BW Corelation to WW

[randiliana]

I know this has been hashed over many times, but since we weighed a bunch of calves yesterday, and it is raining out I have time to play around with my records. Here is how BW and WW relate to each other in our herd.

I divided the calves into groups by BW, Under 75 lbs, 75-90 lbs 90-105 lbs and Over 105 lbs. I did this for the calves from each of the last 3 years.

2005
<75 lbs, avg BW 66, Avg adg 2.09 (10 head)
75-90 lbs, avg BW 82, Avg adg 2.28 (19 head)
90-105 lbs, avg BW 96, Avg adg 2.51 (44 head)
>105 lbs, avg BW 110, Avg adg 2.58 (21 head)

2006
<75 lbs, avg BW 67, Avg adg 1.99 (13 head)
75-90 lbs, avg BW 83, Avg adg 2.30 (46 head)
90-105 lbs, avg BW 96, Avg adg 2.37 (47 head)
>105 lbs, avg BW 111, Avg adg 2.51 (14 head)

2007 (and this is only preliminary as not all calves are weighed yet)
<75 lbs, avg BW 66, Avg adg 2.22 (9 head)
75-90 lbs, avg BW 83, Avg adg 2.43 (23 head)
90-105 lbs, avg BW 96, Avg adg 2.57 (27 head)
>105 lbs, avg BW 111, Avg adg 2.76 (14 head)

The average difference in ADG from the big BW to the smalll BW calves is 0.517 lbs/day. The average difference in BW is 44 lbs. On 205 days that = 150 more lbs on the big BW calves than the small BW calves.

Now, I am not saying I (or anyone else) should be trying for 110 lb calves. Just stating what the differences in this herd were. Keep in mind also that generally the 2 year old's calves had smaller BW's and the cow's calves had the larger BW's. Although there will be 2 year olds in the 90-105 lb group and cows in the <75 lb group.

 

[PPRM]

I think that the averages tend to play out this way....But you'll find exceptions as wieght doesn't say anything about the "Shape" of a calf.

I had a bull who consistently threw 80 pound or lighter calves. However, tey came out a mile long and then would bulk up after hitting the ground....

I have always looked for Bulls who were Lower BW and higher end WW...I have found most of these bulls throw those long stringbean calves, but the above mentioned one was exceptional....

I also haven't pulled a calf for quite some time...Not al the calves are small. I have a vet do pelvic measurements on hiefers and he said, "You could breed these to Charlais.......

My point is that BW is a number, there is more to it. Like you mentioned in your post, age of cow is a factor. However, looking at all of these factors is the key to calving ease IMO,


PPRM

 

[Faster horses]

Pretty interesting.

But we take a couple other factors into consideration.
Labor (we don't like babysitting calving cows because of BW problems)
and big, dead calves don't pay many bills.

However, our neighbor doesn't mind babysitting his cows...he
checks them every 2 hours, so BW is not a big deal to him.

 

[rancherfred]

Have you run any statistical analysis on the numbers to see what your standard deviations are? I would be interested in knowing what the break down of the statistical analysis is.

I guess I am not really surprised by what the initial data is telling you.

 

[DiamondSCattleCo]

Labor (we don't like babysitting calving cows because of BW problems) and big, dead calves don't pay many bills.

We got into a scrap about this topic over on Cattle Today a few months ago. With proper selection of your breeding stock, there is absolutely no need to babysit when dropping large calves. I specifically select my bulls to give me 100 lb BW calves on my 1200 lb cows. And if a heifer around here can't deliver a 90 lb BW calf unassisted, she leaves the place. Having followed a strict regimen of culling out stuff that can't deliver the calf size I want, my calving chains are rusting in the barn and being used to hold a pen gate shut. Its a fallacy that large calves has to mean dead calves. Looking back through my calving books during that scrap a few months ago, I had more calving issues with a 75lb BW Maine bull that I used for a year.

Rod

 

[Faster horses]

It has been our experience that big calves don't get up and get going in a storm. Those 80 lb. black calves get right up and get going.

To each his own.

Our calves gain an average of 3 lbs. a day on grass and mineral. That's good enough for us. Oh, the heifer calves don't do that of course, they are more in the 2.5-2.75 lb. range.

I'm glad heavy calves work for you. They do for our neighbor as well.

 

[DiamondSCattleCo]

It has been our experience that big calves don't get up and get going in a storm. Those 80 lb. black calves get right up and get going.

Thats interesting that you find that. Since I calve in Feb/Mar, I find the lighter calves can't handle the cold near as well as the heavier calves can.

Rod

 

[PPRM]

DSCC,

What Breed do you run???? I find our larger calves tend to be more lethargic even thouhgt they do get up and going eventually...Just seems to be more to get up I guess, LOL...

Ours are Angus/Simmental,

PPRM

 

[DiamondSCattleCo]

What Breed do you run???? I find our larger calves tend to be more lethargic even thouhgt they do get up and going eventually...Just seems to be more to get up I guess, LOL...

