Animal Selection

-expected difference between average performance of individuals progeny and average performance of all progeny -half of the parents breeding value because only half the parents genes will be passed on

-accuracy is only as good as the people measuring the traits -accuracy increases with larger pool -0.1-0.99 scale

-analogous to EPD but for dairy -notation may be different -reliability is expressed as a percent -breed specific

-looks at the individual to assess their genetic merit as a parent -summation of individual, independent alleles that are transmittable -EBV=EPD x2

marker assisted selection -usually we make decisions based on phenotype or another tool -we can now test for certain genetic markers of merit -SNP- single nucleotide polymorphism - a marker for a deriserable trait -beef- disease resistance, embryo mortality, ADG -swine- carcass composition -allows selection of animals before maturity -these tools are a great way to compare animals potential without confounding effects

-select animals that meet a pre-determined threshold -herds and flocks must have variation in order for selection to be effective

-make breeding decisions based on animals -ex. -use a sire with high EBV for calving ease on heifers -use a sire with a high EPD for carcass weight on light-musculed cows