Frankie
Well-known member
Frankie said:
novatech said:
Yes, I can Google. And guess what I found?
http://www.southernlivestock.com/articl ... s.6125.sls
http://www.cattlenetwork.com/Cattle-Bre ... oid=551661
http://edis.ifas.ufl.edu/AN165
Old stuff (1981)
http://jas.fass.org/cgi/content/abstract/53/2/332
Note that not a one of these sources are from the Angus Assn. So let's see your references; I'm anxious to see a few of the hundreds that disagree with these.
But I'll repeat that research indicates highly heritable traits (carcass and ADG) are not influenced much by heterosis (crossbreeding).
novatech said:
Never herd that. It sounded fishy so I googled it up. I was going to cut and paste a few hundred sites that disagree but you do it yourself.
No doubt you can find one that the Angus association put out, but I don't know if even they would go that far. To my knowledge they are big advocates of cross breeding, and for very good reason. Heterosis is what makes my Brahman cross cattle palatable and gives significant gains in the fed lot over and above either individual. That heterosis is retained to the third terminal cross. F1 brafords crossed onto an Angus bull is hard to beat.
It is not only how much they put on but more the cost of doing it.
Yes, I can Google. And guess what I found?
As a general rule, traits that are low in heritability estimate receive the most "kick" from heterosis. Reproductive traits like fertility and cow longevity benefit the most from breed complimentarity, generally a 20-30% in-crease over purebred breeding programs. Traits that are highly heritable, like carcass traits (ranging from 45-65% heritable), receive fewer advantages from crossbreeding systems, approximately 0 to 5%.
http://www.southernlivestock.com/articl ... s.6125.sls
Heterosis is realized in inverse proportion to heritability for a given trait. Lowly heritable traits offer the most heterosis and highly heritable traits the least. In general, reproductive traits are lowly heritable, growth traits are moderate and carcass traits are highly heritable.
http://www.cattlenetwork.com/Cattle-Bre ... oid=551661
Significant and rapid progress can be made through selection for carcass traits, while crossbreeding has little or no effect.
http://edis.ifas.ufl.edu/AN165
http://www.animal-science.org/cgi/reprint/64/5/1332In this study, individual heterosis effects were not significant for any of the feedlot performance traits….
Old stuff (1981)
[/quote]Contrary to previous reports, HAx did not gain significantly faster than H and A straightbreds during the postweaning period (the HAx advantage was only 2.0% for postweaning average daily gain). HAx required more (P<.05) megacalories ME/kilogram gain than H and A straightbreds over time- and weight-constant intervals.
http://jas.fass.org/cgi/content/abstract/53/2/332
Note that not a one of these sources are from the Angus Assn. So let's see your references; I'm anxious to see a few of the hundreds that disagree with these.