Archive for Bull Proofs

Young Sire Sampling, Bacon Wrapped Turkey and the Importance of Being Random

I’ve been known to be random.  Quite random in fact.  Anyone who reads the Bullvine will find that sometimes there will be articles that seem to come out of nowhere.  This is because my mind seems wander all over the place sometimes and then all of sudden I get an idea and a thought for a new article or topic of discussion comes out of the blue.  The other day I was looking through my Facebook news stream and saw a picture of a turkey wrapped in bacon, which I shared of course because, in my unbiased opinion, there is nothing better than turkey and bacon together.  Nevertheless this is not a naturally occurring combination.  And, while delicious, it is definitely selectively controlled. This spurred the thought about the need to be random in sire sampling and how our young sire programs have gone from being random to totally controlled.

The Evolution of Genetic Evaluations

Prior to the introduction of Genomics, a young sire who was selectively sampled, say regionally, would have never been touched as breeders would have limited confidence in this sire’s ability to transmit when used in other herd environments.  That is because in order to get an accurate genetic evaluation of a young sire you needed to have young bulls sampled in many different herd environments where their daughters’ performance could be compared with contemporaries under a range of different circumstances.  This is the very foundation that our “Animal Model” is built on.

Over the years the way we look at sires has changed drastically.  First we looked at how their daughters’ average performance compared to other sires, with no regard for herd mate performance.  A method I see some old school breeders still using today.  In the 1970’s came the Modified Contemporary Comparison (MCC), which started to incorporate the performance of herd mates into evaluating sires.  This system was further improved to incorporate more information from relatives and resulted in the introduction of the full (cow and bull) Animal Model in 1989.

rate of genetic gain 60-86

It is interesting to see that if you look at the rate of genetic gain prior to 1974 (prior to the introduction of the MCC), you see that the rate has greatly increased since.

 

The five key factors that are considered in the animal model are:

  1. The cow’s management group
  2. The cow’s genetic merit
  3. The cow’s permanent environment
  4. The common environment of paternal-half sisters
  5. Other unexplained random environment

Where the problem lies is with that fifth factor” other unexplained random environment.”  Typically, that is meant to refer to the differences that still exist among cows’ records that haven’t been explained by other factors in the model.  In the past this was temporary as it does not affect a cow’s transmitting ability, as in the case of decline in milk yield due to mastitis flare-up.  The problem is this still assumed that everything thing was being done on a random basis with no herd and no selective sampling.

The Genomic Era – Not Random

The simplest way for the Animal Model to account for all things that cannot be explained is as a random event.  When spread over a large enough sample size, those random events will average out and we will be left with the true genetic merit of those animals we are evaluating.  That all worked just fine, prior to the introduction of genomics, when young sires where randomly sampled over many different herd environments, and a wide variety of dams with different degrees of genetic merit.  But with the introduction of genomics, no longer are young sires being sampled on just average cows.  They are now being selectively used on some of the highest genetic merit cattle in the world.  This is totally kicking that random principle out the window.

Young sires are no longer randomly sampled.  In today’s genomic age, a lot of the systems and controls are gone.  Yes, many of the sires are still offered to all breeders (well at least they say they are), but these high-ranking young sires are sold at a much higher price, and marketed much heavier.  In addition often the first release semen is only used on contract matings on extremely high index, carefully selected mates.  This results in anything but random sampling and in reality is almost the perfect method for receiving an inflated proof.  It isn’t just because of the actual mates they are being used on but also because of the care the resulting calves will receive.

Sure you can say that the Animal Model is supposed to account for this.  See bullet number 2 in factors considered by the animal model.  But is it doing so accurately?  Of even more concern is the bias resulting from the preferential treatment that offspring of the highest genomics sires receive (Read more:  Preferential Treatment – The Bull Proof Killer).  It’s only natural for these animals to receive this preferential treatment. The problem is that the Animal Model does not account for it.

This is not a new problem.  It’s just being amplified.  In the past this happened very frequently.  Just look at second country proofs of some elite daughter proven sires, Shottle, Planet, Man-O-Man, preferential treatment and selective use had these sire skyrocket to the top of the lists, only to settle back down once more random sampling occurred.  This is something we have already seen with Observer, His initial proof had him #1 in the US for TPI then once more daughters were added he settled to a respectable #8 among 99% reliable sires (Read more: Genomics at Work – August 2013).

One way this was dealt with in the past was to increase the minimum level of reliability for foreign bulls to receive domestic proofs.  In general this strategy was sufficient in the pre-genomic era, but even the centers that produce the genetic evaluations, such as CDN, are no longer finding this works in the current animal model.

The Bullvine Bottom Line

At the Bullvine we would love to say we know the solution.  The challenge is we don’t. Furthermore, I am not sure even those responsible for solving this problem have a clear grip on how to handle this.  Sure we could up the requirement for sires to receive their first proof, but is that really going to solve the problem?  What I do know is that time is of the essence. Within the next 12 months many of the sires that heavily promoted and selectively used post the introduction of genomics will be receiving progeny proofs in 2014.  If we don’t find a solution to this problem soon, we are all going to look as manufactured as bacon wrapped turkeys.


