An optimal dietary zinc level of broiler chicks fed a corn-soybean meal diet
An optimal dietary zinc level of broiler chicks fed a corn-soybean meal diet
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DOI：
10.3382/ps.2007-00088
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发表时间：
2007-12-01
期刊：
影响因子：
4.4
通讯作者：
Liu, B.
中科院分区：
文献类型：
--
作者：
Huang, Y. L.;Lu, L.;Liu, B.
本试验旨在研究玉米豆粕型肉仔鸡饲粮中锌的适宜水平。选取1日龄肉鸡公雏384只，随机分为2组，分别饲喂28.32 mg Zn/kg的玉米-豆粕型基础饲粮，在基础饲粮中添加0、20、40、60、80、100、120和140 mg Zn/kg的试剂级ZnSO4中心点7H(2)O。每个处理重复6次，每栏8只鸡。通过分析组织锌浓度、锌金属酶活性、金属硫蛋白（MT）浓度、MT mRNA水平和锌转运蛋白-2 (ZnT-2) mRNA水平，确定肉仔鸡饲粮锌的适宜水平。进行回归分析以估计存在二次或渐近反应的最佳膳食锌水平。结果表明：随着饲粮锌水平的提高，增重和采食量均有所增加（P < 0.05），且在饲粮中添加20 ing锌/kg （48.37 mg/kg，总锌）时增重和采食量最大。胰腺MT和MT mRNA随锌添加量的增加呈线性增加。根据渐近模型，雏鸡从孵化至21日龄胰腺锌和骨锌的最佳需取量分别为59.15 mg/kg和61.70 mg/kg。血清5′-核苷酸酶活性和胰腺Zn转运体-2 mRNA水平呈二次响应，饲粮总适宜水平分别为80.50和84.09 mg/kg。本试验结果表明，雏鸡从孵化至21日龄饲粮锌适宜水平为84 mg/kg。
An experiment was conducted to estimate the optimal dietary zinc level for broiler chicks fed a cornsoybean meal diet. A total of 384 one-day-old male broiler chicks were assigned randomly to dietary treatments for 21 d. These treatments included a basal corn-soybean meal diet (28.32 mg of Zn/kg) supplemented with 0, 20, 40, 60, 80, 100, 120, or 140 mg of Zn/kg in the form of reagent-grade ZnSO4 center dot 7H(2)O. All treatments were replicated 6 times using 8 chicks per pen. Tissue Zn concentration, Zn metalloenzyme activity, metallothionein (MT) concentration, MT mRNA level, and Zn transporter-2 (ZnT-2) mRNA level were analyzed for choosing suitable criterion to determine the optimal dietary Zn level for broilers. Regression analysis was performed to estimate optimal dietary Zn level in the presence of quadratic or asymptotic responses. Results showed that weight gain and feed intake were increased with dietary Zn level (P < 0.05), and the maximum weight gain and feed intake were observed in the diet supplemented with 20 ing of Zn/kg (48.37 mg/kg, total dietary Zn). Pancreas MT and MT mRNA increased linearly with Zn supplementation. According to the asymptotic model, the optimal Zn requirement of chicks from hatch to 21 d of age was 59.15 mg/kg for pancreas Zn and 61.70 mg/kg for bone Zn respectively. Quadratic responses were exhibited by serum 5'-nucleotidase activity and pancreas Zn transporter-2 mRNA level, resulting in total optimal dietary levels of 80.50 and 84.09 mg/kg, respectively. Based on results from this study, the optimal dietary Zn level of chicks from hatch to 21 d of age is 84 mg/kg.