Embryo transfer technology; the pros and cons

Embryo transfer requires trained technical personnel and a high level of management. FILE PHOTO |

What you need to know:

  • The main objective of ET is to capitalise on attaining the maximum number of embryos from a genetically superior animal in the shortest time possible.
  • The greatest challenges often associated with this in the developing world are lack of adequate technology and technological skills associated with the entire process.

Embryo transfer (ET) is a dairy technology that entails collecting embryos from a donor cow and transferring them to a synchronised recipient to complete the gestation period.

The main objective of ET is to capitalise on attaining the maximum number of embryos from a genetically superior animal in the shortest time possible.

The greatest challenges often associated with this in the developing world are lack of adequate technology and technological skills associated with the entire process.

However, this is slowly being mitigated and the adoption of this technology is gaining currency in the country, particularly in Agricultural Development Corporation farms and selected individual farms, which charge up to Sh200,000.

MERITS:

Increased reproductive potential: This should be considered in relation to the female animal. For example in cattle, the sperm that can be obtained from a genetically superior bull and be utilised widely through artificial insemination is colossal but this remains untapped for the female, who equally has billions of “ova” that can be extensively utilised.

Naturally, the genetically superior cow can produce approximately 10 calves in its lifespan but through adoption of ET, there is a notable increase in the number of offspring that a genetically superior cow can produce through surrogates.

Relatively faster genetic improvement: There is a noticeable positive upward trend based on the different techniques adopted to improve a herd’s genetic base.

For example, when using natural breeding, it could take up to 20 years while when using AI, the time span is reduced almost by half. The use of ET reduces this time further to approximately four to five years.

Outsmarts natural catastrophes: At times we may have a very good and genetically superior cow that has suffered disease bouts, injuries or has grown relatively old and become moribund.

This animal is often considered infertile but through embryo transfer technology, the animal can be super ovulated to harvest its ova and fertilise them in-vitro. However, it is important that the genetically infertile females are not considered suitable candidates.

Environmental advantage: In ET, passive immunity is passed on by the native dam, giving the offspring a better chance of survival despite the embryo being 100 per cent genetically different from the surrogate mother.

Financial benefits: Once the desired genetic impact is realised, the production of milk and beef will improve culminating to increased incomes. In well-established enterprises, one can also undertake selling of the embryos as additional income.

Embryos can also be stored indefinitely through freezing, thus making the highly superior genetic material available for future use. This technology is also considered cheaper than exporting/importing live animals.

DEMERITS:

Technical specificity: The technology requires trained technical personnel and a high level of management. It needs technical knowledge especially in relation to flushing the embryos and observation of oestrus in the recipient. The detection of oestrus and synchronisation of recipient with donor is also a difficult step and must be undertaken with due diligence.

High cost: The high cost can be attributed to the necessary equipment that must be put in place and the maintenance of recipient animals, among other reasons. However, governments can establish these stations where the service can be accessed when necessary.

Reduced genetic variability: The relatively small gene pool sourced from the donor cows may have a negative impact in future especially in reference to the rare breeds.

Low success rate: The success rate of embryo transfer is reportedly lower than use of artificial insemination. This may be attributed to the numerous processes that have to be undertaken before the embryo is successfully implanted.

This being a labour intensive and time consuming technology, it may be prudent that farmers weigh their options and understand their abilities and goals before embracing embryo transfer technology.

Dr Muchunguh is a livestock expert [email protected]