Five years ago dairy cattle breeders were first hearing the word genomics. Over many generations of cows they had followed the recommended practice of using plus proven A.I. sampled sires on the majority of their herd with limited use (20-30%) of high indexing young unproven bulls. This practice had made it possible for them to improve their herd, help the breed improve and to generate revenue from the sale of breeding animals. And then along came a new way to look at accuracy for young animals and the merits of a cow without having to wait for her to have many milking daughters.
For most of us it was something that shook the foundation of what we knew about breeding cattle. How could an analysis of the genes change the method of breeding we knew and had been very comfortable with using? As expected breeders have had a variety of reactions. Some instantly adopted genomics. Some cautiously considered and used it to a limited extent. Many took a wait and see approach.
Today much has changed to the point where half the semen used is that of genomically evaluated bulls. We are learning more every month and every index run about genomics. The Bullvine decided to address some of the current questions and thoughts about genomics that we are hearing expressed by our readers.
Learning from Observer
De-Su Observer, a former high ranking genomic bull, born in November 2008, received his first official proof, which included daughter performance, in April 2013 and he had a gTPI of 2332. However with last week’s index release (Read more: August 2013 Holstein Sire Evaluations Highlights From Around the World) his gTPI dropped by 188 points to 2144. Many breeders are asking why? Can we trust genomics and the very first proofs with daughter performance included? Let’s think this one through.
High genomic bulls are now used by A.I. and breeders as mating sires for the next generation mostly using ET. The female mates of these bulls, with few exceptions, are also high indexing. Their progeny’s genetic evaluations will be adjusted for their parent’s high genetic merit by the genetic evaluation centres. However the extra care and treatment breeders give to these future star females, from birth to the end of their first lactations, cannot be totally adjusted for in the genetic evaluations. This means we can expect these young bulls to be over-evaluated in their first official proof based on the performance of their first 30-60 daughters. Until we can capture more details at the herd level for yields, health, reproduction, herd management, type assessment and heifer performance we can expect that high genomic bulls, after they get their very first official proof, will subsequently fall back slightly in some part of their proof.
This just happened to Observer. Between April and August he added 582 milking daughters to reach 800 and 283 classified daughters to reach 349. In April he was and in August he still is a 99%RK gTPI sire but he dropped from #1 to #21 on the TPI list (#8 among those with 99% reliability for MF). His breeding pattern for type did not change. His daughters have outstanding mammary systems but are only average feet and legs and below average dairy strength. His ratings for fertility and longevity were essentially unchanged. If anything they are up slightly. However Observer’s ratings for the yield traits dropped. The decreases were milk -14%, fat -26% and protein – 21%. He is still a top proven bull and a good bull to have in the pedigree or to use to make productive profitable cows. With the high number of daughters now in his proof we can expect he will not changed to a similar extent in December.
Considering a bull’s rank on a total merit index list is the first step in selecting bulls. However knowing how his strengths and limitation match your herd’s genetic needs is the important second step.
What about Robust, Bookem, AltaMeteor and AltaRazor?
All these bulls had their first official proofs in August after being highly rated on their genomic information. Their August Reliabilities range from 89% to 91%. So we can expect some movement in their indexes, as they have information added on daughters, the same as happened with Observer. Remember they can go up as well as down. They are all top of the class graduates but like all new graduates we can expect to know their attributes more exactly come December or next April. For discerning breeders this means use them but not any one of them to an excessive amount. Between them these four bring to the industry high NM$, high protein yield, high udder composite and high fat yield. All things commercial breeders include in their breeding plans (Read more: What’s the plan?).
What about Inbreeding?
Some breeders are asking the Bullvine – “so where are the bulls that are below 5% for inbreeding”? Readers have taken seriously the need to decrease the inbreeding level in dairy cattle (Read more: 6 Steps To Understanding & Managing Inbreeding In Your Herd and Twenty Things Every Dairy Breeder Should Know About Inbreeding). It is not easy to find bulls to use that are low for their inbreeding coefficient. To readers it seems that the high genomic bulls come from the same sire lines – Planet, Shottle, Oman, Goldwyn, Bolton,..etc. From time to time the Bullvine does produce lists of outcross sires (Read more: Going off the map: 14 outcross Holstein sires that don’t include GPS and 12 Sires to Use in Order to Reduce Inbreeding) so check those out. It would be a benefit to breeders if CDCB or CDN would produce listings for genomically evaluated bulls over 2000 PA gTPI of +2500 PA gLPI but under, at least, 5-6% for inbreeding coefficient. (Read more: Crossbreeding: Breed Help or Hindrance?).
Can more Genomic Related Information be Published?
To most breeders, it seems that genomic indexes are high, and constantly increasing. It is almost impossible to keep up. Go to an auction sale and hear the pedigree person say that ‘this bull is leaving many high genomic progeny” and what is the average breeder to take that to mean. It can be confusing even for people “in the know”. But what about people who do not follow the results closely? Furthermore for breeders that follow more than one breed, they see what is top numbers in one breed may seem ordinary in another breed. Has the time come to consider changes such as:
- Publishing the %RK for indexes – that way an animal’s strengths and limitations was be easily seen
- Widely publishing the levels for all indexes for 99%RK, 90%RK and 50%RK
- Identifying animals that leave top genomic progeny for all traits not just for the total merit indexes.
Keep moving Forward
Genetic Evaluations Centres around the world are studying ways to use the records from bulls’ daughters where the bull may not have been randomly sampled. Excluding records from analysis is not as easy as not using the data from ET daughters or for the first 50 to 100 daughters born. These steps could be well and good if this matter only involved the genetic side of our business. But it impacts marketing and revenue generation from top animals and therefore it gets complicated. It could well be some time before we have a solution.
Breeders need a breeding and marketing plan for their herd. And then they need to use the most up-to-date genetic indexes for both bulls and cows. It does not change the process: first sort the bulls by your preferred total merit index; and then correctively mate your cows or group of cows with the best mate on your selected list. It is up to each breeder to decide whether to use the genomic information or not. The advantages from using genomic information are a faster rate of genetic improvement by having more accurate indexes on young animals and the use of the very top animals, especially bulls.
The Bullvine Bottom Line
Breeding is about creating animals that are genetically superior to our current herd of animals. It does not simply happen by adding one and one to get two. It involves using all the skills including planning, cow awareness, genetic theory, accurate information, the turning of generations,..etc. Genomics is proving to be a good new tool. No doubt it and genetic evaluations will improve considerably over the next five years. More knowledge is always a good thing.
To see all the latest proofs be sure to check out our Genetic Evaluation Section.
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