添加剂对白三叶青贮的影响

为探讨不同添加剂对白三叶（Trifolium repens）青贮的影响,以营养生长期白三叶为原料,分别设计对照、添加甲酸（6 mL/kg）、蔗糖（2%）处理,袋装密封青贮360 d后取样分析。结果表明,添加甲酸或蔗糖都能显著改善白三叶青贮饲料的发酵品质,极显著降低青贮饲料的pH值、乙酸和氨态氮含量（P<0.01）,极显著增加乳酸含量（P<0.01）。添加甲酸或蔗糖显著提高白三叶青贮饲料的干物质保存率（P<0.05）,显著提高ADF含量（P<0.05）。青贮之后,硝酸盐含量下降。     

吡啶羧酸铬对肉鸭后期作用效果初探

选用21日龄樱桃谷鸭36只,采用有重复对照试验,比较饲粮中添加0．2×10－6吡啶羧酸铬对肉鸭生产性能、屠体品质和血液生化指标的影响。结果表明,吡啶羧酸铬对增重、饲料转化率无显著影响,对屠宰率、胸肌率和皮脂率亦无显著影响;但使心重、血清总甘油三酯显著降低,血清总胆固醇、高密度脂蛋白胆固醇显著增加。     

神犬护主擒犯立奇功

安娜是一个单身的年轻女子,独自居住在美国拉斯维加斯的一栋房子里,和她日夜相伴的是一头心爱的杜伯文犬。     

天然气抗氧化刘的研究概况

按照美国食品药物管理局(FDA)定义,所谓抗氧化剂是指作为延滞因氧化所引起的劣变、酸败或变色的物质[1].     

A novel dendrimeric peptide induces high level neutralizing antibodies against classical swine fever virus in rabbits

The amino acid sequence (TAVSPTTLR, 829-837aa) on the glycoprotein E2 of classical swine fever virus (CSFV) is a conserved and linear neutralizing epitope. In the present study, two peptides were constructed based the core sequence of this neutralizing epitope, the dendrimeric peptide (Th-B(4)) containing four copies of B cell epitope fused to one copy of promiscuous T helper (Th) cell epitope and the peptide Th-B containing a single copy of B cell epitope fused to one copy of Th cell epitope. The dendrimeric peptide Th-B(4) elicited high titers of neutralizing antibodies as detected in an indirect ELISA, blocking ELISA and neutralization test and induced a complete protection against CSFV C strain in rabbits. The Th-B elicited low titers of neutralizing antibodies and did not induce a protection in rabbits. These results suggest that the dendrimeric peptide Th-B(4) may be a promising marker vaccine candidate against CSFV and the multimerization is a requirement for development of a peptide vaccine.     

2013—2014年全球猪流行性腹泻重大疫情分析

2013年以来,猪流行性腹泻（Porcine Epidemic Diarrhea,PED）疫情在美洲和亚洲的部分国家和地区暴发流行,对疫情发生国家或地区的生猪生产和猪肉市场供给造成极大影响。对全球PED疫情进行时间序列分析,发现PED流行范围逐步扩大,毒力不断增强,全球病毒基因序列相似,饲料特别是猪血液制品贸易可能是该病跨国界传播的潜在途径。     

Model Optimization of Litter Size and Genetic Analyses of Model Parameters in Sows

According to two properties of the life cycle and to fluctuation with parities, four mathematical models, the Poisson cycle model, the cubic polynomial model, the modified quadratic polynomial model-I and the modified quadratic polynomial model-II, were used to fit the records of litter size in Jiangquhai sows. From the viewpoint of statistics and biological significance, the modified quadratic polynomial model-I was found to be the optimum model. A single trait animal model and DFREML procedures were further used to estimate the heritability values of optimum model parameters. The results show that the heritability values for the coefficients A and B and the heritability value for the acme of the model pure quadric curve are larger than the heritability value for the litter size. This suggests that selection for model parameters may be more effective than direct selection for litter size.     

镇海巨高长毛兔体重与产毛性能相关的研究

利用原全国家兔育种委员会2000年长毛兔性能测定数据,分析研究了镇海巨高长毛兔12月龄时体重与产毛性能的相关。结果表明:母兔的体重、标准含水率产毛量、单次产毛率和估测年产毛率均显著或极显著地高于公兔;随着体重的增加,标准含水率产毛量相应地提高,单次产毛率和估测年产毛率相应地下降;体重与标准含水率产毛量、单次产毛率的相关系数分别为0.225、-0.324(P<0.01);标准含水率产毛量与单次产毛率的相关系数为0.845(P<0.01)。     

你理解犬的吠叫吗?

犬交流的方式有:面部表情、吠叫、肢体语言、气味语言等。吠叫是表达方式相对单一的交流方式,但其表达的内容却很丰富。从声音特征上分析犬的吠叫吠叫作为犬的一种声音语言,具备声音所有的三个基本特征:音调、音长、频率(声音的重复率)。