Effect of Supplementing Alfalfa Powder to Diet on Growth Performance and Meat Quality of Goose

The experiment was aimed to investigate the effects of dietary alfalfa powder on the growth performance,body size,slaughter performance,organ index and meat quality of Siji geese.A total of 256 15-day-old geese (half male and half female) with similar body weight were randomly divided into four groups with 4 replicates of 16 geese each.The geese in control group were fed with corn-soybean meal-based diet (control diet),and geese in the experimental groups were fed the basal diet replaced with 10%,20% and 30% alfalfa powder,respectively.The results showed that,compared with the control group,dietary alfalfa powder supplementation had no significant effect on the average daily intake,average daily gain,feed conversion ratio,body oblique length,keel length,shin circumference,semi diving length,chest width and shin length (P>0.05),and also had no effect on the carcass ratio,half-eviscerated carcass ratio and pectoral muscle ratio (P>0.05).However,dietary 20% and 30% alfalfa powder supplementation significantly increased the chest depth (P<0.05),dietary 30% alfalfa powder significantly decreased the full-eviscerated carcass ratio (P<0.05),and dietary 10% alfalfa powder significantly increased the leg muscle ratio (P<0.05) of geese.In addition,dietary alfalfa powder significantly decreased the abdominal fat ratio (P<0.05),raised the growth index of liver,jejunum,ileum,and cecum (P<0.05),and increased the water loss rate of pectoral muscle and leg muscle (P<0.05) compared with the control group.Dietary 10% and 30% alfalfa powder significantly increased duodenal growth index (P<0.05) of geese.In conclusion,dietary alfalfa powder supplementation might improve the slaughter performance (increase chest depth and leg muscle ratio,reduce abdominal fat rate) and organ growth index (increase the growth index of liver,duodenum,jejunum,ileum and cecum).However,dietary alfalfa powder increased water loss rates in pectoral muscle and leg muscle,and 30% alfalfa powder reduced the full-eviscerated carcass ratio of geese.The appropriate supplementation level of alfalfa powder was recommended at 10% in the present study.     

红细胞钾作为南方中国荷斯坦牛耐热性遗传标记的研究

为探讨建立奶牛耐热性评定指标,本研究以湖南省奶牛原种场及某企业牛场饲养的144头荷斯坦奶牛为研究对象,于2005年9月从牛尾采集血液样品,分析测定了红细胞中的钾含量及钾含量的遗传力。结果参试牛群红细胞钾含量在牛群中呈正态分布,平均为636．35±141．53 mg／L。红细胞钾含量主要受遗传控制,其遗传力为0．318,表明红细胞钾含量可以作为奶牛耐热性选择指标,通过对该指标的测定和分析有助于建立奶牛高产耐热品系。     

出口兔肉备案养殖场追溯体系的建立

从保证动物源性食品安全的角度论述了建立养殖场追溯体系的必要性,以出口兔肉备案养殖场为例,对建立追溯体系的步骤进行了四个方面的探讨。养殖场在设施合理、制度健全的前提下,确定追溯信息的深度、广度和精确度,并作好信息衔接和代码标识,才可使追溯体系有效实施。同时对追溯体系的应用和发展趋势做了基本论述。     

琼脂扩散试验检测附红细胞体抗体

采用琼脂扩散试验检测自然感染猪附红细胞体抗体和兔抗猪附红细胞体抗体,结果表明,猪附红细胞体抗原与自然感染附红细胞体猪血清、首免和二次免疫后收集的兔抗血清的琼脂扩散试验结果均呈阴性,第3次免疫后的血清效价为1∶16。     

成体干细胞的研究现状与展望

近年来，干细胞特有的生物学特性及其潜在的生物医学应用价值使之成为生命科学领域最热点、最前沿的课题之一。随着对干细胞研究的不断深入，人们发现成体干细胞除了具有较强的自我更新、高度增殖和多向分化潜能外还具有分化方向的可塑性。作者根据国内外研究成果，综述了成体干细胞的“可塑性”研究的最新进展，以及成体干细胞可塑性研究的前景及存在的主要问题。     

DNA疫苗的作用机制及新型免疫策略的研究进展

疫苗是预防和控制严重传染病的重要手段，将基因工程用于疫苗生产已经成为生物技术的热点内容之一。治疗性基因工程疫苗是近些年研究的重点，并迅速从治疗传染性疾病的研究扩展到非传染性疾病的研究，如治疗性乙肝疫苗、治疗性肿瘤疫苗等。本文针对这一热点阐述基因工程DNA疫苗的作用机制及新型免疫策略研究的进展。     

