Understanding EPDs: Expected Progeny Differences

Decoding the Data

Expected Progeny Differences (EPDs) can seem overhwleming to new producers, but they are a powerful tool for genetic improvement. EPDs allow us to compare animals within a breed and estimate how their offspring will perform relative to the breed average.

Key EPDs to Watch

Depending on your breed and sector (beef or swine), different EPDs will carry more weight.

For Beef Cattle:

• BW (Birth Weight): Lower values indicate lighter calves at birth, which is crucial for heifer bulls to avoid calving difficulty.
• WW (Weaning Weight): Predicts the pre-weaning growth potential of calves.
• YW (Yearling Weight): A measure of post-weaning growth to one year of age.
• Milk: Predicts the maternal contribution to weaning weight through milk production.

For Swine:

• NBA (Number Born Alive): A critical maternal trait for sow productivity.
• Days to 250: A growth trait indicating how fast pigs reach market weight.
• TSI (Terminal Sire Index): A multi-trait index combining growth and carcass traits.

Accuracy Matters

Every EPD comes with an accuracy value (0.0 to 1.0). Low accuracy means the number is an estimate based mostly on pedigree. content.