I run an Angus based herd. Mostly Angus/Shorthorn, but I still have a few old baldies left, a few Angus/Simm (from an experiment a few years back) and a few Shorthorn/Simm (neighbor was selling them cheap and I couldn't resist. Probably the best animals on the place). My critters are all in that 12-1300 lb range, and while they don't have as many guts under them as Kaiser's Welsh animals, they lean towards that old fashioned animal with plenty of guts.

One of the myths I tried to address on Cattle Today was the whole 'large calves are slower' thing. Its not necessarily calf weight that makes a calf slower, but rather birthing ease. Hard birth = slow calf, no matter what his weight. I've specifically culled for and selected cows who can EASILY give birth to those 100 lb calves. If a heifer around here can't drop a 90lb calf unassisted and in a reasonable time frame, she leaves. I actually had a bull wreck here a few years back (3? 4?) and the bull I had to go with was theoretically an 80lb BW heifer bull. At least his lineage suggested it, but my birth weights were WAY up there. Heifers were dropping 110 - 120lb calves, and while I had some light pulls, most were doing the job on their own. One poor little girl birthed a 137 lb calf all on her own. I don't have the numbers handy, but my BW average that year was over 120 lbs. I didn't retain any heifers that year, as I didn't want to see any BW creep in my herd, but I was pleased that my animals were able to handle those weights without even thinking about it.

I've always felt that a bull's phenotype was far more important than weight. Small heads, with a nice neck that transitions into smooth front shoulders are what I look for. Then I know I can push the BW up. If I have to settle on a course shouldered bull, I'll look to drop BW down, but then I'll also push my breeding date back so those little jackrabbits don't freeze to death

Rod

 

[SMN Herf]

Randiliana,

Did you group the heifers and the steers/bull calves together in your data analysis or was this just bull/steer calves?

That would certainly scew the data toward the bigger birthweight calves being faster growing as bulls would always outgrow their female counterparts and will tend to be heavier at birth.


Also is this adjusted weights or actual? Age of dam would play a huge role in this too as younger cows would usually have lighter calves at weaning and lighter birthweights too.

Also, age of calf would play a role as well because my late April calves would be lighter at birth than my mid March calves.

Do you break down the data based on sire group? That could play a huge role in the final data too.

Interesting data in your herd. Will you change your breeding program because of it?

Brian


[/quote]

 

[randiliana]

Pretty interesting.

But we take a couple other factors into consideration.
Labor (we don't like babysitting calving cows because of BW problems)
and big, dead calves don't pay many bills.

However, our neighbor doesn't mind babysitting his cows...he
checks them every 2 hours, so BW is not a big deal to him.

Well, we check every 4 hours, and that is mostly because of the time we calve, March can get pretty cold. We have calved the cows away from home and only kept heifers around, then the cows were checked twice a day. It is not very often we lose a calf to dystocia. And most often the calves that need the extra care here are on the smaller end of the spectrum. I've carried in numerous <70 lb calves, but can't remember the last >95 lb calf that spent any time in the house.

This spring we lost 2 calves. One never figured out how to suck the cow, and the other we shot as it was deformed. Our average BW is 94 lbs.....

 

[randiliana]

Have you run any statistical analysis on the numbers to see what your standard deviations are? I would be interested in knowing what the break down of the statistical analysis is.

I guess I am not really surprised by what the initial data is telling you.

OK, you are too scientific for me :shock: . I canrun the data, but what exactly are you looking for?

 

[randiliana]

It has been our experience that big calves don't get up and get going in a storm. Those 80 lb. black calves get right up and get going.

To each his own.

Our calves gain an average of 3 lbs. a day on grass and mineral. That's good enough for us. Oh, the heifer calves don't do that of course, they are more in the 2.5-2.75 lb. range.

I'm glad heavy calves work for you. They do for our neighbor as well.

The thing is, do you actually weigh all of your calves at birth? Unless you do that you have NO idea what your calves weigh when they are born. Even I have a hard time guessing the weight on a calf, and we have been weighing calves for the past 10 years. It is not an easy thing to guess.

 

[Denny]

It has been our experience that big calves don't get up and get going in a storm. Those 80 lb. black calves get right up and get going.

Thats interesting that you find that. Since I calve in Feb/Mar, I find the lighter calves can't handle the cold near as well as the heavier calves can.

Rod

I would bet the larger calves may have been a bit thick and got stressed at birth.That would explain the slowness.A 100# snake is easy to deliver than a 75# bowling ball.

I don't like getting those little bitty 60 to 70 # calves as they don't seem to ever catch up to the larger but if your going to sell bulls around here anything over a 90# birth weight just as well be cut and sold as a fat steer because thats all he'll bring on a sale(with a few exceptions).

