Stacking low birth weight genetics

[gizmom]

I didn't want to hijack a thread but thought this was worth discussion. How many folks always use low bw bulls? Several years ago we started having calves really early, the first year it happened we chalked it up to the extreamly hot summer and fall. I should specify this was happening with our bred heifers. The following year we changed our breeding date to have the calves come a bit later. That year we still had calves coming early, and lost several that were very small and weak. We started researching and came to the conclusion that our problem was self inflicted. Low birth weight bulls typically are shorter gestation bulls, one of the reasons why they are lower birth weight. Stack those genetics long enough you end up with a very short gestation and weak calves, at least that was our conclusion. I am not saying we need to go crazy using high bw bulls but I think we need to be cautious about stacking low bw and pay attention to ced. You can use a higher bw EPD bull and still have acceptable ced for heifers. Anyone have any thoughts on this, or do y'all think I'm nutty as a fruitcake?

Gizmom

 

[holm25]

We calve heifers to CE bulls for their first calves but after that our cows are expected to have 80-90lbs calves. We haven't had an issue. I do believe that stacking up CE genetics causes problems.

 

[MtnCows93]

We calve heifers to CE bulls for their first calves but after that our cows are expected to have 80-90lbs calves. We haven't had an issue. I do believe that stacking up CE genetics causes problems.

yea the cattle will get smaller and smaller over time, plus the cows wont weed theirselves out.( that might not be a bad thing idk) Whats your CE heifer bulls bw?

 

[farmerjan]

I think it has merit. And if you keep heifer calves out of these lbw bulls. and then breed them lbw bulls. the resulting generations seem to get smaller.
We have kept some heifers out of first calf heifers that were bred to lbw bulls. But I make it a point to try to not keep any that seem really small even if they are nice. We do not do registered and don't sell bulls, so not like some of you farmers that do. But I tend to not keep too many heifers out of heifers, and we have several plus wt bulls that we use on our cows so we are not "breeding smaller". I have not noticed the heifers calving that much on a shorter gestation, but don't doubt it could be true. We mostly pasture breed, and they usually have these nice "little calves" but most all have been up and going quick as wink.
One thing too, we calve our heifers out a little older than many, they are 27 to 30 months when they calve usually. So maybe are not seeing the "smaller weaker" calves that a younger heifer might have. KNOCK on wood, have not lost a calf out of a first calf heifer in years, except for one the coyotes got at about 3 days old out at a pasture where they were seeing packs of them for a few weeks. Had the blk basturd buzzards try to get one a year ago, when she was just up and trying to clean it, and we saved it only because someone was there... 30 minutes she had that calf cleaned, up on it's feet, nursed a little, and taking it off into the woods. But no real problems with them being too early and weak.

 

[Bright Raven]

I know my breeding dates because they are all AI. I know exactly the Gestation period for all my calves and keep accurate records. There is no correlation here between CE/BW EPDs and shorter Gestation period.

 

[gizmom]

BR
I know you are 100% AI and I also know you keep excellent records. Have you bred low birth weight bulls to low birth weight heifers for several generations?

Gizmom

 

[Bright Raven]

BR
I know you are 100% AI and I also know you keep excellent records. Have you bred low birth weight bulls to low birth weight heifers for several generations?

Gizmom

No. That could make a difference. I have avoided using bulls with high EPDs for BW and CE. The high CE and BW metrics give up a lot in performance for the low birth weights and calving ease.

My point is more direct. I get the same Gestation average using the sires with high EPD metrics for CE and BW as I do with bulls that have moderate EPDs for CE and BW.

I would caution you to make sure you have enough data to draw the conclusions you might. Not saying you are but something like this takes a threshold level of data in order to draw conclusions. It is why researchers have to take a lot of statistics in the course of their studies.

 

[gizmom]

BR

I have studied it in my herd for a number of years, discussed my concerns with a number of animal scientists, and made an educated conclusion, I didn't say it was the right conclusion. We did adjust our sire selection, and have seen positive results. Heifers holding onto their calves longer, stronger and yes heavier calves, but not so heavy that we have had calving issues. People need to understand that there is a difference between low birth weight or BW EPD and CE. You can have more BW as long as your CE is good, I want to use a bull with at least a +6 CED.

Gizmom

 

[talltimber]

Thank you for bringing this up gizmom, it's something I've been thinking about lately. What do you think would qualify as a low bw/high ce epd? Do you think that the ce is more important to watch than the bw in regards to future problems?

