Interpreting and using Expected Progeny Differences

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 With a little understanding, Expected Progeny Differences may actually be the best tool producers have to address the genetics of their herds.

While calculating EPD takes a lot of math, producers do not have to do the math; they just need to understand the answers. The calculation results usually appear in the first pages of a sire summary before the actual EPD tables. They may look a little confusing, but the information is very beneficial. It comes down to the fact that you are buying the DNA of a particular animal.

The breed average EPD provide a benchmark for you to compare animals.  They are averages for the animals included in that run of genetic evaluation.  Many associations split the breed averages into those for proven sires, young sires, dams, non-parents, etc. Take note though, breeds traditionally had a base year where the EPD were set to zero, so any difference from zero represents a difference from the base year.  Recently some breeds have varied from the base-year idea, and so it is not as easy to determine what zero means across all breeds.

EPD values are divided up into several types:

• Growth traits EPD are the standards for all breeds including birth weight, weaning weight, milk, yearling weight and height, total maternal and mature weight and height. 

• Reproductive trait EPD include scrotal circumference, gestation length, calving ease direct, calving ease maternal and heifer pregnancy.

•Carcass trait EPD include carcass weight, ribeye area, fat thickness, marbling, retail product, yield grade, tenderness, ultrasound and percent intramuscular fat.

Some other EPD trait inclusions are stayability, as an indicator of bulls’ daughters longevity in the cow herd; maintenance energy, which refers to the energy a cow needs to maintain herself; docility, a measure of the behavior of bulls’ calves as they leave the chute; and pulmonary arterial pressure, which provides an indicator of longevity in the cowherd.

As a breeder, you must ultimately set your own selection criteria.

You might think the simplest thing would be to just pick the highest EPD and believe they are the best, but it is not that simple.

Some traits have higher heritability than others, and you have to decide what is most important to you.

Farmers market now open

The Riverview Farmers Market is now open for the 2012 season.  Come out and support your local fruit, vegetable and ornamental producers.

The Farmers Market is open on Wednesday, 2 – 5 p.m., at the Carroll County Courthouse and Saturday, 8 a.m.-1 p.m., at the Hometown Pizza parking lot.

Dates of interest

May 28: Extension Office is closed for Memorial Day.

May 30: 4-H Camp Camper Applications due to the Carroll County Extension Office.

May 31:First 4-H Camp Camper Orientation, 6 p.m., Carroll County Extension Office. All 4-H Campers must attend one of the two camper orientations in order to attend 4-H Camp. Class signups will also take place. The second orientation will be held on June 19.

June 1: Deadline for FSA Sign Ups (DCP and ACRE Programs).

June 1:Final Cut-Off Date for NRCS Sign Ups (EQIP, Hoop Houses, and On-Farm Energy Initiatives).


Christin Herbst is the Carroll County Extension agent for agriculture and natural resources. Call her at (502) 732-7030 or send e-mail to Christin.Herbst@uky.edu.