Rapid determination of metabolisable energy of foods using cockerels

Abstract

1. Adult cockerels were trained to consume their daily food allowance of about 100 g in 1 h. Excreta were collected for the next 24 h and the metabolisable energy (ME) content of the diet was determined. 2. Two different diets were used to study effects of ME on adaptation to diet. Repeatable estimates of ME were obtained without a period of adaptation. 3. No difference in ME was found when a test diet was fed to adult cockerels for 1 h, or fed continuously and excreta collected over 5 d. The conventional total collection method of determining ME using groups of growing chickens yielded similar results. 4. Excreta collected between 24 and 48, or 48 and 72 h post‐feeding yielded constant energy values following feeding of two different diets, indicating that all excreta from the 1‐h feeding were voided during the next 24 h. 5. The method is precise and results can be reported 36 h after receipt of food sample.