Click on "video" to see the video answer for each FAQ. Click on "text" to see a transcript of the video. See the complete list of videos on the eBEEF YouTube channel FAQ playlist. Click on "factsheet" to link to relevant factsheets.
- What is genomics?
- Alison Van Eenennaam (University of California, Davis): Genomics is a term that's used to describe looking at all of the DNA information in an organism. It's really an exciting time to be involved in genomics because now we have the sequence, or all 3 billion base pairs, that make up a cow, for example. We can use that information about the DNA to make better selection decisions about the genetic merit of an animal.
video, factsheet - When are genomics tools useful?
- Alison Van Eenennaam (University of California, Davis): The real value of genomics and the opportunity is that we'll be able to get genetic predictions on what's called hard to measure traits. These are traits like feed efficiency, fertility, disease resistance. For example, bovine respiratory disease is a very economically important trait in the beef cattle industry and we really don't have any good way to predict which animals are going to be less susceptible for that disease. Of course, in order for that to happen you have to have large training populations where you've got phenotypes on the trait, in this case feed efficiency or disease resistance, and genotypes on animals in order for you to be able to work out which SNPs are associated with the traits of interest. For example, which ones are associated with decreased susceptibility to the disease such that then you can submit DNA on an animal that you don't know anything about and get a genomic prediction for those particular traits.
video, factsheet 1, factsheet 2, factsheet 3 - Which is better: collecting phenotypes or getting genomic information on an animal?
- Jared Decker (University of Missouri): Really, these two sources of information work together. So, the phenotypes and the genomics work to improve the accuracy of the EPD. In most situations, we should collect both the genomics and the phenotype information.
video, factsheet - Do genomic predictions work across breeds?
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Alison Van Eenennaam (University of California, Davis): A really important thing we found with genomic predictions in beef cattle, and other animals, is that, if you train in one breed, that the predictions are not accurate in another breed. For example, if I train in Angus, they are not going to be accurate in Hereford. So, it's important to make sure that you're using a test that has been trained in the type of animal that you're getting your genetic prediction from.
video, factsheet 1, factsheet 2 - What is a SNP?
- Megan Rolf (Oklahoma State University): A SNP is short for a single nucleotide polymorphism, which is basically a single base pair change in the DNA.
video, factsheet 1, factsheet 2 - What is a SNP (single nucleotide polymorphism) chip?
- Megan Rolf (Oklahoma State University): A SNP is short for a single nucleotide polymorphism, which is basically a single base pair change in the DNA.
video, factsheet - How do SNP chips predict genetic merit?
- Alison Van Eenennaam (University of California, Davis): SNP chips are able to predict genetic merit because, basically, they have been trained. What I mean by that is breed associations have large populations of animals that have observations on traits of interest and also have been genotyped. That enables the breed association to develop what are called prediction equations, where they've basically estimated the effect of each of the genotyped SNPs throughout the genome for that particular breed. So, when a producer submits an animal that they don't have any information on, they can take that DNA information and make a prediction as to the genetic merit of that animal.
video, factsheet - What is meant by a 50k SNP chip?
- Megan Rolf (Oklahoma State University): A 50k SNP chip we sometimes refer to as a high density chip. It's a genotyping product that lets you collect genotype data on 50,000 different places within the genome.
video, factsheet - What is a high density SNP chip?
- Megan Rolf (Oklahoma State University): A high density SNP chip is a genotyping product that lets us collect information for a large number of places within the genome. So, for example, the 50k, or 50,000, SNP chip that's available on the market would be an example of a high density SNP chip. We also have a 700,000, or 700k, genotyping chip available in the industry.
video, factsheet - What is a low density SNP chip?
- Megan Rolf (Oklahoma State University): A low density SNP chip is the same type of product as a high density SNP chip but it has a smaller number of markers. These types of products are often used for things like imputation. So, an example might be a 384 SNP panel, or all the way up to a 7,000 or 9,000 SNP panel.
video, factsheet - What is imputation and why is it valuable?
