铜和维生素A及其互作效应对肉鸡免疫功能的影响

摘要

A 4×2 (Cu×VA) random experiment was designed to investigate the effect of different dietary levels of Cu (0 mg· kg-1, 8 mg · kg-1, 150 mg · kg-1, 225 mg · kg-1) and VA (1 500 IU · kg-1, 5 000 IU · kg-1) on broiler immune system at 0～4 and 5～7 week-old.The results showed significant effects (P＜0.05, P＜0.01) of Cu at 8 mg · kg-1 on percentage of activated T-lymphocytes in spleen and serum antibody titers of 0～4 week-old broilers. At the same Cu level, percentage of activated T-lymphocytes in spleen, thymus and cecal tonsil, and percentage of activated B/T-lymphocytes in peripheral blood significantly increased (P＜0.05, P＜0.01) in 5～7 week-old broilers. Percentage of activated B/T-lymphocytes decreased at different degrees under high Cu levels of 150～225 mg · kg-1 feed. At VA supplemental level of 5 000 IU · kg-1 feed, percentage of activated T-lymphocytes in peripheral blood also significantly increased (P＜0.05) for the 0～4 week-old broilers, while percentage of activated T-lymphocytes in spleen, cecal tonsil and serum antibody titers significantly increased (P＜0.05, P＜0.01) for the 5～7 week-Id broilers. Percentage of activated B/T-lymphocytes and serum antibody titers were not significantly affected by Cu/VA interaction for 0～4 week-old broilers. However, percentage of activated T-lymphocytes of cecal tonsil, thymus and peripheral blood significantly increased (P＜0.05) for 5～7 week-old broilers, especially under Cu (8 mg · kg-1) × VA(5 000 IU · kg-1) interaction. Cu/VAinteraction had a significant effect on the function of broiler immune system.%采用4×2(铜×维生素A)完全随机试验设计,研究了日粮添加不同水平的铜(0 mg·kg-1、8 mg·kg-1、150 mg·kg-1、225 mg·kg-1)和维生素A(1 500 IU·kg-1、5 000 IU·kg-1)对肉仔鸡不同生长阶段(O～4周龄和5～7周龄)免疫功能的影响.结果表明:添加铜为8 mg·kg-1时,肉鸡生长前期(0-4周龄)可显著(P<0.05)或极显著(P<0.01)提高肉鸡脾脏活化T淋巴细胞百分率和血清抗体效价,生长后期(5-7周龄)可极显著(P<0.01)或显著(P<0.05)提高脾脏、胸腺、盲肠扁桃体活化T淋巴细胞百分率和外周血液中活化T、B淋巴细胞百分率;整个试验期添加高铜(150 mg·kg-1、225 mg·kg-1)时,活化T、B淋巴细胞百分率均不同程度下降.添加维生素A 5 000 IU·kg-1时,肉鸡生长前期可显著(P<0.05)提高其外周血液中活化T淋巴细胞百分率,生长后期可极显著(P<0.01)或显著(P<0.05)提高脾脏、盲肠扁桃体活化T淋巴细胞百分率和血清抗体效价.铜和维生素A互作效应对肉鸡生长前期的活化T、B淋巴细胞百分率和血清抗体效价影响不显著,对生长后期的外周血液、胸腺、盲肠扁桃体活化T淋巴细胞百分率影响显著(P<0.05),以8 mg·kg-1铜×5 000 IU·kg-1维生素A处理最高;以上结果提示铜和维生素A对肉鸡免疫功能的影响存在互作效应.