The genetic map of the Bos indicus Brahman now joins the genomic map of the tropically adapted Bos taurus Tuli and Africander bulls—also sequenced by Australian researchers—to provide the first genetic picture of what makes tropically-adapted breeds different from their temperate cousins.

In the case of the Brahman, the sequencing identified that the breed has more than four million variations in its DNA compared to the DNA of temperate cattle breeds.

That means four million points of difference that scientists can use to identify valuable production traits to be bred into future Brahman cattle and other tropically-adapted breeds.

“It’s critical Australian producers can use DNA markers that incorporate the genetic variation that occurs in tropically adapted cattle – over half of Australia’s beef production is based in the tropics,” said Beef CRC chief executive officer Dr Heather Burrow.

“To date, most of the data used to make DNA markers have been based on breeds which are suited to a temperate climate.”

Gene sequencing maps the order of the four molecules that are the basis of DNA. The molecules occur in infinitely variable chains, with subtle variations giving rise to the differences between different breeds and races of the same animal.

The information gleaned from genome sequencing will be compiled on chips containing Single Nucleotide Polymorphism information—”SNP chips”.

Each SNP chip carries selected DNA sequences that allow researchers to distinguish the genes of one animal from another.

In the early days of the Beef CRC, it was thought that a handful of genes would explain traits like tenderness, feed efficiency or reproductive performance. Through laborious efforts, some of those genes were identified.

It is now understood that each trait may be influenced by hundreds, thousands or even tens of thousands of genes.