Question

A swine producer is trying to decrease backfat in his herd. He decides to measure all the boars and gilts he puts on test. The average boar pig in the herd has 1 inch of backfat and the average gilt has 1.2 inches. His replacement boars average 0.8 inch and his replacement gilts average is 1.1 inches. Assume generation intervals of 1.5 years for both boars and gilts. The heritability of backfat thickness is 0.40.

1. what are the average selection differentials for males and females in inches?

2. What is the expected response per year in females and males?

Answer 1

Q. 1

Here the average boat pig has 1 inch of backfat while replacement has 0.8 inch, so selection differential will be 0.2 for male,

Similarly, for gilts the differential will be = 1.2-1.1=0.1 for female.

Q 2 The responses in both male and female are slightly different because from the observation it is clear that the in heritability of backfat in male is more than female. The heritability is 0.40 thickness, so there will definitely inheritance of backfat.