How traits pass to the next generation

[J+ Cattle]

I've heard a lot of different ideas about how traits are passed to the next generation;
father to daughter
mother to son
or how certain traits skip a generation, etc.
Whereas the current genetics teaching is that traits, no matter where they come from, can be passed on to the next generation and they become expressed or dominant if the offspring receive the trait from both parents. I'm curious as to what you consider fact versus fiction and how these or other ideas come into your breeding plans or selections.

J+

 

[wbvs58]

I don't think things have changed any, like recessive genetic conditions where if both parents are carriers the offspring has a 1 in 4 chance of seeing the condition expressed.
EPD's and EBV's make the assumption that traits get averaged out from both parents but this a starting point until data modifies things a bit.

Ken

 

[Rmc]

Their is a huge differance between genes and traits. Many traits arent simply dominant or simply recessive that are the results of a single gene location. Many traits have multiple gene locations. Then you have inhibitor genes that can block certain genes from being expressed in the phenotype even if they are in the genotype. Then you have modifier genes that can change how a certain gene is expressed. Then you have the whole epstasis/enviromental trigger theory.
How about linked genes/nonindependant assortment?how about prepotentcy?

 

[Jeanne - Simme Valley]

@Rmc - that was a mouthful - LOL
But, you are sooo right. It's not simple. For that reason, I love genetics and planning matings. Having pretty much the same goal for a phenotype for 50 years has helped my herd to be pretty uniform. Not uniform in height or color, but the same "type".
Back to @J+ Cattle - what "traits" were you thinking about?

 

[Rmc]

The expaination that made the most sense to me was look at genetics similiar to a house plan. You have the basic plan. Then you have the plans that tell those making the house what supplies they need to make . Then the instructions for those building the house how to do it.
You can have mistakes or changes at any or all of those steps.same with genetic makeup. If the person cutting the lumber for the house can vary from them houe plan . Or those building the house can vary. So if the new homeowner expects the house and expected to see a 4x4 at a certain location and its only a 2x4 . It could have been caused by different things. 1 the house plan called for a 2x4 not a 4x4.
2 the saw mill wasnt paying attention and cut a 2x4 or didnt have the wood he needed for a 4x4 so only cut a 2x4.
3 person building the house substituted a 2x4 because of lack of attention. Or only had a 2x4 to use so thats what they used.
The homeowner can only see the house so has no idea where the mistake was made.

 

[J+ Cattle]

@Rmc - that was a mouthful - LOL
But, you are sooo right. It's not simple. For that reason, I love genetics and planning matings. Having pretty much the same goal for a phenotype for 50 years has helped my herd to be pretty uniform. Not uniform in height or color, but the same "type".
Back to @J+ Cattle - what "traits" were you thinking about?

@Jeanne - Simme Valley no traits in particular the main purpose of the post was to see if the old timer adages hold true with what modern science says and if these adages are still being used today or if they have been disproven or forgotten.

 

[J+ Cattle]

The expaination that made the most sense to me was look at genetics similiar to a house plan. You have the basic plan. Then you have the plans that tell those making the house what supplies they need to make . Then the instructions for those building the house how to do it.
You can have mistakes or changes at any or all of those steps.same with genetic makeup. If the person cutting the lumber for the house can vary from them houe plan . Or those building the house can vary. So if the new homeowner expects the house and expected to see a 4x4 at a certain location and its only a 2x4 . It could have been caused by different things. 1 the house plan called for a 2x4 not a 4x4.
2 the saw mill wasnt paying attention and cut a 2x4 or didnt have the wood he needed for a 4x4 so only cut a 2x4.
3 person building the house substituted a 2x4 because of lack of attention. Or only had a 2x4 to use so thats what they used.
The homeowner can only see the house so has no idea where the mistake was made.

Other than using only high accuracy sires is there any tricks to make sure the results are according to the plans?

 

[J+ Cattle]

Their is a huge differance between genes and traits. Many traits arent simply dominant or simply recessive that are the results of a single gene location. Many traits have multiple gene locations. Then you have inhibitor genes that can block certain genes from being expressed in the phenotype even if they are in the genotype. Then you have modifier genes that can change how a certain gene is expressed. Then you have the whole epstasis/enviromental trigger theory.
How about linked genes/nonindependant assortment?how about prepotentcy?

I think I need a more entry level course and you're at the post graduate level. Many you could recommend a homework assignment paper for me to read, or YouTube video to watch, remember entry level.