- Megan Rolf (Oklahoma State University): Imputation is a process whereby we take lower density genotyping information and we fill in missing genotypes so that we can get additional data at low cost. For example, we might take a low density chip, like a 7,000 SNP chip, and impute the missing genotypes to get 50k genomic information, or 50,000 genotypes for an animal. We can use, for example, a low density SNP genotyping chip and fill in missing information based on an animal's pedigree, or related animals, so that we can get a larger amount of data at a smaller cost.
video, factsheet - What is an EPD?
- Darrh Bullock (University of Kentucky): EPD stands for expected progeny difference. Expected progeny difference is a measure of genetic merit that we have in beef cattle. Basically, how you use an EPD, is the difference between two bulls' EPDs for a particular trait is the expected difference that we would see in the average of their calf crop. For example, if we had two bulls that differed by 10 pounds on their EPD for weaning weight direct, we would expect the bull with the higher values calves to weigh, on average, about 10 pounds more than the calves from the other bull in a similar environment and bred to similar cows.
video, factsheet - What does the term genomically enhanced EPD mean?
- Jared Decker (University of Missouri): In traditional EPDs, we combined pedigree information and performance information to get an estimate of an animal's genetic merit. In a genomically enhanced EPD, in addition to the pedigree and performance data, we now add DNA testing information.
video, factsheet - Why should beef producers use genomically enhanced EPDs?
- Jared Decker (University of Missouri): One of the main issues with traditional EPDs is that they have a low accuracy or reliability for young animals that we don't have much data to estimate that animal's genetic merit. By adding in the genomic prediction, we're able to increase the accuracy of that EPD. So, it allows us to have more information and more reliable estimates for young animals.
video, factsheet - What does the term accuracy mean and why is it valuable to a producer?
- Jared Decker (University of Missouri): EPD accuracy is a measure of the precision or the reliability of that EPD estimate. It's a measure of how close that animal's EPD estimate is to the true breeding value. It's really a measure of how well we are predicting the EPD for that animal and how much information is going into that prediction. The accuracy gives us a measure of how much that EPD can change as we collect more information. So, if a bull has a low accuracy EPD, that EPD estimate can change, quite significantly, as we collect more information. If that bull has a high accuracy EPD, the possible change for that estimate is quite small.
video, factsheet 1, factsheet 2, factsheet 3 - What is maternal calving ease or calving ease maternal?
- Darrh Bullock (University of Kentucky): The calving ease maternal EPD is the EPD that tells us the calving ease potential of a bull's daughters, or of an animal's daughters. The calving ease maternal EPD is actually a measure of a bull's daughters' ability for calving ease. So, differences of, say 5 percentage points for calving ease maternal means that bull's daughters would be expected to have 5% less calving difficulty when they calve as heifers.
video, factsheet - What is better for decreasing calving problems: calving ease direct EPD, birth weight EPD, or a combination of the two?
- Darrh Bullock (University of Kentucky): The best way to decrease calving problems in your herd is to use the calving ease direct EPD alone. It's often that producers want to look at both the calving ease direct and the birthweight EPDs, but actually when you do this you are double counting for birth weight. Birth weight does contribute a large part of the calving problems that we see but there are other factors that contribute as well that get included in the calving ease direct EPD.
video, factsheet - Should commercial cattlemen select bulls with high scrotal circumference EPDs?
- Darrh Bullock (University of Kentucky): Scrotal circumference EPD is one of the few traits that we deal with that for commercial producers the actual measurement is a better value to use than the EPD. Because, if you think about it, an EPD tells us about a bull's progeny. So if we select a bull with a high scrotal circumference EPD, it means that his progeny are going to have large scrotal circumferences. If you're a commercial cattleman and castrating your calves at weaning time, that advantage in scrotal circumference is not going to do you any good. Whereas a seedstock producer, who is trying to produce bulls with large scrotal circumferences, he would use the scrotal circumference EPD in order to make advancements for that trait. Scrotal circumference in yearling bulls actually impacts serving capacity. So, we like to have bulls with larger scrotal circumferences and feel more comfortable that they can cover a larger number of cows than bulls with smaller scrotal circumferences.
video, factsheet - Why is scrotal circumference important in yearling bulls?
