日粮锌源和锌水平对断奶仔猪血清及组织铜、铁、锌沉积的影响

选用临床检查健康的(26±2)日龄"杜×长×大"三元杂交断奶仔猪100头,按体质量和性别随机分为5组,每组20头,分别饲喂基础日粮、基础日粮+2000mg/kg氧化锌、基础日粮+3000mg/kg氧化锌、基础日粮+250mg/kg蛋氨酸锌、基础日粮+500mg/kg蛋氨酸锌。试验期14d。于断奶后0,7,14d,经前腔静脉采血,用原子吸收光谱仪检测血清中铜、铁、锌水平。试验结束时,每组选5头仔猪放血致死,取心、肝、肾、脑、脾、胸腺组织,测定铜、铁、锌含量。结果显示,仔猪断奶后,血清中铜、锌水平显著或极显著下降(P0.05或P0.01);添加不同锌源和锌水平的高锌日粮能提高断奶仔猪肝、肾、脑、血清锌的含量,显著或极显著降低仔猪血清铜和心、胸腺铜以及脾铁水平(P0.05或P0.01),对血清铁及其他组织铁含量无明显影响。这表明高锌日粮能增加断奶应激仔猪体内锌水平,降低部分组织中铜、铁含量。

Effect of zinc resources and levels in diets on the contents of copper, iron, zinc in serum and tissues of weanling piglets

The purpose of this experiment was to study the effects of different levels and kinds of zinc diets on the contents of copper, iron, zinc in serum and tissues of weanling stress piglets. One hundred "Duroc×Landrace×York-shire" crossbred weanling piglets(26±2 d of age) were randomly divided into 5 groups of 20 piglets each by weight and sex,which were fed a basal diet with 2 000 or 3 000 mg/kg zinc(from ZnO),and 250 or 500 mg/kg zinc(from Zn-Met),respectively. The trial was conducted for 14 d. Blood samples were taken from the anterior vena cave on 0, 7,14 d postweaned. At the end of the experiment,25 piglets (5 per group) were killed by exsanguination and heart, liver, kidney, brain, spleen and thymus tissues were collected for analysis of trace minerals. Copper,iron,zinc concen-trations of serum and tissues were measured with atomic absorption spectrophotometer. The results indicated that the levels of serum Cu and serum Zn were significantly decreased postweand (P<0.05 or P<0. 01). The different levels and kinds of high zinc diets increased the contents of zinc in heart,liver,kidney,brain and serum significantly, decreased the contents of Cu in serum and heart,spleen,thymus,and the contents of Fe in spleen significantly(P<0. 05 or P<0.01) ,but had no difference in the serum and other tissue contents of Fe. It is confirmed that the high level zinc diets enhanced the zinc levels in the tissues of weanling stress piglets,and reduced the copper and iron lev-els in some tissues of piglets.