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Genetic Evaluation Lab. AnS 225 February 5, 2014. Measures of Performance. P = G + E Phenotype = Genetics + Environment Environment = Facilities + Nutrition + Health + Management We measure phenotype, but need to estimate genetic merit. 2. Genetic Evaluation.
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Genetic Evaluation Lab AnS 225 February 5, 2014
Measures of Performance • P = G + E • Phenotype = Genetics + Environment • Environment = Facilities + Nutrition + Health + Management • We measure phenotype, but need to estimate genetic merit 2
Genetic Evaluation • Genetic evaluation takes place at the nucleus level • Similar basic procedures are used by the breeding companies • Each has implemented their own “secrets” • Many are using genetic markers • All companies have specific terminal and maternal lines • Genetic information is proprietary
STAGES -- Swine Testing And Genetic Evaluation System • National Swine Registry (NSR) • Duroc, Hampshire, Landrace, Yorkshire • Multi-trait animal model • Daily across-herd EPDs on association computer • Breed specific variance components and adjustments • Genetic information can be accessed at www.nationalswine.com
STAGES Program Components • Records of ancestry (Pedigree) • Performance measurement program • EBV estimation program • Public access to the genetic rankings • Indexes to combine traits that economically influence selection decisions
STAGES Data Procedures • Litter data recorded in farrowing house • Pedigree information (sire and dam) • Date farrowed • Number born alive • Number after transfer (number allowed to nurse) • 21-day litter weight • Data sent to NSR office when litter is recorded
Postweaning STAGES Data • Pigs scanned at or near 250 pounds • Most breeders scan every 3-4 weeks to form contemporary groups • Boars, gilts, and barrows • Record weight, backfat, loin muscle area • Data sent to NSR office same day • Results returned to breeder next day
Genetic Merit --What Is An EPD? • Expected Progeny Difference • Actual difference in performance a producer can expect from future progeny of a sire or dam, relative to the future progeny of an average parent of the same breed or line
EPDs Are Expressed in Units of the Trait Measured: • Days/250 (days) • Backfat (inches) • Number Born Alive (no. pigs) • Litter Weight (lbs.) • Intramuscular Fat (%) • May be positive (+) or negative (–)
Example • Boar A – EPD for Backfat = –.05 • Boar B – EPD for Backfat = .00 • Boar C – EPD for NBA = 1.0 • Boar D – EPD for NBA = 0.2
STAGES Selection Indexes • Indexes are used for multiple trait selection • Indexes combine the traits that economically influence a selection decision • Selection objective determines which index should be used 11
Sow Productivity Index (SPI) • Number Born Alive • 21-Day Litter Weight • Use to evaluate maternal performance only
Maternal Line Index (MLI) • Number Born Alive • 21-Day Litter Weight • Days to 250 Pounds • Backfat • Use to select maternal sires and replacement females
Terminal Sire Index (TSI) • Days to 250 Pounds • Backfat • Loin Muscle Area • Pounds of Lean in 185 pound carcass • Use to select terminal sires
Terminal Crossbreeding - Maximum Heterosis MLI/SPI Grandparent Landrace x Yorkshire MLI X TSI Parent Landrace x Yorkshire F1 MLI X Market Hogs 1/2 D, 1/4 Y, 1/4 L
Duroc Sire Trait Leaders for Terminal Sire Index (born after 8/3/2009)
Duroc Sire Trait Leaders for Terminal Sire Index (born after 8/3/2009)
TSI Example • Value is $.10/pig for each point • Sire A has TSI of 118 • Sire B has TSI of 108 • Difference of 10 TSI index points • Sire 100 litters @ 9 pigs/litter • 10 index point difference X $.10/pig X 900 pigs = $900 favoring Boar A over Boar B
Yorkshire Sire Trait Leaders for Maternal Line Index (after 8/4/2009)
Yorkshire Sire Trait Leaders for Maternal Line Index (after 8/4/2009)
How Do Breeders Use the STAGES Results? • Improve Genetics - Selection Decisions: • Sow culling • Replacement gilt selection • Sire culling and selection • Marketing by seedstock producers: • Published national sire summaries • Farm sales materials