• If you are having problems logging in please use the Contact Us in the lower right hand corner of the forum page for assistance.

DNA testing question

G

Grassfarmer

Well-known member
Joined
Aug 21, 2005
Messages
998
Location
Central Alberta, Canada
We are about to DNA test some cattle for parentage verification as they were ET calves and will be using the new SNP test for the first time. I am curious whether it would be worth doing the test for RFI (residual feed intake) at the same time. The donor animals we used are my best for gaining condition and weight on grass - does that mean they would likely show up as good scorers on the RFI test or are they better because they eat more or for some other reason? What I'm really asking is how applicable is the RFI test to proving or disproving the efficiency of cattle under a system like ours?
 
If the price is not prohibitive test them and report the results back to us. You can compare actual to expected from the test. I would be interesting in hearing how the best doing animals score? :D What other things will you be testing for? I will be testing 4 young bulls this spring thru Igenity. I have not seem many actual testimonials on expected to actual results.
 
I am not an expert on this by any means, but I have heard that even the Igenity tests are far off from being real dependable.

I can't figure out how you can test for feed intake and efficiency from a blood test alone. To me, the only way to figure feed intake and efficiency is through those feeders that document when each animal comes into feed and how many pounds it eats compared to the gain on the animal.
 
I'm by no means a believer in the ability of a test to determine feed efficiency either. I'm going to use the test to parentage verify as it is half the cost of the older microsatellite test. I was just curious what everyone elses opinion was and whether this test was even relevant to what I'm doing.
Looking at some of the other tests they offer indicates to me they don't have what I would call a high accuracy level. The maternal tests includes a "heifer pregnancy rate" component and they identify your animals on a 1-10 scale with 10 being the most fertile. If you select all 10's for your heifers the prediction is that 10% more of them will be bred than if you had kept all 1's.
Similarly on the stayability test ranked 1-10, if you select all 10's (best) the prediction is that 23% more of them will still be in your herd at 6 years old versus having retained all your #1s.

I don't know how much have these tests really have to offer. Wouldn't a good stock person with a knowledge of their own animals, and some records, be able to select with higher accuracies than the above examples?
 
I have 2 dozen Igenity cards by my desk. I can't bring myself to pay $38 per animal for the testing. Parentage would be the only thing I'd care about since I have multi-sire pastures. But, I agree with you grassfarmer, being knowledgeable about your cows should give you adequate information to make heifer selections. I have an older cow #016. She's a 2000 model. I also have 4016,5016,7016 & 8016. Her daughters....We've all been told to keep 1st calf heifers daughters because they are the "newest" genetics, but I really like to go back to my oldest cows for replacements. It's their history that makes my best replacements. It's not some guy in a lab coat looking at a hair under a microscope IMHO
 
Grass farmer how much more is it above parent ID for the carcass portion of the test battery? I would like to see some real world results before buying into this technology too heavy.
 
Costs are as follows; basic Igenity profile - all the carcass traits plus maternal traits - heifer pregnancy, stayability etc $40. The RFI test is an additional $20. The parentage test is $25 and it can be done as a stand alone test and doesn't require the basic profile.
I must say I'm tempted to try all 3 mentioned tests on a bull and cow we used for ET - for $85 each we would get a lot of interesting information that I probably wouldn't know how to use or apply in my breeding program :? Compared to the $50 a time we have been paying with the old type simple parentage test it doesn't add a lot of expense. It's certainly insignificant compared to what it costs to ET cows :shock:
I'm interested in the concept but not a believer by any means - like EPDs it may be proven in time that they work but how we can use them advantageously in a breeding program without screwing things up remains to be seen.
 
I need to get 4 young bulls in the chute to get dna samples to have the complete profile ran plus several genetic defects also. I am not sure if I trust the projected results but I am willing to sample the technology. In 3 or 4 years of small samples I should have a idea if the results corrrespond with observations by sampling the young herd bulls every year. What does the best growing animals profile look like and their offsprings profile? Rumor has it that the tenderness profile is fairly accurate. How would one compare dna projected results to actual observations? The Dairy industry will have an easier time of doing projected to actual comparasions. They have projections for milk, leg, udder, feet and longevity. We are intering a new frontier in cattle breeding that has alot of potential if used with common sense and a good eye for quality.
 
This is a pretty broad set of questions. SNP technology works very well for pedigree verification. Several of the tests that are marketed explain a portion of the variation in a trait (not all). The other thing to be cautious about is that many of these tests are not validated in the breed you may be testing. A couple of reasons, 1. the genes that impact a trait (eg WWT) in one breed may have more/less or no influence on the trait in another breed. Most of the DNA tests have been developed in AN cattle and work well in those populations, and the companies do make a real effort to test the markers in broad populations with diverse breeds to see if they are of value.
2. the test may be looking at anything from 1 to several hundred markers for a trait. This is in context of the fact that a trait may be controlled to varying degrees by as few as 1 gene to as many as several thousand genes each contributing differing amounts.
As we progress it is likely that gene markers will be integrated into genetic evaluation with pedigree and performance data to produce more accurate EPD or indexes on younger animals. This is the approach Holstein is taking and also AAA.
:D
 
Oh :? - So basically you are saying apart from parentage testing there would be little benefit in me doing any of the other tests because it needs background data within my breed to validate/ provide a comparison to? For example my bull couldn't be tested successfully for carcase traits because there would only be Angus to compare him too? Angus DNA and Luing DNA are so different under a microscope, huh, I totally didn't anticipate that :(
 
GF -some traits work well across many/all breeds, but not all traits do. As we get down the road, we are using higher density panels (more SNPs) to test for traits and are finding more "informative" SNPs that are conserved across breeds.
Tenderness is an example of a test that works well across many breeds and explains lots of the variation. Longevity is a test I question a bit.
I think the best thing a breeding community can do at this point is make sure they have both DNA and data available, and also to be ready to jump fast if the opportunity presents itself.
The cost keeps dropping on this technology (think computers) and I think some of the basics (like sire sorting) will provide really good value even at the commercial level when the price point is right.
 

Latest posts

Back
Top