Consider a hypothetical quantitative weight trait affected by five loci. assume complete dominance at all loci, and no epistasis. the independent effect of each dominant allele is +8 lb and the independent effect of each recessive allele is -2 lb. the population mean for the trait is 500 lb.
a. if an animal is heterozygous at all loci, and the environmental effect is -12 lb, what are the values for the animal’s breeding value, genotypic value, gene combination value, and phenotypic value?
b. if an animal is homozygous dominant at three loci and homozygous recessive at the other two, and the environmental effect is +10, what are the values for the animal’s breeding value, genotypic value, gene combination value, and phenotypic value?
c. which animal would produce the heaviest offspring, on average? why?