Maybe a stupid question but....

I'm intrigued with the look/performance of a couple of closely bred yearlings I have just now - one bull, one heifer.
To back up - I took on a small herd of lease cows last summer because they were slightly different bloodlines to the ones I have and I wanted to capture these different genetics to expand our breeds limited gene pool. The guy that had them is an amateur, the cattle a hobby and all severely malnourished growing up. He was also unknowingly concentrating the blood by using home bred bulls. The cows were a pretty sorry bunch to look at and although they are in better condition now they are still far from shining examples of the breed/type I'm looking for.
So from last years calf crop I decided to retain only two offspring. The yearling heifer has an IBC of 13.48% - her mother was 25% being the product of a dam/son mating and then mated to a half brother on the sire side to produce the calf I kept.
The yearling bull I kept has a 25% IBC being the product of a full brother/sister mating.
Now what I don't understand is how good these two animals look and how good their relative performance has been. The bull has been the second highest gaining since weaning and looks tremendous - he is sound, large testicles just a really pleasing all round bull. The heifer was very late born but has caught up with my earlier born heifers and again looks a picture of health and type. How come I'm not seeing any inbred regression? I had kind of convinced myself that I am seeing regression through a reduction in performance and thrift in my own linebred animals some of which are not bred as closely as these ones. Could the enhanced performance be almost a hybrid vigor like effect of having the cattle on adequate feed for the first time - ie the parents are artificially depressed phenotypically or is something genetic that I'm not aware of going on? Any ideas?
I'll try and get some pictures to illustrate tomorrow.

Not to hijack your thread, but I have a similar dilemma here. All the talk about inbred depression but my 40% IBC bull calf is a quite robust specimen...am I supposed to hate him for this???

So, back to your topic, YEAH WHAT'S UP WITH THIS????.... I DON"T KNOW!!!!

outsidethebox wrote:

Not to hijack your thread, but I have a similar dilemma here. All the talk about inbred depression but my 40% IBC bull calf is a quite robust specimen...am I supposed to hate him for this???

So, back to your topic, YEAH WHAT'S UP WITH THIS????.... I DON"T KNOW!!!!

your time will come... remember that ibc , like epds, are expected numbers based on AVERAGES...

If the parents were stunted due to lack of groceries then they are not a good representation of what the genetics are. If Gavin's philosophy of retaining the best animals for breeding stock for what ever traits you desire is correct then every generation should have superior animals over the general population. You might of selected 2 of the best calfs that got the right combination of genes for desired traits. If you kept the whole calf crop you would have calves that show inbred depression as well as ones that excell. If a person keeps the replacement out of the top animals that express the desired traits aren/t they concetrating the genes for selected traits. Look at the line 1 herdford project and what happen to the other lines they started with. If you decide to use these animals in your program please keep us posted on the results.

MKeeney wrote:

outsidethebox wrote:

Not to hijack your thread, but I have a similar dilemma here. All the talk about inbred depression but my 40% IBC bull calf is a quite robust specimen...am I supposed to hate him for this???

So, back to your topic, YEAH WHAT'S UP WITH THIS????.... I DON"T KNOW!!!!

your time will come... remember that ibc , like epds, are expected numbers based on AVERAGES...

Outstanding phenotypic performance means they aren't as inbred as you think they are. I sure wouldn't hate them, but I'd just doubt the ibc.

Here's something that would be interesting to know-- since the inbreeding coefficient is an average, I wonder what the expected variation about the average would be?

I would not hold out too much hope for a late born heifer. She will probaly breed true and be a late calver. If you keep the biggest and "best" of each calf crop then the L1 HH will be your parallel if your gene package survives the test of time and you will see MW climb with the generations. If you are scared of losing the line, I'd keep the bigger ones. If you have any average calves that might make your cut, keep some of them around to keep your group stable. I am not too sure what to do with a select few of the bottom third. That's a question that I have pestered Larry and Mike with for years. I think that answer is based on a level of courage, hope, expected loss/expense, and will go towards learning experiences and only a glimmer of hope that the ugly duckling will become a swan.

I agree with Mike and MS, I think it is a time deal, in that the expected variation will lessen over time if the management stays constant.
I wouldn’t be complaining and I know you’re not, the bottom line for me is that if nature is not worried about what the IBC% was, then there is no need for me to put much stock in it either.
Looking forward to the pictures if you can find the time... was that the outfit that you had posted a picture a while back of the horned bull?


Eb, would you mind expanding on this thought process... TIA

EddieM wrote:

I would not hold out too much hope for a late born heifer. She will probaly breed true and be a late calver. If you keep the biggest and "best" of each calf crop then the L1 HH will be your parallel if your gene package survives the test of time and you will see MW climb with the generations. If you are scared of losing the line, I'd keep the bigger ones. If you have any average calves that might make your cut, keep some of them around to keep your group stable. I am not too sure what to do with a select few of the bottom third. That's a question that I have pestered Larry and Mike with for years. I think that answer is based on a level of courage, hope, expected loss/expense, and will go towards learning experiences and only a glimmer of hope that the ugly duckling will become a swan.

