BIF 2019: The Next Generation of Genetic Tools

John Genho
Neogen GeneSeek

Why do we use a crossbreeding system? To gain the advantage of heterosis, the cross outperforming the parent average. Retained heterosis is the amount of this advantage that is maintained after multiple generations of mating crossbreed animals (not mating the purebred parents).

Dominance, over dominance, and epistasis likely all contribute to heterosis.

In general, traits with higher heritabilities have lower heterosis and traits with low heritability have higher heterosis.

Why don't commercial producers use crossbreeding? The average herd size is 40 head and 9% of herds have >100 head. It is harder to implement a crossbreeding program in a smaller herd.

Researchers in Canada have developed genomic indicators of retained heterosis. They use the genomic data to infer the breed proportion of the animals. They can then square these breed proportions, add them up, and subtract from zero to estimate the retained heterosis. Another approach is to count the number of heterozygote loci.

The genomic indicator of retained heterosis significantly predicted the heifer pregnancy and stayability of crossed cows in the University of Alberta data. Genho also looked at this in King Ranch and Eldon Farms data, and the genomic measures of heterosis and retained heterosis predicted heifer pregnancy and stayability.

You can't fix heterosis in a herd by selecting for it. Mendelian segregation means that each generation of mating crossbreeds you end up with homozygous loci in the progeny. These homozygous loci result in decreased heterosis.



Comments

Joe Paschal said…
Jared,
You are right on. You cannot select in the traditional sense for heterosis! I haven't read the Canadian work but heterosis is the sum of thousands of genetic interactions, I doubt there are major genes as was once considered in additive genetic action. The reason that so many of the American breeds (those with Brahman genetics) and the American Tweeners (those more recent with solely Bos taurus)was to provide those with smaller herds that could not create their own crossbreds an opportunity to use heterosis more easily and less expensively. However, no matter the current re-emphasis on heterosis or hybrid vigor, the breed effect should not be ignored. The Lasaters and the Klebergs and many others understood that.
Joe
Herbal Penis Enlargement product is 100% guarantee to Enlarge and get a better ERECTION ,
the reason why most people are finding it difficult
to enlarge Penis is because they bedlieve on medical
report, drugs and medical treatment which is not
helpful for Penis Enlargement . Natural roots/herbs are the best remedy which can easily Enlarge your Penis permanently 
Contact Dr Olu via Email : Drolusolutionhome@gmail.com or via WhatsApp : +2348140654426 for Natural root and herbal remedies put together to help you get Enlarge and Erect healthy. 
Thank you. 
Anonymous said…
NO MORE COMPLAIN ABOUT SEX WITH DR PAUL HERBAL MEDICINE!!! @herbalistjoe
When I first saw posts about herbal medicine been used to enlarge manhood and make him last longer in bed, I doubted it, however, with more findings I gave it a trial to cure my husband of quick ejaculation and enlarge his P**is, guess what, it worked and we now have wonderful s*x. Feel free to contact him via WhatsApp: +2347031846539, email: drpaulherbals@outlook.com
cambell spivey said…
Hello I'm cambell by name, I'm giving a testimony about Dr.Emmanuel the great Herbalist, he has the cure to all manner of diseases, he cured my herpes disease, though I went through different website I saw different testimonies about different spell casters and herbalist, I was like: 'Many people have the herpes cure why are people still suffering from it?' I though of it, then I contact Dr. Emmanuel via email, I didn't believe him that much, I just wanted to give him a try, he replied my mail and Needed some Information about me, then I sent them to him, he prepared it (CURE) and sent it to Airfreight Online Courier Service for delivery, he gave my details to the Courier Office, they told me that 3-5 days I will receive the package and i took the medicine as prescribed by him and I went for check-up 2 weeks after finishing the medicine, I was tested herpes negative, if you are herpes positive do me a favor for you to contact him and I will try my possible best to make sure you get cured, when you contact him, make sure you tell him that I referenced you.. contact him via: nativehealthclinic@gmail.com or WhatsApp +2348140073965 or IG:@dremmanuel2

Popular posts from this blog

New Show-Me-Select Sire EPD Requirements Announced

2019 National Beef Essay Contest: “What does it mean to be a beef breeder in the 21st century?”

Hereford and Red Angus Heifers Recruited for Genomics Research