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Genetics or environment?

Big Swede

Well-known member
I asked this question in a different post but didn't get much response. Most cows are at their peak production at 5 to 8 years of age, give or take I suppose. As they age, their calves wean off lighter because of the cows inability to produce milk like she used to among other reasons. Her calves still have the same genetic make up as long as she keeps having calves so even though they may be lighter at weaning they still have the genetic ability to gain and grow when they get on better feed at weaning. If you background your calves shouldn't those calves have a better chance of catching up to the rest of the herd with compensatory gain when they get the nutrition that they need. And if that is true maybe it would be a good idea to keep those old cows in production as long as they are sound because they have already paid for their keep unlike younger cows. At what point do you pull the plug on those old grannies.
Her calf at 6 years old is the same genetically as her calf at 15 years old.
If you sell your calves at weaning I can see where that stategy might not work the best but if you figured the cost of raising or buying replacements maybe it would still pencil out up to a point.
 

DiamondSCattleCo

Well-known member
Big Swede said:
If you background your calves shouldn't those calves have a better chance of catching up to the rest of the herd with compensatory gain when they get the nutrition that they need.

Well yes and no. While what you say is true, genetically wise, its been my experience that a young calf that has a rough start or has been lacking nutritionally will never _quite_ catch up to where it would/should have been. While it would be tough to prove, I think you can look at sick calves to see proof of my claims. A calf thats been direly ill early in life will often times fall into the tail end of the herd with regards to overall weight.

Rod
 

Big Swede

Well-known member
I'll agree with you if the calf has been sick that he probably won't catch up ever, but the calf I'm talking about is the one that might have been getting 20# of milk when the cow was in her prime but now that she is older is only getting 10# of milk a day. Will that calf be stunted enough that he won't gain as well when he hits feed or will he gain even more now that his needs for growth are being met?
 

milkmaid

Well-known member
Big Swede said:
Will that calf be stunted enough that he won't gain as well when he hits feed or will he gain even more now that his needs for growth are being met?

I've found they'll usually gain better than their contemporaries... it's called compensatory growth and is a pretty neat phenomenon.
 

per

Well-known member
I haven't found that those older than prime cows have less of a calf until that last one where it is obvious and she must go. Compensatory gain because of genetics is a harder one for me. We do keep our calves and for lack of a better term "rough winter" them. Have done comparisons with neighboring ranches and even wintered each others calves to figure it out. What we have found is that if the calves went into winter (November) in good bcs (4-5.5) and were fed for 1 to 1.25lb gain they will go onto grass in May much lighter than their regular fed contemporaries. By September 30 the rough wintered calves will weigh at least the same as the calves that went to grass heavier.

Compensatory genetic gain is another matter, I think. I will say that a calf that gets stunted for what ever reason too early never catches up. So, would the smaller than she used to have calf be considered stunted too early and never reach the same as 5 years ago potential? Maybe.

Sorry it seems I was typing while thinking of this topic. Literally those were the thoughts that came to mind. :?
 

roger dodger

Well-known member
Question, Are you going to breed at cow to the same bull at 4 or 5 years of age as you would at 12 or 13? The bulls you use should be getting better as you go just like the cows. Just a thought. rd
 

RSL

Well-known member
This is pretty interesting. We "rough winter" our calves as well. Calves that are poor from older cows don't seem to catch up over the winter with our system, but they look pretty good coming off grass in August. Unrecognizeable is the term that would most apply. That said the first poor calf is usually the start of a slide or precipitous decline.
In this same vein, there is some neat work that was done in Montana that showed how you could restict intake on replacement heifers to control mature size with no impact on fertility or longevity.
 

DiamondSCattleCo

Well-known member
Big Swede said:
Will that calf be stunted enough that he won't gain as well when he hits feed or will he gain even more now that his needs for growth are being met?

Don't get me wrong, I think the "starvation" needs to be pretty severe, much like a calf being sick, before you'll see stunting that affects compensatory gains. I've actually got two poor calves out there right now from dams who are well over-age, and you can tell the calves right off. Normally those dams raise above average calves, but right now their calves are well below average and not gaining well, even though I gave them extra time on the dams before weaning.

