Before I even start this blog, I want to say that my approach is “less is more” when it comes to using hormones to A.I. cows or heifers. That being said, life is not perfect, and we can not set aside our entire life for 30-60 days to get all of our cattle A.I.ed at the perfect time. There are many different regimens that I use to synchronize, but they all include at least 2 of the following drugs: Lutalyse, Cystorelin, and CIDRs. I will highlight my 3 favorite regimens.
1. When I want to keep the cattle fairly close together, but I have some time to heat check and A.I. for several days, I use this. Heat check for 5 days and A.I. cow or heifer 12 hrs after standing heat is observed, then on Day 6, give a shot of Lutalyse to any cattle not A.I.ed and apply heat detection patch on tail head, then heat check an additional 5 days and A.I. any cattle 12 hrs after standing heat is observed. The total number of days is 11. 1/4 of the cattle only go through the chute 1 time, and the other ¾ of the cattle go through the chute 2 times and only get 1 shot of Lutalyse.
2. In times when I have more time immediately, and my working facilities are better, I use this schedule. On Day 1, I give all animals a shot of Lutalyse and apply heat detection patches to the tail heads, then heat check and A.I. all animals demonstrating estrous 12 hrs after observing them in standing heat on days 1 thru 6. All animals that did not have a detectable heat and were not A.I.ed, approximately ¼ if all animals are cycling, are given a second shot of Lutalyse, then detect and A.I. all animals 12 hrs after observed in standing heat for an additional 5 days. Total number of days is 12. ¾ of the cattle go through the chute 2 times and only receive 1 shot of Lutalyse, and the other ¼ are run through the chute 3 times and receive 2 shots of Lutalyse. This regimen is different than the typical 2 shot method because ¾ of the cattle only get one shot of Lutalyse, and more of the cattle are run through the chute less times.
3. The last method is used when a mass A.I. is planned, or a minimal number of days are available to A.I. cattle. I prefer heat checking and A.I.ing animals observed in standing heat, but sometimes it just isn’t feasible. Day 1, a CIDR is applied vaginally to the heifer or cow. A shot of Cystorelin can also be administered at this time. On Day 7, the CIDR is removed, a shot of Lutalyse is injected, and the heat detection patch is applied to the tail head. At this point, cattle can either be heat checked and A.I.ed 12 hours after observing standing heat over a 5 day period, or all cattle can be mass A.I.ed 60-72 hours after the CIDR is removed.
When A.I.ing cattle, either after a natural heat or synchronized heat, I like to administer 2cc of Cystorelin at time of insemination. Another money saving tip I just learned about is cutting the heat detection patches in half, thus doubling the number of patches for the same money.
Disclaimer: Any of your prostaglandin drugs such as Lutalyse and your GnRH drugs like Cystorelin, must be prescribed by a licensed veterinarian, administered according to their label. Any extra-label use of these drugs must first be discussed and approved by a licensed veterinarian.