维生素A水平对早期断奶仔猪生长性能和免疫功能的影响

试验研究饲粮添加不同水平维生素A对 4～ 9kg早期断奶仔猪生长性能和免疫功能的影响。结果表明 ,添加VA2 2 0 0～ 4 4 0 0 0IU kg使仔猪的日增重显著提高 (P <0 .0 5 )、采食量和饲料转化率趋于提高 ;但添加 2 2 0 0IU kg和 5 5 0 0IU kg两组间生长性能较接近 (P >0 .0 5 ) ,添加量超过 5 5 0 0IU kg时 ,日增重和采食量随VA添加量增加而趋于降低(P >0 .0 5 ) ,添加 110 0 0 0IU kg组生长性能显著降低 (P <0 .0 5 )。添加VA对免疫功能的影响主要为 :(1)使血液白细胞数趋于降低 ;血液白细胞中单核细胞比例趋于提高 ,在添加 5 5 0 0IU kg和 110 0 0IU kg组较高 ,进一步提高VA添加量 ,反而趋于降低 ;(2 )使血清T淋巴细胞中CD4 亚群比例趋于降低、CD8亚群比例极显著降低 (P <0 .0 1) ,但在添加 5 5 0 0～110 0 0 0IU kg组间较接近 ,各组CD4 CD8比值差异不显著 ;(3)随添加VA水平提高 ,PHA诱导的皮褶厚度增长值趋于提高 ,至添加VA110 0 0IU kg组较高 ,之后变化不大。综合试验结果认为 ,于基础饲粮上添加VA2 2 0 0IU kg可满足 4～ 9kg早期断奶仔猪获较好生长性能的需要 ,添加VA110 0 0IU kg仔猪各免疫功能较高。

Effects of Vitamin A Levels on Performance and Immune Function of Early-weanling Piglets

The trial was conducted to evealuate the effects of different dietary vitamin A levels on performance and immune function of early-weanling piglets weighing from 4 to 9 kg.The results showed that daily gain increased significantly,feed intake and gain over feed ratio tended to increase when added vitamin A 2200,5500,11000,22000,44000IU/kg to basal diet.But daily gain and feed intake tended to decrease when increaed vitamin A levels from 5500IU/kg to 110000IU/kg,performance of piglets fed diets containing vitamin A 110000IU/kg was significantly lower than that of others.Blood leukocyte counts tended to decrease as vitamin A levels increased from O to 5500IU/kg,proportion of monocyte in leukocyte tended to increase as increased vitamin A levels from O to 5500 IU/kg or 11000IU/kg but tended to decrease as vitamin A levels increased from 11000 to 110000UI/kg.Percentage of CD4 + and CD~+-8 in T lymphocyte of piglets fed diets containing Vitamin A 0 and 2200IU/kg was higher than that of others,CD~+-4/CD~+-8 ratio in T lymphocyte of all piglets had no difference,Skin thickness after stimulated by PHA tended to increase as vitamin A levels increased from 0 to 11000IU/kg,It was concluded that vitamin A requirement of piglets weighing from 4 to 9 kg was 2200IU/kg for the better performances and 11000IU/kg for the better immune function.