A good read on birth weights

[BroncoFan]

http://www.angusbeefbulletin.com/extra/2016/11nov16/1116mg_Shike-convention.html#.WDaGadZlDqD

 

[aj]

Pretty good.

 

[Sugna]

Not a decisive, definitive answer on numerical BW EPD

 

[Sugna]

Does anyone have calving experience on the S Sis GQ Angus bull?

 

[BroncoFan]

Not a decisive, definitive answer on numerical BW EPD

I believe the point of the article is each individual breeder must decide what is an acceptable BW to them and what is acceptable to each operation's replacement heifers.

Of our replacement heifers, our biggest one could physically handle a bigger birthweight by looking at her body type in comparison our smallest one would probably benefit with a <70 birthweight bull.

 

[ROAD WARRIOR]

The "old cowboys" all used the 8% rule. The idea was that any cow/heifer should be able to have 8% of her body weight in a calf assuming it is a normal presentation without complication. Example - a 1000 lb heifer should have an 80 lb calf without and complications if presentation is normal. The "old cowboys" also studied the way the bulls were made, clean fronted bulls with smooth shoulders and nice heads were selected for calving ease prospects. I think that we should all take a lesson from the "old cowboys" and pay attention to the animals more and the papers less with their computer generated guesses on what the bull will produce. There is far too much manipulated data being turned in for the EPD's to be even slightly usable in many cases. In my opinion, a 40 to 65 lb calf is a throw away. Yes I will concede that there are a few that occasionally go on and perform but the percentage is relatively small.  If your heifers can only physically have a 60 -70 lb calf unassisted, maybe you should be looking for a different maternal base for your herd. RW

 

[BroncoFan]

The "old cowboys" all used the 8% rule. The idea was that any cow/heifer should be able to have 8% of her body weight in a calf assuming it is a normal presentation without complication. Example - a 1000 lb heifer should have an 80 lb calf without and complications if presentation is normal. The "old cowboys" also studied the way the bulls were made, clean fronted bulls with smooth shoulders and nice heads were selected for calving ease prospects. I think that we should all take a lesson from the "old cowboys" and pay attention to the animals more and the papers less with their computer generated guesses on what the bull will produce. There is far too much manipulated data being turned in for the EPD's to be even slightly usable in many cases. In my opinion, a 40 to 65 lb calf is a throw away. Yes I will concede that there are a few that occasionally go on and perform but the percentage is relatively small.  If your heifers can only physically have a 60 -70 lb calf unassisted, maybe you should be looking for a different maternal base for your herd. RW

Our one heifer, we're giving her a chance to see what she'll do. We have bred her dam to some real cow killers and the resulting calves come out 70-80lbs and go on to sell well and do well in the show ring.

 

[beebe]

The "old cowboys" all used the 8% rule. The idea was that any cow/heifer should be able to have 8% of her body weight in a calf assuming it is a normal presentation without complication. Example - a 1000 lb heifer should have an 80 lb calf without and complications if presentation is normal. The "old cowboys" also studied the way the bulls were made, clean fronted bulls with smooth shoulders and nice heads were selected for calving ease prospects. I think that we should all take a lesson from the "old cowboys" and pay attention to the animals more and the papers less with their computer generated guesses on what the bull will produce. There is far too much manipulated data being turned in for the EPD's to be even slightly usable in many cases. In my opinion, a 40 to 65 lb calf is a throw away. Yes I will concede that there are a few that occasionally go on and perform but the percentage is relatively small.  If your heifers can only physically have a 60 -70 lb calf unassisted, maybe you should be looking for a different maternal base for your herd. RW
[/quote
My personal preference is that the first calf comes as easy as possible to enhance rebreeding.  My heifers first calf all go to meat sales so an easy birth and a premium price is a good combination.  Birth weight is important but shape may be more so. 

 

[WT]

Pretty good read.

Just had my first Size Matters calf and she was 39#. I knew they were supposed to come a little smaller but I'm a little disappointed.

 

[RyanChandler]

Calf weight in relation to dam pelvic size has the greatest effect on ease of calving. 

