肉鸡对不同铬源吸收的比较研究

Absorption of Different Sources of Chromium by Broiler Chickens

为了比较肉仔鸡对不同铬源的吸收,本试验选取36只7周龄健康、体重相近的艾维茵肉仔鸡,比较无机铬(CrCl3)、氨基酸铬(AACr)、小肽铬(SPCr)、烟酸铬(NiCr)和吡啶羧酸铬(PiCr)的吸收转运效果及其对锌吸收的影响。试验设6个处理,对照组饲喂基础日粮,不同铬源均按1.6mg/kg体重的剂量经口腔引入,2h后于心脏和门静脉采血,屠宰取十二指肠样本,测定其中铬和锌含量。结果表明:SPCr组的十二指肠和门静脉血中铬含量分别比AACr组提高30.53%和30.43%,极显著高于其他各组(P<0.01);SPCr组的心脏全血中铬含量比AACr组提高17.24%,与十二指肠和门静脉血提高的幅度比显著降低(P<0.05);无机铬组血清锌含量低于对照组,而SPCr和AACr有提高血清锌含量的趋势(P>0.05)。结论:铬的吸收受铬源影响较大。SPCr和AACr的吸收较其他铬源要好,与锌不形成竞争,且在一定程度上可促进锌的吸收;SPCr和AACr的吸收效果更优,可能与其利用了小肽和/或氨基酸的吸收机制,以整体的形式被吸收有关。

The absorption of different sources of chromium and their effects on the absorption of zinc were studied in this experiment. Thirty-six healthy Avian broilers of 7 weeks old were divided randomly into six treatments,which included control, inorganic chromium （CrCl3）,amino acids chelated chromiun （AACr）, small peptides chelated chromium （SPCr）, chromium nicotinate （NiCr）,and chromium picolinate （PiCr）. Different sources of chromium were all infused through mouth with a dose of 1.6 mg/kg （chromium/body weight）. Blood samples of heart and portal vein were collected 2 hours later, and samples of duodenum were collected after they were killed, and then all samples were analyzed for chromium and zinc content. The results showed that the chromium contents of portal vein and duodenum of SPCr group were 30.43% and 30.53% higher than those of AACr group respectively, and significantly higher than those of the other groups （P〈0.01）. The increase of chromium content of the blood of heart, comparing SPCr group with AACr group, was 17.24%, significantly lower than that of portal vein and duodenum （P〈0.05）. The zinc content in serum of basal diet group was higher than that of inorganic chromium group, but lower than that of the other groups （P〉0.05）. In conclusion, chromium absorption was subjected to its source. The blood zinc content in different treatments indicated that SPCr and AACr were not competitive with the absorption of zinc, but enhancing the absorption of zinc. The absorption of SPCr and AACr were better than that of other forms of chromium, PiCr, NiCr, and CrCl3. It might be benefited from the absorption mechanism of small peptides and amino acids.