For many people, their first brush with DNA was Jurassic Park. Today, areas of life untouched by genetics are rarer than a dinosaur petting zoo. A perfect example is the Genome Alberta project to develop more accurate genomically-enhanced breeding values for traits critical to the commercial cattle industry.
Co-led by Dr. John Basarab, Dr. Donagh Berry and Dr. John Crowley, this project is harnessing the power of DNA in animal breeding. Below are just some of the potential uses of DNA in animal production:
Parentage verification or parentage assignment
Knowledge of an animal’s parents is vital to achieving genetic gain, but also to avoiding the mating of relatives. Farmers using artificial insemination can employ genotyping to verify the identity of the sire and dam of calves born. Also, Dr. Berry said that “obtaining genotypes for all animals in a herd allows you to match them up,” a process known as parentage assignment.
“This can be particularly important where multiple breeding bulls are run with many cows, a situation most common in North America,” said Dr. Basarab.
The benefits of DNA here are twofold.
“For producers, it enables testing of lost or stolen animals to identify which farmer they belong to,” said Dr. Berry.
As well, the technology can determine which animal produced a particular cut of meat, something that’s of increasing interest to consumers.
Mating advice and inbreeding
“We currently think that every animal is carrying between two and six lethal mutations, so if a bull and cow carry the same mutation mate, there’s a 25% chance that flaw will come to the fore in their offspring,” said Dr. Berry. “The problem is, in most cases the offspring will die at the embryo or fetal stage.”
That’s where DNA comes in, as the only way to determine which animal carries which mutation is through genomic testing.
Monitoring major genes
As you might guess, major genes are ones that have a major effect on the herd. For example, Belgian Blue beef cattle have a natural mutation in the myostatin gene leading to double muscling. The downside (and you knew there would be one) is that as people introduce the mutation into other breeds like Angus, calving difficulties can result.
Fortunately, “DNA technology lets you monitor the frequency of these genes in your population and see if that frequency is increasing over time,” said Berry. “If it is, you can take remedial action to address the problem.” This is particularly important for breed societies.
“When you order an Angus steak at a restaurant, how do you know if it’s really Angus?” Berry asked.
Once again, the answer is DNA.
“DNA can tell you how much Angus is inside that carcass and it allows herd books to check for the purity of breeds.”
It also helps abattoirs ensure that the “Angus” animal they slaughter is in fact an Angus.
“Crossbreeding is the most prevalent system for beef production in North America and globally,” said Dr. Basarab. “Knowing breed composition of dams and sires will assist in mating decisions that will maximize hybrid vigor and improve lifetime fertility, productivity and sustainability.”
Genomic selection can increase the accuracy value of EPDs (Expected Progeny Differences), which are numbers that predict the genetic merit of future offspring or progeny of a particular bull, cow or heifer.
“The accuracy value for an EPD of a newborn calf is low,” said Berry. “As the animal ages, it accumulates information such as weaning weight that improves accuracy.”
Normally, a bull must have many progeny before the accuracy values reach a high level, and by then, it’s very old. Proper use of DNA can help producers achieve that accuracy far sooner in the bull’s life cycle. The main focus of this Genome Alberta project is on improving the accuracy of EPDs.
What do certain beef cattle and the actress Angelina Jolie have in common? Apart from great stage presence, they have both reaped health benefits from genetic testing.
“Testing found mutations in Jolie’s BRCA1 and BRCA2 genes, giving her greater susceptibility to breast cancer and prompting a mastectomy to hopefully prevent the cancer.”
Similarly, if genes can be identified in cattle that make them more prone to respiratory diseases and other conditions, “farmers can put all high-risk animals in one pen and all lower risk ones in another, avoiding needless and costly vaccinations for the latter group.”
Given enough time and resources, there’s little that genetic researchers can’t accomplish. Maybe they’ll never use frog DNA to breed dinosaurs, but that’s probably a good thing.