The Dairy Breeders No BS Guide to Genomics

 

Not sure what all this hype about genomics is all about?

Want to learn what it is and what it means to your breeding program?

Download this free guide.

 

 

 

Let’s Talk Mating Strategies

Whenever two or more breeders get together they talk ‘bulls’. Which ones are you using? Why? What results are you seeing?  Do your results match what his proof says he will do? More recently talk has been about genomic indexes and if, when proven, bulls’ proof will match the genomic index. So why is this talk so important? Today half the semen being sold is from genomically evaluated bulls. And quite simply it is because 90% of the improvement in herd comes from the sires used in a herd or a population. Some may disagree saying that cow families are extremely important. However in the majority of herds a cow has one to two heifers and not all of those heifers will calve at least once in the herd. So which sires and how they are used will make the difference between genetic progress or genetic backsliding.

Before Bull Proofs

Before Bull proofs, well in fact before BLUP bull proofs, genetic progress was limited at best. Breeders used cow families to select their bulls from. often crossing cow families to get the result they wanted. In the history books we read about the successes but there were in fact more failures than successes. BLUP indexes (1970’s) were the first accurate genetic measurements available and they started the upward climb genetically. Today we take for granted that proven bulls will do what the proofs say they will do. How fortunate we are that the animal breeding industry has dedicated researchers that made the study and application of cattle breeding their careers. We no longer need to hope that the bull we choose will click with our herd. We have the facts to base our decisions on.

Mating Programs

A.I. organizations for many years now have provided services to interested breeders on which sires should be used in a herd or on which cows a sire will work best. As we all know many breeders use these services, at least as a guide, while other breeders wish to retain sire selection to their own system.

One key factor in mating programs, no matter who offers it or if a breeder has his own is what results a breeder wishes to achieve. Breeding is not simply using top ranked sires. It is about taking the cows in your herd and mating them to a sire to achieve your goals. Even the very elite sires have limitations. Doubling up their limitations with cows will the same limitations is not progress.

How Accurate

Until heifers and cows had genomic results, breeders often selected bulls based on their genetic indexes and females on their phenotypic information (yields and classification). Now with genomic values breeders know with 65-70% accuracy a female’s genetic merit and that plus their phenotypic information, if a breeder wants to use it, represent the female side. For bulls their genetic indexes are the most accurate information to use. The only difference between genomic indexes and a daughter proven bull in addition to the genomic index is the accuracy / reliability of the information 70% vs 90+%.

Corrective Mating

Breeders need to ask themselves if they want a solid herd for the traits of importance to them.  In which cases using a corrective mating strategy is likely the way to go. Most A.I. mating services are based on this strategy. You take each cow or group of cows and you determine their limiting factors. Traits like low milk yield, low %F, high SCS and weak fore attachment. The program searches for the bull or bulls that correct the limitations that the females have. By breeding this way breeders wanting a uniform herd with reasonably high genetic merit for most traits can be achieved within 5-6 generations of females.

An example of corrective mating would be if you have a typical Baxter daughter you would look for a bull that would, at least, improve %P, wide front teats and daughter fertility. Most breeders whose major income source is the milk check would be satisfied to achieve those corrections.

Complimentary Mating

There are breeders that take a different approach to improving their herd. These breeders are not so concerned about having a very uniform herd. They want to have a herd that excels for certain traits. Traits like show type, fat & protein yield and longevity.  Breeders practicing this strategy will first off select bulls that sire daughters that build upon the breeder’s priority areas. The example where we often see this practiced by breeders are those who participate in showing. They always make sure the bulls they use leave daughters with style and stature. But there are other examples. For instance breeders that have the goal of having a least half their cows complete five lactations and 125,000 lbs of milk. These breeders are willing to give up on items of lesser importance to them to achieve their big ticket traits.

An example of complementary mating would be if you have a typical Baxter daughter you would look for a bull that would build on Baxter’s genetic strengths in milk yield, fat yield, median suspensory, heel depth and herd life. Breeders planning to derive significant income from the sale of breeding stock will want to have available for sale stock that excel above average.

Plan for Improvement

So many traits and various methods of expressing indexes can make the job of reading and understanding a challenging one. The Bullvine provides the following table to show where indexes are relative to the cows in North America:

tableupdate

It is important to use bulls that are significant improvers if a breeder wishes to make advancement. For cows or heifers that already have high indexes it takes a significant improver bull to even holder these females at their current indexes. Remember that if a cow is -0.5 for Daughter Pregnancy Rate (in Canada 95 for Daughter Fertility) it takes using a bull that is +1.5 (110 in Canada) to even get the resulting calf to be above average.

The Bullvine Bottom Line

First know what you want to achieve from the matings in your herd. Make sure that you or your advisors base sire selection on corrective mating to limit faults. Use complimentary mating to enhance the strengths already present in your females.  Every journey has a starting point and an end point. The route to get to the end is the breeder’s choice.


The Dairy Breeders No BS Guide to Genomics

 

Not sure what all this hype about genomics is all about?

Want to learn what it is and what it means to your breeding program?

Download this free guide.

 

 

 

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