70lb calves out of heifers is plenty big.  If you have a hold on mature cow size, that's over 8% of a 2 year old's body weight. 

 

[HerefordGuy]

Not a decisive, definitive answer on numerical BW EPD

The definitive answer on BW EPD is don't use BW EPD.
Please, please use CED instead. And only use CED.
Don't use some combination of actual BW, BW EPD, and CED EPD.
http://blog.steakgenomics.org/2014/06/economically-relevant-traits-for-new.html

 

[HAB]

The "old cowboys" all used the 8% rule. The idea was that any cow/heifer should be able to have 8% of her body weight in a calf assuming it is a normal presentation without complication. Example - a 1000 lb heifer should have an 80 lb calf without and complications if presentation is normal. The "old cowboys" also studied the way the bulls were made, clean fronted bulls with smooth shoulders and nice heads were selected for calving ease prospects. I think that we should all take a lesson from the "old cowboys" and pay attention to the animals more and the papers less with their computer generated guesses on what the bull will produce. There is far too much manipulated data being turned in for the EPD's to be even slightly usable in many cases. In my opinion, a 40 to 65 lb calf is a throw away. Yes I will concede that there are a few that occasionally go on and perform but the percentage is relatively small.  If your heifers can only physically have a 60 -70 lb calf unassisted, maybe you should be looking for a different maternal base for your herd. RW

Could not agree more.  The low birth weight mentality has created a cowherd that struggles with "normal" sized calves.  I prefer using 10%.  Heifers have to have pelvic area.

 

[beebe]

The "old cowboys" all used the 8% rule. The idea was that any cow/heifer should be able to have 8% of her body weight in a calf assuming it is a normal presentation without complication. Example - a 1000 lb heifer should have an 80 lb calf without and complications if presentation is normal. The "old cowboys" also studied the way the bulls were made, clean fronted bulls with smooth shoulders and nice heads were selected for calving ease prospects. I think that we should all take a lesson from the "old cowboys" and pay attention to the animals more and the papers less with their computer generated guesses on what the bull will produce. There is far too much manipulated data being turned in for the EPD's to be even slightly usable in many cases. In my opinion, a 40 to 65 lb calf is a throw away. Yes I will concede that there are a few that occasionally go on and perform but the percentage is relatively small.  If your heifers can only physically have a 60 -70 lb calf unassisted, maybe you should be looking for a different maternal base for your herd. RW

Could not agree more.  The low birth weight mentality has created a cowherd that struggles with "normal" sized calves.  I prefer using 10%.  Heifers have to have pelvic area.

We pelvic measure our heifers before they meet a bull.  Do you have a minimum standard that you use?

 

[aj]

Why isn't there more pelvic measurements of potential herd sires done. I am not sure I've ever seen this data listed. Is it because it's not a real heritable trait? Could you head off a problem of a bull sired small pelvics by doing this?

 

[RyanChandler]

100lb calves aren't normal. It is this mentality that has crippled the advancement of many breeds, shorthorns as much as any. 

 

[Hopster1000]

I don't think anyone in the article or in the thread is advocating 100lb calves, and I agree with you that wouldn't be the best approach.

Although if a cow is able to easily calve a 90lb calf, would it be right to target a 65lb or 70lb calf from her, which could reduce the offsprings ability in turn to calf easily?
Likewise if a heifer has the size and pelvic are to easily calve a 75lb calf would it be sensible to use a bull that will produce a 50lb or 55lb calf?
Surely there is an area of optimal size, where calf survivablity from being born alive unaided to weanling, is at its highest percentage?
Yes, if a heifer is small with a smaller pelvic area, then those bulls are most definitely needed, although if those lower birthweight calves have a smaller frame and smaller pelvic area, I would think that they shouldn't be retained to compile the problem?

