The dream of finding the right DNA to build the perfect animal is getting closer to reality as powerful computers analyze millions of snips of genetic information.
The information sold to cattle producers is getting better all the time but much more needs to be done, said Jerry Taylor of the University of Missouri.
He is working with an international team of researchers, including scientists at the University of Alberta, on bovine genome sequencing that seeks valuable genetic traits.
“The cost is coming down and the technology is going up,” he said at the World Angus Forum in Calgary July 13-16.
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Scientists have been working with the American Angus Association and Merial through its genetics division, Igenity, to make genomic enhanced expected progeny differences (EPDs) available from an Angus specific DNA profile.
The information is especially useful for young animals that could only be evaluated once they had multiple progeny. The company promises to analyze 15 traits so producers can make better selection and marketing decisions.
The dairy industry is already using genomic selection to increase the probability of getting certain desirable traits. Some barriers exist, said Taylor.
Analysis is costly and more samples of bulls from all breeds are needed.
The first experiments cost thousands of dollars but as computing power improves and databases build, the cost drops from the original $60,000 per test to about $300.
About 2,800 Angus bulls have been genotyped. Another 2,200 Limousin and 700 Herefords have been genotyped from semen samples.
To analyze the genetics of individuals, scientists search for SNPs, pronounced “snips.” It’s an acronym for single nucleotide polymorphism, a base that is variable within the genome.
Cattle have 30 different chromosomes and considerable variability has been found as scientists look at the thousands of SNPs along the chain. They may need 5,000 to 10,000 SNPs for accurate EPDs. At this point, technology is not ready to assess more than 5,000 SNPs to identify desirable traits at a reasonable cost.
In the past breeders relied heavily on pedigree information, that states the extent to which two individuals are expected to have identical genes transmitted through the parents.
“The pedigree information is only approximate when you get animals separated by more than one generation,” Taylor said.
By analyzing DNA, researchers can go beyond pedigrees and mathematically calculated EPDS to create molecular breeding values for such things as feed efficiency, weight gain and meat tenderness.
Bob Church, a Calgary area rancher and geneticist, said pedigrees should not be abandoned in spite of the tremendous advances made in genomics. Some of his work covers epigenetics, which are all the factors involved in making one animal an individual.
“The problem you have as cattle breeders is the following: how do you pick and choose to raise breeding stock and subsequently commercial cattle in your environment under your management conditions supplying your market? That is not an easy thing to do.”
Most breeding decisions start with the judgment of the cattle producer using pedigrees that have been available for 150 years through breed registries.
“Don’t throw out the reputation that your piece of paper as a pedigree has,” Church said.
Besides assuring certain production traits exist, he suggests disease resistance needs further research and should be added to this stock of information included on a pedigree.
With that information, people would know an animal does not have the genetic predisposition to develop diseases like BSE, bovine viral disease, Johnes or bovine rhinotracheitis.
