Roman Bochno

Age-related changes in the distribution of lean, fat with skin and bones in duck carcases.

1. The experimental birds were Pekin ducks (352 and 352) reared to the age of 13 weeks. They were fed standard diets ad libitum. Starting from the second week, 21 males and 21 females were slaughtered every 7 d. Their carcases were divided into the following elements: neck, wings, legs, breast and back, which were then dissected into lean, skin with fat and bones. 2. The body weights of one-day-old ducklings were similar (circa 62 g), but at 5 weeks of age the males were heavier than the females, and at 13 weeks of age their body weights were 3537 g and 2994 g, respectively. 3. In 2-week-old ducks 55·77% of lean was located in the legs, 15·91% in the back part, 2·78% in the wings, 12·47% in the neck and only 13·12% in the breast. 4. Considerable changes in the distribution of lean were noted in the ducks aged 7 weeks. Its percentage decreased in the legs (to 29·34%) and increased in the breast and wings (to 36·86% and 10·96%, respectively). 5. Age-related changes in the distribution of skin with fat were smaller. Its percentage increased in the wings, legs and back, and decreased in the neck and breast. 6. Until the age of 7 weeks the percentage of bones was decreasing quickly in the legs and increasing in the neck and breast, compared with their total weight in the carcase.

Use of a modified skin slice with subcutaneous fat and carcase weight without this slice for prediction of meatiness and fatness in young slaughter geese

1. White Italian geese (40 males and 40 females) were reared until 12 weeks of age and fed standard diets ad libitum. After rearing ended, the geese were weighed (males–5216 g, females–4945 g) and killed. Carcases were chilled and skin slices with subcutaneous fat removed. The remaining part of the carcase was dissected into meat, intermuscular fat and bones. 2. The weight of a skin slice with subcutaneous fat, taken from the carcase surface excluding the forewings and wing tips (X 2), and the weight of a carcase excluding this slice, the forewings and wing tips (X 1) were very good indicators of the content of skin with fat (r > 0·99) and meat (r > 0·98) in a whole carcase. 3. The above traits provided a basis for deriving regression equations to estimate the content of meat (Ŷ) or skin with subcutaneous and intermuscular fat (Û) in whole carcases of White Italian geese. The following equations are recommended for practical application: Ŷ = 0·755X 1 – 27·8 (Sy  = 26·3 g); Û = 1·070X 2 + 19·5 (Su  = 11·4 g)