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WHAT ARE EPD’S?

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What is an EPD?

  • E-xpected
  • P-rogeny
  • D-ifference

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A measure of the degree of difference between the progeny of the bull and the progeny of the average bull of the breed in the trait being measured. It is calculated from data collected on the progeny of the bull.

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EPD Vocab

Accuracy (ACC)

  • EPD's are often presented with a corresponding accuracy value, which measures the strength of the relationship between the genetic prediction and the true genetic value

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  • Accuracies are reported as a decimal number from zero to one

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  • As accuracy value approaches 1.0, the EPD is "accurately" or closely estimating the true genetic merit of an animal for a given trait.

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EPD Vocab

Birth Weight (BW)

  • Predicts the difference in pounds, for birth weight

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  • Expressed in pounds

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EPD Vocab

  • Weaning Weight (WW)
  • Predicts the difference, for weaning weight (adjusted to age of dam and a standard 205 days of age)

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  • This is an indicator of growth from birth to weaning

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  • Expressed in pounds

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EPD Vocab

Yearling Weight (YW)

  • Predicts the expected difference, for yearling weight (adjusted to a standard 365 days of age)

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  • This is an indicator of growth from birth to yearling

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  • Expressed in pounds

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EPD Vocab

Maternal Influence (MILK)(MLK)

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  • Predicts the difference in maternal production of an individual animal's daughters as expressed by the weaning weight of their calves.

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EPD Vocab

Total Maternal (TM)

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  • Predicts the rancher’s actual observation of weaning weights of calves raised by an animal’s daughters

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  • Includes the daughters MILK EPD plus half of her genetic contribution to her calf's weaning weight EPD

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EPD Vocab

Calving Ease Direct (CED)

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  • Predicts the probability of calves being born unassisted out of two year-old heifers

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EPD Vocab

Heifer Pregnancy (HPG)

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  • Predicts the probability of heifers conceiving to calve at two years of age

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EPD Vocab

Calving Ease Total Maternal (CETM)

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  • Predicts the probability of a given animal's daughters calving unassisted at two years of age

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EPD Vocab

Stayability (STAY)

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  • Predicts the probability that a bull’s daughter will remain in the herd until at least six years of age

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EPD Vocab

Docility (DOC)

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  • Based on a scoring system ranging from:
    • 1=Docile
    • 2=Restless
    • 5=Nervous
    • 6=Very Aggressive

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EPD Vocab

Marbling Score (MARB)

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  • Predicts the differences for carcass marbling score as expressed in marbling score units

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  • Higher marbling scores are positively correlated with higher carcass quality grades

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EPD Vocab

Rib Eye Area (REA)

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  • Predicts differences of carcass rib eye area between the 12th and 13th rib

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EPD Vocab

12 Rib Fat Thickness (FAT)

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  • Predicts differences for the carcass fat depth over the 12th rib

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  • Expressed in inches