 

[Rmc]

High accuracy sires are only good if they cross well with your line of cattle
Doesn't matter if the bull is homozygous at every location of a particular trait you want at the house plan level . If your herd is homozygous for the trait at the assembly level. (Your cows over ride the expression of the trait)to me inbred coefficient is far more important than accurate epds.
I want to now how well the two line cross

 

[Jeanne - Simme Valley]

I don't know the scientific explanation, but I do know a "trait" can skip generations and pop up further down the line. Like for me, I hate heavy front ends. There might be a son or daughter out of a short, thick fronted cow or bull that has a beautiful front, just what I love. I generally will not breed to that offspring because I know, sooner or later, the ugly front end will come back and bite me.
I'm an old timer, I don't have the lingo to explain, I just know. LOL
KISS - use the horn trait gene. You might go 5 generations with no horned calf, but OOPS, there's a horned calf. All it takes is just 1 of the horn gene to keep getting passed down without ever getting the 2nd horned gene from the other parent to be expressed. Then 5 generations later, that animal is matched up with another animal that is carrying the hidden horned gene and BOTH parents happen to pass their horn gene down to the offspring. Now you have a horned calf. This is an easy explanation of a one recessive gene. Takes 2 to be expressed. A dominant gene is much easier to follow. If it gets passed by one parent, it is expressed.
So cattle can carry good or bad genes that are not expressed until mated to another animal with the same hidden gene - if they are recessive.

 

[J+ Cattle]

to me inbred coefficient is far more important than accurate epds.

Let me see if I understand your meaning and if not, you can correct me.
You want a sire that has been linebred (increased inbred coefficient) because he will have more matched-up pairs of genes and therefore more likely to pass on his traits. I watched a video about the Ohlde operation where he talked about some of his cattle pedigrees containing certain animals up to 8 times.

My commercial cow base started with heifers of unknown original and over the last 15 years I've retained heifers from them using bulls with Traveler X N Bar Emulation EXT on the top and bottom side in their pedigree.

 

[Ebenezer]

Let me see if I understand your meaning and if not, you can correct me.
You want a sire that has been linebred (increased inbred coefficient) because he will have more matched-up pairs of genes and therefore more likely to pass on his traits. I watched a video about the Ohlde operation where he talked about some of his cattle pedigrees containing certain animals up to 8 times.

My commercial cow base started with heifers of unknown original and over the last 15 years I've retained heifers from them using bulls with Traveler X N Bar Emulation EXT on the top and bottom side in their pedigree.

You can also want to avoid a sire or herd that has been linebred if the breeder merely was blind to the obvious or is unscrupulous.

I know that the cow has more influence that the sire on a calf. Gestational programming is one thing that the sire can never contribute. Mitochondrial DNA is something that the sire can never contribute to a calf. The environment of the cow can also cause epigenetic triggers to turn on and turn off genes. Cow behavior can do the same. The 50/50 replies do not hold water anymore.

But a sorry sire can still wreck your herd.

 

[Rmc]

I am not much of a fan of epds . To me they are just a mathematical number that is not based on genetics and numbers will change from generation to generation without changes in genetics.
Yes I would like to see all pure breeds publish inbred coefficient.
Linebreeding increases homozygosity. Which leads to more predictable offspring of similar type. Out crossing increases hybrid vigor but reduces predictability.
I also think a key to producing similar calves is the inbred coefficient of the females in your herd .
The closer they are to each other genetically the similar their calves will be to each other regardless of the sire used.
It will be also interesting to see how the new genetic tests for heterozygosity are used to produce maximum hybrid vigor

 

[J+ Cattle]

You can also want to avoid a sire or herd that has been linebred if the breeder merely was blind to the obvious or is unscrupulous.

I understand that linebreeding magnifies or concentrates both the good and the bad qualities, before DNA testing was available, I think linebreeding was used to expose genetic defects.

 

[J+ Cattle]

I know that the cow has more influence that the sire on a calf. Gestational programming is one thing that the sire can never contribute. Mitochondrial DNA is something that the sire can never contribute to a calf. The environment of the cow can also cause epigenetic triggers to turn on and turn off genes. Cow behavior can do the same. The 50/50 replies do not hold water anymore.

Gestational programming and environmental conditions having an effect on genes is a new concept for me. This suggests that an embryo transfer calf would be different, because of the recipient cow, than if the cow had the calf naturally. Or did I totally misunderstand?

 

[Rmc]

A perfect example of how suragate cow and environment play in the roll of a embryo look at the clone calves of the rodeo bull Panhandle Slim.
The theory of epstasis says that some changes aren't the result of gene mutation but the result of environmental triggers activation or deactivation of genes already present in the genetic makeup. Similiar to how people with certain genotypes are at higher risks for certain diseases such as cancer and autoimmune diseases but require a environmental trigger.

 

[Ebenezer]

Gestational programming and environmental conditions having an effect on genes is a new concept for me. This suggests that an embryo transfer calf would be different, because of the recipient cow, than if the cow had the calf naturally. Or did I totally misunderstand?

There is a researcher who has found donor effects in embryos. The university declined to print the study due to the assumed negative it would cause.

 

[J+ Cattle]

There is a researcher who has found donor effects in embryos. The university declined to print the study due to the assumed negative it would cause.

I thought University studies were government funded and not funded by companies that would be upset with the outcome. Misinformation is as bad or worse than no information. In any case it doesn't help the industry to protect a few people's revenue stream.

 

[Jeanne - Simme Valley]

"There is a researcher who has found donor effects in embryos"
I do not understand what you are saying here. The "donor" is the actual dam, she should effect the embryo????