline for the people giving the injections, and press Add to calendar (.ics) to get phone reminders.
Reading the result
Each row is one visit: the date, the clock time and protocol day, what to give, and a note on the interval where timing is critical. The green row is the timed AI. For heat-detection protocols an amber row shows the days to watch for heat; check at least twice a day and inseminate about 12 hours after standing heat is seen. A red box appears if a protocol uses a product that is banned or restricted in many countries. Doses on the timeline are examples from typical labels, not a prescription: use the product you have, at its label dose, as your vet directs.
Common questions
Can I start at a different time of day?
Yes. The whole timeline moves with your start time and keeps the intervals between steps. If a step falls at night, talk to your vet before shifting it, because changing the 56-hour and 16-hour gaps can lower conception.
Why doesn't the tool give exact doses?
Doses and injection volumes depend on the product and its strength. Use the dose on your product label. For PGF2α you can pick dinoprost or cloprostenol to see their usual label doses.
Does this work for buffaloes?
These protocols were developed mainly in cattle. Ovsynch and CIDR-based programs are also used in buffaloes, but response varies with season and body condition. Plan buffalo programs with your veterinarian.
Can I start a protocol on an animal that might be pregnant?
No. PGF2α can end a pregnancy. If an animal has been bred since she last calved, have your vet confirm she is not pregnant before day 0, and keep breeding records up to date.
What if an injection is missed or given late?
Do not simply carry on as if it was on time. Tell your vet, who may advise restarting the protocol or breeding on observed heat instead.
What comes after timed AI?
A pregnancy check. Enter the AI date in the gestation calculator to get the ultrasound window and the expected calving date. Animals found open can be synchronized again; ask your vet which program to use.
References
- Pursley et al. (1995), Theriogenology. Ovsynch.
- Brusveen et al. (2008), Journal of Dairy Science. Ovsynch-56 timing.
- Moreira et al. (2001), Journal of Dairy Science. Presynch-Ovsynch.
- Souza et al. (2008), Theriogenology. Double Ovsynch.
- Bello et al. (2006), Journal of Dairy Science. G6G.
- Bridges et al. (2008), Theriogenology; Santos et al. (2010), Journal of Dairy Science. 5-day CO-Synch + CIDR.
- Pancarci et al. (2002), Journal of Dairy Science. Heatsynch.
- Beef Reproduction Task Force. Recommended synchronization protocols (CO-Synch, 7-day CO-Synch + CIDR).
Decision support only. Not a substitute for your veterinarian.