- Darrh Bullock (University of Kentucky): Scrotal circumference in yearling bulls actually impacts serving capacity. So, we like to have bulls with larger scrotal circumferences and feel more comfortable that they can cover a larger number of cows than bulls with smaller scrotal circumferences.
video, factsheet - What does it mean when there's a $ in front of an EPD? What is a selection index?
- Matthew Spangler (University of Nebraska - Lincoln): Oftentimes, beef breed associations represent their economic index values with a dollar sign. A prominent example is Angus's $beef. The dollar sign indicates that, in fact, that's an economic index. While we're thinking about $beef, that's very much a terminal-based index. So it would include things like growth and carcass merit and would be appropriate for producers who are selling their cattle through the feedlot phase on a branded beef program like Certified Angus Beef. However, that would not be an appropriate index to use if I'm actually retaining replacement heifers. In that case, an index that focuses on maternal traits, and certainly things like fertility, would be much more appropriate. So, when using indexes, it's important to understand the assumptions that go into them, the traits that go into them, and then use the ones that actually align with your own marketing objectives.
video, factsheet - What is an economically relevant trait, or ERT?
- Darrh Bullock (University of Kentucky): Economically relevant trait, or ERTs, are what we refer to as the EPDs that directly impact profit or income, or, actually, output when we look at the particular trait. We have both ERTs, or economically relevant traits, and we also have the indicator traits. For example, calving ease direct would be an economically relevant trait because if we can reduce calving difficulty, that's going to help us with our bottom line. Whereas birthweight is an indicator trait; it's an indicator of calving ease but we don't really get paid directly for birthweight. So, think of it in terms of traits that you can get paid for, or that may take money out of your pocket; that's what we refer to as an economically relevant trait.
video, factsheet - How is a selection index calculated?
- Matthew Spangler (University of Nebraska - Lincoln): An index, or an economic index, is a collection of EPDs multiplied by an economic weight. So, let's think of a simple example. If I have three EPDs, each of them has their own economic weighting. So, I can multiply EPD #1 times its economic weight and then I add to that EPD #2 multiplied by its economic weight and then so on and derive the economic index. Now, the economic weightings can be thought of as this: if I hold everything else constant and increase one EPD by one unit, that economic weighting represents the change in my profitability or income.
video, factsheet - What is the unit of measurement for a selection index?
- Matthew Spangler (University of Nebraska - Lincoln): Those are really represented in dollars per head of either added income or, hopefully, increased profit for a sire's progeny. So, if we think about two bulls, both having the same economic index value, let's say that one bull is 100 and the other bull has an index value of 50, then we can say that the bull with the index value of 100, on average, his calves would average $50 more per head in added income if we market our animals according to the assumptions of the index.
video, factsheet - What is whole herd reporting?
- Matthew Spangler (University of Nebraska - Lincoln): Whole herd reporting is really a system that many beef breed associations use to incentivize some of their members to return phenotypes on all animals in their respective herds. So, oftentimes there's a different fee structure associated with whole herd reporting to provide some kind of economic incentive for producers to do this. Where this has become extremely beneficial is getting phenotypes for things like fertility, that oftentimes are harder to collect and for some people not routine to collect. Because of whole herd reporting, in many cases it has actually offered up the opportunity to calculate EPDs for some of those more novel traits like heifer pregnancy or stayability.
video, factsheet 1, factsheet 2 - What is heterosis?
