I am pretty carefull who I deal with when I add a bull to our listing. I deal with breeders that I know and trust. I have rejected bulls from some individuals that I don't trust simply for that reason.
The premise that the breed was based on is good, it's the tainted information that has made the data less than reliable in my opinion.
If you do not turn a BW in the calf will be assigned breed average EPD's and register the calf. If you do not turn in a WW, they will "preregister" the calf but it will become a cat II if the data is not completed.
In the past 30+ years that I have been around the breed I have seen several bulls numbers change drastically. Some were BW EPDs and some were MILK EPDs. Recently a fairly popular bulls MILK numbers took a serious drop. This was a 7 year old bull with accuracies in the high 60's. Makes me go Hmmmmm.
As far as my experience with my heifers and having to assist the calves, the heifers were all 1/2 to 3/4 sibs, all managed the same. They were all AI bred to 3 different bulls and then cleaned up with one of the bulls that was also one of the AI sires. 2 out of 22 required assistance. Maybe they would have needed help bred to one of the other bulls as well but I found it odd that they were both out of the same AI sire and were the only ones that needed assistance. Maybe a coincidence, but I will probably not use those genetics again in my herd to find out. [quote/]
Actually RW Hobo was born in 1989 so he ain't 30 yet! One doesn't have to be an ancient bull to have high accuracies - Ole's Oscar is a 2002 model with > 90% accuracy and 602 contemporary groups. Younger bulls are more likely to have lower accuracy based on the fact they have fewer progeny
IMHO your "high accuracy" BW is pretty meaningless unless accompanied by a high accuracy CE - an 80 pound square calf is much more likely to be a problem than an 80 pound long headed slim shouldered calf.
Further EPDs are actually comparisons - not absolute values but variations around a preset base - one would expect EPDs to change based on information provided and the formula used to calculate the specific EPD-
A large number (thousands and often millions) of calculations are performed by computers that ultimately result in an EPD. In order to perform these calculations so that results are unbiased and predict only genetic differences, data need to be adjusted for any known non-genetic effects. This is done in two ways. The first is by preadjusting the data for environmental factors with known effects, such as age of dam and calf age. The second is through the formation of contemporary groups and
using those classifications in the data analysis.
When information from different contemporary groups or different breeders is added one would expect a change and 70 % accuracy is merely an expression of reliability - of the EPD - not the fact that it shouldn't change
for example a BW of 2 with an accuracy of 70% says that 70 % of the time the calf will weigh 2 lbs greater than the breed average (it also says that 30% of the time if will weigh something different but it doesn't say that the EPD itself will not change -
According to the RAAA BW data is not mandatory (WW and CE is) but they do not adjust or calculate a BW when one is not given - EPDs provide a tool that can be used when making decisions about breeding
The premise that the breed was based on is good, it's the tainted information that has made the data less than reliable in my opinion.
If you do not turn a BW in the calf will be assigned breed average EPD's and register the calf. If you do not turn in a WW, they will "preregister" the calf but it will become a cat II if the data is not completed.
In the past 30+ years that I have been around the breed I have seen several bulls numbers change drastically. Some were BW EPDs and some were MILK EPDs. Recently a fairly popular bulls MILK numbers took a serious drop. This was a 7 year old bull with accuracies in the high 60's. Makes me go Hmmmmm.
As far as my experience with my heifers and having to assist the calves, the heifers were all 1/2 to 3/4 sibs, all managed the same. They were all AI bred to 3 different bulls and then cleaned up with one of the bulls that was also one of the AI sires. 2 out of 22 required assistance. Maybe they would have needed help bred to one of the other bulls as well but I found it odd that they were both out of the same AI sire and were the only ones that needed assistance. Maybe a coincidence, but I will probably not use those genetics again in my herd to find out. [quote/]
Actually RW Hobo was born in 1989 so he ain't 30 yet! One doesn't have to be an ancient bull to have high accuracies - Ole's Oscar is a 2002 model with > 90% accuracy and 602 contemporary groups. Younger bulls are more likely to have lower accuracy based on the fact they have fewer progeny
IMHO your "high accuracy" BW is pretty meaningless unless accompanied by a high accuracy CE - an 80 pound square calf is much more likely to be a problem than an 80 pound long headed slim shouldered calf.
Further EPDs are actually comparisons - not absolute values but variations around a preset base - one would expect EPDs to change based on information provided and the formula used to calculate the specific EPD-
A large number (thousands and often millions) of calculations are performed by computers that ultimately result in an EPD. In order to perform these calculations so that results are unbiased and predict only genetic differences, data need to be adjusted for any known non-genetic effects. This is done in two ways. The first is by preadjusting the data for environmental factors with known effects, such as age of dam and calf age. The second is through the formation of contemporary groups and
using those classifications in the data analysis.
When information from different contemporary groups or different breeders is added one would expect a change and 70 % accuracy is merely an expression of reliability - of the EPD - not the fact that it shouldn't change
for example a BW of 2 with an accuracy of 70% says that 70 % of the time the calf will weigh 2 lbs greater than the breed average (it also says that 30% of the time if will weigh something different but it doesn't say that the EPD itself will not change -
According to the RAAA BW data is not mandatory (WW and CE is) but they do not adjust or calculate a BW when one is not given - EPDs provide a tool that can be used when making decisions about breeding
