angus sire to add muscle?

[DOC HARRIS]

Posted: Wed Feb 07, 2007 4:04 pm

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George Monk wrote:
We have a large framed Vermillion Dateline cow that we would like to flush. One of the goals I want to achieve is to add muscle to this gal. What would be a good choice. Gridmaker comes to mind but I am worried about the frame size. I really don't want bigger framed calves from this cow.

i like the muscle on the gar bulls

George-

Strictly from a point of interest - what is the criterion you use when considering the "muscle" on G A R Bulls? Also, what is the Frame size of the cow in question? It is a little difficult to quantify her from this picture because of the camera angle and also her nursing calf. And, of course, are you considering the resulting calf(s) to be Terminal or Replacement(s)?

Thank you.

DOC HARRIS

 

[DOC HARRIS]

Capt.
That is the OCC bull I was looking at. He really looked good and had the muscleing I was wanting but the scrotal epd is the eliminator for me. My 9 yr goal is to sell bred heifers and I have been told scrotal size is directly related to fertility. I guess this is an argument against epd's but when you are looking at pictures and numbers what do you do????
thanks

George- You are right - Fertility IS directly related to scrotal size - and vice versa! However, it is true that the accuracies at one year of age are not too accurate. It takes time for Testosterone to make a Phenotypic impact on Scrotal size.

Unfortunately, if looking at pictures and numbers is your option, you do the best that you can, and considering everything that is available, it is what you have to do. And I don't agree that this is an argument against EPD's. They are a method of selecting seedstock that is far and away ahead of "dart throwing" while blindfolded! You just have to have your priorities established well in advance of making operative decisions when it comes to long term goals.

Don't get discouraged.

DOC HARRIS

 

[Badlands]

CSU did some more reach on SC vs heifer pregnancy a few years back, maybe about 5 years.

The correlation between SC andheifer pregnancy rate was low.

Basically only 5% of the differences in heifer pregnancy are attributable to SC.

SC had nothing to do with heifer pregnancy in the Red Angus population.

It's gaining status as an old wives tale.


Badlands

 

[MikeC]

I thought that a larger scrotum size indicated the heifers from those bulls would have an earlier estrus cycle.

By one to two weeks from what I read. Big deal.

 

[SEC]

I read something about that, 1cm means 1-2 days earlier, very minimal.

But SC has lots to do with ability to reproduce and a storage bank.

We have educated our customers for long enough up here that if they are under 34cm, the buyers get pretty picky! So to use bulls that take it away isn't that smart.

 

[handydandy]

I thought that a larger scrotum size indicated the heifers from those bulls would have an earlier estrus cycle.

By one to two weeks from what I read. Big deal.

Excellent pont Mike! I suggest people do a google search for scrotum size and female fertility in cattle and read exacltly what the research says.

My question is comparing different sized animals. Should we expect a 4 frame bull to have to have the same scrotum as a 7 frame bull that may 600 pounds more?

 

[MikeC]

I thought that a larger scrotum size indicated the heifers from those bulls would have an earlier estrus cycle.

By one to two weeks from what I read. Big deal.

Excellent pont Mike! I suggest people do a google search for scrotum size and female fertility in cattle and read exacltly what the research says.

My question is comparing different sized animals. Should we expect a 4 frame bull to have to have the same scrotum as a 7 frame bull that may 600 pounds more?

I think scrotum size is related to early maturity which can be a double edged sword.

Have seen bulls that barely made 32 cm at yearling but measured 40+ as 2 year olds. This would indicate to me that his calves might take longer to finish?

I also think (nothing but speculation) that there is a relation between early/late maturity in the marbling/IMF aspect because we have altered the growth curve in cattle.

Badlands, could you expand on this more?

 

[Frankie]

I think the BIF recommends a minimum scrotal cir for a breeding bull of 30 cms. That would be for any breed, any height, any weight. If they don't have a factory that large, the general agreement is they can't do a satisfactory job breeding cows. At our test station sale, Angus bulls must have a yearling scrotal measurment of 32 cms to qualify for a sale. I really think anything above that might be good, but not necessary.

 

[KNERSIE]

For early maturity and for grassfinishing genetics the recommendation is no smaller than 36 cm and no bigger than 40 cm at 12 months.

 

[handydandy]

For early maturity and for grassfinishing genetics the recommendation is no smaller than 36 cm and no bigger than 40 cm at 12 months.

Could you refer me to where you found those recommendations?
thanks

 

[SEC]

What isn't right is the bulls at 32cm test like a damn, but the ones that are 40 cm will often be wonky. This is at a year of age of course, give them 40cm and 14 months and they'll be fine.

