Embryo Production In Composite Cattle

What is Heterosis?

Heterosis is the effect of crossing two breeds or lines of breeds to improve the expression of desirable traits such as size, growth and fertility.

The Brangus Breed specifically, is a very fertile breed and from experience at Absolute Genetics, we have seen just that.

Our brand-new In Vitro Fertilization (IVF) Laboratory in Bloemfontein have produced embryo’s for Le Roc Brangus over a period of 5 months. During this time, we collected oocytes from 26 donors, completed 131 aspirations, fertilized 1198 oocytes and produced 366 Blastocysts. The average production percentage was 30.5%.

We used several different bulls for fertilization. The bulls used for fertilization included Maradona (LR15181), Clio (LR15258), Meneer (T+1531) and SB11830.

In the group of donors, we had better and weaker embryo producers like expected. The top embryo producer was TGX1029. This cow came to the embryo centre with natural bred twin calves and weaned them while in the centre. This cow alone produced 106 embryos.

The table below shows the statistics on the Top 3 embryo producers from Le Roc Brangus:

 

Oocyte DonorTotal AspirationsTotal OocytesMaximum Oocytes for one aspirationTotal Blastocyst ProducedProduction %
LR1139216167406539%
TGX1029182225510648%
LR1314515145357753%

 

In March 2019 we transferred 12 fresh and 15 frozen IVF embryo’s, where 8 and 5 recipients were confirmed pregnant respectively. This calculates to 66% of fresh IVF and 33% for frozen-thawed IVF embryos. The transfer took place on the breeder’s farm, where they managed the recipient synchronisation themselves.

Over the world, the average production rate for Bovine IVF is considered to be 30%. The conception rate is expected to be between 40-50% on fresh transfer and 30-40% with frozen embryos.

Absolute Genetics look forward to working more with this breed in the future.

Contact us today to schedule your program.

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