But I'll tend to keep a cow until her calves start doing poor (barring any other age issues). I'd say the whole "only keep a cow during her prime" comes more from the dairy side, where every cow needs to put out her maximum milk.

Rod
 

Kato

Well-known member
Exactly. It takes a couple of calves to pay the cow's startup expenses, so it makes sense that every calf after that will be more money in your pocket. Amortized over a longer time so to speak.

We prefer to keep heifers from these long lived cows. We figure those older cows are there for a reason, and it's probably exactly the reason you are looking for in a replacement. :D
 

WyomingRancher

Well-known member
RSL said:
This is pretty interesting. We "rough winter" our calves as well. Calves that are poor from older cows don't seem to catch up over the winter with our system, but they look pretty good coming off grass in August. Unrecognizeable is the term that would most apply. That said the first poor calf is usually the start of a slide or precipitous decline.
In this same vein, there is some neat work that was done in Montana that showed how you could restict intake on replacement heifers to control mature size with no impact on fertility or longevity.

Do you have the research? I totally believe it, and am trying to do something similar this year to my yearling heifers... not starve them by any means, but not pour it to them either. I think the concept is like yo-yo dieting, pretty soon your body adjusts to maximize calories you do consume, then you gain weight on minimal input. I think doing this while an animal is growing shows the body just what sort of feed they're going to be surviving on in the future, and it adapts growth accordingly. I'm against feedlot developed heifers.

I think this partly explains why cattle from the same genetics can grow out differently in different environments.
 

Big Swede

Well-known member
The 2 poorest calves I weaned last fall were from cows that should be in their prime. Problem is that they evidently must not give enough milk to feed a cat and if that was their prime then their prime wasn't worth a crap. They'll be prime rib soon by the way.
 

RSL

Well-known member
I will try to go back through my pile. I think it may have been Rick Funston that did the work. It may even be on the Beef Improvement Federation website. I will let you know what I find.
 

RSL

Well-known member
Here's the abstract from one of Rick's papers on the subject. He has a few others that are related to this general area of work.

Comparison of target breeding weight and breeding date for replacement beef heifers and effects on subsequent reproduction and calf performance1
R. N. Funston2 and G. H. Deutscher
University of Nebraska, West Central Research and Extension Center, North Platte 69101

2 Correspondence: 461 W. University Dr. (phone: 308-532-3611; fax: 308-532-3823; e-mail: [email protected]).


A 3-yr study was conducted with spring-born heifers (n = 240) to determine the effects of developing heifers to either 55 or 60% of mature BW at breeding on reproduction and calf production responses. A concurrent study was also conducted with summer-born heifers (n = 146) to examine effects of breeding heifers with the mature cow herd or 1 mo earlier on reproduction and calf production variables. Spring-born crossbred heifer calves were weaned and developed on two different levels of nutrition to achieve the desired prebreeding BW. Summer-born heifers were developed to similar target breeding BW (60% of mature BW) to begin calving either 1 mo before (May) or at the same time as the mature cowherd (June). Blood samples were taken before breeding to determine differences in estrous cyclicity. Pregnancy rates through the fourth pregnancy were determined. Cow and calf production variables were evaluated through the third gestation. Spring-born heifers reached 53 or 58% of mature BW at breeding and had similar reproduction and first calf production traits between the two groups. Calving difficulty with the second calf was greater (P < 0.05) for heifers developed to 58% of mature BW at breeding. Subsequent second calf weaning weight and ADG were decreased (P < 0.05) for heifers developed to 58% of mature BW at breeding. Feed costs were $22/heifer less for heifers developed to 53% of mature BW. Summer-born first-calf heifers calving in June had less (P < 0.01) calving difficulty than did heifers calving in May; however, calf birth weights were similar. Breeding summer-born heifers 1 mo before the cowherd did not influence pregnancy rates over three calf crops; however, first calf adjusted weaning weights and ADG were greater for calves born earlier. Development costs were $11/heifer more for heifers developed to calve in May vs. June. Developing spring-born heifers to 53% of mature BW did not adversely affect reproduction or calf production traits compared with developing heifers to 58% of mature BW, and it decreased development costs. Breeding summer-born heifers before the cowherd increased heifer development costs, increased calving difficulty, and improved calf performance, but had no effect on pregnancy rates.
 

