Test your Knowledge on Genomics
Genomics has been a prominent word in the dairy industry now for a little over a year. During this time, much has been published on the subject. But how much have you really learned about genomics? Take this quiz to test your knowledge or just to learn a few more facts!
1. What is genomics?
Answer: Genomics is the study of the structure, function and inheritance of the genetic material (the genome) of an organism, such as dairy cattle. The genetic material is contained within DNA which, among other things, consists of pairs of nucleotides.
2. What is a SNP?
Answer: A SNP (pronounced snip) is a genetic variation in DNA (in the sequence of nucleotides). SNPs create the differing genetic abilities that exist among dairy cattle.
3. How many SNPs does the current genomic test examine?
A. 50 B. 500 C. 5,000 D. 50,000
Answer: The genomic test used to determine the genomic genetic evaluations of dairy cattle examines 50,000 SNPs (Answer D).
However, additional genomic tests are on the horizon. Earlier this year Illumina, Inc. announced the creation of a chip that examines over 500,000 SNPs. As technology and information systems are developed to utilize information from 500,000 SNP genomic tests, the industry should have even greater ability to describe the genetic characteristics of cows and bulls.
On the flip side, research is also being conducted on a low-density chip which will look at about 3,000 SNPs. The low-density chip is expected to be a low-cost system used for widespread genotyping on commercial farms and should return fairly reliable estimates of an animal's genetic level for Lifetime Net Merit (LNM) and most yield, conformation and health traits routinely summarized by the USDA and breed associations.
4. For Holsteins, the gain in reliability of genomic evaluations over traditional parent averages is approximately _______ for LNM, yield and conformation traits.
A. 50% B. 30% C. 15% D. 5%
Answer: The correct answer is B.
Table 1 below shows the parent average, genomic and combined reliability levels for several traits. For example, a typical Holstein sire has a 35 percent reliability for his LNM parent average. The gain in reliability for a typical Holstein sire's LNM according to genomic information is about 24 percent. The proofs of genomic-proven sires include both parent averages and genomic information so sires average about 59 percent reliability for LNM. Each bull and each trait has it's own individual reliabilities.
Reliability | |||
Trait | Parent | Genomic | Parent Ave. |
LNM | 35% | 24% | 59% |
Milk | 39% | 31% | 70% |
Fat | 39% | 36% | 75% |
Prod. Life | 33% | 33% | 66% |
Daughter | 33% | 20% | 53% |
PTA Type | 29% | 25% | 54% |
5. True or False: The genomic-proven sire reliabilities could be greater in the future.
Answer: True. The overall reliabilities of genomic-proven sires will continue to increase as more animals in the breed are genomically tested and calculation methods continue to be refined. In addition, a genomic test based on more than the current 50,000 SNPs could result in reliability improvements.
6. Name three benefits genomics provides.
Answer: There are several benefits to genomics and a whole world of new opportunities on the horizon.Currently, genomics can be used to identify elite animals (males and females), verify parentage, increase genetic gain, decrease the generation interval and increase accuracy. More simply, genomics can be used to select service sires or females for breeding purposes.
7. How many Holstein sires in the Genex lineup are graduates of the GENESIS program?
A. 3 B. 10 C. 19 D. 32
Answer: The correct answer is D. Currently, 32 sires in the Genex Holstein lineup were produced through GENESIS and are considered graduates of the GENESIS program. These sires can be identified by their Co-op prefix.
Genomic results have shown GENESIS, the cooperative's nucleus herd, is home to some of the industry's highest genetic merit cows and heifers. Genex members and customers benefit by having offspring of these elite females available in the active lineup.
8. The industry's highest ranking, genomic-proven sire in 2009 was______ .
Answer: Debuting in January 2009, 1HO08784 FREDDIE %-I was the industry's highest ranking genomic-proven sire. Today, FREDDIE has 75 daughters and still ranks among the industry's most elite at +$752 LNM, +7.2 Productive Life and +2.7 Daughter Pregnancy Rate.
9. True or False: Half of the sires entering the Quantum sampling program are genomically tested.
Answer: False. All Holstein and Jersey sires are genomically tested before entering the Quantum program. Sires are actually tested as bull calves on the farm. This allows for the proper selection between full brothers. Conducting genomic testing at a young age also facilitates early semen sales of elite young bulls to cooperative members and the usage of these bulls as Genex mating sires as these animals are most often the best choice for genetic progress.
10. What two suggestions are commonly made regarding the use of genomic-proven sires?
Answer: When using genomic-proven sires, dairy producers should use the very best genetics available. While the average sire's change to a proof is minimal as the bull goes from genomic-proven to daughter-proven, choosing the best genetics available should allow for the bull to improve the herd's genetic level after receiving milking daughter information. Since reliability levels of genomic-proven sires are slightly lower than those of daughter-proven sires, the second recommendation is to spread semen usage over more bulls.
posted April 2010, updated July 2011
