Regression equations for in vivo estimation of the meat content of Pekin duck carcases.

1. Pekin ducks (strain A-44; 108 males and 108 females) were reared on standard diets for 7 weeks, after which the following measurements were taken: body weight (X1), thickness of breast muscles (measured by means of an ultrasonic apparatus; (X2) and length of breast-bone crest (X3). The birds were slaughtered and chilled carcases were dissected, separating meat, skin with subcutaneous and intermuscular fat, and bones. 2. The data were used to derive multiple regression equations for in vivo estimation of the meat content of whole carcases (Y; g). Separate calculations were made on males and females. The above-mentioned traits--X1, X2 and X3 constitute independent variables of those equations. The following equation (calculated on the basis of the data on both sexes) may be recommended for use in breeding work: Y = 0.184X1 + 125.4X2 + 25.12X3 - 255.8 (S(Y) = 39 g).