Assume the mean number of eggs a hen lays per year in a particular flock is 234. Given in the following table are values for some of the genetic and environmental effects that influence egg laying prolificacy for two hens, Princess Lay-a, and Dora the Eggsplorer. Assume the contemporary group effect is + 1.1 eggs. *Note: this is a hypothetical example. In real life we would not know the "true" values for these individual genetic and environmental effects, only their estimates. Term BV Ep ET Princess Lay-a 1st year +7.70 eggs +1.35 eggs -1.65 eggs 2nd year +7.70 eggs +1.35 eggs 3.65 eggs Dora the Eggsplorer 1st year 2nd year -2.50 eggs -2.50 eggs +4.15 eggs +4.15 eggs +0.85 eggs +3.85 eggs a. [6 points] The first year, Princess Lay-a produced 248 eggs. Dora produced 235 eggs. What is the total genetic effect for each hen? b. [6 points] In the 2nd year of laying, does Princess Lay-a or Dora the Eggsplorer produce more eggs? How much more/less than the other? Strategy: quantitative genetic model Producing Ability (PA) Breeding Value (BV;) Concept Definition (for a trait) Model (for an individual) Parameter (for a population) Prediction Application Phenotype (P) A single performance P = + BV + GCV +Epi + Ecgi + Eti P = + G + E f = obv + occv +0+0+0 0px ox P = P + bp.x(X-X) Marketing bp.x = Repeated performance PA = BV + GCV +Epi PA = G + Epi "" obv + ocv +o of bPA-P = r PA = bpA-P(P-P) Commercial (culling) Additive part of performance BV = BV h Y bBv.p =h BV = bgv.p (P-P) Seedstock (selection)