ENERGY AND PROTEIN REQUIREMENTS OF KHAKI CAMPBELL × THAI NATIVE GROWING DUCKS

The experiment was carried out to estimate the energy and protein requirements of Khaki Campbell $\times$ Thai Native growing ducks. The growing stage was divided into 2: the first was a starting stage from 0 to 4 weeks of age and the second was a growing stage from 4 to 18 weeks of age. In the starting stage, the birds were given diets containing 2.70, 2.75, 2.80, 2.85 and 2.90 Mcal ME/kg and ME/protein ratio of 150/l for the energy requirement trial, and diets containing 17.0%, 18.5%, 20.0% and 21.5% protein and 2.8 Mcal ME/kg for the protein requirement trial. It was found that there were no significant differences in body weight gain of feed efficiency among the energy or protein levels. In the growing stage, no significant differences in body weight gain or feed efficiency were found among the energy levels from 2.70 to 2.90 Mcal ME, or protein levels from 15.5% to 20.0%. The age at first lay was 105-117 days and this is earlier than that observed in purebred Khaki Campbell ducks. The feed cost for raising ducks was lower in the low energy and low protein diets. In conclusion, Khaki Campbell $\times$ Thai native ducks can be raised with a diet low in ME as 2.7 Mcal/kg during the whole growing period. As for the protein. 7.0% in the starting stage and 15.5% in the growing stage is practical.