Effect of the growth intensity on cholesterol and fatty acids content in broiler chicken tissues

The dependence of the content (Y) of total lipid, cholesterol and fifteen f atty acids (FA) in breast muscle (BM), thigh muscle (TM), and skin (S) on t he growth intensity (live weight at 42 days, g x 10(2); X) was determined i n 54 broiler chickens (ROSS 208) fed a commercial diet. Cholesterol was det ermined by the liquid chromatography and FA by the gas chromatography after total lipid extraction using a hexane/isopropanol mixture. Total lipid content (%) increased with the increasing growth intensity in B M (P < 0.05), TM (P < 0.01) and S (P < 0.01). Cholesterol content (mg/100 g ) was influenced (P < 0.01) by the growth intensity only in S. However, cho lesterol concentration in total lipid (%) decreased significantly (P<0.01) both with the increasing live weight in BM (Y = 5.34 - 0.1368X, r = -0.45), TM (Y = 1.99 - 0.0512X, r = -0.46) or S (Y = 0.42 - 0.0099X, r= - 0.46), a nd also in the sequence BM (2.7%) > TM (1.0%,)> S (0.2%). With the increasing growth intensity the content of C20:4n6 and C22:5n6 dec reased in all tissues (P < 0.01). However, linoleic acid content did not ch ange. On the other hand, with the significant (P < 0.05) increase of linole nic acid content, the content of any other n3 polyunsaturated FA (PUFA) was not influenced (P > 0.05) by the increasing growth intensity of chickens. The PUFAn6/PUFAn3 ratio decreased with the increasing live weight in BM (Y= 12.40-0.2480X, r=-0.30, P<0.05), TM (Y = 23.17 - 0.5007X, r=-0.39, P < 0.01 ) and S (Y = 22.41 - 0.5391X, r = -0.33, P < 0.05). This ratio was higher ( P < 0.01) in TM and S (13.5 and 11.9, respectively) in comparison with BM ( 7.6).