Please explain outcross genetics to Red

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red

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Ok, one thing you have to know about me, I'm never afraid to ask the stupid questions!
When someone says they have an animal that has total outcross genetics say of Shorthorn or Maine; what are they actually says? I guess this looses me sometimes. ???

Thanks for teaching this old dog some new tricks! (dog)

Red
 

red

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As simple as that? I'm not picking on Dan, with his bull for sale, but when he says outcross genetics what does he mean? Only cattle raised from his herd & no one elses?

Red
 

ELBEE

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I don' t know Dan, but he must have a bull with different blood lines than anybody else. Or, just different than yours. If his bull is a cross between 2 totally different lines the heterosis will be dilluted. (See a post by Scott, I believe on American Muscle.)
 

genes

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Inbred is defined as more closely related than the average of the population.

Conversely, outbred is less closely related than the average of the population.


If you consider the breed your population, when you pick two animals out of it, they can be inbred (more closely related to each other), or out bred, or average I suppose.  So when someone has a line that doesn't share much ancestry to the one you have, they call it outcross genetics.

 

ELBEE

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I can't find that thread from Scott explaining the order of breeding 2 linebred herds. Maybe he, or someone can find\reexplain it.
 

sjcattleco

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ELBEE said:
I don' t know Dan, but he must have a bull with different blood lines than anybody else. Or, just different than yours. If his bull is a cross between 2 totally different lines the heterosis will be dilluted. (See a post by Scott, I believe on American Muscle.)
What am I getting blamed for now??

I hope this makes sence...outcross is an industry buzz word that is code for " It not the same crap that 90% of the other breeders are using"......  It also rings a bell with EPD freaks becasuse out crossing is how you make EPD numbers change...

so a total out cross would be if I brought a native Argentine shorthorn bull to my place and bred my cows..... 
 

farmboy

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THIS MAY NOT BE CORRECT BUT THERES A BULL NAMED ENDANGERED SPECIES WITH NO POWER PLANT IN HIS PEDIGREE AT ALL. IF  I BRED A POWER PLANT DAUGHTER WITH NO RELATION TO ENDANGERED SPECIES TO HIM, THAT WOULD BE AN OUTCROSS RIGHT?. I WOULDN'T ACTUALLY DO THAT, JUST AN EXAMPLE. FIRST THING OFF MY HEAD
 

knabe

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here's a definition from most genetics type material

A type of genetic cross in which an organism is crossed to a strain from which it was not recently derived.

now of course the gnat frass problem is that  thorny word is what does recently mean.  since a lot of breeds are "inbred" since the 1750's or whatever start date, and we have only vague attempts to measure relatedness through molecular markers (which is currently insufficient, even though there are a couple of companies selling this), as oppossed to just pedigree's, two supposedly unrelated lines could be closely related, just independently derived, though statistically tougher to do  than by two groups raised independently with the same pedigree.  a group raised in isolation long enough are called land races, and were normally separated by geography.  now we do it by design. 

the variability of heterosis may be due to actual relatedness.  so if two lines are bred in isolation, and they both "select" for the same genes and they are both homozygous for the same heterosis important factors, when they are combined, there may be little heterosis.  this may be why it is important to not have everyone select for the the same kind of cattle, which we are doing for feedlot performance, which is cool that we have local growing conditions that force differences by things like different climate, maturity, fertility, grass, people selecting, etc.

here's a good explanation of heterosis, it's in plants mostly, but has some merit. 
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=540269


a couple of quotes from the paper
Furthermore, the quality of two inbred lines does not necessarily predict the amount of heterosis; this must be determined in a cross.  this would account for cattle nicking well.  it may not be prudent to obsess about outcrosses to get vigor in breeding cattle.  if we continue to "get rid" of diseases like PHA, TH, etc, and there are no deleterous effects, but we just get to play with a better lego set, it might not be bad to get a little more inbred overall.

final comment, really.  it is possible with what we are doing, to arrive at the same animal, just with different hair coats.  one needs to ask the buyers at places like harris feed yards if the "optimum" animal has changed over time, which of course they won't tell you, because it allows them to make more profit.  that's why it's cool to have a little tenderness power and retained ownership once the skin is off if you believe in your product.

 

knabe

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yes, but with the caveat that they may be related in what is not shown in their pedigree's either by actual pedigree, or chance that they have accumulated similar genotypes compared to what they are compared against.

here's another take on relatedness and some other links

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9363594&dopt=Abstract

the numbers used in these tests is kinda low, even though for statistics, they like at least 30 individuals to start to make conclusions.  in some organisms in the lab, we use 96 offspring, and 96 individuals.  barrel racer probably could add a little with the TH/PHA issue.  by the way barrelracer, how's the pub date looking for that?
 

genes

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Farmboy, yes you are right in the way the terms are commonly used.  But really, while Endangered species is an outcross to DP, he still might not be to your particular heifer, if they share some other common ancestors (doesn't even need to be a good ancestor.....).  But when people are advertising they say outcross to the most popular lines ....something for the people who are like "geez I don't want to line breed but DP is in like everything.  What do I do?"  :p
 

aj

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I know of a shorthorn bull that was"an outcross to the doublestuffs". Shazam, what they didn't say was that he was th positive and went back to improver through improver 57.  So they implied through hints that he was th free but he wasn't. Truth in advertising doesn't apply to cattle.
 

garybob

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The GaryBob definition is Outcross=The end result of mating two  unrelated individuals within a breed population, resulting in hybrid vigor, without crossbreeding.
 

aj

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Aren't all cattle related to the bull and female on noahs arc or from the garden of eden? Except bos indicus cattle who I think came from an alien spaceship. Are you getting flooded garybob?
 

DL

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aj said:
Aren't all cattle related to the bull and female on noahs arc or from the garden of eden? Except bos indicus cattle who I think came from an alien spaceship. Are you getting flooded garybob?

unless there was a tank on the ark that contained billions of embryos and really there weren't 2 of anything what you say aj has to be correct!
 

aj

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Now that everbody is chasing the black hide, aren't simmental,gelbveih,salers, limis,chianina,(what am I forgeting?) all tied into angus bloodlines now? Not that thats a problem but everybreed but the herfords are trying to look like angus in this decade.
 

genes

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Haha....so there was an ark and a spaceship ark?

But anyway, sure all the animals of a species or breed or whatever are related to some degree, related being having a common ancestor (or more than one).....like that lucky pair  :D  That is why the definition of inbreeding says "more related than the average of the population", it's all relative.  So say you pull 2 animals out of a population [and yes ... "population" is also a fuzzy definition, by design.  It can be as wide as the whole species, or small such as just your herd.  But for the rest of this discussion, consider it a breed, as it fits the question and common use of the term outcross best.]    How closely related two animals are comes from 2 factors (1) How many common ancestors they share and (2) how many generations back those common ancestors are.

So for example, say you raise Beefpacas ;) and the average amount the breed is related is to have about one ancestor shared 5 or 6 generations back.  You take your best female and want to breed her to "Rainbow Randy" but they share the same grandsire, "Fluffy".....you recognize that this is inbreeding, and say you aren't sure you want to do that, so you start looking in your Beefpaca sire guide at other options.  There it is in big bold letters on Purple Pete's ad...."Outcross to the Fluffy lines".  So you look it up and sure enough....it takes 7 generations to find a common ancestor....so he really would be an outcross to your female.
 

shortdawg

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I would call " Jake's Proud Jazz " an outcross bull to most of the popular shorthorn lines today. He's hot right now because you can breed him to most anything in the Shorthorn breed (outcross genetics).
 
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