【作者】 何小佳；

【导师】 吴金节；

【作者基本信息】 安徽农业大学 ， 临床兽医学， 2008， 硕士

【摘要】 在早期断奶仔猪日粮中分别添加氧化锌(3000 mg·kg^-1)、蛋氨酸锌(500 mg·kg^-1),研究高锌日粮长期暴露对断奶仔猪生长性能、血清生化指标、血清及组织中铜、铁、锌沉积的影响及高锌日粮的应用安全性。试验选用60头（23±1）日龄临床检查健康的“杜×长×大”三元杂交断奶仔猪,按体重和性别随机分成3组,每组20头,分别饲喂基础日粮（Ⅰ组）、基础日粮+3000mg·kg^-1氧化锌（Ⅱ组）、基础日粮+500mg·kg^-1蛋氨酸锌（Ⅲ组）。所有试验猪均于断奶后0、21、42、70 d空腹称重,计算采食量。同时于断奶后0、21、42、70 d,经前腔静脉采血,测定血清总蛋白、白蛋白、总胆固醇、尿素氮水平和碱性磷酸酶、谷草转氨酶、谷丙转氨酶、铜-锌超氧化物歧化酶、谷胱甘肽过氧化物酶的活性,以及血清铜、铁、锌含量;同期收集粪便,测定铜、铁、锌含量。3组仔猪均于断奶后70 d,各剖杀5只仔猪,共剖杀15只仔猪,取心、肝、肺和肾,用于测定铜、铁、锌的含量;另取肝脏、肾脏,立即放入10%福尔马林溶液中,待做组织切片。试验结果如下:（1）高锌日粮长期暴露对断奶仔猪生长性能的影响与对照组相比,在断奶后的21、42d,Ⅱ、Ⅲ组仔猪体重显著或极显著提高（P<0.05或P<0.01）,但是试验结束时,3组仔猪体重没有显著差异（P>O.05）。断奶后0-21d,处理组仔猪平均日增重极显著高于对照组仔猪（P<0.01）;断奶后21-42d,处理组仔猪平均日增重显著高于对照组仔猪（P<0.05）;断奶后42～70d,处理组仔猪的平均日增重显著低于对照组仔猪（P<0.05）。在整个试验期内,Ⅱ、Ⅲ组仔猪的体重和平均日增重差异均不显著（P>0.05）。（2）高锌日粮长期暴露引起机体中毒在断奶后42、70 d,Ⅱ、Ⅲ组仔猪血清AST和ALT水平显著或极显著高于Ⅰ组（p<0.05或p<0.01）,Ⅱ、Ⅲ组间差异不显著（p>0.05）;在断奶后21、42、70d,Ⅱ、Ⅲ组仔猪血清ALP水平极显著高于Ⅰ组（p<0.01）;在断奶后70 d,Ⅱ、Ⅲ组仔猪血清TP、ALB水平显著或极显著低于Ⅰ组（p<0.05或p<0.01）,Ⅱ、Ⅲ组间差异不显著（p>0.05）;在整个试验阶段,3组仔猪血清CHL、UN水平差异不显著（p>0.05）。结果表明,高锌日粮长期暴露,断奶仔猪血清TP、ALB含量显著降低,血清AST和ALT的活性显著升高;临床出现锌中毒症状,肝、肾有病理变化。说明长期饲喂高锌日粮,可造成肝、肾损害,引起中毒反应。（3）高锌日粮长期暴露引起仔猪体内微量元素失衡断奶后42、70d,Ⅱ组、Ⅲ组仔猪血清铜水平极显著低于Ⅰ组（P<0.01）;与断奶时相比,Ⅱ组、Ⅲ组仔猪血清锌水平在断奶后21、42、70d极显著升高（P<0.01）。断奶后,Ⅱ组、Ⅲ组仔猪血清锌水平显著或极显著高于Ⅰ组（P<0.05或P<0.01）;断奶后42、70d,Ⅱ组、Ⅲ组仔猪血清铁水平极显著低于Ⅰ组（P<0.01）。在断奶后70d,Ⅱ组、Ⅲ组仔猪心、肝。肾中锌含量显著高于Ⅰ组（P<0.05或P<0.01）,铜、铁含量显著低于Ⅰ组（P<0.05或P<0.01）。试验结果表明,高锌日粮长期暴露,增加仔猪血清和组织中锌含量,抑制铜和铁的吸收,导致粪便中铜、铁、锌含量显著增加,致使体内铜、铁含量明显减少。试验结果显示,断奶早期饲喂高锌日粮能显著地缓解仔猪断奶应激综合征,促进仔猪生长。高锌日粮长期暴露,抑制体内铜、铁吸收,影响肝、肾功能,导致机体中毒。更多还原

