维生素A对0～3周龄北京鸭生产性能和肠道发育的影响

本研究旨在评价日粮中添加维生素A对0～3周龄肉鸭生产性能、血清中维生素A含量和肠道发育的影响.选择1日龄健康北京鸭360只,随机分为5个组,每组6个重复,每个重复12只鸭,分别饲喂在基础日粮中添加0.2500、5000、10000、15000 IU/kg维生素A的试验日粮,试验期为3周.结果表明:日粮中维生素A水平为2 500 IU/kg即能满足北京鸭基本需要;维生素A添加水平在0～10000 IU/kg时,血清中维生素A含量随着日粮中维生素A添加水平的增加而极显著提高(P<0.01),10 000和15 000 IU/kg添加组之间差异不显著(P>0.05);2500 IU/kg组的绒毛长度、十二指肠隐窝深度和肠壁厚度均显著或极显著高于0 IU/kg组(P<0.05或P<0.01),但与其他组差异不显著(P>0.05).由此可见,饲料中适量增加维生素A的添加水平可提高北京鸭生产性能,增加肠道的绒毛长度;肠道绒毛的发育状况和血清中维生素A均可以作为评价肉鸭维生素A营养状况的指标.

Effects of Vitamin A on Performance and Intestinal Development of Beijing Ducks from 0 to 3 Weeks of Age

The experiment was conducted to evaluate the effects of vitamin A on the performance, vitamin A content in serum and intestinal development of Beijing ducks from 0 to 3 weeks of age.A total of 360 one-day-old Beijing ducklings were ran-domly allocated to 5 groups with 6 replicates each and 12 birds in each replicate.The birds were fed corn-corn starch-soybean basal diet supplemented with 0, 2 500, 5 000, 10 000 and 15 000 IU/kg vitamin A, respectively from the age of 1 to 21 days.The results showed as follows: the addition of 2 500 IU/kg vitamin A could meet the needs of Beijing ducks; for the diet with 0～10 000 IU/kg vitamin A, the levels of vitamin A content in serum were significantly increased while the addition level of vitamin A in the basal diet increased (P<0.01), and no significant difference was observed between the 10 000 and 15 000 IU/kg groups; compared with the 2 500 IU/kg group, the intestinal villus length, crypt depth and intestinal wall thickness in the 0 IU/kg group were significantly decreased (P<0.05 or P<0.01), but there was no significant difference between the 2 500 IU/kg and other groups.It was concluded that the addition of vitamin A into the diet could improve the growth performance and intestinal villus length of Beijing ducks, and the situation of intestinal villus and the serum vitamin A could be used as indicator for evaluating the vitamin A nutrition status of Beijing ducks.