Bull prospect

[cowgirl8]

I'm no expert in breeding cattle, and my sample size is small, but I don't regret doing some linebreeding. I found I just never had good animals from a mating that resulted in more than 50% influence from any parent/grandparent.. breeding siblings/cousins, etc has made me a lot of great, productive cows though

Just like any breeding program, cull what isn't working for you and your environment.

View attachment 31238

Exactly... Nice heifer....

 

[Mark Reynolds]

Here is an interesting fact, and think about it, because very few people realize it. I'll start with a question: "How many generations doe it take to eliminate ALL the inbredness within a closed herd or line?..........Answer: ONE! .....If you breed ANY inbred animal with another animal from outside the pedigree, the resulting progeny will not have a single gene pair where both genes come from the same parent somewhere in the lineage history of that animal........which is essentially the definition of inbred.

 

[Ebenezer]

Inbreeding
noun

1. The breeding or mating of closely related individuals.
2. The intentional breeding of closely related individuals so as to preserve desirable traits in a stock.
3. Breeding between members of a relatively small population, especially one in which most members are related.

So to declare an animal "inbred" you have to set a level of IBC that is your limit. Mating of first cousins, taboo for modern humans, creates an IBC of 6.25%. Is that the upper limit for livestock some are discussing? I find that low for livestock.

 

[Rmc]

In-breeding enhances the good traits, but it also enhances the bad traits.
You have to be careful when in-breeding or like Mark Reynolds said, it "may be disastrous."

And I think in many cases the exact opposite to be true.linebreeding or inbreeding increases homozygousity .
If a gene is present it is most likely active even if recessive. They're for easier to identify and remove from the population if undesirable. In multiple generations of outcross you have a genetic mess with no clue what genes are being carried. Never understood the ignorance is bliss method of breeding being so heavily promoted.

 

[Allenw]

Here is an interesting fact, and think about it, because very few people realize it. I'll start with a question: "How many generations doe it take to eliminate ALL the inbredness within a closed herd or line?..........Answer: ONE! .....If you breed ANY inbred animal with another animal from outside the pedigree, the resulting progeny will not have a single gene pair where both genes come from the same parent somewhere in the lineage history of that animal........which is essentially the definition of inbred.

There is a degree of inbreeding within any pure breed.

 

[Travlr]

And I think in many cases the exact opposite to be true.linebreeding or inbreeding increases homozygousity .
If a gene is present it is most likely active even if recessive. They're for easier to identify and remove from the population if undesirable. In multiple generations of outcross you have a genetic mess with no clue what genes are being carried. Never understood the ignorance is bliss method of breeding being so heavily promoted.

Ignorance is bliss is usually closer to both extremes of any spectrum.

 

[Mark Reynolds]

There is a degree of inbreeding within any pure breed.

You are correct. But note that I said mate with an animal outside the pedigree, which would mean a different breed.

 

[Rmc]

Ignorance is bliss is usually closer to both extremes of any spectrum.

Can't ignore recessive genetic defects if they are expressed in the phenotype.

 

[Rmc]

You are correct. But note that I said mate with an animal outside the pedigree, which would mean a different breed.

So how is creating an animal that has the potential recessive genotypes from two different breeds beneficial?
How is increasing the potential for additional genetic defects a benifit?

 

[Mark Reynolds]

So how is creating an animal that has the potential recessive genotypes from two different breeds beneficial?
How is increasing the potential for additional genetic defects a benifit?

I've noted in a couple of my prior posts a couple things. Using 2 different breeds can create 'hybrid vigor' which may be something the producer doing this desires. There is a somewhat common practice in place that creates hybrid vigor referred to as a 3 way cross. The hybrid vigor comes from rotating 3 different breeds using a purebred bull from each breed in rotation on hybrid cows from the other 2 breeds. Its rather simple to do in rotation but takes a bit of explaining. One other thing I've noted in my posts is that it depends on what the producers objectives are. Example: is the producer producing animals for breeding, or for market, or potentially for either as an option.

So, the risk/potential of ending up with expression of genetic defects may be outweighed in the view of the producer creating this risk by the potential benefits/gains that result from the producers actions.

It comes down to what the producers objectives are and what the producer is willing to risk to meet those objectives.

 

[Rmc]

I've noted in a couple of my prior posts a couple things. Using 2 different breeds can create 'hybrid vigor' which may be something the producer doing this desires. There is a somewhat common practice in place that creates hybrid vigor referred to as a 3 way cross. The hybrid vigor comes from rotating 3 different breeds using a purebred bull from each breed in rotation on hybrid cows from the other 2 breeds. Its rather simple to do in rotation but takes a bit of explaining. One other thing I've noted in my posts is that it depends on what the producers objectives are.

