Scientists now have a complete picture of how the genome is arranged, but they don't know all relationships between the gene variations and the traits they control.

It's a bit like having a series of relatively detailed maps of the United States, but without a clear understanding of which maps adjoin one another, says Dorian Garrick, Iowa State University geneticist.

At last week's Beef Improvement federation meeting in Sacramento, California, geneticists repeatedly said they still lack identification of many markers for important traits.

Progress is being made, but they are anticipating another leap in technology within this year.

These scientists said the much anticipated release of the 300,000-SNP chip will advance testing for the location of genes controlling desirable traits.

SNPs are single nucleotide polymorphisms, which are the measurable and now mapped variances in the genetic code. Industry lingo calls them "snips."

In the past couple of years the 50,000-SNP chip has helped track down significant percentages of genetic variation, such that genetics companies can say their DNA tests can account for 20-40 per cent of the genetic variation in certain traits, such as carcass traits or tenderness or feed efficiency.

Within the year, these genomic scientists collectively said they think the accuracy of the correlations between SNPs and genetic variations could increase significantly, and very soon they could double, accounting for 60-80pc of the variation of some traits.

Yet the entire answer to selecting these traits has not been found, they said.

Further, traits with small heritability need even more testing; therefore the larger testing chips will help with that process this year.

It also requires large numbers of animals, therefore large collections of DNA samples to especially to correlate the less heritable traits with the gene sequences.