养猪小区粪便资源化处理工艺设计

影响我国养猪小区健康发展的关键问题是养猪小区的环境控制,降水、污水、粪便混合排放,加剧了养猪小区的环境污染,使粪便资源化处理更加困难。根据现代养猪生产工艺流程,利用工程技术手段,设计了一个现代化示范型养猪小区粪便资源化处理工艺,首先解决天然降水与污水混合排放问题,其次实现污水与粪便有效分离,第三步通过充氧发酵、搅拌干燥最终实现养猪小区粪便资源化开发利用,解决捆扰我国养猪小区健康发展的环境控制问题。     

桂牧1号草地内冬种一年生黑麦草的效果(一)

于深秋至晚春，在桂牧1号草地的行间种植一年生黑麦草，观察测定这种种植方式给2种草及草地带来的影响。试验设计3个处理：①在桂牧1号草地内冬种一年生黑麦草，②单种桂牧1号，③单种一年生黑麦草。把处理②的产草量与处理③的首次产量相加作为处理④，以代表桂牧1号与一年生黑麦草轮作时的产量。结果是：处理①与②中桂牧1号的越冬率无显著差异；处理①的单位面积产草量极显著高于②、④；春季，处理①的杂草极显著地少于②。这表明，在桂牧1号草地内冬种一年生黑麦草是可行可取的。     

Isolation and Identification of Variant HeNZK-2014 of Pseudorabies Virus and Sequence Analysis of gE Gene

In order to learn the situation of pig pseudorabies virus (PRV) variant in this study, tissue samples such as lymph nodes which were collected from clinical pigs with suspected PRV infection were identified by PCR. PRV positive sample were inoculated on PK-15 cells after grinding and degerming, with further experiment including virus isolation, plague purification, PCR and IFA identification, TCID₅₀ confirmed by Reed-Muench method, inoculation test and observation of clinical symptoms in mice. The gE gene of purified PRV and brain tissue samples of dead mice were identified by sequencing analysis. The results showed that the virus grown on PK-15 cells could produce typical cytopathic effect (CPE) after 24 h; After three rounds of plaque purification,the isolate was PRV positive identified by PCR and IFA, and nominated as HeNZK-2014; The TCID₅₀ of the isolate was 10^-9.77/0.1 mL; The virus in 1×10⁸ TCID₅₀ inoculation was able to cause itching, tearing, death in infected mice, and PRV could be detected in tissues of dead mice; The molecular genetic variation analysis of gE gene by PCR amplification and clone sequencing indicated that the gE gene from brain tissue of infected mice shared 100.0% homology with HeNZK-2014, and located in a relatively independent branch with newly pandemic isolates in recent years after 2011, but was far from the classical strains before 2011, and both had two insertion of aspartic acid (D) at sites of 48 and 496 amino acids, which were considered to be the typical characteristics of PRV variants. This study successfully isolated a PRV variant, which laid a foundation for further research on vaccine development, prevention and control against PRV variants.     

串联表达猪繁殖与呼吸综合征病毒GP5表位蛋白间接ELISA方法的建立

利用猪繁殖与呼吸综合征病毒（porcine reproductive and respiratory syndrome virus,PRRSV）GP5抗原表位串联表达重组蛋白作为包被抗原,建立检测PPRSV抗体的间接ELISA方法。重组蛋白最佳包被浓度为7.5 μg/mL,最佳封闭液为5%脱脂奶粉,37 ℃封闭2 h;血清最适稀释度为1∶100,37 ℃作用2 h;兔抗猪IgG/辣根酶（HRP）（1∶3000）,37 ℃作用2 h;37 ℃避光显色15 min读取D_{450 nm}值。结果经统计学分析得出,S/P值≥0.254为阳性,S/P值≤0.212为阴性。所建立的ELISA方法检测其他5种猪常见病原阳性血清,其D_{450 nm}值均小于0.212。利用建立的ELISA方法对临床免疫勃林格殷格翰猪繁殖与呼吸综合征活疫苗4周后的猪血清70份进行检测,其D_{450 nm}值均大于0.85,表明本研究建立的重组GP5表位蛋白间接ELISA方法可用于临床样品的监测。