Artificial insemination is an important tool in agriculture, but freezing semen for later use can reduce its potency (ability to produce offspring). Here we are trying to understand the effect of freezing on the potency of chicken semen. Four semen mixtures are prepared, consisting of equal parts of either fresh or frozen Rhode Island Red semen, and either fresh or frozen White Leghorn semen. Sixteen batches of Rhode Island Red hens are assigned at random, four to each of the four treatments. Each batch of hens is inseminated with the appropriate mixture, and the response measured is the fraction of the hatching eggs that have white feathers and thus White Leghorn fathers (data from Tajima 1987). Analyze these data to determine how freezing affects potency of chicken semen.
