Bovine Superovulation & Embryo Transfer

Summary

The video script delves into the process of cattle embryo transfer, which began in the 1930s and gained popularity in the 70s and 80s. It allows for superior genetics to be utilized by inducing super ovulation in donor cows, collecting embryos, and transferring them to recipient females or freezing for later use. The process involves careful selection of donors and recipients, synchronization of estrous cycles, and precise handling of embryos. Embryo transfer is a valuable tool in advancing genetic potential in beef and dairy herds, with embryos being sold domestically and internationally.

Takeaways

• 🐑 Cattle embryo transfer began in the 1930s with sheep and goats and became popular with beef and dairy producers in the 1970s and 80s.
• 💊 The process involves drug-induced super ovulation in a cow or heifer, resulting in multiple embryos that are collected and transferred to recipient females or frozen for future use.
• 🌐 Non-surgical methods have increased the use of embryo transfer across the United States and the world.
• 🐄 Donor females are selected based on pedigree, genetic value, phenotypic superiority, and production records.
• 💉 A series of shots are given to the donor cow over a four and a half day period to synchronize and super ovulate, leading to the production of a larger number of eggs.
• 🌡️ Embryos are collected seven days after the cow is in heat, evaluated, and graded on a scale of one to four for quality and one to nine for development stages.
• ❄️ Proper handling of frozen embryos is crucial for ensuring viability, with cryogenic freezing at a specific rate and storage in liquid nitrogen.
• 🔄 Frozen embryos can last indefinitely, similar to semen, and can be used for transfer years later.
• 👶 Recipient females are selected for their mothering ability and reproductive health, and the process involves synchronization with the donor's heat cycle.
• 🚑 The transfer of embryos requires careful palpation, anesthetic, and the use of a specialized gun for deposition into the uterine horn.
• 💰 Embryo transfer can be costly but offers significant rewards by allowing producers to utilize superior genetics for their herds or for the market.

Q & A

What is the history of embryo transfer in food animals?

Embryo transfer in food animals began in the 1930s with sheep and goats, and gained popularity with beef and dairy producers in the 1970s and 80s.

How is cattle embryo transfer defined in the script?

Cattle embryo transfer is a process involving drug-induced super ovulation of a cow or heifer, resulting in the production of multiple embryos that are collected and transferred to other recipient females or frozen for future use.

What was the significance of the development of non-surgical methods in embryo transfer?

The development of non-surgical methods increased the use of embryo transfer across the United States and the world, making the process more accessible and less invasive.

What criteria are used to select donor females for embryo transfer?

Donor females are selected based on pedigree, genetic value, phenotypic superiority, production records, and other factors that contribute to their suitability as a maternal base for beef and dairy herds.

Can you describe the process of preparing a donor female for embryo transfer?

The process involves checking the donor female for reproductive soundness, followed by a series of shots over four and a half days to synchronize and super ovulate the cow. This includes shots of follicle-stimulating hormone in declining dosages and prostaglandin F2 alpha on day four.

What is the role of Gennady tropen releasing hormone in the embryo transfer process?

Gennady tropen releasing hormone is given to the donor female at the first signs of standing heat to facilitate breeding, which occurs twice at 12 and 24 hours following standing heat.

How are embryos evaluated and graded after collection?

Embryos are evaluated and graded on a scale of one to four, with grade one being excellent or good, grade two fair, grade three poor, and grade four indicating dead or degenerating embryos.

What are the stages of embryo development as mentioned in the script?

The development stages range from stage one (unfertilized) to stage nine (expanding hatched blastocyst), with stages two through eight representing various stages of cell division and blastocyst development.

How are frozen embryos handled to ensure viability?

Frozen embryos are put into an extender, packaged into straws, and cryogenically frozen at a rate of 32 degrees Fahrenheit per minute down to negative 29 degrees Fahrenheit. They are stored in liquid nitrogen until needed.

What is the process of transferring a frozen embryo to a recipient female?

Frozen embryos are removed from liquid nitrogen, held at air temperature for five seconds, and then placed in a water bath at 80 degrees Fahrenheit for 15 seconds before being transferred to the recipient female.

What factors are considered when selecting recipient females for embryo transfer?

Recipient females are selected mainly on their mothering ability or potential to successfully raise and/or carry a calf. Age does not matter as long as the female is in good condition and is reproductively sound.

How does embryo transfer benefit cattle producers?

Embryo transfer allows producers to take advantage of quality genetics, increase the genetic potential of their herd more quickly, and market across the industry, leading to significant rewards.

What is the average number of embryos flushed from a donor cow?

The average flush is around seven, but the quality and number can vary depending on the animal, with beef cattle generally having larger flushes and more embryos.

How does the price of embryos vary and what factors affect it?

Embryos can range in price from a few hundred dollars to thousands of dollars, depending on the quality of the embryo, the donor female's genetics, and the bulls used for the flush.

What is the gestation period for embryo calves and what happens after birth?

The gestation period for embryo calves is approximately 283 to 285 days. After birth, the recipient mother raises the calf as if it were her own, and many of these calves may become replacement females, donors, or stud bulls.