- Bob Weaber (Kansas State University): Heterosis is really the extra little boost of performance we get from animals that have a genetic makeup that has an origin in more than one breed. So, two or more breeds crossed together produces a little boost in performance. That little boost in performance, typically, is in economically important traits and helps us leverage genetic improvement in lowly heritable traits. Heterosis has the tendency to impact traits that have low heritability, or from a genetic improvement perspective, traits that we can't improve through traditional selection tools like EPDs. Heritability describes the portion of variation that's under genetic control. Since we have a number of economically important traits in the beef value chain that are lowly heritable, crossbreeding presents an opportunity to improve those. Examples of those traits might include traits like longevity and fertility that we know have major economic impact in terms of profitability for the commercial cow/calf producer.
video, factsheet 1, factsheet 2 - What is breed complementarity?
- Bob Weaber (Kansas State University): Breed complementarity is the idea of putting animals together, or breeds together, that have different core strengths. So, we might think about, a particular breed might be great say in terms of growth, but may be deficient in terms of carcass merit. We might combine that breed with another breed that excels in terms of carcass merit so we get the best of both breeds, or multiple breeds, when we put them together, to build an offspring that's more complete in terms of its genetic profile across a number of traits.
video, factsheet - Are there different types of heterosis and do they have the same value to a beef producer?
- Bob Weaber (Kansas State University): It's important for producers to recognize, when they think about a crossbreeding system, that there are different kinds of heterosis. We can think about individual heterosis, or the performance of an individual calf, or heterosis like maternal heterosis, that is the additional performance of a cow in terms of maternal traits and even paternal heterosis. It turns out in beef production systems that about 2/3 of the economic benefit of a crossbreeding program comes from having crossbred cows. So we encourage producers to think about building systems and crossbreeding programs that will allow them to maintain and retain heterosis in their cowherd and replacement heifer selection strategies to leverage the value of improved fertility and longevity in those females; that brings economic performance into their cowherd.
video, factsheet 1, factsheet 2 - What traits does crossbreeding impact the most?
- Bob Weaber (Kansas State University): Heterosis has the tendency to impact traits that have low heritability, or, from a genetic improvement perspective, traits that we can't improve through traditional selection tools like EPDs. Heritability describes the portion of variation that's under genetic control. Since we have a number of economically important traits in the beef value chain that are lowly heritable, crossbreeding presents an opportunity to improve those. Examples of those traits might include traits like longevity and fertility that we know have major economic impacts in terms of profitability for the commercial cow/calf producer.
video, factsheet 1, factsheet 2, factsheet 3 - Why should I crossbreed?
- Bob Weaber (Kansas State University): Producers should consider crossbreeding for a number of reasons. Maybe at the top of the list is improved revenue streams and profitability. Contemporary analysis suggests that the value of a crossbreeding system can be as much as $250 per cow per year. That motivation in terms of economic performance helps us think about what we might capture out of a crossbreeding system. The two important components to consider are heterosis, or the hybrid vigor, or increased performance we get from crossing two or more breeds as well as breed complementarity. So, combining the core strengths of numerous breeds to produce an animal that excels across a wide range of traits that are economically important in the beef value chain.
video, factsheet 1, factsheet 2 - Do crossbred calves qualify for breed specific branded beef programs?
- Bob Weaber (Kansas State University): The idea of branded beef programs typically has a variety of requirements in terms of either portion of breed composition or phenotypic traits in terms of carcass merit, carcass quality, as well as coat color, or hide color. Most of the branded beef programs do have enough flexibility that so long as you can produce an animal that meets the phenotypic specifications you can get those animals qualified. So, for instance, a program like Certified Angus Beef has a black coat color requirement as well as carcass and marbling requirements. So, we can combine animals that may be half or three-quarter Angus that easily fit into those specification programs and help us leverage a crossbreeding system on the cow side that lets us leverage maternal heterosis but still produces calves that qualify for these value added programs.
video, factsheet - How can a genome evaluation of feed efficiency take into account gene interactions?
