🐄 Cattle Synchronization Calculator
Calculate exact protocol dates, TAI date, pregnancy check, and calving date for your herd
| Protocol | Total Days | Injections / Steps | Est. Pregnancy Rate |
|---|---|---|---|
| 7-Day CO-Synch + CIDR | 9 days | GnRH D0 + CIDR insert; Remove CIDR + PGF2α D7; GnRH + TAI D9 | 50–60% |
| Ovsynch | 10 days | GnRH D0; PGF2α D7; GnRH D9; TAI D10 | 45–55% |
| CIDR-Synch 7-Day | 7 days | CIDR insert D0; Remove CIDR D7; PGF2α D7; TAI D9–10 | 45–55% |
| MGA-Prostaglandin | 31 days | MGA fed D0–14; PGF2α D31; TAI D33–34 | 50–60% (heifers) |
| Select Synch + CIDR | 9 days | GnRH + CIDR D0; Remove CIDR + PGF2α D7; Heat detect + AI D9–11 | 50–65% |
| 5-Day CO-Synch + CIDR | 7 days | GnRH + CIDR D0; PGF2α D5 (AM); PGF2α D5 (PM); Remove CIDR D5; GnRH + TAI D7 | 55–65% |
| HEAT Detect + Timed AI | Variable | Estrus detection 12–14 days; TAI at detected estrus | 55–70% |
| Drug / Item | Per Animal | 25 Head | 50 Head | 100 Head |
|---|---|---|---|---|
| GnRH (Cystorelin/Factrel) | 2 mL | 50 mL | 100 mL | 200 mL |
| PGF2α (Lutalyse/Estrumate) | 2 mL | 50 mL | 100 mL | 200 mL |
| CIDR Insert | 1 unit | 25 units | 50 units | 100 units |
| MGA Supplement | 0.5 mg/hd/day | 175 mg (14d) | 350 mg (14d) | 700 mg (14d) |
| Semen Straws | 1–2 per AI | 25–50 | 50–100 | 100–200 |
| Synch sleeves + gloves | 1 set | 25 sets | 50 sets | 100 sets |
| Protocol | Day 0 | Mid-Protocol | TAI Day |
|---|---|---|---|
| 7-Day CO-Synch + CIDR | GnRH + CIDR in | Day 7: Remove CIDR + PGF2α | Day 9: GnRH + TAI |
| Ovsynch | GnRH | Day 7: PGF2α; Day 9: GnRH | Day 10: TAI |
| CIDR-Synch 7-Day | CIDR insert | Day 7: Remove CIDR + PGF2α | Day 9: TAI |
| MGA-Prostaglandin | Start MGA feed | Day 14: Stop MGA; Day 31: PGF2α | Day 33–34: AI |
| Select Synch + CIDR | GnRH + CIDR in | Day 7: Remove CIDR + PGF2α | Day 9–11: AI on heat |
| 5-Day CO-Synch + CIDR | GnRH + CIDR in | Day 5: 2x PGF2α + Remove CIDR | Day 7: GnRH + TAI |
| HEAT Detect + TAI | Begin observation | Detect standing estrus | AI 8–12 hrs post-detection |
Cattle synchronization intends to have a group of cows or heifers cycling simultaneously so that all enter heat during the same period. Beef cattle naturally follow a 21-day estrous cycle but you can change that time by means of a good synchronization method. That procedure operates by means of hormones that urge the reproductive system of the cow, controlling when it will enter estrus and ovulate.
Organize synchronization program give big advantages to beef producers during the breeding season. The main profit? Submission rates mount.
How to Synchronize Cows for Better Breeding
If you synchronize before start the breeding outside, you ensure that more females cycle well and are ready to match early in the window, that directly causes higher pregnancy for the whole group.
Here the key cause: estrus synchronization forms the base of a good AI program. You give a series of hormones to a group of cows or heifers, timing everything so that they are fertile almost simultaneously. That predictability simplifies the cause to know when the creatures genuinely are ready.
New estrus synchronization and fixed-time artificial insemination protocols altered the game, producers now can match more cows in a shorter time and improve the whole reproductive impact of the group.
Synchronization protocols range a lot, and almost every producer finds one apt for his farm. They combine different hormones, different delivery methods (injections, vaginal inserts or feeds) and differ according to handles and need to observe heat. Because the field continuously progresses, those methods adapt with new techniques that are tested and refined.
Synchronize estrus also simplifies the work for the team. Rather than lose hours searching heat, you work according to clear data. Research and technological progress of the last ten years well explained the reproduction of livestock, so now it is much more easily to control estrus and ovulation in replacement heifers and postpartum cows.
The 7 and 7 Synch protocol deserves attention. It shortens the postpartum interval at cows and helps creatures that are not in ideal condition. It also gives good results with horned livestock.
On Day 0 you enclose a CIDR and inject prostaglandin.
Logistics matter more than you think. Cows that go comfortably through the holding space and chute have more chance to conceive than stressed ones that run chased. A closed area for heat checking spares time, only care about feed and water during that period.
When you choose a protocol, consider your targets, available work and what is possible by means of your resources. The Beef Reproduction Task Force issues updated protocols annually, and the Estrus Synchronization Planner tool helps to create daily timetables for every task in smooth synchronization.
