Genetic relations between carcass fat and body weight in mice

Abstract

Three different stocks of mice were selected for five generations for high body weight at 3, 4½, or 6 weeks of age. Changes in body weight at the three ages and in abdominal fat weight, an index of carcass composition, which occurred in the three lines were compared. It was found that the proportion of fat in the carcasses of the selected animals increased markedly in the lines selected for high 3-week weight, while in the other two lines the proportion remained the same as that in the control line.The theoretical treatment of the genetic relationship between body weights at different ages and between body weight and abdominal fat was reasonably adequate in accounting for the correlated responses actually observed.