山羊痘病毒与小反刍兽疫病毒双重PCR检测方法的建立

为建立一种灵敏、准确、快速的山羊痘病毒(GTPV)和小反刍兽疫病毒(PPRV)双重PCR检测方法,根据GenBank上登录的GTPV、PPRV两种病毒的基因序列设计检测引物,在常规PCR基础上,对反应条件及反应体系进行优化,建立了这两种病毒的双重PCR检测方法,并进行了特异性、敏感性检验。结果显示:仅GTPV和PPRV核酸样品扩增出与预期目标相符的目的片段,而其他病原对照均未出现目的条带;GTPV的最低检出量为0.283 ng/μL,PPRV的最低检出量为6.459 ng/μL。结果表明,本研究建立的双重PCR检测方法可一次性同时完成PPRV、GTPV两种病原的检测,且具有较高的特异性和敏感性。本方法的建立为山羊痘和小反刍兽疫的临床诊断、流行病学研究、疫情监测提供了技术支持。     

昆明草坪草混播配方优化组合模式探讨

在昆明独特的气候条件下，通过对运动场草坪、观赏草坪和护坡草坪三类草坪混播配方的调查研究，探讨出了适应云南地区种植的9种优化组合。运动场草坪：草地早熟禾（Poapratensis L．）＋高羊茅（Festucaarundinacea Schreb．）＋多年生黑麦草（Lolium perenne L．），草地早熟禾＋高羊茅，草地早熟禾＋狗牙根（Cynodon dactylon（L．）Pers、）＋多年生黑麦草；观赏草坪：草地早熟禾＋匍匐翦股颖（Agrostisstolonifera L．），草地早熟禾＋紫羊茅（Festuca rubraL．），草地早熟禾（优异）＋草地早熟禾（蓝月）＋草地早熟禾（新哥来得）＋草地早熟禾（肯塔基）；护坡草坪：高羊茅＋多年生黑麦草＋狗牙根，高羊茅＋多年生黑麦草＋狗牙根＋白三叶（Trifolium repens L．），高羊茅＋多年生黑麦草＋狗牙根＋白三叶＋紫花苜蓿（Medicago sativa L．）。     

酪蛋白钙肽的研究进展及其在乳品中的应用

酪蛋白钙肽是含有磷酸丝氨酸残基的多肽，现已证明其具有重要的生理功能。本文介绍酪蛋白钙肽的功能、制备工艺、检测方法，以及与酪蛋白磷酸肽区别，并简述其在乳品中的应用。     

湖南省部分地区病猪和屠宰猪群猪圆环病毒感染状况调查

为了解湖南省猪圆环病毒（PCV）流行情况,采用荧光PCR方法,对来自湖南省14个市州的821份临床病料和屠宰场猪淋巴结样品进行PCV1、PCV2、PCV3和PCV4荧光PCR检测。结果显示：在821份样品中,PCV阳性检出率为88.06%（723/821）,阳性检出率由高到低依次为PCV2（81.49%）、PCV3（33.98%）、PCV1（8.04%）和PCV4（1.10%）;278个样品存在两种及以上的PCV混合感染,以PCV2+PCV3混合感染最多,占82.01%;在地域分布上,PCV1、PCV2、PCV3在湖南省各地区均有分布,而PCV4分布范围较小,感染率低。结果表明,湖南省内PCV流行较为普遍,4种基因型病毒都存在,但以PCV2流行最为广泛,需要加强防控。     

基于两种生态学理论监控草地质量

准确理解中度干扰假说和冗余结构理论,并将两者有机结合,有助于草地质量的调控。关于这两种生态学理论所取得的相关研究成果,对于认识和理解草地生态系统的结构、功能、演替以及生产潜力具有积极作用,这也使其逐步成为指导草地畜牧业生产实践十分重要的科学依据。阐述了草地质量及其具体表示指标,以及中度干扰假说和冗余结构理论与草地质量的关系,并论述了中度干扰假说和冗余结构理论在封育、中度放牧、毒害草防治等管理措施条件下草地质量变化的生态学过程中的作用。     

