甜叶菊异绿原酸盐对蛋鸡产蛋后期生产性能、免疫及血清激素指标的影响

Effects of stevia isochlorogenic salt on production performances, immune and serum hormones indexes of laying hens in late laying period

为了探究甜叶菊异绿原酸盐对蛋鸡产蛋后期生产性能及血清免疫、激素指标的影响,试验将720只健康且生产性能相近的450日龄海兰灰蛋鸡随机分为4组,分别为对照组及高、中、低剂量组,每组6个重复,每个重复30只。对照组饲喂基础日粮,高、中、低剂量组分别饲喂添加400,200,100 mg/kg甜叶菊异绿原酸盐的基础日粮,预试期7 d,正试期56 d。试验结束后统计蛋鸡的生产性能指标(产蛋率、破蛋率、血壳蛋率、沙壳蛋率、蛋壳厚度、平均蛋重、平均日采食量、料蛋比);每个重复随机选取3只蛋鸡,采血后解剖,检测血清免疫指标[肿瘤坏死因子α(TNF-α)、γ干扰素(IFN-γ)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、白细胞介素-10(IL-10)、免疫球蛋白G(IgG)、免疫球蛋白M(IgM)]、激素指标[血清雌二醇(E_(2))、卵泡刺激素(FSH)、黄体生成素(LH)、甲状腺素(T4)、三碘甲状腺原氨酸(T3)]和卵巢指数。结果表明:与对照组相比,高、中、低剂量组产蛋率和蛋壳厚度均显著提高(P<0.05),同时沙壳蛋率、破蛋率显著降低(P<0.05),平均日采食量差异不显著(P>0.05)。与对照组相比,高、中剂量组血壳蛋率显著降低(P<0.05),中剂量组料蛋比显著降低(P<0.05);高、中、低剂量组蛋鸡血清中TNF-α、IFN-γ、IL-8、IgM和IgG质量浓度均显著降低(P<0.05),IL-10质量浓度显著提高(P<0.05);高、中剂量组IL-6质量浓度显著降低(P<0.05);高、中、低剂量组E_(2)浓度均显著提高(P<0.05),但FSH、LH活性及T4、T3浓度均差异不显著(P>0.05);高、中、低剂量组卵巢指数分别提高了9.35%、15.11%和6.11%。说明在日粮中添加甜叶菊异绿原酸盐能提高产蛋后期蛋鸡生产性能,改善鸡蛋品质,增强机体免疫力,最佳添加剂量为200 mg/kg。

In order to investigate the effects of stevia isochlorogenic salt on performances, immune and serum hormone indexes of laying hens in late laying period, a total of 720 healthy 450-day-old Hy-line grey laying hens with similar performance were randomly divided into 4 groups with 6 replicates in per group and 30 hens per replicate: control group and high, medium and low dose groups. The animals in the control group were fed a basal diet, and the animals in the high-dose, medium-dose and low-dose groups were fed the basal diet supplemented with 400, 200, 100 mg/kg stevia isochlorogenic salt, respectively. The pre-trial period lasted for 7 days and the formal trial period lasted for 56 days. After the experiment, the performance indexes(laying rate, broken egg rate, blood shell egg rate, sand shell egg rate, eggshell thickness, average egg weight, average daily feed intake, and feed to egg ratio) of laying hens were determined. At the end of the experiment, 3 laying hens were randomly selected from each replicate and dissected after blood collection. Serum immune indexes(tumor necrosis factorα [TNF-α], interferon γ [IFN-γ], interleukin-6 [IL-6], interleukin-8 [IL-8], interleukin-10 [IL-10], immunoglobulin G [IgG], immunoglobulin M [IgM]), hormone indicators(serum estradiol [E2], follicle-stimulating hormone [FSH], luteinosis hormone [LH], thyroxine [T4], triiodothyronine [T3]) and ovarian index were detected. The results showed as follows: compared with the control group, the laying rate and eggshell thickness in the high, medium and low dose groups were significantly increased(P<0.05), while the sand shell egg rate and broken egg rate were significantly decreased(P<0.05), and the average daily feed intake was not significantly different(P<0.05). Compared with the control group, the blood shell egg rate in the high and medium dose groups, the feed to egg ratio in the medium dose group, the mass concentrations of serum TNF-α, IFN-γ, IL-8, IgM and IgG in the high, medium and low dose groups in laying hens, and the mass concentration of IL-6 in high-dose and medium-dose groups were significantly decreased(P<0.05), while the mass concentration of IL-10 and the concentrations of E_(2) in the high, medium and low dose groups were significantly increased(P<0.05), but the activities of FSH and LH and the concentrations of T4 and T3 were not significantly different(P>0.05). Compared with the control group, the ovarian index in the high, medium and low dose groups was increased by 9.35%, 15.11% and 6.11%, respectively. The results indicated that adding stevia isochlorogenic salt to the diet could improve the performances, egg quality and immunity of laying hens in late laying period. The optimal dosage was 200 mg/kg.