A comparative study of metabolisable energy in ducklings and domestic chicks

Abstract

Four experiments were carried out to compare metabolizable energy (ME) values of some diets in Muscovy ducklings and broiler chickens at 8 weeks of age. In the first experiment, cumulative excretion was measured after feeding. There were no differences between the two species in the kinetics of dry matter excretion over time. In the second experiment, endogenous energy losses (EEL) were estimated by two methods: (1) in starved birds; (2) by regression of excreted on consumed gross energy by birds fed on the basal diet. When estimated by Method 2, EEL was 14.13 and 10.71 kcal/bird/day in ducks and chicks; 9.44 and 4.94 kcal/bird/day, respectively, after correction to zero N-retention. Similar, but slightly higher, values were obtained with starved birds. In the third experiment, apparent and true ME (both corrected and uncorrected for nitrogen balance) were determined for some diets containing different energy sources. The ducklings had higher ME values than the chicks only when fed on diets rich in soya bean meal and alfalfa meal. The fourth experiment was carried out to determine whether or not the ME value of a high fibre diet differed between birds fed on the diet for the first time and birds which had been fed on the diet for some time. There were no consistent differences in the ME values obtained for ducklings and chickens. The adaptation period exerted no beneficial effect on the ME values.