The experimental birds were Pekin ducks (352 males and 352 females) 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. 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. 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. 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). 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. 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.

The experimental materials comprised White Italian geese (128 males and 128 females) reared to 14 wk of age. The birds were fed standard diets ad libitum. Starting from 2 wk of age, 14 males and 14 females were killed at 2-wk intervals. The carcasses were divided into neck, wings, legs, breast, and back, which were then dissected into muscle, skin with fat, and bones. Before slaughter, the BW of males and females were 6,814 and 5,736 g, respectively. At 2 wk of age, more than half of total muscle content was in the legs (60.98%), and the rest was in the back (17.84%), neck (9.43%), breast (8.78%), and wings (2.97%). To 10 wk of age, the rate of muscle deposition was relatively slow in the legs (a decrease to 31.29%) and fast in the breast and wings (an increase to 34.12 and 12.90%, respectively). Age-related changes in the distribution of skin with fat in the carcass were smaller, compared with changes in muscle distribution. A rising tendency was observed in the muscle content of wings and breast and in the content of skin with fat in the wings and neck, whereas a falling tendency was observed in the other carcass parts. Over the first 8 wk, the proportion of bones decreased in the legs, back, and neck and increased in the wings and breast, as compared with the total bone weight in the carcass.

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).

The aim of the study was to compare the slaughter quality of layer-type cockerels and broilers reared under identical conditions. The experimental materials comprised broiler (Ross -*2 ; +** males and +** females) and layer-type (Messa ../ ; +** males) chickens. The birds were reared in accordance with universally accepted technological standards. Broilers were reared to six weeks of age, and layer-type cockerels ῌ to six, eight and ten weeks of age. Twelve Ross males, +, Ross females (aged six weeks) and +, Messa males (aged six, eight and ten weeks) were selected randomly for slaughter quality assessment. The birds were sacrificed, the carcasses were eviscerated and warm carcass weight, giblets weight (gizzard, heart, liver) and abdominal fat weight were determined. The carcasses were chilled for about +2 hours at .῎ and weighed again, and then divided into the following parts : neck, wings, legs, breast and back. These elements were dissected into lean, bones, skin with subcutaneous and intermuscular fat. Breast muscle weight was determined during breast dissection. At six weeks of age the mean body weights and carcass weights of layer-type cockerels were -.3-fold and ..0-fold lower, compared with broilers (000 g vs. ,/11 g and .+, g vs. +231 g respectively). The values of most slaughter quality indices were less desirable in layer cockerels ῌ lower carcass dressing percentage, lower breast content of a carcass, lower meat percentage in a carcass. Only the percentage of fat with skin in a carcass was more desirable in layer-type chickens than in broilers.

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