I am guessing down there if there was a 32cm minimum there might be lots not get in. We were at a very prominent Angus place MT a few years back and they might have averaged 30-32cm, just brutal for size. Midland bull test seemed to have a fair share of it's little nutted buddies.

 

[Frankie]

What isn't right is the bulls at 32cm test like a be nice, but the ones that are 40 cm will often be wonky. This is at a year of age of course, give them 40cm and 14 months and they'll be fine.

I think you're saying bulls with smaller scrotal test better than ones with larger? They adjust to yearling, just as they adjust ADG, hip height, etc., to yearling. That way all the bulls can be compared properly.

I am guessing down there if there was a 32cm minimum there might be lots not get in. We were at a very prominent Angus place MT a few years back and they might have averaged 30-32cm, just brutal for size. Midland bull test seemed to have a fair share of it's little nutted buddies.

I don't see many Angus bulls that don't qualify for the sale based on scrotal measurement. Like everything else, some will be smaller, some will be larger. Weather conditions might cause a different measurement, too. Or the cold hands of the vet doing the measurement. :lol:

 

[MikeC]

University of Saskatchewan, Western College of Veterinary Medicine, Saskatoon, Canada.

Performance testing started after it was recognized that growth traits were heritable. In the early years of performance testing there was a tendency to feed higher levels of energy for longer periods of time. More recently, the trend has been to feed lower levels of energy for shorter periods. There are still differences in opinion as to the appropriate level of energy to use. Clinical observations and research on overfeeding clearly show that both libido and spermatogenesis can be impaired by excess energy intake. The damage in 2-year-old bulls can be very extensive and in some animals it may not be reversible. The scant amount of research in yearling bulls indicates that there is considerable potential danger from overfeeding energy as well. Test stations are under used in regard to performing research that would help identify heritable defects that would interfere with the productive and reproductive efficiency of beef cattle. The first performance testing programs emphasized average daily gain from weaning to 1 year of age, so "performance" has traditionally meant rate of gain to most cattle raisers. The term "performance" is now starting to acquire a broader and more inclusive definition. For many breeders, it now includes weight per day of age, which is in part a maternal trait, and some kind of male evaluation for reproductive potential that can also be extrapolated to the female side. One of the first breakthroughs in this regard was to recognize the heritability of testicular size, and that testicular size could be fairly accurately determined by scrotal circumference measurement. It was also found that there was a favorable relationship between larger testicle size and the ability to produce high quality semen. As a result, it became a common practice to include scrotal circumference measurements in the published bull test results. However, many test station patrons were, and still are, content to consider the scrotal circumference measurement alone as an evaluation of a bull's breeding potential. Unfortunately, less than half of the bulls finishing a performance test at ages ranging from 11 to 14 months will be able to produce semen of completely acceptable quality.(ABSTRACT TRUNCATED AT 400 WORDS)

PMID: 2049671 [PubMed - indexed for MEDLINE]
Related LinksEvaluations of genotypexenvironment interactions of beef bulls performance-tested in feedlot or pasture. [J Anim Sci. 2002] PMID: 12162638 Scrotal measurements in beef bulls: heritability estimates, breed and test station effects. [J Anim Sci. 1982] PMID: 7085507 Effect of energy intake after weaning on the sexual development of beef bulls. I. Semen characteristics and serving capacity. [J Anim Sci. 1985] PMID: 4077765 Effects of rate of gain on scrotal circumference and histopathologic features of the testes of half-sibling yearling beef bulls. [Am J Vet Res. 1996] PMID: 8725811 Estimates of heritabilities and of genetic and phenotypic correlations among growth and reproductive traits in yearling Angus bulls. [J Anim Sci. 1984] PMID: 6725151 See all Related Articles...

 

[KNERSIE]

in reply to handydandy...

according to James E Drayson's book "Herd Bull Fertility" where there is a chart on dimensional scrotal measurements on page 122 the requirements are as follows

bulls 12-16 months

circumference % live sperm % conception rate

optimal 38-40 cm, 75-90 %, 80-90
tolerable 36-37 cm, 65-70 %, 70-75
objectionable 35 cm, 55-60 %, 60-65
undesireable 34 cm, 50-55 %, 45 -55
unacceptable 30-33cm, 10-45 %, 5-40

the full chart is all but two pages long and the requirements from ages 7.5 -9 months through to 7 -14 years are given, but my typing skill doesn't allow me to replicate the full chart here. Should anyone have age specific questions send me a pm and i'll look it up for you.

 

[Badlands]

Drayson's book is the result of heavy editing on the statistics.

He tortured his data until it confessed.
:lol:
Now, there is some truth to it, but it isn't the nice picture he painted in the book.