- Matt Spangler (University of Nebraska - Lincoln): There might be two types of interactions that are of interest. One is the interaction between genes. From a selection standpoint, we are interested in the additive genetic effects, and thus gene x gene interactions might not be critical to capture. The other interaction is Genotype x Environment. This is important to quantify and the current project is evaluating potential Genotype x Environment interactions where Environment is defined as different diet types. If Genotype x Environment interactions do exist, we can accommodate those in the way we develop genomic prediction equations. (This question was originally posted as part of the National Program for Genetic Improvement of Feed Efficiency in Beef Cattle.)
- What will be different in this program’s estimation of feed efficiency than Gene Star and Igenity’s programs? Were these and the current genome estimations of feed efficiency of any value?
- Matt Spangler (University of Nebraska - Lincoln): The current project seeks to develop genomic predictors that can be included in National Cattle Evaluations across multiple breeds utilizing 50K and 770K (panels including either 50,000 or 770,000 SNP) genomic assays. That is a critical difference, the expansion to multiple breeds. In doing so, the current project is building large phenotypic resources to develop these genomic predictions, given that we know more information used to develop these tests means higher accuracy tests. The other critical difference is the use of higher density assays (e.g. 770K). Additionally, the current project seeks to identify specific causes of genetic variation (identifying QTL). The commercially available products mentioned, if incorporated into NCE for Angus and thus integrated into EPDs, have value in providing some insight into genetic differences. The current project seeks to expand this dramatically. (This question was originally posted as part of the National Program for Genetic Improvement of Feed Efficiency in Beef Cattle.)
- How do I collect a DNA sample?
- Megan Rolf (Kansas State University): There are two common ways to collect a DNA sample in beef cattle. The first of those is an FTA card. An FTA card is basically a card that includes some specialized paper that traps the DNA on the paper so that it can be sent off and extracted later. To collect a sample on an FTA card, you need a couple of drops of blood, typically collected from an ear or the tail of an animal and place that blood within the spot, or the circles, on the card. Be careful when using an FTA card to not have too much blood on the card so that it’s soaked and might mold but you want to make sure that you have enough blood on the card to cover that circle so that there’s enough DNA to be genotyped later. The second common method is collecting a hair sample for DNA testing. To collect a hair sample, go to the back of an animal and pull about a pencil sized group of hair out of the s of the tail. The thing you need to be sure is that you have actually collected the root bulb. So, when you take a look at the ends of those pieces of hair, it should have a little bulb like structure on the end and that’s important because that’s where the DNA is housed. From there, take those samples and make sure you have the end with the root bulb and place it on the sticky part of the collector card and then cover that sample up. You can cut off the excess hair on the bottom and then you’re ready to ship that sample off for testing. Regardless of the type of sample, make sure that you always have the ID clearly written on the card so that you can track which sample belongs to which animal.
video, factsheet - I have all black cows and bred to a black bull, how did I end up with some red calves?
- Megan Rolf (Kansas State University): For black and red coat color inheritance, black is dominant to red. So, in this situation, the bull is heterozygous black, we know because he has produced red calves. So, he has one black allele and one red allele. A certain proportion of those cows are also heterozygous black in this scenario because we know they have produced red calves. When we mate the heterozygous black bull to the heterozygous black cows, we get, on average, about 25% frequency of red calves. Some of those cows may also be homozygous black, in which case we won’t get any red calves out of that particular mating.
video, factsheet - What are the consequences of inbreeding?
- Darrh Bullock (University of Kentucky): When you practice inbreeding, some of the consequences are going to be things like reduced performance in general. You’re going to typically have lower reproduction rates when you practice inbreeding. You’re also going to have some reduced thriftiness in terms of you might have some increased health issues, particularly after weaning time and just overall reduced performance on traits like growth and in future milking ability and things like that. So, we actually get just the opposite effect of what we get when we practice good crossbreeding. So with crossbreeding we get increase reproductive performance and general performance in the cattle. With inbreeding we get just the opposite. We get reduced performance, reduced reproduction. There’s also a greater incidence of getting a genetic defect to show up in your herd as well when you practice inbreeding. So you have some increased risk that you do need to be aware of.
video, factsheet 1, factsheet 2 - Is it ok to breed a cow to a related bull?
