The Multiple Ovulation and Embryo Transfer (MOET) technique of obtaining multiple offspring from a single cow has been around since the 1950s and hasn’t really changed since.
In Vitro Embryo Production (IVP) is an alternative technique which involves collection of unfertilised eggs from a donor cow using Ovum Pick Up (OPU) followed by In-Vitro Fertilisation in the lab (IVF). OPU is a technique where eggs are ‘sucked out’ of the follicles using a sterile needle through the vaginal wall using ultrasound to guide the needle. After the IVF, there is a 7-day maturation phase in the lab which results in a blastocyst stage embryo ready for implanting straight away or freezing.
IVP Vs MOET – Pros & Cons
|Doesn’t require hormone stimulation of the donor (although some cows do better with stimulation)||Requires a series of hormone injections and devices to produce the multiple ovulation|
|Takes as little as one handling per collection||Requires 13 handlings per flush|
|Can still collect from pregnant or very recently calved cows||Can’t flush pregnant or post-partum cows|
|Requires only 1 straw of semen per collection||On average, requires 3-5 straws of semen per flush|
|Average pregnancy rate following implantation is 45% (but getting better!)||Average pregnancy rate is 50%|
|Less invasive than MOET as the cervix isn’t broached||Risk of damage to the uterus|
|Can result in 8-12 embryos per month per cow||Can results in 4-5 embryos per month per cow|
Another useful thing to note is that IVP is classified as a surgical technique so it must be carried out by a vet, whereas MOET can be carried out by a trained technician. However, costs do seem to be comparable when you take into account the higher yield of embryos.
Whichever technique you choose, management of the donor cows is the key to success: body condition, energy plane, mineral status and disease status all need to be optimal.