Dietary supplementation with Acanthopanax senticosus extract enhances gut health in weanling piglets

The present study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut health in weanling piglets by examining diarrhea frequency, intestinal microbiota and morphology. A total of 96 Duroc× (Landrace × Yorkshire) piglets weaned at 21 days of age with an average initial body weight (BW) of 5.6 ± 0.4 kg were randomly assigned to 3 treatment groups with 4 duplicates of 8 piglets each. The piglets were fed basal diet to which had been added 0 or 1 g/kg of ASE, or 0.7 g/kg antibiotics, respectively. Fecal consistence was monitored twice daily and the frequency of diarrhea was calculated. On day 21 after the initiation of supplementation, 8 piglets were randomly selected from each treatment group (2 piglets per pen) and slaughtered. The jejunum, ileum, colon and cecum were then excised and fixed in 10% neutral formalin solution to determine villus height and crypt depth, after their contents were collected to determine microbiota. The results showed that dietary supplementation with ASE increased (P < 0.05) the density of bacterial populations that co-migrated with Lactobacillus amylovorus, Lactobacillus salivarius, Bacillus subtilis, and Clostridium lituseburens, but decreased (P < 0.05) those co-migrating with Staphylococcus aureus, Salmonella typhimurium, Ruminococcus forques, and E. coli O157:H7 in the PCR-DGGE profiling analysis when compared with the control group. The villus height of the duodenum, jejunum and ileum increased (P < 0.05) by 14.8, 13.7 and 10.0%, while the crypt depth decreased (P < 0.05) by 17.9, 9.1 and 12.1%, respectively, in response to dietary ASE supplementation. Additionally dietary supplementation with ASE or an antibiotic decreased (P < 0.05) the frequency of diarrhea by 55.6 and 52.2%, respectively, compared with the control group. In conclusion, these findings suggest that dietary supplementation with ASE could regulate the microbiota composition and maintain a normal morphology of gut mucosa in weanling piglets, thereby decreasing diarrhea that resulted from weaning stress.     

高钙牛奶稳定性研究

钙强化后的高钙牛奶可以提供更多利于人体的钙质,研究了制备高钙牛奶时所需要的钙源、乳化剂以及增稠剂,采用正交试验确定了复配稳定剂的成分及用量,并利用粒径分析仪对高钙牛奶稳定性进行了研究.     

市售禽肉产品中沙门氏菌污染状况调查

<正>沙门氏菌是引起人类食物中毒的主要致病菌,该病菌可通过食物传播,禽肉等动物产品是引起人类感染该病菌的主要来源之一。据资料统计,在我国细菌性食物中毒中,有     

Increasing selenium supply during the close-up dry period improves nutrient metabolism and attenuates inflammatory response after calving in dairy cows

The objective of this study was to investigate whether feeding selenium (Se)-replete cows a Se-yeast supplement in late pregnancy affects nutrient metabolism and inflammatory response during the periparturient period. Twenty cows were randomly assigned to two groups with 10 cows each. Cows in one group received Se-yeast at 0.3 mg Se/kg DM during the last 4 weeks before calving in addition to fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Se-yeast), while cows in another group were only fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Control). Blood samples were collected and analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), glucose, insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, serum amyloid A (SAA), haptoglobin (Hp), and albumin. In control cows, plasma NEFA, IL-1β, IL-6, SAA, and Hp levels increased after calving, but glucose, insulin, and albumin levels decreased after parturition. Se-yeast supplemental cows had lower postpartum concentrations of NEFA, TNF-α, IL-1β, IL-6, SAA, and Hp, and higher postpartum levels of glucose, insulin, and albumin compared with control cows. The results indicate that feeding Se-replete cows a Se-yeast supplement in late pregnancy improves nutrient metabolism and attenuates the inflammatory response after calving.     

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58. Fragments consisting of amino acids 133-163 of VP1 and amino acids 1-33 of VP2 contained epitopes, and both induced lymphoproliferation in guinea pigs. Only the VP1 fragment induced neutralizing antibodies but the VP2 peptide dramatically increased the neutralizing antibody response induced by the VP1 peptide.