Immune responses and protective efficacy of a recombinant swinepox virus co-expressing HA1 genes of H3N2 and H1N1 swine influenza virus in mice and pigs

The recombinant swine poxvirus rSPV/H3-2A-H1 co-expressing HA1 genes of H3N2 and H1N1 subtype SIV has been constructed and identified. Inoculations of rSPV/H3-2A-H1 yielded ELISA and neutralization antibodies against SIV H1N1 and H3N2, and elicited potent H1N1 and H3N2 SIV-specific INF-γ response from T-lymphocytes in mice and pigs in this study. Complete protection against SIV H1N1 or H3N2 challenge in pigs was observed.     

狗牙根草坪冬季盖播黑麦草的可行性研究

用2种黑麦草在广州赛马会高尔夫球练习场的狗牙根草坪上进行了冬季盖播可行性试验。结果表明，冬季盖播黑麦草后，盖播处理区的狗牙根草坪同没有盖播的对照区草坪相比，绿期延长，同时其它坪用性状也明显提高，因而证明，在广州地区的狗牙根草坪上用黑麦草进行了加绿盖播是完全可行而必要的。同时试验结果表明，草坪型黑麦草盖播草坪的坪用性状远远好于牧草型黑麦草的盖播处理。此外，合理的施肥和播量等因素也将直接影响盖播草坪的冬季坪用性状以及夏枯时狗牙根草坪的恢复生长。播量以20g/m^2最为理想，可根据建植和管理水平酌情增减。生长前期以高施肥（90g/m^2）为宜，夏枯前后的过渡阶段，以低施肥（45g/m^2）为佳。     

Changes in growth performance, digestive enzyme activities and nutrient digestibility of cherry valley ducks in response to aflatoxin B1 levels

The objective of this study was to investigate toxic effects of aflatoxin B1(AFB₁) on growth performance, organs, hepatic enzyme activities, apparent digestibility of nutrients and digestive enzyme activities in ducks. Ninety 1-day-old Cherry Valley commercial ducks were designed to three treatment groups with three replicates of ten birds each. Group I (control) was fed conventional feed free of AFB₁, group II or III was fed the diets containing 20 μg/kg or 40 μg/kg AFB₁-contaminated rice respectively. The feeding trial lasted 6 weeks. The results were that decreased body weight gain and feed intake, increased feed to gain ratio and selected organ weights (liver, kidney and pancreas) were observed in AFB₁-treated groups. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in AFB₁-contamined groups. The apparent digestibility of crude protein (CP) was significantly lower while activities of digestive enzyme from duodenum contents including protease, chymotrypsin, trypsin and amylase were increased in AFB₁-treated group. These results indicated that AFB₁ of feed could decrease growth performance and apparent digestibility of nutrients, change digestive enzyme activities of duodenum contents in duck.     

省力化养蚕技术及其应用

降低生产成本，降低劳动强度，提高蚕桑生产比较效益，是当前和今后蚕桑生产稳定发展的重要问题，本文概要介绍我省省力养蚕技术的发展过程，提出了省力化养蚕技术规范，应用省力化养蚕技术的五条技术关键和推广措施以及应用效益。     

功能性饲料在动物健康养殖中的应用研究进展

功能性饲料是一种新型的绿色环保饲料,具有维护动物健康、保证畜产品安全和降低养殖污染等特殊功效.文章就近几年来国内外有关功能性饲料开发和应用等方面的研究进行概述,为进一步研究提供理论参考.     

免疫卵黄抗体预防家蚕血液型脓病的探讨

给母鸡注射纯化的家蚕NPV抗原，获得免疫卵黄抗体，测定效价为1：160。用免疫卵黄抗体进行添食试验，结果表明其对家蚕血液型脓病有一定的预防效果，并且对养蚕生产安全无毒。     

Seroprevalence of chlamydial infection in dairy cattle in Guangzhou, southern China

Chlamydia spp. are obligate intracellular gram-negative bacteria that cause a wide range of significant diseases in humans and animals worldwide, resulting in significant economic losses. Chlamydial infection in cattle has been reported in many countries including China. However, there has been no survey of chlamydial infection of dairy cattle in Guangzhou, southern China. The objective of the present investigation was to examine the chlamydial seroprevalence in dairy cattle in Guangzhou, subtropical southern China by using an indirect hemagglutination assay (IHA). The overall seroprevalence of chlamydial infection in dairy cattle was 7.25% (29/400). Greater than or equal to eight-yr-old dairy cattle had the highest seroprevalence (10.34%), followed by those that were ≥ 6 years old or < 7 years old dairy cattle (10.20%), although there were no statistically significant differences among different groups (P > 0.05). Dairy cattle with 5 pregnancies had the highest seroprevalence (10.81%). These results indicate that chlamydial infection was present in dairy cattle in Guangzhou, subtropical southern China, and integrated strategies and measures should be executed to control and prevent chlamydial infection and disease outbreak in the study region.     

抗球虫药新剂型的制备与研究

采用固体分散技术,利用溶剂法,以处方比例马度米星铵:聚维酮(聚乙烯吡咯烷酮,PVPk30)分别为1:1、1:2、1:3制备了3个马度米星铵固体分散体,通过差示扫描量热法(DSC)分析鉴定,当马度米星铵与PVP k30的比例为1:3时马度米星铵的药物特征吸热峰消失,说明固体分散体制备成功。对药物进行体外累积溶出度研究,结果马度米星铵固体分散体在60 min内体外累积溶出度可达98.46%,比马度米星铵预混剂的2.57%提高了38倍多。抗球虫效果研究表明,马度米星铵固体分散体的抗球虫指数(ACI)为197.7,明显高于ACI为191.8的马度米星铵预混剂。     

饲料中磺胺二甲基嘧啶的测定

用对-二甲氨基苯甲醛作显色剂,采用分光光度法测定饲料中磺胺二甲基嘧啶,最小检测量为0.05mg/kg,平均回收率分别为99.2%,变异系数≤5%,且该方法具有操作简便、快速,试剂消耗少,结果准确、离散程度小等优点。