Milk EPD calculation

[LCP]

Does anyone know how they calculate Milk EPD's? It is my understanding that the number represents the lbs at weaning attributed to the mother's milk. So how exactly do you figure that out?

What made me think about this was looking at Diamond D Angus's sale catalog. Their bulls probably average around +12 on milk, and most of their cows are weaning 50% of their body wt or better. The bulls I've bought in the past few years probably averaged +25 Milk, but I am fairly certain those cows were not weaning 50% of their body wt. So those cows are bigger (eat more to maintain wt), milk harder (eat more to produce), and don't wean a calf that matches the increased inputs. I am speculating of course, because the other places I've bought bulls from don't post cow wt or compare cow/calf wt. If it was good, I think they would probably post that kind of data.

 

[Denny]

I've got some Diamond D genetics and from the few I have they are weaning calves 50% of their weight because they are great grass converters. The milk is iceing on the cake but these cattle I've got are top in their age group for fleshing ability here.Bottom line is those cattle convert grass to protein.

 

[Mike]

Does anyone know how they calculate Milk EPD's? It is my understanding that the number represents the lbs at weaning attributed to the mother's milk. So how exactly do you figure that out?

An EPD is nothing more than a comparator between two individual sire's or dam's genetic ability to pass a certain trait to it's progeny. It is not a predictor of an individual's ability, per se.

The results are calculated by comparing the weaning weight of many, many separate contemporary groups (adjusted for environmental conditions) and by comparing bull "A's" calves to all the other bulls calves that had data submitted for comparison in that particular Sire Summary Evaluation..

If within those individual contemporary groups, bull "A's" calves were found to weigh more than bull "B's" calves yet both the mothers & calves were fed & treated exactly equal in each separate contemporary group, the only thing left to attribute the difference in weaning weight's is the genetics passed to those calve's mothers by it's sire & dam.

It doesn't matter what part of the country or what feeding regime is used.

Remember, a yearling bulls EPD's are only an average of his parents. It could change dramatically if data is collected on his calves.

When using EPD's, find the "Base/Baseline" of a breeds EPD traits and use the "Accuracy" values as well.

Added:
The present average for the Angus Maternal Milk EPD is 22.
The Heritability for Maternal Milk is .14
(For comparison the Mature Ht. Heritability is .82)