EPD ?
- Thread starter smartin0022
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Silver
Well-known member
Looks to me like the 108 is an index number so you'd have to know what 100 is and work from there. But someone who understands EPD's will be along shortly with a proper answer I'm sure.
Pep Union
Member
as I understand, his birth weight (BW) was 3 kg (or lbs) more than breed average but still calving ease (CED) was 5 point better than breed average. I believe these statistics can be quite misleading and we should have known much more details, these are not enough.
Katpau
Well-known member
His birth weight was 108% of the average of his 15 contemporaries which would include the bull calves in the group of calves who were grouped together as contemporaries because they calved under the same conditions. He weaned at 98% of the average of 15 contemporaries. If you want actual numbers, you can see them at AAA. You will need to be a member and log into your account. There will be detailed information under AHIR data.
I bet he's an attractive bull with that pedigree, but I would also expect a bit more birth weight with it. That may not be a bad thing. What matters is calving ease and his numbers aren't too bad in that area, but with no proof those numbers could change dramatically either way. I'd pay the $37 and have a genomic profile run and then see where his DNA puts him. His own birth weight and weaning weight may not be representative of how he produces. I once had a bull with a 99 pound birth weight turn out to be a heifer bull. His calves were smaller than those of the calves sired by proven calving ease A.I. bulls in my herd. I don't remember ever pulling one. After a DNA test and almost 100 calves his Birth weight EPD moved from a +3.2 to +0.3.
Your bull may take after his mom whose +14 Caving ease EPD and -1.0 birth weight EPD put her in the top 4% of the breed for calving ease and top 10% for small birth weights, or he may take after his dad whose +1 Caving ease EPD and +4.0 birth weight EPD indicate 85% of the breed are easier calving and 95% of bulls sire smaller calves. He is most likely somewhere in between. A genomic profile would be an inexpensive way to get a better idea of who he got more DNA from, mom or dad.
I bet he's an attractive bull with that pedigree, but I would also expect a bit more birth weight with it. That may not be a bad thing. What matters is calving ease and his numbers aren't too bad in that area, but with no proof those numbers could change dramatically either way. I'd pay the $37 and have a genomic profile run and then see where his DNA puts him. His own birth weight and weaning weight may not be representative of how he produces. I once had a bull with a 99 pound birth weight turn out to be a heifer bull. His calves were smaller than those of the calves sired by proven calving ease A.I. bulls in my herd. I don't remember ever pulling one. After a DNA test and almost 100 calves his Birth weight EPD moved from a +3.2 to +0.3.
Your bull may take after his mom whose +14 Caving ease EPD and -1.0 birth weight EPD put her in the top 4% of the breed for calving ease and top 10% for small birth weights, or he may take after his dad whose +1 Caving ease EPD and +4.0 birth weight EPD indicate 85% of the breed are easier calving and 95% of bulls sire smaller calves. He is most likely somewhere in between. A genomic profile would be an inexpensive way to get a better idea of who he got more DNA from, mom or dad.
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Katpau
Well-known member
Breed average of current sires for birth weight is +1.3 and calving ease is +6, so he is +1.9 pounds over today's breed average on birth weight and 1% over today breed average on calving ease. Breed averages were established at various dates in the past, and today's sires are compared to those numbers. Birth weights are expressed in pounds, and the breed average was set at 0 in 1984, so the average birth weight is now 1.3 pounds greater than it was in 1984. Calving ease is expressed as a difference in percentage of unassisted births, with a higher value indicating greater calving ease in first-calf heifers. This number was set at 0 in 1982-1983. Since then the average percentage of heifers requiring assistance has dropped by 6%, so that 6 is today's breed average.
simme
Old Dumb Guy
Every thing that Katpau said. The 108 is a ratio, not a weight in pounds. If the 15 bulls in that group averaged 100 pounds of birth weight, then this bull had a 108 pound birth weight. If the 15 bulls averaged 75 pounds birth weight, then this bull had a 81 pound birth weight. From the information listed, you cannot determine the birth weight. Only that his birth weight was 8% more than the other bulls in that group and his weaning weight was 2% less than the others and yearling weight 4% less that the average of the others.
Point is that EPD values do not predict or calculate the numerical number for birth weight or weaning weight. You can compare EPD numbers between animals in the same breed to PREDICT the difference in pounds between animals (with everything else being equal). But not the absolute value which is so dependent on other environmental factors such as nutrition, weather, etc.
Other factor to be aware of is accuracy of the EPD. BW EPD accuracy here is 36% which is typical for a young animal with no or few progeny. When looking at EPD's, also look at the accuracy numbers. Even if EPD's are top 10% of the breed or bottom 10%, a low accuracy makes the numbers less dependable. The sire Resource has a BW accuracy of 98% based on 16,293 calves he sired. Accuracy is high, so you can pretty much count on Resource siring higher than average birth weights (and weaning weights and yearling weights).
Point is that EPD values do not predict or calculate the numerical number for birth weight or weaning weight. You can compare EPD numbers between animals in the same breed to PREDICT the difference in pounds between animals (with everything else being equal). But not the absolute value which is so dependent on other environmental factors such as nutrition, weather, etc.
Other factor to be aware of is accuracy of the EPD. BW EPD accuracy here is 36% which is typical for a young animal with no or few progeny. When looking at EPD's, also look at the accuracy numbers. Even if EPD's are top 10% of the breed or bottom 10%, a low accuracy makes the numbers less dependable. The sire Resource has a BW accuracy of 98% based on 16,293 calves he sired. Accuracy is high, so you can pretty much count on Resource siring higher than average birth weights (and weaning weights and yearling weights).
OP
OP
smartin0022
Well-known member
Wow, thank you all. That's way more informative than the reading I had done so far or anyone else's explanation. I wasn't looking for a heifer bull but I got scared thinking 108 was actual BW pounds. The breeder did say none of the bulls in the field of bulls I looked at were heifer acceptable. I purchased him off phenotype and curb appeal, but now I will be able to make a more educated decision in the future. Even though with the information provided I still feel confident with my purchase.
