Evaluation of Simmental carcass EPD estimated using live and carcass data

Area of Science:

• Animal Breeding and Genetics
• Quantitative Genetics
• Beef Cattle Production

Background:

• Accurate prediction of carcass traits is crucial for genetic selection in beef cattle.
• Traditional methods rely on live animal measurements, but carcass data offers direct phenotype information.
• Evaluating different data sources for predicting breeding values is essential for optimizing selection strategies.

Purpose of the Study:

• To compare carcass EPDs derived from yearling live animal data versus progeny carcass data.
• To quantify the association between progeny carcass phenotype and sire EPDs.
• To determine the optimal data model for predicting carcass traits in Simmental cattle.

Main Methods:

• Three models were used: live data (L), carcass data (C), and combined live/carcass data (F).
• Data included ultrasound measurements (live) and carcass traits (weight, fat, muscle, marbling).
• Animal model procedures were applied to pedigree data of 39,566 Simmental animals.

Main Results:

• The combined data model (F) demonstrated the highest average accuracy for carcass EPDs.
• Live animal data alone (L) resulted in smaller variance and range in EPDs compared to C and F.
• Models including carcass data (C and F) showed greater similarity and significantly re-ranked sires compared to L.

Conclusions:

• Carcass EPDs derived from a combination of live and carcass data (F) are optimal due to increased accuracy.
• Models incorporating carcass data provide more reliable predictions of progeny phenotype.
• The study validates that combined data models effectively predict differences in progeny carcass traits.