F1 or Fnone?
Are composite bulls living up to the hype? Through many associations, I would say they are mainstream in their uptake. Purely based on their popularity, they are entrenching themselves as valuable assets in the genetic tool chest. However, as I go back and review the data, I think we can make better genetic advancements by refining the process. It has been commented by many researchers that the need for an updated estimate of heterosis is needed and I agree. Breeds have changed and the genetic makeup of the nation’s cow herd has changed. Through genetic testing, IVF, and other rapid advancements our genetic turnover has rapidly increased. This increase in pressure has backed our pedigrees into a corner. With most everyone bowing at the altar of the E.P.D. god’s, this has created a real crisis revolving around phenotypic selection and outcross pedigrees. Why not jump on the bandwagon? Composite bulls have used the angus database to create much of their success and have had what most have thought of as a successful ride thus far. What is happening now in many pastures though is severely limiting the expression of heterosis. One day we will know the SNP’s that contribute to fertility, stayability, and growth heterosis. As of today, we don’t have that luxury. Based upon working with several ranches that utilize composite bulls I have drawn some conclusions based upon our current status of heterosis.
The research data splits composites into two different groups.
Group 1 is the utilization of F1 (first generation cross) two-breed (minimum) composite bulls. This model was really bastardized and some theories out of group 2 stolen to create a hodgepodge of systems to fit ease of production.
Group 2 are the Beefmasters and the Santa Gertrudis of the world where three or more breeds where initially crossed. A huge population was utilized and this is where “retained heterosis” was coined.
Two different systems with different applications. Let’s take a peek at most crossbred/composite/hybrid messaging that exists today. “Use _______ bulls to take advantage of the widely known benefits of heterosis in a simple easy to implement package.” This is usually followed with a reference or chart referencing one of the studies that promote either Group 1 or Group 2 mentioned above. The issue is that data is based around F1 Bulls for Group 1! That means when we take a half blood F1 bull and cross him on an F1 half-blood female we are now out of bounds from that data.
That doesn’t mean there aren’t advantages. Compared to straight breeding angus there will be more heterosis. Also, heterosis aside there are great breed complementarity traits that are extremely important. My point is you cannot reference something that is eluding to using F1 bulls that are unrelated when your program is to breed composite on composite on composite.
A similar example is the latest premium baldy maker program between Hereford and the Red Angus Association. Great idea, uninformative advertising. Particularly where they are selling this program based on above average genetic merit bulls creating F1 females and then in the requirements at the bottom they state they can be between ¼ and ¾ of either respective breed. If they are ¼ to ¾ they aren’t F1s! This may seem like a minute detail to most, but in reality it’s a big deal. F1’s aren’t easy to make, however, the value they create is legitimate.
I can now step down off my purist soap box and get back to the real world. In the real world things are not that clean. If we are looking at both breed complementarity and heterosis we can work different percentage bulls into different scenarios. Many producers just want a shot of muscle shape and size from half-blood bulls on mostly straight bred cows. In this case any heterosis is just a bonus, this is just breed complementarity. If they wanted heterosis I would recommend a purebred.
For composite herds looking to revive heterosis ¾ blood continental bulls do a great job of injecting muscle, growth, and stepping up the heterosis game. It’s really easy to manage a breeding program from behind a computer screen. In the real world things are never that neat and tidy. Marketing is a huge factor and the success of CAB has a much to do with our current lack of heterosis as any other variable out there. That is not derogatory towards the Angus Association. Hats off to them for creating demand! I’m simply acknowledging that it’s a more complicated issue than it is made out to be. My wish list for commercial producers seeking to maximize heterosis while capitalizing upon complimentary traits is as follows:
1. Shop around to find someone that will make F1 bulls for you and will help manage both the EPD’s, phenotype, and pedigree to maximize genetic gains
2. Consider having a second F1 bull made of unrelated breeds. If you are using SimAngus bulls then consider having someone make you an F1 with Hereford and perhaps South Devon or some other range-type breed.
3. If you are serious about heterosis, creating a system where you are running mostly F1 females bred to a terminal bull is a lot of work but is rewarded with fantastic results.
4. For those who don’t want to mess with sexed semen or buying outside replacements, perhaps the best system that captures the most heterosis is a 3-way cross using purebred bulls as seedstock. If you can't pull this off then 2 breed cross using purebred parents works very well.
As always, I would love to talk cows. Give me a call 402.310.5056 or shoot me an email tyler@stockmangenetics.com. Until next time.