Our average birth weight on bull calves is 79#s and the heifers were 74#s..We don't weigh the commercial calves unless they are REAL big or REAL small.

 

[randiliana]

Randiliana,

Did you group the heifers and the steers/bull calves together in your data analysis or was this just bull/steer calves?

That would certainly scew the data toward the bigger birthweight calves being faster growing as bulls would always outgrow their female counterparts and will tend to be heavier at birth.


Also is this adjusted weights or actual? Age of dam would play a huge role in this too as younger cows would usually have lighter calves at weaning and lighter birthweights too.

Also, age of calf would play a role as well because my late April calves would be lighter at birth than my mid March calves.

Do you break down the data based on sire group? That could play a huge role in the final data too.

Interesting data in your herd. Will you change your breeding program because of it?

Brian

[/quote]

I included every calf, heifers and bull calves, young cows to old cows. Actual BW, not adjusted. Age of calf doesn't have much to do with it, as I only figured the ADG, I didn't use the WW, because of the age factor.

I could go back, and just figure on the older cows, I imagine that that would give a clearer picture, but I was just doing a quick comparison. I think what you would see in the mature cows is that there would be very few under 75 lb calves. Same would go for the heifers, there would be very few over 95 lb calves, although most of our heifers would fall in the 75-90 llb range.

I don't see a big difference in BW here from March to April. That is something I have never looked very closely at, though.

For this I just combined all the calves, didn't worry about the sire groups. I could easily figure that one out though as I already have the sire groups figured out and all the data is there. I do know that some bulls will totally skew my results, I was just trying to show what happened on average.

I don't think this will affect the breeding program too much, already, we are doing our best to stay away from the <75 lb calves, but that is hard when we always end up buying some replacement bred heifers. I won't push the cows to have >100 lb cows either, because some cows just can't handle a calf that big. We do cull on BW to some extent. On the theory that if you have to assist a heifer with an <75 lb calf the chances are that she won't be able to handle a bull that averages 90+ lb BW's. Better to be safe than sorry.

Think I covered it all.

 

[rancherfred]

The reason I was asking is so that we could tell what the difference on ADG has to be in order to be statistically significant. If you significant difference is a half a pound then you wouldn't be able to say that there is a real appreciable difference between your light ones and your heavy ones on ADG. I haven't really thought through the implications yet but that alone might be able to tell you if you are better off pursuing those heavier BW calves. If there is no significant difference between the light and the heavy ADG then I say forget the heavy BW and stick to the lighter ones that you don't have so much trouble calving.

 

[randiliana]

The reason I was asking is so that we could tell what the difference on ADG has to be in order to be statistically significant. If you significant difference is a half a pound then you wouldn't be able to say that there is a real appreciable difference between your light ones and your heavy ones on ADG. I haven't really thought through the implications yet but that alone might be able to tell you if you are better off pursuing those heavier BW calves. If there is no significant difference between the light and the heavy ADG then I say forget the heavy BW and stick to the lighter ones that you don't have so much trouble calving.

You still have me confused. To me .5 lb/ day is significant. It sounds small, but if you add it up over the long run (200 days) it really shows you what the difference is.

So am I anywhere close to what you are saying? If not can you give an example of what you mean? Thanks

 

[Faster horses]

No, the calves are not weighed at birth. (that would be more labor). I give them all an 80 lb. BW, based on the ones that were weighed. Our herd is based on 80-85 lb. BW and we have bred this line of cattle long enough that I'm comfortable with that weight. But I guess I get your point...if one weighed 90 lbs. and one weighed 75 lbs., I don't know the exact difference in their daily gain.

I do think daily gain is important and most ranchers don't consider it, or
figure it. That is why some calves are a lot heavier at shipping time; they are simply OLDER.

We try not to keep the calves on the cows more than 205 days at the most. We calve late March and sell by the 15th of October, so the calves are fairly young yet. We just don't like pulling the cows down which is easy to do in our area. Ranchers who can put their cows on irrigated or sub irrigated pasture probably have more lee-way with shipping dates.

 

[Texan]

A lot of people around my part of the country have sure taken low birthweights to the extremes. Some of them seem to think that 55 or 60 pound calves are just perfect - even for mature cows.

To each their own, but give me a 90 pound calf over a 60 pound calf any day. I've never found a cheaper time to put that 30 pounds on a calf than while the cow is dry.

As far as I'm concerned, if I've got a cow that can't lay down and have a 90 or 100 pound calf, she can die trying - I sure as hell don't need her.

 

[Northern Rancher]

Pretty hard to pick the big calves from the small ones when they ship cattle from the feedlot-been there done the big calf thing used to argue as hard as anybody they were just as lively-some are but alot aren't. I'll never be caught pushing a another big dumb calf up to an udder to suck-I don't care if he's black,white,hairy,slick,long, square or polkadotted-the misery from pushing the BW deal just isn't worth it. It does make interesting coffe shop talk.