Prediction of True Metabolizable Energy (TMEn) of Broilers Compounded Starter Feeds

An experiment was conducted to predict the true metabolizable energy (TMEn) of compounded starter feeds of broiler chickens trough their chemical composition using precision-feeding method of Sibbald in male boilers. In the first، eight compounded feed samples provided from eight feed plants and their chemical composition determined in laboratory. Results of chemical composition showed that average values of dry matter، crude protein، ether extract، crude ash، crude fiber، calcium and phosphorus were 90. 47، 20. 99، 2. 79، 2. 88، 6. 69، 1. 08 and 0. 49 percent، respectively with coefficient of variation between 2. 01 to 13. 29 percent. The average value of TMEn in compounded starter feeds was also obtained 3006 Kcal/kg with variation from 2884 to 3275 Kcal/kg and differences between them were significant. The variation between metabolizability values in the compounded feeds was 0. 7 to 0. 8 percent and differences between their values were not significant. The average value of dry matter true metabolizability in starter feeds was obtained as 54 percent and those having higher crude fiber، showed lower dry matter true metabolizability. The TME and TMEn values of compounded starter feeds showed a negative correlation as 0. 38 and 0. 59 percent with crude ash of feeds، so that the feeds containing higher crude ash had lower TME and TMEn values. Regression analysis showed that we can predict the TMEn value of broiler compounded starter feeds via regression equations from crude ash، crude protein، calcium and phosphorus contents of feeds from their crude ash، crude protein، calcium and phosphorus with R2 value as 0. 67 (P=0. 002).