Scrotal circumference

[Alan]

I was reading and article in this months Hereford World. It stated that a bulls scrotal circumference at 1 yr has a high correlation to the percentage of his daughters that will reach puberty at 1 year of age.

My impression that the scrotal circumference was a fertility issue, the daughter puberity issue is news to me, but then much about the cattle business is.

Your thoughts?

Thanks,
Alan

 

[dun]

I was reading and article in this months Hereford World. It stated that a bulls scrotal circumference at 1 yr has a high correlation to the percentage of his daughters that will reach puberty at 1 year of age.

My impression that the scrotal circumference was a fertility issue, the daughter puberity issue is news to me, but then much about the cattle business is.

Your thoughts?

Thanks,
Alan

I've alwasy equated early puberty with fertility, seem to go hand in hand over the years.

dun

 

[MikeC]

Wonder if I had a bull with a 50-60 cm scrotum at yearling, would the heifers come in heat at 2-3 months of age? ;-)

I don't have a reason to not believe the theory, but I mainly believe scrotal size helps in higher volumes of sperm production and libido due to higher testosterone production.

On other words.............."SETTLING COWS".

 

[Alan]

I guess it would make sense that if the bull had reached puberty by the time he was a year old, he would have a better pertange of offspring reaching puberty at a yr.

Alan

 

[Alan]

Wonder if I had a bull with a 50-60 cm scrotum at yearling, would the heifers come in heat at 2-3 months? ;-)

I don't have a reason to not believe the theory, but I mainly believe scrotal size helps in higher volumes of sperm production and libido due to higher testosterone production.

On other words.............."SETTLING COWS".

This was my thought on relating scroctal circumference EPD's to the bull, rather than daughter puberity rate.

Alan

 

[orcow]

I would have a hard time putting much faith in Hereford World.
I would get ahold of WSU in Pullman Washington or OSU at Corvallis Oregon. To get some kind of a straight answer.

 

[Alan]

I guess it would make sense that if the bull had reached puberty by the time he was a year old, he would have a better pertange of offspring reaching puberty at a yr.

Alan

It makes sense in the way that I'm 6'4", a higher percentage of my offspring will be taller.

MikeC wrote:
Wonder if I had a bull with a 50-60 cm scrotum at yearling, would the heifers come in heat at 2-3 months?

I don't have a reason to not believe the theory, but I mainly believe scrotal size helps in higher volumes of sperm production and libido due to higher testosterone production.

On other words.............."SETTLING COWS".


This was my thought on relating scroctal circumference EPD's to the bull, rather than daughter puberity rate.

Alan

 

[Frankie]

I was reading and article in this months Hereford World. It stated that a bulls scrotal circumference at 1 yr has a high correlation to the percentage of his daughters that will reach puberty at 1 year of age.

My impression that the scrotal circumference was a fertility issue, the daughter puberity issue is news to me, but then much about the cattle business is.

Your thoughts?

Thanks,
Alan

I'm not so sure about "a hig correlation", but the information that daughters of bulls with larger scrotal measurments tend to cycle at an earlier age has been around for a long time. But what I've read says we're only talking about a few days difference. Maybe there's some new research?

The main reason to select a bull with adequate scrotal development is that he'll be more likely to settle more cows.

I'm for early fertility in heifers, but I don't see a lot of advantage in cycling 6-7 month olds. We've had a few cycle even earlier than that.

 

[Texas Ranch Man]

Im feeling a little depressed here, my kids did not reach puberty untill they were 14 or 15 yrs old. I thought everything was going just fine, up till now.

 

[aplusmnt]

Has anyone ever heard of Large Scrotum size having an affect on Pelvic size in heifers? Seems like I heard that but I am getting old and forgetful forgot where.

 

[MikeC]

Has anyone ever heard of Large Scrotum size having an affect on Pelvic size in heifers? Seems like I heard that but I am getting old and forgetful forgot where.

Never heard that, but I do know that calves from Larger Scrotum Size bulls finish earlier in the feedlot. Goes back to earlier puberty I suppose.

 

[cypressfarms]

I guess I'm gonna go against the grain here, but I believe that:

1. larger scrotum size (to an extent), will sire offspring that are more fertile.

2. I don't feel that more sperm is the same as more fertile. Motility. Quality instead of quantity.

3. To me the important factor is not how early (young) a heifer cycles, as much as that she remains fertile and settles. We've all seen cows that cycle but don't settle.

 

[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

 

[Tod Dague]

2. I don't feel that more sperm is the same as more fertile. Motility. Quality instead of quantity.

To me larger scrotal circumference means more sperm generating capacity thus greater servicing capacity. As in more cows per bull.

 

[cypressfarms]

2. I don't feel that more sperm is the same as more fertile. Motility. Quality instead of quantity.

To me larger scrotal circumference means more sperm generating capacity thus greater servicing capacity. As in more cows per bull.

T D, how does sperm generating capacity relate to serving capacity, unless your talking about a nitrogen bull?

 

[Diehard40]

Scrotal Circumference in bulls is directly related to age in puberty in heifers.
Just remember that the larger the SC the better.
yrlng sc should always be over 32cm
I wouldn't go with anything under 34 personally.

 

[bigbull338]

i jusy bought a 3yr ole reg beefmaster bull with an sc of 42cms.an the guy said the bigger the scrotum the more fertle they are.

 

[Tod Dague]

2. I don't feel that more sperm is the same as more fertile. Motility. Quality instead of quantity.

To me larger scrotal circumference means more sperm generating capacity thus greater servicing capacity. As in more cows per bull.

T D, how does sperm generating capacity relate to serving capacity, unless your talking about a nitrogen bull?

They have to replenish what they expel. When they are in with a large group of cows they will need to rebuild their reserves quickly as their will be another cow cycling soon if not already. I have seen yearling bulls breed 60 cows in a 45 day period. These were 40-44CM bulls. I personally would not advice this for the vast majority of ranchers or bulls since he will use up a lot of condition quickly. I have also seen yearling bulls breed a couple of cows then fall their BSE because of low counts.

 

[Tod Dague]

BTW I don't have any research on that aspect just my personal theory based on my limited observations.