Composition of meat in La Belle and White Plymouth Rock chickens, slaughtered at different age

Т. Popova*, E. Petkov, M. Ignatova

Institute of Animal Science, 2232 Kostinbrod, Bulgaria
(Manuscript received 16 May 2015; accepted for publication 8 June 2016)

Abstract. An experiment with two lines of chickens – synthetic line La Belle and White Plymouth Rock was carried out in the Institute of Animal Science, Kostinbrod to assess the meat quality in regards to chemical composition and the fatty acid profile at the age of 9 and 18 weeks. The age affected the lipid content which decreased significantly in breast (p<0.05) and thighs (p<0.01) in the older chickens of both lines. The content of protein and moisture in breast differed between the lines (p<0.05), showing higher protein and lower moisture in White Plymouth Rock chickens, while in the thigh muscles the line and age significantly interacted (P<0.001) in regards to these traits. Interactions between the two factors (p<0.01) was observed for the ash content in the breast, whereas in the thighs it tended to decrease with the age in both lines. The fatty acid composition of the meat was influenced mainly by the age of the chickens. The total content of the saturated fatty acids was increased in the thighs of the older birds (p<0.01), while the proportion of the monounsaturated fatty acids was decreased in the breast (p<0.01) and thighs (p<0.001) with advancing age of the chickens. The opposite was observed for the content of the polyunsaturated fatty acids in the breast, which increased at higher age of slaughter (p<0.001). In thigh meat, the changes of the polyunsaturated fatty acids induced by age followed the same pattern, however significant interaction with the line was observed (p<0.05). The cholesterol content in the breast differed significantly between the two lines (p<0.05) and reduced with age (p<0.001). In the thighs considerable decrease (p<0.001) of the cholesterol was observed in La Belle birds.