A few points using a purebred bull on cross bred cows resulting in a three way cross is great for a Terminal cross. But any hybrid vigor is lost after the third cross. And studies have proven that the loss of hybrid vigor decreases dramatically after the 2nd breed cross in many of todays cattle because so many of the breeds are so closely related.
But the main point is this discussion is about bulls . You are promoting the genetic benifit of using crossbreed bulls . On any cow . Wich I strongly disagree with.
There is no benefit of outcrossing past the third generation.

 

[Rmc]

Here is an interesting fact, and think about it, because very few people realize it. I'll start with a question: "How many generations doe it take to eliminate ALL the inbredness within a closed herd or line?..........Answer: ONE! .....If you breed ANY inbred animal with another animal from outside the pedigree, the resulting progeny will not have a single gene pair where both genes come from the same parent somewhere in the lineage history of that animal........which is essentially the definition of inbred.

Not factually correct on many different levels . Cattle and humans share 80 percent of our genotype .
On a smaller scale if both parents are homozygous for the same gene ,both parents homozygous recessive or both parents homozygous dominant for the same .neither a outcross or full sib. Mating will make any genetic change at the gene location in question.
If you mate a homozygous polled bull to a polled homozygous cow at the same gene locations. Your out cross will have zero gene variation at the specific gene in question.

 

[Davemk]

Inbreeding
noun

1. The breeding or mating of closely related individuals.
2. The intentional breeding of closely related individuals so as to preserve desirable traits in a stock.
3. Breeding between members of a relatively small population, especially one in which most members are related.

So to declare an animal "inbred" you have to set a level of IBC that is your limit. Mating of first cousins, taboo for modern humans, creates an IBC of 6.25%. Is that the upper limit for livestock some are discussing? I find that low for livestock.

6.25 is low without a doubt and will not allow for genetic improvement.

 

[Mark Reynolds]

"So how is creating an animal that has the potential recessive genotypes from two different breeds beneficial?"
That was your question.
Which you basically answered for yourself when you admitted hybrid vigor was a gain from 2 different breeds when you said:
"But any hybrid vigor is lost after the third cross."
The first cross: (breed "A" x breed "B") = hybrid vigor (breed ".5A/.5B")
The second cross: (breed "C" x breed "A/B") =increased hybrid vigor (breed ".25A/.25B/.5C")
The third cross: (breed "B" x breed ".25A/.25B/.5C")=no appreciable vigor increase (breed ".125A/.25C/.625B")
The fourth cross (breed "A" x breed ".125A/.25C/.625B")=no appreciable vigor increase (breed ".563A/.125C/.312B") (with rounding error)
The fifth cross (breed "C" x breed ".563A/.125C/.312B")=no appreciable vigor increase (breed ".282A/.563C/.156B") (with rounding error)
The sixth cross (breed "B" x breed ".282A/.563C/.156B")=no appreciable vigor increase (breed ".141A/.282A/.578B") (with rounding error)

Hybrid vigor will not continue to increase after the second cross, but will be maintained at the vigor level gained with the second cross provided the crossing continues according to the pattern illustrated above with the resulting percentage bloodline from the 3 breeds in each resulting progeny being roughly 14%, 28%, and 58% for each breed. Percentage of each breed in the progeny depends on the generation cross.

The resulting hybrid vigor, that you pointed out, is the how.

 

[Mark Reynolds]

Not factually correct on many different levels . Cattle and humans share 80 percent of our genotype .
On a smaller scale if both parents are homozygous for the same gene ,both parents homozygous recessive or both parents homozygous dominant for the same .neither a outcross or full sib. Mating will make any genetic change at the gene location in question.
If you mate a homozygous polled bull to a polled homozygous cow at the same gene locations. Your out cross will have zero gene variation at the specific gene in question.

OK. I'm trying to follow your logic here. Are you implying that if you crossed a human with a cow that because 80% of the genotype is shared that the progeny would be inbred?
On the smaller scale, inbred means 2 related individuals have bred and resulted in progeny that are inbred. Are you suggesting for instance a chinaman that is homozygous for blue eyes that marries a mexican that is honozygous for blue eyes are going to have children that are inbred?

(I apologize to everyone of Mexican and Chinese decent. I could have very well chosen 2 totally different cultures. I needed 2 different cultures for illustration purposes and no intent was meant by using either. I could have/maybe should have used Irish or English, which is my heritage)

 

[puzzled in oregon]

Guys Please !!!!!!! The "Original" title was "Bull prospect"

 

[Rancher]

There is a degree of inbreeding within any pure breed.

true hence the purebred

 

[Nesikep]

I think heterosis is far overrated.. I see no appreciable gains from the outcrosses than the linebreds.. maybe if you go to vastly different breeds AND have linebred animals from them you'd notice it?

 

[cowgirl8]

Guys Please !!!!!!! The "Original" title was "Bull prospect"

They do this to flood out my post... Happens on just about every one of them.

 

[Mark Reynolds]

Guys Please !!!!!!! The "Original" title was "Bull prospect"

I find it interesting some of the tangents that threads end up going. This has strayed a bit from "Bull prospect". I didnt meant to annoy, frustrate or upset anyone.