Genetics: Exposing and managing genetic defects | TSLN.com

Genetics: Exposing and managing genetic defects

Loretta Sorenson

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

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“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

Technology is beginning to take the sting out of genetic defects identified in U.S. beef herds. Researchers are quickly improving methods for identifying recessive alleles responsible for expression of genetic defects. That makes it much easier and faster for the beef industry to reduce a genetic defect’s impact and evaluate the full range of genetic traits possessed by animals carrying specific recessive alleles.

“Many of the recent defects that were identified appear to be either lethal or significantly inhibit performance,” Matthew Spangler, assistant professor of animal science at the University of Nebraska-Lincoln says. “It is important for producers to manage around genetic defects and avoid producing affected calves. Twenty years ago, if an animal was identified as having a defect, the prevailing thought was that the entire herd needed to be purged. We know that these defects can be managed such that problems do not arise. That’s particularly beneficial when carrier animals are desirable for genetic merit for other traits.

“We also know genetic defects will continually be discovered given that they occur due to mutations,” Spangler says. “The majority of these defects are never expressed because these alleles drift out of the population and no mating ever occurs between two carrier animals. Even when two carriers do mate, there’s just a 25 percent chance that the mating will produce an affected calf revealing the presence of the defect. On the other hand, there is a 50 percent chance that the mating will create a new carrier.

“With the new molecular tools that have been provided by next-generation sequencing, we can develop tests to determine if animals carry a specific defect. That allows producers to make informed breeding decisions and makes it much simpler to manage any known defect,” Spangler concludes.

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