Mass Selection for 45-Day Body Weight in Japanese Quail: Selection Response, Carcass Composition, Cooking Properties, and Sensory Characteristics

Abstract

Mass selection for increased, live body weight at 45 days of age was carried out for 17 or 20 generations in three lines (1, 2, 3) of Japanese quail. One line (C) was an unselected control. At the end of the study, the respective mean body weights for the four lines for males and females were: 237.6 g and 261.4 g; 251.9 g and 274.3 g; 195.1 g and 218.1 g; and 147.7 g and 169.4 g. Mass selection was effective in Lines 1, 2, and 3; the realized heritabilities were equal to .13 and .22, .19 and .24, and .17 and .18, respectively, for males and females. No genetic change occurred in Line C. Selected lines produced heavier carcasses, more meat, and more abdominal fat However, as a percentage of body weight, the carcasses from Line 3 contained more meat (Pectoralis major, Pectoralis minor, and thigh muscles) and less abdominal fat than those from Lines 1 and 2. Moreover, the protein contents of the Pectoralis major muscles and the thigh muscles as a proportion of dry matter were 92.03% and 89.38%, respectively, for Line 3. Those values were at least equal to the ones for Line C, and were 2 to 4% higher than the ones for Lines 1 and 2. The fat percentage of the same muscles was 2 to 5% lower for Line 3 than for the others. The relative losses due to cooking (drippings) were lower for Lines C and 3 than for the others. The meat from the Line-3 carcasses, although quite acceptable in flavor, was less juicy than that from Line C and was also the least tender of all the lines. Overall, the birds from Lines 1 and 2 grew bigger and fatter and the individuals from Line 3 were leaner and relatively meatier than the others. Both the initial genetic differences between the experimental lines and the differential correlated responses to selection for body weight may have caused the line differences observed in the carcasses and in the composition of the meat.