【Abstract】 An experiment was conducted to study the effects of feeding high level zinc diet (from 3000 mg·kg^-1ZnO or 500 mg·kg^-1Zn-Met) on the growth performance,serum antioxidative enzyme activities,serum biochemical indexes,the contents of copper,iron, zinc in sera and tissues,and high level zinc diet-applying security in piglets.Sixty "Duroc×Landrace×Yorkshire" crossbred weanling stress piglets（23 d±1 of age） were randomly divided into 3 groups of 20 piglets each by weight and sex.The piglets in GroupⅠwere fed a basal diet,the piglets in GroupⅡwere fed the diets plus 3000 mg·kg^-1 Zinc（from ZnO）,the piglets in GroupⅢwere fed the diets plus 500 mg·kg^-1 Zinc（from Zn-Met）.The trial was conducted for 70 d.All piglets were weighed on d 0,21,42,70 postweaned,and feed takes were evaluated.Blood samples of sixty piglets were taken from the anterior vena cava on d 0,21,42,70 postweaned for measuring the levels of serum total protein （TP）,albumin（ALB）,cholesterol（CHL）,urea nitrogen（UN）,and the activities of serum alkaline phosphatase（ALP）,aspartic acid transferase（AST）,alanine amino transferase （ALT）,CuZn- superoxide dismutase（CuZn-SOD）,GSH-Px,and the contents of copper, iron,zinc in sera and dejectas.At the end of the trial,15 male piglets（5 per group） were bled via the anterior vena cava,heart,liver,lung and kidney were collected for determining the contents of copper,iron and zinc;the tissues of kidney and liver were recollected and stored in 10%formalin solution immediately for preparing tissue sections.The results were as follows:（1） The effect of high zinc diet long-term exposure on growth performance of weanling pigletsCompared with the control group,AW of piglets in GroupⅡandⅢwere significantly improved on d 21 and d 42 postweaned（P＜0.01 or P＜0.05）,but there were no significant difference（P＞0.05） among 3 groups of piglets at the end of the trial.Compared with the control Group,ADG of piglets in GroupⅡandⅢwere very significantly improved from d 0 to d 21 postweaned（P＜0.01）,and significantly improved from d 21 to d 42 postweaned （P＜0.05）,and significantly decreased from d 42 to d 70 postweaned（P＜0.05）.In the whole experimental period,there had no significant difference of AW and ADG of piglets between GroupⅡandⅢ.（2） High zinc diet long-term exposure could cause poisoning response of weanling piglets The levels of serum AST and ALT were higher in piglets of GroupⅡandⅢthan that of control group（P＜0.05 or P＜0.01） on d 42,70 postweaned,and there were no significant difference between GroupⅡandⅢ（P＞0.05）;the levels of serum ALP were higher in piglets of GroupⅡandⅢthan that of control group（P＜0.01） on d 21,42,70 postweaned; the levels of serum TP and ALB were lower in piglets of GroupⅡandⅢthan that of control group（P＜0.05 or P＜0.01） on d 70 postweaned,and there were no significant difference between GroupⅡandⅢ（P＞0.05）.In the whole experimental period,there had no significant difference of serum CHL and UN among 3 groups of piglets（P＞0.05）.The results indicated that the levels of serum TP and ALB were significantly decreased and the activities of serum AST and ALT were significantly increased in weanling piglets feeding high level zinc diets;zinc toxic symptoms were performed,and there had some pathological changes in liver and kidney.These showed that high zinc diet long-term exposure could cause poisoning response of weanling piglets（3） High zinc diet long-term exposure could cause the imbalance of trance elements in weanling pigletsThe levels of serum copper were lower in piglets of GroupⅡandⅢthan that of control group（P＜0.01） on d 42 and d 70 postweaned.Compared with d 0,the levels of serum zinc in piglets of GroupⅡandⅢwere significantly improved（P＜0.01） on d 21,42 and 70 postweaned.The levels of serum zinc were higher in piglets of GroupⅡandⅢthan that of control group（P＜0.05 or P＜0.01） postweaned;the levels of serum iron were lower in piglets of GroupⅡandⅢthan that of control group（P＜0.01） on d 42 and d 70 postweaned.The contents of zinc were higher in heart,liver,kidney of piglets in GroupⅡandⅢthan that of control group（P＜0.05 or P＜0.01）,and the contents of copper and iron were lower in heart,liver,kidney of piglets in GroupⅡandⅢthan that of control group （P＜0.05 or P＜0.01） on d 70 postweaned.The trial results indicated that high zinc diet long-term exposure could increase the contents of zinc in sera and tissues of piglets, inhabit copper and iron absorbing,and increase the contents of copper,iron,zinc in dejecta, decrease the contents of copper and iron in body.The results showed that high level zinc diets could significantly alleviate weanling stress syndrome,enhance the growth performance of piglets on the early period postweaned.High zinc diet long-term exposure could inhabit copper and iron absorbing in body,influnce the liver and kidney function,and cause poisoning response of piglets.更多还原