本试验旨在研究枯草芽孢杆菌锌对先天性缺锌大鼠生长性能、器官指数、养分利用率和器官中微量元素（锌、铜、铁）含量的影响，以确定枯草芽孢杆菌锌的作用效果和微量元素减量化添加的可行性。选取同期受孕母鼠进行先天性缺锌大鼠模型建立试验，即模型组大鼠从怀孕第10天开始饲喂缺锌饲粮（锌水平13.00 mg/kg），对照组大鼠同期饲喂正常饲粮（锌水平38.00 mg/kg），持续到哺乳期结束。建模成功后，选择模型建立试验对照组中24日龄正常大鼠幼鼠18只作为正常组（Ⅰ组，锌水平13.00 mg/kg），饲喂正常饲粮；另外，选取模型建立试验模型组中24日龄先天性缺锌大鼠幼鼠90只，随机分成5个试验组，分别为缺锌组（Ⅱ组，锌水平13.00 mg/kg）、硫酸锌（ZnSO₄）组（Ⅲ组，锌水平38.00 mg/kg）和低（Ⅳ组，锌水平15.00 mg/kg）、中（Ⅴ组，锌水平30.00 mg/kg）、高剂量枯草芽孢杆菌锌组（Ⅵ组，锌水平45.00 mg/kg），均饲喂缺锌饲粮，每组3个重复，每个重复6只大鼠。试验期5周。结果表明：1）与Ⅰ组比较，Ⅱ组体重（BW）和平均日采食量（ADFI）显著或极显著降低（P<0.05或P<0.01）。与Ⅱ组比较，Ⅳ、Ⅴ、Ⅵ组BW、ADFI显著或极显著增加（P<0.05或P<0.01）。与Ⅲ组比较，Ⅴ组BW、平均日增重（ADG）、ADFI显著增加（P<0.05）。2）与Ⅰ组比较，Ⅱ组的肝脏指数显著降低（P<0.05）。与Ⅱ组比较，Ⅴ、Ⅵ组的心脏、肝脏指数显著或极显著增加（P<0.05或P<0.01）。与Ⅲ组比较，Ⅵ组的心脏指数显著增加（P<0.05），Ⅴ组的心脏、肾脏指数显著或极显著增加（P<0.05或P<0.01），Ⅳ组的肾脏指数显著增加（P<0.05）。3）与Ⅰ组比较，Ⅱ组的粗蛋白质（CP）、粗脂肪（EE）、粗纤维（CF）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、钙、锌利用率均显著或极显著降低（P<0.05或P<0.01）。与Ⅱ组比较，Ⅴ、Ⅵ组的CP、CF、EE、NDF、ADF、钙、锌利用率显著或极显著增加（P<0.05或P<0.01）。与Ⅲ组比较，Ⅳ组的EE利用率显著升高（P<0.05），Ⅴ组的EE、CF、NDF、ADF、锌、钙利用率均极显著增加（P<0.01），Ⅵ组的EE、CF、NDF、ADF、锌利用率显著或极显著增加（P<0.05或P<0.01）。4）与Ⅰ组比较，Ⅱ组的食入氮、沉积氮、氮利用率均显著或极显著降低（P<0.05或P<0.01）。与Ⅱ组比较，Ⅴ、Ⅵ组的食入氮、沉积氮、氮利用率显著或极显著升高（P<0.05或P<0.01）。与Ⅲ组比较，Ⅳ的食入氮、沉积氮显著降低（P<0.05），Ⅴ组的食入氮、沉积氮显著升高（P<0.05）。5）与Ⅰ组比较，Ⅱ组心脏、肝脏、肾脏中锌含量显著或极显著降低（P<0.05或P<0.01）。与Ⅱ组比较，Ⅴ、Ⅵ组心脏、肝脏、肾脏中锌含量显著或极显著增加（P<0.05或P<0.01）。与Ⅲ组比较，Ⅳ组心脏、肾脏中锌含量显著降低（P<0.05），Ⅳ、Ⅵ组肝脏中锌含量显著或极显著降低（P<0.05或P<0.01）。6）与Ⅰ组比较，Ⅱ组心脏、脑、肾脏中铜含量显著降低（P<0.05）。与Ⅱ组比较，Ⅳ、Ⅴ、Ⅵ组心脏中铜含量显著升高（P<0.05）。与Ⅲ组比较，Ⅳ、Ⅵ组脑中铜含量显著降低（P<0.05），Ⅴ组心脏中铜含量显著升高（P<0.05）。7）与Ⅰ组比较，Ⅱ组心脏、肝脏、肾脏中铁含量显著或极显著降低（P<0.05或P<0.01）。与Ⅱ组比较，Ⅳ、Ⅴ、Ⅵ组心脏、肝脏、肾脏中铁含量显著或极显著增加（P<0.05或P<0.01）。与Ⅲ组比较，Ⅳ、Ⅴ、Ⅵ组肝脏中铁含量显著或极显著降低（P<0.05或P<0.01）。由此可见，枯草芽孢杆菌锌能够促进先天性缺锌大鼠生长发育，提高肝脏指数、心脏指数和养分利用率，调节微量元素的分布，作用效果优于ZnSO₄，且降低了饲粮中锌添加量。

This experiment was conducted to study the effects of Bacillus subtilis-zinc on growth development, organ index, nutrient utilization and organ trace elements (zinc, copper and iron) content of congenital zinc deficiency rats, and to determine the feeding effects of Bacillus subtilis-zinc and feasibility of the trace elements reduction. The same pregnancy period rats were selected for the model establishment experiment of congenital zinc deficiency rats, rats in the model group were fed a low zinc diet (zinc level was 13 mg/kg) and rats in the control group were fed a normal diet (zinc level 38 mg/kg), from 10 days after pregnancy to the end of lactation. After that, eighteen 24-day-old normal juvenile rats from the control group in the model establishment experiment were selected as a normal group (group Ⅰ, zinc level was 13 mg/kg), and fed a normal diet; in addition, ninety 24-day-old congenital zinc deficiency juvenile rats from the model group in the model establishment experiment were selected and randomly divided into 5 experimental groups, which were zinc deficiency group (group Ⅱ, zinc level was 13 mg/kg), zinc sulfate (ZnSO₄) group (group Ⅲ, zinc level was 38 mg/kg), low-dose Bacillus subtilis-zinc group (group Ⅳ, zinc level was 15 mg/kg), mid-dose Bacillus subtilis-zinc group (group Ⅴ, zinc level was 30 mg/kg) and high-dose Bacillus subtilis-zinc group (group Ⅵ, zinc level was 45 mg/kg), respectively, and fed low zinc diets; there were 3 replicates in each group and 6 rats in each replicate. The experiment lasted for 5 weeks. The results showed as follows:1) compared with group Ⅰ, the body weight (BW) and average daily feed intake (ADFI) of group Ⅱ were significantly decreased (P<0.05 or P<0.01). Compared with group Ⅱ, the BW and ADFI of groups Ⅳ, Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the BW, average body gain (ADG) and ADFI of group Ⅴ were significantly increased (P<0.05). 