Effect of dietary supplemental levels of vitamin A on the egg production and immune responses of heat-stressed laying hens
Effect of dietary supplemental levels of vitamin A on the egg production and immune responses of heat-stressed laying hens
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DOI：
10.1093/ps/81.4.458
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发表时间：
2002-04-01
期刊：
影响因子：
4.4
通讯作者：
Yang, QM
中科院分区：
文献类型：
--
作者：
Lin, H;Wang, LF;Yang, QM
本试验旨在研究在商品蛋鸡饲粮中添加维生素A对热应激蛋鸡产蛋性能和免疫功能的影响。试验1采用不同水平的维生素A(3000和9000 IU/kg)，研究热应激母鸡的产蛋性能和新城疫病毒抗体效价。结果表明：与对照组（3000 IU/kg）相比，高水平添加维生素A （9000 IU/kg）对热应激仔猪采食量和产蛋率均有显著提高（P < 0.05）。抗体滴度不受维生素A水平的影响（P < 0.05）。试验2研究了4种维生素A水平（3000、6000、9000和12000 IU/kg）对新城疫抗体滴度和T淋巴细胞比例的影响。在新城疫疫苗接种后15 d（处理1）或立即（处理2）暴露于高温（31.5℃）。结果表明：高水平添加维生素A（6000和9000 IU/kg）可显著提高蛋重（P < 0.01），但对采食量、产蛋率和失重无显著影响（P < 0.05）。在处理1中，维生素A对正常和高温环境下抗NDV抗体滴度无显著影响，但增加了α-乙酸萘酯酶（ANAE）阳性细胞的比例（P < 0.01）。在处理2时，添加维生素A对NDV抗体滴度和anae阳性细胞比例有显著影响（P < 0.01）。由此可见，热应激条件下，在商品蛋鸡饲粮中添加维生素A有利于蛋鸡的产蛋性能和免疫功能。
Two experiments were conducted to evaluate the effect of vitamin A supplementation of a commercial layer diet on the laying performance and immune function of heat-stressed hens. In Experiment 1, two different levels of vitamin A supplementation (3,000 and 9,000 IU/kg) were used to investigate the laying performance and antibody titer against Newcastle disease virus (NDV) of heat-stressed hens. Results showed that the high level of vitamin A supplementation (9,000 IU/kg) had a beneficial effect on the feed intake and laying rate of heat-stressed liens (P < 0.05), compared with the control group (3,000 IU/kg). The antibody titers were not influenced by the level of vitamin A (P > 0.05). In Experiment 2, the effect of four levels of vitamin A (3,000, 6,000, 9,000, and 12,000 IU/kg) on the antibody titer to NDV and T lymphocyte proportion was studied. The experimental birds were exposed to a high temperature (31.5 C) 15 d after NDV vaccination (Treatment 1) or immediately (Treatment 2). The results showed that the egg weight was increased (P < 0.01) by the high levels of vitamin A supplementation (6,000 and 9,000 IU/kg), but feed intake, laying rate, and body weight loss were not (P > 0.05). in Treatment 1, vitamin A had no significant effect on antibody titers against NDV in normal or hot environments but increased (P < 0,01) the proportion of α-naphthyl acetate esterase (ANAE)-positive cells. Vitamin A supplementation had a significant effect on NDV antibody titer and ANAE-positive cell proportion in Treatment 2 (P < 0,01). The results of the present study suggested that vitamin A Supplementation in commercial layer diets to layer chickens under heat stress was beneficial to laying performance and immune function.