Selecting and breeding better livestock is about to shift to a whole new playing field. It will be a lot less about how the animals look to your eye and much more about the secrets in their genes.
A single drop of blood or one hair follicle will tell you – maybe with as much as 70% accuracy – if a calf or a pig has extra disease resistance, gains weight on less feed, or can sire offspring with more tender meat. Using this information to assist in decisions about an animal’s breeding potential or its best use in the food chain will become more commonplace as we learn more about specific gene combinations and what they tell us.
Increased efficiency of animal and meat production will be a big part of this focus, says Max Rothschild, an animal genetics professor and specialist at Iowa State University. “We have a first draft of the genomic sequencing for all species of livestock. We are learning what individual genes do,” he says. “Our eventual goal is to determine what they do to help us design animals.”
As an example, he says, you may select cattle that have tender meat even though they are only grass-fed because the genes tell us the animal is capable of that. Or, you’ll identify pigs with more tender pork for an exclusive upscale market.
Jerry Taylor, a professor of animal genomics at the University of Missouri, calls the testing for specific genes that predict animal performance “the holy grail” of the industry.
“It will become a cost-effective way to genotype animals for a number of traits that we like to measure, such as weights and growth and carcass traits, and even feed intake and conversion,” he says. “The key phrase is cost- effective. What genetic information can we get that will give us information that is an effective predictor?”
He reminds livestock producers that using genetic selection tools won’t eliminate the need to measure animal phenotypes such as growth rate or fertility traits.
“The genome technology may never be to the point that we can explain 100% of the variation by genotype. That’s why it’s vitally important that livestock breeders and producers continue to record data on animals.”
Seedstock and commercial livestock producers will use the new barrage of genetic information, Taylor says.
“You will give the information to customers such as cattle feedlots and other livestock breeders. Once it all becomes clear how to use this information, it will give extra value to some animals,” he says.
Taylor lists several ways this new round of livestock genetic technology may be used. Low-cost tests will be developed that predict the genetic merit of animals for growth, feed efficiency, marbling score, and resistance to respiratory disease. The best heifer replacements will be identified for fertility, calving ease, and milking ability. As the remaining animals are sold to sale barns or feedlots, their genetic information will accompany each animal to enable the feedlot to feed them to different end points or for different customers.
“Of course, the feedlot would need to pay for this information,” Taylor says.
Rothschild says it is important to note that what we do with livestock genetics isn’t genetic modification in the same sense as in crop GMOs, where new genes are inserted into plant cells. Rather, it’s selecting for the genes that are already present in a species; the ones that produce the desired results.
“It’s doing things that occur naturally as we have been doing for years,” he says. “We’re just selecting animals using gene-based tools.”
What it costs
DNA testing comes in different forms, says Taylor. “We can test single points in the genome, such as for a genetic defect. Or, we can test all of them if we sequence an animal. The costs vary from $10 to about $5,000 for full sequencing. The costs will come down in the future, but we really need some competition in the technology marketplace for that to happen.
“DNA testing to predict genetic merit for complex traits like feed efficiency is still a little too expensive for the technology to have taken off in a major way in the beef industry,” he says.
Taylor advises livestock farmers not to get left behind. “Putting your head in the sand won’t make technology go away. If you do that, others will embrace it, and your economic competitiveness will decrease. You don’t want to be on the outside looking in,” he says.
Who are the players?
A lot of the animal genomic technology is being developed at universities in collaboration with breed associations, says Jerry Taylor. This is the prediction equation side of the business, he explains, or figuring out how to convert the known genotypes into a predictable expected difference. (For example, if a certain version of a gene is present, you can expect an extra 2.6 pounds of weight gain.)
He lists these companies as being on the cutting edge of developing the technologies to produce the genotyping tools:
• Illumina
• Affymetrix
• Eureka Genomics
• Life Technologies
The companies that are involved in developing the specific assays that deliver the technology to the livestock industry and also specific tools to address the needs of the different end-users include:
• GeneSeek/Neogen
• Zoetis
Source: Agriculture.com
