بررسي ميزان انرژي قابل سوخت وساز حقيقي تصحيح شده براي نيتروژن چربيها در سنين پايين در جوجه هاي گوشتي

True Metabolizable Energy Corrected to Zero Nitrogen Equilibrium (TMEn) Values of Fats for Young Broiler Chickens

An experiment was conducted to determine the effect of different inclusion rates and degree of saturation of fat sources on true metabolizable energy corrected to zero nitrogen retention( TMEn) values in broiler chickens. Animal fat and cotton seed oil were blended in the proportions of (Animal fat : cotton seed oil ): 0.25:0.75 , 0.50:0.50 , 0.75:0.25 . The three blends together with the animal fat and cotton seed oil were each added at 3, 6 and 9 percent to a basal diet. Fats were analyzed for most chemical variables (fatty acid profile, gross energy, dry matter, peroxid value, acid value, sophonification index, iodin index, unsophonification index). The experimental diets were evaluated for TMEn. From 250 day-old Arian male strains, 136 birds were selected at 18 days of age and randomely distributed in 68 cages. Each treatment was replicated four times and each experimental unit consisted of two birds. There was significant deviation from linearity in the response of dietary TMEn to added fat. Synergism, as demonstrated by the difference of determined TME,, values from those of calculated values, was substantially low, specially for the third fat blend adding at 9 percent to the basal diet. For all fats, the best regression equation (R2 = 0.966) can be achieved from the 3 following variables fat levels, dry matter digestibility, and oleic plus linoleum acid levels.