- Darrh Bullock (University of Kentucky): You can breed your females to related bulls but you need to realize there’s going to be some increased risk when you do so. Some of those risks that you would have when you have inbreeding, which is breeding the females to either their own sire, or grandsire, or an uncle or other relative, you have an increased incidence of genetic defects. You can have, basically, if there is a genetic defect in that population, there’s a higher incidence that it will then show up. You also have just general reduced performance in the cattle. You’re going to have maybe some higher incidences of disease, just because they are a little bit more susceptible, not as resist. You’re also going to have some more incidences of lower performance in reproduction and also in general growth and performance. So, realize that you’re taking some risks. The more closely related the bull is to the female, the greater that risk is as well. Sometimes there are economic situations, say you only have one daughter of a bull and instead of replacing that bull and having the expense of replacing the bull, sometimes it’s ok to go ahead and have that inbreeding situation. But if you do, we do recommend that you wouldn’t keep back a female from an inbreeding situation.
video, factsheet 1, factsheet 2 - Can I test for the polled allele? If so, which breeds?
- Darrh Bullock (University of Kentucky): Do we have a genomic test for the polled allele? The answer is yes. What I recommend is that you make sure you contact the breed association for the breed that you’re interested in buying a bull from or check with the seedstock producer that has that breed and find out if that bull has been tested for the polled allele, for homozygousness for the polled allele and that’s the best way to ensure that you have a genomic test. Be careful with terms like “double polled bred” because that just means that both parents were polled but doesn’t necessarily mean that the bull that you’re interested in is homozygous for the polled allele. So, as I say, check with the breed association for the specific breed that you’re interested in, find out what companies they deal with to do their testing and then make sure that the bull you’re interested in has been DNA tested for homozygousness.
video, factsheet - How can I ensure I have polled calves?
- Darrh Bullock (University of Kentucky): In order to ensure that you get all polled calves, you need to breed to a homozygous polled bull. The way that polledness or hornedness is inherited is that the polled allele is dominant to the horned allele. So if you have calves that at least have one polled allele, you’re going to get polled calves. A homozygous polled bull only has the polled allele, so you’re ensured that you’re going to get at least one polled allele passed on to the calf crop if your bull is a homozygous polled bull. So, if you want to get polled calves, make sure that you breed to a homozygous polled bull.
video, factsheet - What does “generational interval” mean and why is it important?
- Jared Decker (University of Missouri): Generation interval is the average age of the parents when their progeny, in this case calves, are born. Generation interval is important because it can limit or improve the rate at which we’re able to make genetic progress. For example, if our generation interval is 8 years, in other words the average age of the parents is 8 years old, our genetic progress is going to be slower than if we had a generation interval of 4 years. So, as we turn those generations over more rapidly, use younger sires and dams, we’re able to make more rapid genetic progress.
video, factsheet - How does genomic testing impact generation interval?
- Jared Decker (University of Missouri): One of the real benefits of genomic testing is it allows us to have more reliable estimates of an animal’s genetic merit earlier in their lifetime. What this means is that we can use a younger bull earlier with more confidence. As we use those younger bulls, we’re able to shorten the generation interval and increase the rate of our genetic progress.
video, factsheet - What makes EPDs unreliable in young animals?
- Jared Decker (University of Missouri): EPDs are unreliable for young animals because every generation when we produce a new calf we have random sampling of chromosomes and genes. So, chromosomes are just the string of DNA on which genes are inherited. So when a bull produces a sperm, that sperm gets a random sample of his chromosomes. So every animal carries two copies of each chromosome, one inherited from the father and one inherited from the mother. When that bull produces that sperm cell, we get a random sample of his maternal and paternal chromosomes. There are billions of combinations of these maternal and paternal chromosomes, so we see lots of variation between full siblings. So, when we mate a bull and a cow and produce a large set of full siblings, the amount of variation that we would expect to see between those full siblings is actually equal to half of the variation that we would expect to see in the entire population.
video, factsheet - How do I get improved accuracy?