 

[Bright Raven]

BR

I have studied it in my herd for a number of years, discussed my concerns with a number of animal scientists, and made an educated conclusion, I didn't say it was the right conclusion. We did adjust our sire selection, and have seen positive results. Heifers holding onto their calves longer, stronger and yes heavier calves, but not so heavy that we have had calving issues. People need to understand that there is a difference between low birth weight or BW EPD and CE. You can have more BW as long as your CE is good, I want to use a bull with at least a +6 CED.

Gizmom

Well. I didn't say you were as "nutty as a fruit cake". ;-)

To be clear, the theory is that if you stack low birth weight genetics over a period of time, the result is shorter gestation periods. Is that right?

Seriously, it takes a lot of data to provide a level of confidence in making this kind of statement. It is something that could provide an incentive for a research undertaking. Having said that, we all base our decisions and refine our objectives based on what information we have and our experiences. I think you are using your head!

 

[gizmom]

Tall timber

To clarify I think CE is the number to look at as an example a bull with an actual birth weight of 81 pounds and a 3.2 birth weight EPD with a +6 CED, would you use this bull on heifers?

How about a bull with a 75 pound actual birth weight and a 3.1 birth weight EPD with a +5 CED?

I started this thread not because I know all the answers but because I have been giving the subject a lot of thought. Most folks would look at bulls with over a 3.0 bw EPD and not even consider using him. I honestly would consider using them, but I would also factor in the actual birth weight, and genetics.

Gizmom

 

[T & B farms]

I have noticed smaller mature size when stacking low bw's. That's why I picked Hickok,and black granite to go in my heifers this year. Good choice or bad,we will know in a couple years.
My heifers bred to low birthweight bulls always seem to calve earlier than cows bred to power bulls.
Almost all of my ai bred cows calve 6-10 days before the due date. Heifers are more 10-12 days early.

 

[Ebenezer]

Tall timber

To clarify I think CE is the number to look at as an example a bull with an actual birth weight of 81 pounds and a 3.2 birth weight EPD with a +6 CED, would you use this bull on heifers?

How about a bull with a 75 pound actual birth weight and a 3.1 birth weight EPD with a +5 CED?

I started this thread not because I know all the answers but because I have been giving the subject a lot of thought. Most folks would look at bulls with over a 3.0 bw EPD and not even consider using him. I honestly would consider using them, but I would also factor in the actual birth weight, and genetics.

Gizmom

When we go back several decades prior to CED being around, the BWs meant more and got more discussion. Actual BW is not a thing that is going to get a scientific guy excited if you have EPDs for BW. Long story short, "back when" a BW EPD of 3 was getting high for heifers regardless of other data. Now the CED as positives and a knowledge of actual BW might get you into a closer fit but I'd have to know for sure that a 3+ BW EPD bull had calves born looking like a snake before I bred a heifer. This general type bull would not be compromised on height nor selected to be built like a rhino. He will be quite adequate on muscling and quite balanced in weight to height. +2 would be high enough to gamble on for me with heifers and with a +CED.

BR can poo poo this non-scientific thought, too, but the BW in the maternal grand dam has a lot to do with the issue on a heifer's or cow's birth weights regardless what she is bred to. A high BW back in the MGD is going to create an issue - opinion.

A great bull with a BW EPD of over 3 is going to set some calves up to not be "heifer bulls" as you know. But I think that you will be more pleased with the average type and performance. Buyers just need to understand that you have not stacked high BWs or selected a sire that is unbalanced. Folks seem scared of bulls bred for cows anymore but they like the calves. Go figure. But I have come to wonder about the comparative value of EPDs as some, like MM, have raced into the 30's or higher and folks, I assume, are still mainly forage based. But I think that you are hitting the nail on the head with length of gestation being a compounded problem in CED.

Side note if you believe in the voodoo of Bonsma applications: if a bull sires calves in your environment and the bull calves are smaller than the heifer calves that is an indication that the sire is not a good fit for your environment. BR can poo poo again and is welcomed to do so. Just a thought as I shake my rattle and dance around the fire.

 

[Nesikep]

Everyone is talking about "early" and "late", and no one is giving actual gestation times.. Lets put some numbers to it
My herd has an average gestation of 288 days, most bull calves go longer, 295 is about as high as I ever see barring a couple exceptions.. very few are born before 282 days, even on the first timers.
Different cow families here have different typical gestation times.. Completely anecdotal evidence, but the cow family with the shortest gestation times is the one with the most miscarriages as well.
I'm pretty good at keeping track of breeding dates.. there's always one or two cows that I don't catch, thankfully the bull doesn't miss them though.

 

[Son of Butch]

Different breeds have different lengths of gestation.

