Scrotal EPD

[Chuckie]

Scrotal EPD's are used to show fertility in the bulls and the cows as well. If the number is higher, the earlier both the bull and the heifer are supposed to mature as well. I have never heard that it causes them to have a longer reproduction life, but if that is so, maybe someone could let us know.

So many of the well known bulls, with great carcass numbers, BW's, etc......but when they get to the scrotal EPD, they totally crash. I have seen some as low as -.53. In the past, I have purchased bulls that would allow a cow to be a 0 scrotal, and his EPD be high enough to bring hers up to par. This would help raise the fertility in their offspring, and allow me some slack in the Sc on the cow's number. Of course, I would like her's to be average as well. I try to find more traits in a bull that will pull up a cow that is lacking in any area, such as REA.
Has anyone actually found that the scrotal size had affected the fertility of the herd?

When purchasing a bull, how important are the scrotal numbers to you, and what is the lowest number Scrotal EPD you would purchase to put in with your cows, knowing that you would be keeping some heifers along the way?
Chuckie

 

[Aaron]

Scrotal EPD is not important to me at all. Actual scrotal circumference is very important, however. Never buy anything average or below. All bulls must have above average sized, proper testicles. :cowboy:

 

[SRBeef]

I have been told by an experienced breeder that scrotal size is important and even in my limited experience it appears to be true. Scrotal size is very important to me for all the reasons mentioned above.

Fertility is the #1 key to profitability. Getting the cows bred so the calving period is very tight is extremely important to me. Does a larger SC mean my cows get bred sooner? I don't know but it seems like there would logically be a positive relationship there.

To the extent that the SC EPD is a predictor of actual Scrotal Circumference then it is very important. the question as always in EPD's is how accurate is the EPD. And that goes back to the quality of the data turned in to generate the EPD. A good SC EPD from a good breeder who reports accurate timely info and truly believes in the value of EPDs is very valuable, in my humble beginners opinion.

Jim

 

[AllForage]

I have to admit that epd's are suspect to me. Self reporting and lack of an overall management standard on weights and such. With that said, scrotal epd is pushing it in my opinion. Cow fertility has so many other factors and influences how can you possibly take that epd seriously? On the Bull side, the larger the testicles, the more testosterone and sperm produced. How much is enough? Just the right amount. If a bull is covering plenty of cows in an efficient amount of time at say 35cm. Then how would a 45cm be of any more benefit. There is an optimum on everything and any past that gets extreme. Like speed bags swinging between bull's legs.

I think a system of monitoring scrotal progress like the chart in the Drayson book would be more effective. The faster a bull attains circumference correlates to early maturity. Which I would think would help out the cow side. I have also read the Walters/Fry book that talks about the shape and conformation of the testicles relating to the udder shape of the resulting heifers. Not sure about that just thought I would throw it out.

I know it is said to be a tool but, folks still get trapped in the single trait numbers w/o realizing it.
Just a different point of view.

 

[EAT BEEF]

The faster a bull attains circumference correlates to early maturity. Which I would think would help out the cow side.

I think a avg. matureing cow,tends to make for a longer productive life for the cow.

 

[Baldie Maker]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

 

[vclavin]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

That's also what I understand. You also have to take into account the milk EPD and I believe it is the YW that also influences early maturity. I think it was only by a few days however. I can't help but think that early maturing will negatively affect longevity. Seems the sooner an animal or plants matures the shorter the lifespan.
Valerie

 

[EAT BEEF]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

That's also what I understand. You also have to take into account the milk EPD and I believe it is the YW that also influences early maturity. I think it was only by a few days however. I can't help but think that early maturing will negatively affect longevity. Seems the sooner an animal or plants matures the shorter the lifespan.
Valerie

Wow we agree on something

 

[vclavin]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

That's also what I understand. You also have to take into account the milk EPD and I believe it is the YW that also influences early maturity. I think it was only by a few days however. I can't help but think that early maturing will negatively affect longevity. Seems the sooner an animal or plants matures the shorter the lifespan.
Valerie

Wow we agree on something

:banana: :banana: :banana:

 

[Stocker Steve]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

Banded some 5 to 6 wt black and bwf last month and they had big ones.
Handled some 7 to 8 wt Limis at the same time and they had acorns in comparison. The Limis were one to two months older...

 

[Jake]

How many deer do you see with 40cm saggy testicles? With the populations we have around here they must be extremely fertile. I have also seen that MARC study that shows zero correlation. In my experience of testing yearling bulls there are a lot more 42cm bulls that fail than 36 cm bulls.(this is yearlings) Seems there just reaches a point where the body cannot function correctly. This is just another thing where moderation is key.

 

[bigag03]

May be opening a can of worms.. but the MARC has did studies on scrotal circumference and fertility and found there is a correlation of zero. This would mean that, by their study it neither makes more or less fertile. They did however find that scrotal circumference positively effect the age at which a bulls sons or daughters reach puberty.

Baldie Maker, I am glad you brought this up. I get into this discussion several times a year with different breeders, and it is a very common misconception that scrotal circumference affects fertility. The initial studies and several subsequent ones show that bulls with larger SC sire daughters that reach puberty earlier. There is no correlation to fertility. The age of puberty is very important in most of our herds, in which we require females to calve at 2 years of age. I have seen herds that do not calve heifers until 2.5 years of age and age of puberty is much less important, since most will reach puberty in time to meet this calving date even without selection.