Cattle owners have many reasons for having their cows calve at a certain time. Especially those with show cattle that need to be born for a specific show season. This is true in both beef and dairy animals.
In our case, we have an Ayrshire heifer, Olive that will be 2 years old this month. Ideally she should be having a calf at the age of 2. However, she has “silent” heat cycles. She does not show any outward signs of being in heat to be bred. She is a 2 year old dairy cow, so she needs to have an udder to keep her in the show ring. Plus she isn’t doing us any good raising babies or providing milk. Farm animals all have a job, and she isn’t doing hers.
In this case, we are going to nail down her time of ovulation so that we can breed her with frozen semen. The protocol we will use is this:
Day 0: Give injection of GnRH (Cystorellin), Implant CIDR (progesterone)
Day 7: Remove CIDR, Administer prostaglandin (Lutalyse)
Breed when heifer is in standing heat, or in 54-72 hours. Give 2nd dose of GnRH at breeding.
Since she is a difficult breeder, I will breed her starting at hour 60, and continue every 12 hours until she ovulates. Hopefully she will ovulate within the scheduled time.
I will update as we remove the CIDR and begin the AI process.
Dr Vet Sonya 