Determination of metabolizable energy of wheat, barley and corn produced in Iran using biological method (InVivo) and comparison with with estimates from conventional equations and NIR

This experiment was conducted to determine the metabolizable energy of wheat, barley and corn produced in Iran using biological method (in vivo) and comparison with equations and estimates obtained from NIRs and NRC. Wheat, barley and corn grains were chemically analyzed according to AOAC standard methods and NIRs. Biological method was performed using 48 adult roosters (Red Island) at the age of 83 weekswere using the precision-feeding method. Results of using equations for wheat and barley the highest amount of metabolizable energy (3.71 and 3.45 kcal / g) and the lowest (3.11 and 2.87 kcal / g) by equations respectively Carpenter and Jensen were observed (P <0.05). Corn grain showed the highest amount of metabolizable energy (3.91 kcal / g) by Carpenter and Jensen equations and the lowest amount of metabolizable energy (3.06 kcal / g) by EEC equation (P<0.05).The amount of metabolizable energy obtained from biological methods for corn, wheat and barley (3.323, 3.1724 and 2.9543 kcal / g), compared to standard NRC tables (3.350, 3.120, and 2.640 Kcal / g) and NIR (3.324, 3.324 and 2.735 kcal / g), respectively (P<0.05). It is suggested that equations be prepared for domestically produced cereal cultivars and that rations be adjusted according to the amount of energy variation. Because this variation is important in regulating feed economically and cost-effectively.