Journal of Animal Science.
In 1920 283 days was considered to be the average length of gestation for all breeds of cattle.
1937 study of 27,810 gestations found the average for all breeds to be 282.1 days.
1943 study found Herefords mated to Herefords had an average gestation of 289 days and Black Angus mated to
Black Angus averaged 272.8 days. When Angus and Herefords were crossed the cows averaged 281.4 days.
Conclusion: gestation length is a heritable variation.

Since 1943 average Angus gestation length has increased at a rate of about 1 day per decade to current average of
280 days along with the increased gestation length has come an increase in average birth weight for Angus cattle.
Conclusion: birth weight and gestation length are heritable variations with a reciprocal relationship.

 

[True Grit Farms]

I just want a live black calf every 12 months, I'll leave all the figuring to those that like to figure. My take is, Angus is wanting more carcass and Simmental is trying to over take Angus on CE and BW.

 

[Bright Raven]

When we go back several decades prior to CED being around, the BWs meant more and got more discussion. Actual BW is not a thing that is going to get a scientific guy excited if you have EPDs for BW. Long story short, "back when" a BW EPD of 3 was getting high for heifers regardless of other data. Now the CED as positives and a knowledge of actual BW might get you into a closer fit but I'd have to know for sure that a 3+ BW EPD bull had calves born looking like a snake before I bred a heifer. This general type bull would not be compromised on height nor selected to be built like a rhino. He will be quite adequate on muscling and quite balanced in weight to height. +2 would be high enough to gamble on for me with heifers and with a +CED.

BR can poo poo this non-scientific thought, too, but the BW in the maternal grand dam has a lot to do with the issue on a heifer's or cow's birth weights regardless what she is bred to. A high BW back in the MGD is going to create an issue - opinion.

A great bull with a BW EPD of over 3 is going to set some calves up to not be "heifer bulls" as you know. But I think that you will be more pleased with the average type and performance. Buyers just need to understand that you have not stacked high BWs or selected a sire that is unbalanced. Folks seem scared of bulls bred for cows anymore but they like the calves. Go figure. But I have come to wonder about the comparative value of EPDs as some, like MM, have raced into the 30's or higher and folks, I assume, are still mainly forage based. But I think that you are hitting the nail on the head with length of gestation being a compounded problem in CED.

Side note if you believe in the voodoo of Bonsma applications: if a bull sires calves in your environment and the bull calves are smaller than the heifer calves that is an indication that the sire is not a good fit for your environment. BR can poo poo again and is welcomed to do so. Just a thought as I shake my rattle and dance around the fire.

It is only a thought at this point.

The essence of the concept in the OP is that breeding of low birthweight bulls to low birth weight heifers/cows over several generations will result in shorter and shorter gestation periods - thus lowering the birth weight. That is why Gizmom ask me the following: Have you bred low birth weight bulls to low birth weight heifers for several generations? Your "side note" at the bottom of the last paragraph does not speak to the issue of "length of gestation".

Son of Butch has introduced another factor - direct inheritance. Quote - "Conclusion: gestation length is a heritable variation".

If you have some quotes from Bonsma on low birth weight being influenced by length of gestation, could you please post them? If you have actual research that addresses that concept, IMO, that would be even better.

 

[Son of Butch]

Tall timber

To clarify I think CE is the number to look at as an example a bull with an actual birth weight of 81 pounds
and a 3.2 birth weight EPD with a +6 CED, would you use this bull on heifers?

How about a bull with a 75 pound actual birth weight and a 3.1 birth weight EPD with a +5 CED?
Gizmom

Actual birth weight is a poor measurement in determining an inherited trait as it is too often a measurement of
management and environment.
EPD should be used instead of actual birth weights. EPD is a much better predictor because it factors in actual birth
weight comparison with herdmates birth weights under the same management and environmental conditions.

Accuracy of epds are very important.
ced 7 and bw 1.3 is breed average
IF a sire was CED 10 and BW 3.5 with less than .70 acc I would have very low confidence in using on heifers
when more data comes in those numbers are going to change.... spreads that look too good to be true usually are.
.70 is my minimum standard for me to believe it.

 

[True Grit Farms]

When we go back several decades prior to CED being around, the BWs meant more and got more discussion. Actual BW is not a thing that is going to get a scientific guy excited if you have EPDs for BW. Long story short, "back when" a BW EPD of 3 was getting high for heifers regardless of other data. Now the CED as positives and a knowledge of actual BW might get you into a closer fit but I'd have to know for sure that a 3+ BW EPD bull had calves born looking like a snake before I bred a heifer. This general type bull would not be compromised on height nor selected to be built like a rhino. He will be quite adequate on muscling and quite balanced in weight to height. +2 would be high enough to gamble on for me with heifers and with a +CED.