- Darrh Bullock (University of Kentucky): The initial information we get on a bull is based on his parental average and maybe some genomics information. This information is not extremely reliable, however, because it is limited in terms of what we know about that bull. This bull could have gotten a particularly good set of genes from his parents, or he may have possibly gotten a bad set of genes from each of his parents. We don’t know this until his daughters go into production. Once the daughters go into production, now we have a much clearer picture of the true genetic merit of that bull.
video, factsheet - What is the milk EPD?
- Darrh Bullock (University of Kentucky): The milk, or maternal, EPD is an indicator of how good a bull’s daughter should milk and is reflected in the average weaning weight of the bull’s daughters’’ calves. So therefore, when we get a difference between two bulls for a milk EPD, say of 5 pounds, it means that the bull with the higher value, his daughters will raise calves that weigh, on average, 5 pounds heavier than the other bull’s daughters’ calves.
video, factsheet - What is a genetic antagonism?
- Megan Rolf (Kansas State University): A genetic antagonism is a relationship between two traits that we find undesirable. It would be a result of a genetic correlation where if we select for genetic merit in one trait, we also cause a change in the other trait that is undesirable.
video, factsheet - How do I break genetic antagonisms?
- Megan Rolf (Kansas State University): Genetic antagonisms can be hard to break if that genetic correlation is really strong. But there are two ways that you can begin to overcome genetic antagonisms. The first is selecting for both of those traits simultaneously. So, if we wanted to increase weaning weight and moderate mature size, we would select for those two traits separately to try and control mature size while still increasing growth rate. The second option is to use a selection index where both of those traits have been included in the index and have appropriate economic weightings to help balance those traits in a selection.
video, factsheet - If I select for higher growth, will that affect my future cow size?
- Megan Rolf (Kansas State University): When selecting for increased growth at one stage stage of an animal’s life, for example at weaning, we can cause changes in growth at other stages of an animal’s life - birth weight for example, or in mature cow size. In a scenario where we wanted to increase growth at weaning and moderate mature size, we would need to be aware of the genetic antagonisms between those 2 traits, which is essentially a genetic correlation that causes an unfavorable result. So, in this scenario, as we would select for increased weaning weight, we would also increase mature cow size, which would be undesirable.
video, factsheet - What is gene editing?
- Alison Van Eenennaam (University of California, Davis): Gene editing is a molecular technique whereby breeders can go in and make very precise double stranded breaks in the DNA at a particular gene, or genetic loci. And a number of results can happen. You can knock a gene out; for example maybe a gene where a virus gains entry, so you would make a disease resistant animal in that particular example. Or you might do what’s called “allele substitution”. So you might bring the polled allele in from beef cattle, Angus for example, into horned dairy cattle so that at that particular loci they now have the polled allele and would be genetically dehorned.
video, factsheet - Is gene editing the same thing as GMO?
- Jared Decker (University of Missouri): GMO stands for a genetically modified organism. When we were creating GMOs we were using a very rudimentary, imprecise technology to take a sequence of DNA and insert it into a plant or an animal. Because of the imprecision of this technology, there were many concerns about independent, unintended consequences of using that approach. Now with gene editing, we can make these changes much more precisely with much fewer unintended consequences. In fact, early evidence shows there have been no unintended consequences. So, the precision of these new technologies used in gene editing allow us to have more confidence that we’re making the changes that we want to make and avoiding any of these unintended consequences.
video, factsheet - Is gene editing currently being used in the beef cattle industry?
- Jared Decker (University of Missouri): Gene editing is not currently being used in the beef cattle industry but it’s important for producers to note that this is a rapidly developing technology and that the recent developments in the technology have made it much easier to use and much more rapid to use to make these gene edits. In addition, because these gene edits are more precise, we can have more confidence that there’s going to be fewer or no side effects to making those gene edits.
video, factsheet