بررسي اثرات سطح استفاده و درجه اشباعيت چربي ها بر ميزان انرژي قابل متابوليسم حقيقي تصحيح شده براي ازت TMEN آنها

The influence of chemical composition and inclusion level of fats on their true metabolisable energy values for poultry

Animal fat (AF) and cotton seed oil (CSO) were blended in the proportions (AF: CSO) of: (1) 0.25: 0.75, (2) 0.5: 0.5. (3) 0.75: 0.25. The three blends together with the AF, CSO, fish oil, two heated vegetable oil and a by product of vegetable oil refining were each included at 3, 6, 9 precent in to a basal diet. Fats were anlayzed for most chemical parameters (fatty acid profile, gross energy, dry matter, peroxid value, saponification and unsaponification index and iodin index). The experimental diets were evaluated for true metabolisable energy corrected to zero nitrogen (TMEn) with 4 replicates of two adult single comb white Leghorn cockerels per cage using force feeding methed. There was no significant departure from linearity in the response of dietary TMEn to added fat. Synergism, as drived from the differences between determined and calculated TMEn values, was detected with two fat combinations (1 and 2). For all fats and oils, the best regerssion equation could be derived (R2 =0.976) , based on 4 chemical parameters (oleic acid, acid value, Saponification index and unsaponification index).