当饲粮烟酸缺乏时，1 ~14日龄北京鸭色氨酸需要量显著升高。

The tryptophan requirement of Pekin ducks aged 1 to 14 days significantly increases when niacin is deficient in diets.

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当饲粮烟酸缺乏时，1 ~14日龄北京鸭色氨酸需要量显著升高。

The tryptophan requirement of Pekin ducks aged 1 to 14 days significantly increases when niacin is deficient in diets.

youdao