Three experiments were conducted to measure the ME,S of five broiler diets of increasing in energy and nutrients density . The calculated TMEn of five diets were 2600, 2750, 2900, 3050 and 3200 Kcal/kg, respectively. Thirty six adult leghorn cockeris were repeatedly used to do the first two experiments (expt.1 and2) .The third experiment was done with broiler chicks from 0 to 21 days of age (expt.3).The ME,S of these diets were determined by the use of Sibblad method (expt.1), total collection (expt.2) and indicator method with broiler chicks(expt.3). The AME and the TMEn by the sibbaled method had higher accuracy than others. The results of the first experiment showed that the TMEn is more closely related to the chicks performances than other ME,S.
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