矮小型肉鸡的早期选择研究

研究测定了部分携带有ｄｗ基因鸡群从出壳到１０周龄体重及跖长的生长发育情况,并对前后期体重、跖长作相关分析。结果证明：ｄｗ基因对雏鸡２周龄前的体重增长及跖长发育无显著影响,４周龄时矮小型鸡与正常型鸡相比体重轻３８．３８％,跖长短１３．２８％,差异显著。初生重、跖长与１０周龄体重及跖长无显著性相关;４,６,８周龄各周体重与１０周龄体重间均表现为极显著相关;本研究得出的６条直线回归方程可用来根据早期体重预测１０周龄体重。矮小型鸡和正常型鸡一样可根据４周龄体重进行早期选种。４,６,８周龄各周跖长与１０周龄跖长间均有极显著相关;对矮小型鸡跖长的选择可提前到４周龄进行,而不必等到１０周龄之后,以利于种鸡早期进行限制饲养。     

莱茵鹅和朗德鹅早期生长规律及体尺比较

为了比较莱茵鹅和朗德鹅的生产性能差异以及经过多个世代育种后各自生产性能的变化,测定了莱茵鹅和朗德鹅体质量和10周龄体尺,用3种非线性生长模型拟合其生长曲线。结果表明:除初生体质量外,朗德鹅体质量显著高于莱茵鹅。在中后期,朗德鹅公、母鹅体质量差异不显著,莱茵鹅公鹅体质量显著高于母鹅。3种生长曲线模型均能很好地拟合2个鹅品种早期生长发育规律,以Gompertz模型拟合生长曲线效果较佳,朗德鹅的极限体质量、拐点体质量大于莱茵鹅,2个鹅品种的拐点周龄几乎一致。大多数朗德鹅的体尺指标显著性高于莱茵鹅。朗德鹅的生产性能明显优于莱茵鹅,2个鹅品种经过多世代育种后仍保持了较高的生产性能。     

基于Copula函数的权重基因共表达网络分析法

利用Frank-Copula函数构建相关系数,并应用于权重基因共表达网络分析模型的改进。同时,利用该改进模型分析小鼠基因数据,发现在相关度最大的模块中有67个基因与小鼠肥胖导致的体质量问题相关。其中,模型的筛选结果有效率为62.6%,说明其在功能基因筛选应用前景中的科学性、有效性和可行性。     

建鲤苗种体长与体重间相互关系的分析

利用建鲤实测体长和体重数据,应用统计分析方法进行体长-体重线性回归分析.结果表明:建鲤体长和体重之间呈曲线相关关系,其相关公式为:W=0.011L3.077(R=0.9919)。     

Toltrazuril and diclazuril: comparative evaluation of anti-coccidial drugs using a murine model

Intestinal coccidiosis caused by Eimeria protozoan species is an economically important disease, especially in poultry and cattle. Anti-coccidial drugs commonly used for controlling coccidiosis are toltrazuril (TTZ) and diclazuril (DCZ). In this study, the efficacies of TTZ and DCZ were compared using a murine model, and the effect of these treatments on the induction of acquired resistance was evaluated. Male C57BL/6J mice were inoculated with 1,000 sporulated E. vermiformis oocytes and treated with TTZ or DCZ. The recommended TTZ dose for cattle (15 mg/kg) completely prevented oocyte excretion. But, mice required 5 mg/kg of DCZ, which is five times the recommended dose for cattle, to reduce oocyte excretion. In E. vermiformis re-infection, TTZ (15 mg/kg) and DCZ (5 mg/kg) treatments did not interfere with the development of acquired resistance. Bodyweight gain was significantly higher in the TTZ-treated group than in the control (untreated/infected) group and the DCZ-treated group, and no significant difference in bodyweight gain was observed between the TTZ-treated group and the healthy (uninfected/untreated) group. Analysis of T lymphocyte subsets in the spleen and mesenteric lymph nodes indicated that the relative populations of CD4⁺ and CD8⁺ T cells were reduced in the DCZ-treated and control (untreated/infected) groups, suggesting there was immunosuppression during the infection. However, no reductions in T cell populations were observed in the TTZ-treated group. The results indicated that an optimal anti-coccidial drug is one that can completely break the parasite life cycle in the host animal.     

增肉素对羔羊的增重试验与残毒检验及羊肉蛋白质含量测定

增肉素(RALGRO)可以促进羔羊及犊牛的生长发育,而且只增长瘦肉但不长脂肪。取六月龄羔羊40只分为两组,每组各20只,随机取样,试验组羔羊在左耳脂肪囊包埋增肉素12mg/只。在相同的饲养管理条件下饲养40d后屠宰。试验组胴体重比对照组平均多增重242.3％,通过方差分析差异十分显著(P<0.01)。屠宰后每只羊均左耳脂肪囊与臀部取肉样通过紫外分光光度计检测残毒,结果表明增肉素已全部吸收,肌肉中增肉素的残留量低于24ng/gm。低于美国FAD的安全量。用自动定氮仪对试验组与对照组的羊肉做蛋白质含量与含水量的测定,然后做方差分析,试验检测结果表明两组羊肉蛋白质与含水量基本相似,无显著差异。(P值分别为P>0.01,及P>0.05)。