Genetical Researches on the Number of Vertebrae in the Pig

Abstract

The variation of the number of vertebrae in pigs is inherited. Heritability seems to be about .74 (table 6). The type of inheritance is intermediate. The number of the factors is not known. The number of ribs increases with increasing number of presacral vertebrae. With increasing number of ribs the number of lumbar vertebrae decreases. Rudimentary ribs when present have about the same genetical value as fully developed ribs. When the breeding animals are selected, the correlation between parents with respect to the selected character will render the regression coefficient on either parent too high to represent the influence of that parent alone. Copyright © . .