It's pretty easy to see right through it if you have looked at stats very much. There is simply no instance in the charts where the variables overlap; this is not the case with any experimental data I have ever seen. His charts that talk about "approximate %" are just that, HIS chosen approximations.

In other words, the picture is too perfect to be completely credible.


Most of the rest is just Bonsma rehashed.


I think much of his work needs to be looked at again, and better quantified because there is something to it. It's just not the "perfect" picture he described.


Badlands

 

[Tod Dague]

This is from the Red Angus Association.

Before producers are faced with the challenge of keeping females in the breeding herd, they must first meet the goal of increasing the pregnancy rate in their heifers, and breeding them to calve at two years of age. Historically, producers have relied on the relationship between when heifers reach puberty and the scrotal circumference of their sires to ensure that this goal is met. Heifer pregnancy is as heritable as most growth traits such as weaning weight and yearling weight, directly affects profitability, and is the ERT that scrotal circumference indicates. The THR Heifer Exposure Inventories along with historical heifer exposure records provided the RAAA with the information necessary to develop the Heifer Pregnancy EPD which is more accurate than utilizing scrotal circumference when trying to increase fertility in heifers.

Research has long shown that increased yearling scrotal circumference is positively correlated with earlier puberty and relative earlier puberty in daughters. However, more recent research with Red Angus cattle indicates that this relationship is not as straight forward as once believed. Recent analysis of Red Angus data has demonstrated that there is a positive relationship between scrotal circumference and yearling weight, and there is generally an unfavorable relationship between yearling weight and genetic merit for heifer pregnancy. Some genes that favorably affect yearling weight tend to increase scrotal circumference. If the scrotal circumference is large due to its association with yearling weight, it may cause small to moderate decreases in genetic potential for pregnancy in heifers bred to calve as two year olds. Genetically larger cattle tend to mature more slowly. However, there are genes that increase scrotal circumference and are not related to growth, but are favorably associated with fertility. It is difficult for breeders to determine which genes are responsible for the reported scrotal circumference, and then separate these two antagonistic genetic effects when trying to utilize scrotal circumference to reduce the age at puberty in their heifers. The Red Angus Heifer Pregnancy EPD alleviates this problem.

Here is the link to the full article. http://old.redangus.org/newredsite/them ... ility.html

I had posted this last year about this time. Sorry but I was no longer able to find the article on the net.

 

[KNERSIE]

I can't vouch for the credibility and there is indeed a lot that is very Bonsma-ish. I think that we should remember that Bonsma was a real pioneer in trying to quantify observations and that very little further research has been done after him with regards to functionality and adabtility in cattle and the effects in there of in practice.

Maybe we shouldn't stare ourselves blind in the boundaries set in the "statistics", byt rather try and get the bigger picture.

Breeding has been in the past and will be in future a very imprecise science with a lot of it being down to common sense. I think we should learn from this type of research and use our own common sense in the application in our own breeding programs.

 

[DOC HARRIS]

I can't vouch for the credibility and there is indeed a lot that is very Bonsma-ish. I think that we should remember that Bonsma was a real pioneer in trying to quantify observations and that very little further research has been done after him with regards to functionality and adabtility in cattle and the effects in there of in practice.

Maybe we shouldn't stare ourselves blind in the boundaries set in the "statistics", byt rather try and get the bigger picture.

Breeding has been in the past and will be in future a very imprecise science with a lot of it being down to common sense. I think we should learn from this type of research and use our own common sense in the application in our own breeding programs.

KNERSIE-This is probably the most PRACTICAL and LOGICAL approach to this entire subject that has been presented yet. It is necessary for the Academitians to be accurate, precise and meticulous to the utmost extent in order to preclude unnecessary rhetoric from their peers which would accomplish nothing in the realm of practicallity to benefit the serious Beef Producer. But they have to get down to the "Nitty-Gritty" in order to get down to the "Nitty-Gritty!"

DOC HARRIS

 

[SEC]

I was actually meaning 32cm at a year of age. We don't adjust scrotal up here like down south.

The general rule of them is for a breeder bull

12month- 36cm
13 months- 37cm
14 months-38 cm

and so on.

What is tricky if you buy a 2 year old bull that measures 42 what did he measure at 1 year of age? We have all seen bulls go from 32 cm as a yearling to huge increases, not impossible.

If you look at some of the AI bulls around their mature size isn't indicative of the ability to pass on scrotal to a year of age. It's wrong to think they will always do such.

Then there are others that are 38 cm as a yearling and only end up at 43 cm mature. Would that be a curve bender?

 

[MikeC]

I was actually meaning 32cm at a year of age. We don't adjust scrotal up here like down south.

Adjust scrotal sizes? No adjustments in the Chars. We turn in scrotal measurements when yearling data is turned in.

His scrotal measurements are what they are at sale time.