"Outstanding phenotypic performance means they aren't as inbred as you think they are. I sure wouldn't hate them, but I'd just doubt the ibc."

MS, I do not believe this is a scientifically valid statement. Please explain.

Outsider,

It has been gone over several times here, my take or understanding, the IBC is hypothetical measurement assuming the progeny is exactly 25 percent of all his grandparents which may or may not be so. It would be possible, but unlikely, for the said progeny to carry virtually no genetic information from a grandparent. Therefore your 40 percent IBC calf may only be 10 percent inbred in reality, or much more inbred, but doubtful if carrying superior phenotype, due to the corelation of heterozygosity creating the hybrid vigor effect, thus the reciprical would also be true.

If the above is unclear, I apologize, as it is just the way it sounds in my head.


Bootheel

Thanks for the replies, it helps to get different perspective when I have no clue what I'm dealing with. These cattle won't play a part in my linebreeding program but I'll keep them around and see how they do out of interest as well as maintaining a bit of variation in the gene pool. I'm basically keeping everything at the moment as long as it meets minimal functional levels (ie can calve and rear a calf). If they can't do that they get culled, if they can do that but don't impress me too much they will be used commercially.

EddieM, I don't agree with you on the late born calf thing. It would be true if purely genetics controlled calving date but they don't - management conditions are more important in my experience. One of our best cows who usually calves @ April 25th calved June 25th last year - normally my bulls are pulled earlier so she got lucky. This year she calved April 18th and had twins. Almost certainly management and environment rather than genetics. So I think there is every chance a late born calf out of cows that were half starved will work out fine. I've had the kind that are genetically programmed to be late calvers, the sub-fertiles, but I've found them to be in the minority compared to management/environmentally caused ones.

Hilly, Yes it was the group that came with the horned bull. I'll post pictures when I get the chance.

Boothill, I understand/agree with what you are saying regarding the theoretical nature of the IBC. However, I do not believe one can know this early whether the conformation and performance are due to hybrid vigor. It is my contention that the genome is too complicated to rule out prepotency-homogeneous dominance. While chance would be in favor of hybrid vigor my understanding is that it is not a given.

outsidethebox wrote:

"Outstanding phenotypic performance means they aren't as inbred as you think they are. I sure wouldn't hate them, but I'd just doubt the ibc."

MS, I do not believe this is a scientifically valid statement. Please explain.

I guess it's not definitely true that your 40% IBC calf with outstanding performance is anything other than 40% inbred. But its certainly the rule that cattle that are actually 40% inbred generally show regression, not outstanding performance. On the other hand, cattle that have pedigrees that indicate that they'd be 40% inbred may have simply gotten the evolutionarily best set of genes from their closely-related parents. Can your bull be truly homozygous and show outstanding phenotypic performance? I guess he could, but I don't think its the most likely answer. Seems like a bit too much "having it all" in that answer. But I guess it happens sometime.

this is very unscientific...but very logical...
what is the real reason JLents says to limit linebreeding from "incestous" matings?
why has Wye decided to limit inbreeding?
why has the line one herefords decided to limit inbreeding?
why don`t more breeders of all breeds inbreed instead of continous outcrossing?
Wht does Falloon limit inbreeding?

the same sentence will answer all of the above

So that they can sell them.

Tom D wrote:

So that they can sell them.

Unfortunately, we have a winner.

why can`t we sell inbreds? because they tend to be __________________

Mean Spirit wrote:

Tom D wrote:

So that they can sell them.

Unfortunately, we have a winner.

Is that the right answer?
I was going to suggest to maintain a level of heterosis and hence growth within their herds.

or

To avoid inbred regression and hence lack of growth

To MKs later question

why can`t we sell inbreds? - because they tend to be perceived as inferior by people who don't understand how to use them properly?

Mean Spirit wrote:

Outstanding phenotypic performance means they aren't as inbred as you think they are. I sure wouldn't hate them, but I'd just doubt the ibc.

outsidethebox wrote:

MS, I do not believe this is a scientifically valid statement. Please explain.

Bootheel wrote:

Outsider,
It has been gone over several times here, my take or understanding, the IBC is hypothetical measurement assuming the progeny is exactly 25 percent of all his grandparents which may or may not be so. It would be possible, but unlikely, for the said progeny to carry virtually no genetic information from a grandparent. Therefore your 40 percent IBC calf may only be 10 percent inbred in reality, or much more inbred, but doubtful if carrying superior phenotype, due to the corelation of heterozygosity creating the hybrid vigor effect, thus the reciprical would also be true.
If the above is unclear, I apologize, as it is just the way it sounds in my head.
Bootheel

outsidethebox wrote:

Boothill, I understand/agree with what you are saying regarding the theoretical nature of the IBC. However, I do not believe one can know this early whether the conformation and performance are due to hybrid vigor. It is my contention that the genome is too complicated to rule out prepotency-homogeneous dominance. While chance would be in favor of hybrid vigor my understanding is that it is not a given.