2) Compared with group Ⅰ, the liver index of group Ⅱ was significantly decreased (P<0.05). Compared with group Ⅱ, the heart index and liver index of groups Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the heart index of group Ⅵ were significantly increased (P<0.05), the heart index and kidney index of group Ⅴ were significantly increased (P<0.05 or P<0.01), the kidney index of group Ⅳ were significantly increased (P<0.05). 3) Compared with group Ⅰ, the utilizations of crude protein (CP), crude fat (EE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium and zinc of group Ⅱ were significantly decreased (P<0.05 or P<0.01). Compared with group Ⅱ, the utilizations of CP, CF, EE NDF ADF, calcium and zinc of groups Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the EE utilization of group Ⅳ was significantly increased (P<0.05), the utilizations of EE, CF, NDF ADF, calcium and zinc of group Ⅴ were significantly increased (P<0.01), the utilizations of EE, CF, NDF ADF and zinc of group Ⅵ were significantly increased (P<0.05 or P<0.01). 4) Compared with group Ⅰ, the nitrogen intake, deposit nitrogen and nitrogen availability of group Ⅱ were significantly decreased (P<0.05 or P<0.01). Compared with group Ⅱ, the nitrogen intake, deposit nitrogen and nitrogen availability of groups Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the nitrogen intake, deposit nitrogen of group Ⅳ were significantly decreased (P<0.05), the nitrogen intake, deposit nitrogen of group Ⅴ were significantly increased (P<0.05). 5) Compared with group Ⅰ, the contents of zinc in heart, liver and kidney of group Ⅱ were significantly decreased (P<0.05 or P<0.01). Compared with group Ⅱ, the contents of zinc in heart, liver and kidney of groups Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the contents of zinc in heart and kidney of group Ⅳ were significantly decreased (P<0.05), the liver zinc content of groups Ⅳ and Ⅵ was significantly decreased (P<0.05 or P<0.01). 6) Compared with group Ⅰ, the contents of copper in heart, brain and kidney of group Ⅱ were significantly decreased (P<0.05). Compared with group Ⅱ, the heart copper content of groups Ⅳ, Ⅴ and Ⅵ was significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the brain copper content of groups Ⅳ and Ⅵ was significantly decreased (P<0.05), the heart copper content of group Ⅴ was significantly increased (P<0.05). 7) Compared with group Ⅰ, the contents of iron in heart, liver and kidney of group Ⅱ were significantly decreased (P<0.05 or P<0.01). Compared with group Ⅱ, the contents of iron in heart, liver and kidney of groups Ⅳ, Ⅴ and Ⅵ were significantly increased (P<0.05 or P<0.01). Compared with group Ⅲ, the liver iron content of groups Ⅳ, Ⅴ and Ⅵ were significantly decreased (P<0.05 or P<0.01). In conclusion, Bacillus subtilis-zinc can promote the growth and development of congenital zinc deficiency rats, improve liver index, heart index and nutrient utilization, regulate the distribution of trace elements, the effects are better than ZnSO₄, and reduce the addition amount of zinc in the diet.