Abstract: The yolk eolour is controlled by genetic and nutritional factors. The heritability ot yolk eolour of Jinding duck at 200 days and 300 days of age is 0.05 and 0.22 respectively. The additions of 0.008%of Lucantin Red or 7% of Spirulina platensis powder can increase the yolk colour from 9 to 14—15 or more in the Roche score. 6% of Porphyra sp. or 6% of Laminaria sp. powders or 2% of rapeseed oil can all improve yolk pigment. In addition, the yolk colour is relative to the shell colour, but is not affected by the age.

Key words: Yolk colour, Heritability, Nutritional factors, Jinding duck, Potentilla fruticosa, subalpine meadow, spatial pattern, slope aspect, spatial correlation