Question

You've just finished college and have your diploma in hand. Your family is thrilled to have you back since they know you are now an animal breeding and statistics whiz. After reviewing the production records you have calculated covariance, correlation and regression for the number of days for a pig to reach 230 pounds and backfat thickness and found them to be -0.569,-0.29, and -0.0034, respectively. what do these values tell you about the relationship between the two traits of interest? If you wanted to decrease the number of days to reach 230 pounds 5 days earlier, what would your breeding objective be?

Answer 1

The values indicate that the number of days to reach 230 pounds and backfat thickness are inversely correlated to each other. A negative covariance value( -0.569) means that the movement of one variable is opposite to the movement of the other variable. A negative correlation value( -0.29) means between two variables, when one variable increases, the other decreases. A negative regression coefficient( -.0034) suggests that as the independent variable increases, the dependent variable tends to decrease. All these data suggests that as trait of number of days to reach 230 pounds decreases, backfat thickness will increase and vice versa.

In order to decrease the number of days to reach 230 pounds, the breeding objective should be to increase the backfat thickness of the pig. To achieve this, required quality of lipid rich feed can be used for stipulated amount of time.