OTB,
I guess my question would be what are you saying they are possibly prepotent for... performance? And what are you using as the constant to measure against? I would think it would take many years to establish a baseline or true performance level of a closed population, with consistent breeder culling pressure on the outliers or standouts. If you are saying that these standouts may be prepotent for the genes you are trying to fix I guess there is a possibility, but I don’t like the odds and would seek the safety of the numbers in the population for slow but steady progress. Testing every outlier for the possible homerun of prepotency, certainly could not be determined at an early age and although possible seems futile to me especially on the performance end of the deal as that can be restored with a simple out cross.

MKeeney wrote:

why can`t we sell inbreds? because they tend to be __________________

Ugly, littler, unthrify comparitively or the new catchphrase.....REGRESSED

Quote :

If you are scared of losing the line, I'd keep the bigger ones.

Hilly, I'm slow getting back to your question. I probably did not read the first post well enough but I fixed a mental picture of a population without known background but some inbreeding. This was a wide screen mental picture so I saw a lot of variation in this year's calf crop. The actual photographs and further discussions will sift the husks from my assumptions. But if you do not know what you have and there is regression already showing up in the youngest part of the group, it is like a number have already said here better than me: a hedged bet is to keep the genetics that exhibit the least regression to use later. It is an act of desperation to buy time and see how future matings go. If the average animals continue to regress, the outlier is your last hope. All of this probably does not make sense.

Eb, I think it does make sense. At least my interpretation of it makes sense to me-- if you are in fact desperate to save a line of genetics for some reason, and some very inbred ones were "less fit" to the point of being a risk for not reproducing, but some less inbred ones were "more fit", and thus a better risk reproductively, picking the more fit ones to go forward seems an easy call. Maybe the less fit one needs an outcross to reproduce successfully, so she is less valuable to save the line.

Mean Spirit wrote:

outsidethebox wrote:

"Outstanding phenotypic performance means they aren't as inbred as you think they are. I sure wouldn't hate them, but I'd just doubt the ibc."

MS, I do not believe this is a scientifically valid statement. Please explain.

I guess it's not definitely true that your 40% IBC calf with outstanding performance is anything other than 40% inbred. But its certainly the rule that cattle that are actually 40% inbred generally show regression, not outstanding performance. On the other hand, cattle that have pedigrees that indicate that they'd be 40% inbred may have simply gotten the evolutionarily best set of genes from their closely-related parents. Can your bull be truly homozygous and show outstanding phenotypic performance? I guess he could, but I don't think its the most likely answer. Seems like a bit too much "having it all" in that answer. But I guess it happens sometime.

MS, I agree with this...and this is what I was trying to say. And it is not that this "40%" calf is growing in outlier proportions-he and his "29%" 3/4 brother who were born minutes apart are virtually identical. I would be glad to hear thoughts on how to employ this calf...I think I have to use him to try to uncover/discover what is really in him.

EddieM wrote:

Quote :

If you are scared of losing the line, I'd keep the bigger ones.

Hilly, I'm slow getting back to your question. I probably did not read the first post well enough but I fixed a mental picture of a population without known background but some inbreeding. This was a wide screen mental picture so I saw a lot of variation in this year's calf crop. The actual photographs and further discussions will sift the husks from my assumptions. But if you do not know what you have and there is regression already showing up in the youngest part of the group, it is like a number have already said here better than me: a hedged bet is to keep the genetics that exhibit the least regression to use later. It is an act of desperation to buy time and see how future matings go. If the average animals continue to regress, the outlier is your last hope. All of this probably does not make sense.

Thanks Eb,

Defiantly helped me comprehend what you were trying to say, not sure how I didn’t see it before hand...

I think your right. Probably the only way to evaluate a closely herd bull is to breed him to unrelated cows. Sounds like a lot of fun.

I'll add some pictures because I said I would but I don't know what they will tell anybody. I was surprised by their growth performance of the cattle relative to their contemperories not by their look. In answer to EddieM you are right I have no idea what I have with this group but regression ISN'T showing up in the youngest part of the group that is what I'm surprised at.
Anyways here is the sire


and his full sister who is the dam of my yearling bull, still relatively poor condition but probably 150-200lbs heavier than this time last year when I brought them here.


and two shots of the bull himself, neither very good as it was dull this morning. His weight gain has been about 17% ahead of the group average. He takes more after the dam in terms of haircoat, horns and general looks.



The other cow product of a dam/son mating so a 25% IBC. She was 960lbs a year ago as a 4 year old and weighed 1150lbs in June this year.

I didn't get a picture of her daughter but despite being 6 weeks younger and poorer reared than the rest of my heifer group she was in the top half for weight before 11 months old.