Jeanne, I never thought that you posted that information as just a way to "bash" Herefords. I just fail to understand the concept of homozygous and heterozygous alleles that was put out there specifically with respect towards thier effect on heterosis levels.
TXAG is right about the combination of more unlike alleles leading to a bigger kick in heterosis. A great example is the tiger stripe cow that works so well down in the southern US. Talk about 2 pretty distinctly different breeds. That is the fundamental basis for the whole concept of heterosis. The bigger difference in the two parents genes, the bigger the heterosis kick.
Now if you have a more homozygous animal, no matter what trait you talk about, they would tend to breed more 'true' to themselves than a heterozygous animal would. An example would be the homozygous polled versuse heterozygous polled animal.
With respect to color patterns, the concept of homozygous versus heterozygous comes into play. Since red is a recessive gene, you would have to have a homozygous red animal in order to express that gene, but I do not believe the same holds true when it comes to other economic traits like BW, ADG, WDA, CW, calf survivability, IMF, YG, REA, etc. Either that animal has those particular genes inherited from their parents or they don't and when crossed with other cattle, they will be expressed depending on wich genes get passed on.
Thats why I questioned your assessment of Dr Cundiff's talk. Nothing personal.
I came across some information a while ago that talked about the advantages in Hereford Heterosis and I will track it down and post it. It may take a few days.
Kent and L4ANGUS, I agree with you on your assesment of MARC data. I also know of some cattle comeing out of Miles City research station that certainly didn't do the Hereford breed any favors.
The old saying that there are more differences within the breeds than there are between them would make alot of this data that MARC, or any other researcher, puts out very dependent upon what bulls were used in the research. Same goes for bull tests that only test a few bulls in each breed. I tend to take most of this breed research data very lightly. I much prefer actual close out data on several pens of cattle as a comparison amongst breeds of cattle. Every breed excels at some things and haveing been around a lot of different cattle throughout my lifetime, I know the economic value that Hereford cattle bring to the cattle and beef industry and I know it is significant.
Have a great day everyone.
Brian