BR can poo poo this non-scientific thought, too, but the BW in the maternal grand dam has a lot to do with the issue on a heifer's or cow's birth weights regardless what she is bred to. A high BW back in the MGD is going to create an issue - opinion.

A great bull with a BW EPD of over 3 is going to set some calves up to not be "heifer bulls" as you know. But I think that you will be more pleased with the average type and performance. Buyers just need to understand that you have not stacked high BWs or selected a sire that is unbalanced. Folks seem scared of bulls bred for cows anymore but they like the calves. Go figure. But I have come to wonder about the comparative value of EPDs as some, like MM, have raced into the 30's or higher and folks, I assume, are still mainly forage based. But I think that you are hitting the nail on the head with length of gestation being a compounded problem in CED.

Side note if you believe in the voodoo of Bonsma applications: if a bull sires calves in your environment and the bull calves are smaller than the heifer calves that is an indication that the sire is not a good fit for your environment. BR can poo poo again and is welcomed to do so. Just a thought as I shake my rattle and dance around the fire.

It is only a thought at this point.

The essence of the concept in the OP is that breeding of low birthweight bulls to low birth weight heifers/cows over several generations will result in shorter and shorter gestation periods - thus lowering the birth weight. That is why Gizmom ask me the following: Have you bred low birth weight bulls to low birth weight heifers for several generations? Your "side note" at the bottom of the last paragraph does not speak to the issue of "length of gestation".

Son of Butch has introduced another factor - direct inheritance. Quote - "Conclusion: gestation length is a heritable variation".

If you have some quotes from Bonsma on low birth weight being influenced by length of gestation, could you please post them? If you have actual research that addresses that concept, IMO, that would be even better.

Well that's a no brainer, shorter gestation equals lower birthweight. Doctors have been inducing labor on humans because of BW issues for years.

 

[Bright Raven]

When we go back several decades prior to CED being around, the BWs meant more and got more discussion. Actual BW is not a thing that is going to get a scientific guy excited if you have EPDs for BW. Long story short, "back when" a BW EPD of 3 was getting high for heifers regardless of other data. Now the CED as positives and a knowledge of actual BW might get you into a closer fit but I'd have to know for sure that a 3+ BW EPD bull had calves born looking like a snake before I bred a heifer. This general type bull would not be compromised on height nor selected to be built like a rhino. He will be quite adequate on muscling and quite balanced in weight to height. +2 would be high enough to gamble on for me with heifers and with a +CED.

BR can poo poo this non-scientific thought, too, but the BW in the maternal grand dam has a lot to do with the issue on a heifer's or cow's birth weights regardless what she is bred to. A high BW back in the MGD is going to create an issue - opinion.

A great bull with a BW EPD of over 3 is going to set some calves up to not be "heifer bulls" as you know. But I think that you will be more pleased with the average type and performance. Buyers just need to understand that you have not stacked high BWs or selected a sire that is unbalanced. Folks seem scared of bulls bred for cows anymore but they like the calves. Go figure. But I have come to wonder about the comparative value of EPDs as some, like MM, have raced into the 30's or higher and folks, I assume, are still mainly forage based. But I think that you are hitting the nail on the head with length of gestation being a compounded problem in CED.

Side note if you believe in the voodoo of Bonsma applications: if a bull sires calves in your environment and the bull calves are smaller than the heifer calves that is an indication that the sire is not a good fit for your environment. BR can poo poo again and is welcomed to do so. Just a thought as I shake my rattle and dance around the fire.

It is only a thought at this point.

The essence of the concept in the OP is that breeding of low birthweight bulls to low birth weight heifers/cows over several generations will result in shorter and shorter gestation periods - thus lowering the birth weight. That is why Gizmom ask me the following: Have you bred low birth weight bulls to low birth weight heifers for several generations? Your "side note" at the bottom of the last paragraph does not speak to the issue of "length of gestation".

Son of Butch has introduced another factor - direct inheritance. Quote - "Conclusion: gestation length is a heritable variation".

If you have some quotes from Bonsma on low birth weight being influenced by length of gestation, could you please post them? If you have actual research that addresses that concept, IMO, that would be even better.

Well that's a no brainer, shorter gestation equals lower birthweight. Doctors have been inducing labor on humans because of BW issues for years.

Absolutely, that is a given. The question is: what produces those shorter and shorter gestation periods and thus a continual decline in birth weight. The end result being small weak calves.

In the Simmental Breed, I don't see shorter gestation periods in low birth weight bulls. They simply inherit and pass on the genetic predisposition to produce a smaller calf in the same gestation period which is 285 days in Simmentals. Uno Mas is low birth weight deluxe but the gestation period is still 285 days.