Big Muddy rancher

Well-known member
I used to feed my calves at a place that put another man's calve up on the cement beside the Harveststore and mine down behind the barn. The other fellow fed his calves to gain over 2lbs/day and they went to the back grounding lots in the spring. Mine were fed to gain1.25to 1.5 lbs/day and were sold to go to grass. The feedlot owner knew how much we each had invested in feed and my calves usually brought close to the same dollars those heavier calves returned.
 

per

Well-known member
Kato said:
Exactly. It takes a couple of calves to pay the cow's startup expenses, so it makes sense that every calf after that will be more money in your pocket. Amortized over a longer time so to speak.

We prefer to keep heifers from these long lived cows. We figure those older cows are there for a reason, and it's probably exactly the reason you are looking for in a replacement. :D

Right on, another thought beyond that is, because the start up costs are paid off and the prime years calves should have made a profit while depreciating the factory to its lowest level, it goes that these older cows should be profitable even with a lesser calf.
 

Nicky

Well-known member
That is very interesting. I agree on keeping a cow as long as possible...seems hard to draw the line in rough country though :???:

If you remember, we had some high nitrate hay this year...after 4 tests we decided it was 'moderate high :???: ' so are feeding a small amount to the cows and the rest to the calves that we didn't sell this fall. They are doing well but not gaining alot. We will put the bulls in with the heifers for 21 days and keep those who get bred. So am glad to see that research cause they sure aren't very fat!!!
 

Grassfarmer

Well-known member
That was interesting RSL. From my own experience there is something I call "old cow's last calf syndrum" A smaller calf than previous years with the same genetics. We have found these to be really good calves though if we keep them for replacements - smaller mature weights than the genetics would indicate but very healthy, robust little cows. We have had a number of these over the years and they have always done well for us.
I would contrast that with attempts I've seen to limit mature cow size by manipulating feeding regimes to growing heifers. I have seen that done a lot of times (mostly in Scotland) and most have not worked well. They just finished up with cows that struggled all their lives - lacked condition and had poor re-breed rates. This type of size restriction may work better in a drier climate - it certainly didn't on the west coast of Scotland.

So my speculative theory on why old cow's calves don't struggle whereas feed restricted ones sometimes do is that they do not start out equal - I think the old cow's calves were predetermined to be smaller but still thrifty and I suspect that it may have to do with the condition of the egg before fertilization - older cow, deteriorating egg quality or size?
 

Northern Rancher

Well-known member
You might as well sort the wheat from the chaff when the females still have value-really other than the breeding cost there's no more investment in a breeding heifer that a yearling heifer off grass-at least at my place. You'll find less structural problems on heifers that aren't pushed either-much like horses-our young horses run out on the mares till she runs them off in the spring to have another one-then it's grass and hay until they get started. Any heifer that c an't winter on hay-lick snow-and slick up and breed on grass I can't use as a cow-she better be able to calve and be a mother on her own too. As far as compensatory gain by the time we ship finished cattle you can't tell who was thin and who was fat at weaning.
 

RSL

Well-known member
Rick has done a lot of neat work. If you go to jas.fass.org and type Funston in the author box there is more stuff like this.
The reason we were interested in some of this work is that we tend to breed heifers when they are pretty small (compared to the neighbours). We have a set of resources that we try to fit our cows into, so we don't really pound a lot of feed through calves (or cows), and they catch up on what for us is a less expensive resource. We background things but we don't intend to feed cattle out at home at any point in the future as it doesn't fit our resource base or ambition level.
It is sometimes nice to have governments etc. pay to figure things out so we don't have to experiment strictly on our own dime and risk.
 
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