 

[ROAD WARRIOR]

I really don't understand how we have arrived at the point where people are convinced an 80 - 85 lb calf is a calving issue especially for mature cows. My heifers will routinely have calves in that weight range without incident if the position of the calf is normal. This is a product of necessity as we are on the road 2 to 4 days a week during most of the calving season with our business. I simply cannot have heifers that struggle to have a live calf if it is above 70 lbs. My chore crew will check them in the morning while feeding and again at night while doing the evening chores but they are on their own the rest of the time. Last year we lost 4 calves out of 70 cows and heifers, all 4 were lost when we were at home and were not related to BW. One was lost in a snow bank in a storm, two were a set of twins that were not positioned correctly and the fourth was a first calf heifer that we had bought as a bred who had a 50 lb calf that didn't survive the cold.  We have a 7 year running average of having 82 lb heifers and 84 lb bulls. I can count on one hand the number of calves that we have had in the last 20 years that were 100 lbs. I recently read an article published by a university claiming that a 3.8 frame score cow that weighs 1100 lbs is the ideal cow and that may work for some people but out here in my little corner of the world it's not a functional idea. Yes I understand that the 1100 lb cow eats less but her 60 to 65 lb calf that they were promoting as ideal won't generate the revenue per cow that my 5.5 to 6 frame cows do having 80 to 87 lbs calves do. The simple truth is that 90% of our bull and heifer calves that are born here weighing 70 lbs or less end up in the cull pen because they typically are finer boned and low performing cattle that never catch up to their counterparts that are born in the 80+ lb range. Everyone likes to talk about about % of the cows body weight in comparison to the weaned calf weights. I much prefer to talk about the % of revenue a cow produces compared to their counterparts in the herd

 

[RyanChandler]

Revenue per cow tells us very very little about profitability as it completely disregards the other side of the equation, the cost of production!  I'd bet the farm that the cows in your herd that generate the most revenue are not even close to being the most profitable ie revenue less expenses.  Weaning weight % is the only economically relevant trait as it is the only metric that accounts for ALL indicator traits. Females with narrow pelvic have dead calves and thus wean 0%. Same with cows w/ excessive Bw's. Poor milkers wean poor WW%.  Heavy milkers don't breed back and wean 0%.  High maintenance cows don't breed back and wean 0%. Poor udders? Poor ww%.  Bad legs/feet => cant travel, loses body condition, either weans poor % or fails to breed back altogether.  No matter the flaw, it will be exposed in the WW%.

Rather than putting direct selection pressure on indicator traits such as frame or weight, or even birweight or calving ease!, start selecting for weaning weight % and you'll have a new found love for those 4 frame 1100lbers.  If you have 1500lb cows that are weaning half their body weight without supplementation then that's great! But for most environments, selecting for a 50% weaning weight % will self regulate cow size to 11-1200lbs,, and even smaller in many locations. 


Now I don't know anyone who thinks 85lb calves are too big for COWS but MANY quality commercial heifers will need assistance calving 85lb calves as that is over 10% of their body weight.  And this is where this topic just becomes circular.  No matter the metric, weight without context is arbitrary! Cow or heifer size has to be taken into consideration when talking about 'ideal birthweights.' 

I also believe this is why BW EPD is still a valuable tool as it presents some context, when analyzing CE EPD, as to the type (size) of heifers the bull in question has been bred to. It gives context as to the size of heifers the CE EPD was generated around.  Just because a +2 BW bull has the same CE EPD as a -2BW bull doesn't mean their calving ease will be the same on ALL heifers.  They may calve the same when bred to 1200lb grown out heifers but when bred to common 800lb commercial heifers, this is where their ease of calving tends to vary. 

 

[huntaway]

I also believe this is why BW EPD is still a valuable tool as it presents some context, when analyzing CE EPD, as to the type (size) of heifers the bull in question has been bred to. It gives context as to the size of heifers the CE EPD was generated around.  Just because a +2 BW bull has the same CE EPD as a -2BW bull doesn't mean their calving ease will be the same on ALL heifers.  They may calve the same when bred to 1200lb grown out heifers but when bred to common 800lb commercial heifers, this is where their ease of calving tends to vary.
[/quote]

I have seen you make this comment a number of times and I'm not sure how it works. As WW YY are attempting to eliminate the influence of environment, CED is trying to eliminate the influence of the cow and CEM is trying to eliminate the influence of the bull. These bigger heifers, able to calve easily should have good CEM and maybe larger Pelvic areas. Larger birthweight bulls that have better CED numbers to me indicates a better calf shape for calving.

 

[ROAD WARRIOR]

Revenue per cow tells us very very little about profitability as it completely disregards the other side of the equation, the cost of production!  I'd bet the farm that the cows in your herd that generate the most revenue are not even close to being the most profitable ie revenue less expenses.  Weaning weight % is the only economically relevant trait as it is the only metric that accounts for ALL indicator traits. Females with narrow pelvic have dead calves and thus wean 0%. Same with cows w/ excessive Bw's. Poor milkers wean poor WW%.  Heavy milkers don't breed back and wean 0%.  High maintenance cows don't breed back and wean 0%. Poor udders? Poor ww%.  Bad legs/feet => cant travel, loses body condition, either weans poor % or fails to breed back altogether.  No matter the flaw, it will be exposed in the WW%.

Revenue generated per cow is huge for me. The cow that consistently produces progeny that sell for $3,500 to $10,000+ will more than pay for herself and her upkeep as well as make the payments on other things. Compare her to the cow that consistently puts one in the cull pen to be sold as a feeder calf for $800 to $1,000, the choice is pretty easy for me to make on which cow that I will be feeding the next year. Our most prolific money generating cows will average 1450 lbs. They will all consistently wean off calves that will weigh 700 to 850 lbs without creep and on endophyte infected fescue. I do not have a 4 frame score animal on the place anymore simply because they could not produce the performance that would make them keepers. The last of the 1100 lb cows that were here struggled to wean off 500 lb calves in the same conditions as the other cows. We weigh our cows twice a year so I have a pretty good handle on their weights as well as what they produce.

Rather than putting direct selection pressure on indicator traits such as frame or weight, or even birweight or calving ease!, start selecting for weaning weight % and you'll have a new found love for those 4 frame 1100lbers.  If you have 1500lb cows that are weaning half their body weight without supplementation then that's great! But for most environments, selecting for a 50% weaning weight % will self regulate cow size to 11-1200lbs,, and even smaller in many locations. 

I do not select for B.W. when I select a herd bull or AI sire. I select for a bull that has good feet and legs first and foremost, how the bull is made, cow families and actual performance next. I pay very little attention to EPD's as there is far too much corrupt data involved in their formulation to be even remotely accurate.


Now I don't know anyone who thinks 85lb calves are too big for COWS but MANY quality commercial heifers will need assistance calving 85lb calves as that is over 10% of their body weight.  And this is where this topic just becomes circular.  No matter the metric, weight without context is arbitrary! Cow or heifer size has to be taken into consideration when talking about 'ideal birthweights.' 

Truthfully, BW has a fairly limited effect on calving ease. It's the square peg in the round hole concept. Typically our heifer will have 78 to 85 lb calves unassisted, but that is due a large part to the fact that the calves are made to come out easily. Long, smooth shouldered with a nice sized head. I have pulled 75 lb calves from purchased first calf heifers that were built like a box, about as wide as they were long.

I also believe this is why BW EPD is still a valuable tool as it presents some context, when analyzing CE EPD, as to the type (size) of heifers the bull in question has been bred to. It gives context as to the size of heifers the CE EPD was generated around.  Just because a +2 BW bull has the same CE EPD as a -2BW bull doesn't mean their calving ease will be the same on ALL heifers.  They may calve the same when bred to 1200lb grown out heifers but when bred to common 800lb commercial heifers, this is where their ease of calving tends to vary.

For an EPD to be a valuable tool it has to be based on the belief that the data used to obtain that EPD is accurate and not manipulated. Our Association does not require a BW to be turned in. If there is not an actual BW turned in the Association assigns them "breed average" BW EPD. I fail to see how this EPD can be a valuable tool when thousands of calves are assigned a breed average EPD. In all actuality the EPDs on a young animal are pretty much irrelevant until it produces enough progeny to accurately identify it's traits. For the bulk of breeding bulls, they will not have enough progeny to identify until they are 5 to 7 years old and in most cases they are long gone by then.