鸭传染性浆膜炎疫苗的研究

用从浙江省分离鉴定的鸭疫里氏杆菌RA-J、RA-L菌株研制疫苗,采用改进的液体培养和鸭胚培养工艺,抗原含量分别达120-186亿CFU／ml和280-310CFU／ml,免疫0.5ml/只,2MLD强毒攻击,平均保护率达94.2％（48／52）,免疫后第7天保护率达80％（16／20）,10天达93.8％（15／16）,疫苗在4℃-8℃条件下保存7个半月和1年的保护率达90％和85％。野外扩大试验和临床推广试用236万羽份表明,效果良好。     

Habitat fragmentation in marine landscapes: relative effects of habitat cover and configuration on juvenile crab survival in California and North Carolina seagrass beds

Processes that dictate faunal abundance (e.g. predation) may be linked primarily to the configuration of habitat (e.g. patch size, patch isolation, proximity to edge) or simply to the amount of habitat (i.e. habitat cover) in marine and terrestrial systems. I asked whether juvenile crab survival in marine seagrass habitats is linked to habitat cover or to habitat configuration, and whether relationships between crab survival and habitat features were similar in two widely separated seagrass landscapes (Bodega Harbor, California and Back Sound, North Carolina, USA). I also evaluated the independent effects of seagrass structural complexity (shoot density and shoot biomass per unit area) and habitat fragmentation on crab survival. Juvenile red rock crabs (Cancer productus: 1+year class) were tethered in Bodega Harbor and juvenile blue crabs (Callinectes sapidus: 0+year class) were tethered in Back Sound. Seagrass cover in both landscapes ranged from <10 to 100% over 10×10 m areas. Crab survival was correlated with elements of landscape structure and structural complexity in both landscapes, but relationships between crab survival and specific habitat features differed between the two landscapes. In California, juvenile red rock crab survival was negatively correlated with seagrass cover and was positively correlated with seagrass shoot density, and was marginally (P=0.06) negatively correlated with seagrass shoot biomass. In North Carolina, juvenile blue crab survival was positively correlated with log₁₀ patch area and was negatively correlated with seagrass shoot biomass. The results indicate that (1) both seagrass cover and configuration may influence crab survival; (2) seagrass structural complexity influences crab survival independently of landscape structure; (3) the relative influence of cover, configuration and structural complexity on survival likely differ among seagrass landscapes; and (4) increasing structural complexity (e.g. shoot biomass) may not always lead to increased faunal survival. The results correspond to those of recent studies in marine and terrestrial landscapes showing widely variable faunal responses to landscape structure among species, geographic location and through time, and imply that seagrass restoration and conservation strategies should incorporate species-specific responses to habitat structure at multiple scales.     

氨基多糖螯合盐对扣蟹非特异性免疫力的影响

[目的]探讨氨基多糖螯合盐对扣蟹非特异性免疫力的影响。[方法]通过在配合饵料中添加氨基多糖螯合盐,研究其对扣蟹非特异性免疫力[碱性磷酸酶(AKP)活性、酸性磷酸酶(ACP)活性、超氧化物歧化酶(SOD)活性、溶菌酶活性]的影响。[结果]氨基多糖螯合盐可以有效提高扣蟹AKP、ACP、SOD和溶菌酶活性。[结论]在饲料中添加氨基多糖螯合盐对于增强扣蟹非特异性免疫力有一定功效。     

量天尺和仙人掌为砧木嫁接的蟹爪越冬情况及对策

量天尺(Hylocereus undatus)和仙人掌(Opuntia dillenii)是蟹爪(Zygocactus truncates)嫁接最常用的砧木。主要分析了由它们嫁接的植株越冬结果及产生不同结果的原因,提出了应对方法。     

大规格河蟹健康养殖的种质研究

河蟹苗种的质量是大规格河蟹健康养殖成功与否的关键因素之一。在选择蟹种前,必须掌握不同水系蟹种的特点,要善于从不同水系的蟹种中选择优质亲本和苗种。另外,既要能识别性早熟的蟹种,也要尽可能自行培育优质蟹种。在合理放养时,要注意河蟹种的优先选择顺序,同时要掌握放养的技术要点。     

苏柳932等5个柳树优良无性系幼林生长及干形的初步研究

为进一步了解柳树优良无性系的生长特点,为无性系的合理利用提供依据,对苏柳932,799,795,797和172等5个柳树优良无性系2年生幼林的树高、胸径、材积等生长指标以及生物量和形率进行了测定分析。结果表明,苏柳5个无性系的胸径平均值为4．28cm,其中苏柳172的平均胸径最大（4．71cm）;树高平均值为6．97m,其中苏柳795平均树高最高（7．75m）。苏柳795的形率qo．5、q0．7值分别为0．68,0．44,是各无性系中形率的最高值,主干生物量占单株地上部分总生物量的比例最高（76．02％）,出材率高,是优良的用材林树种;而苏柳932的总生物量最高,为12．35kg／株,枝量、叶量占总生物量的比例最大,为42．0％,14．4％,属于防风防浪和生物能源林的造林良种。     

Stress response of extensively reared young bulls being transported to growing-finishing farms under Spanish summer commercial conditions

To evaluate the effect of Spanish summer commercial journeys on the stress response of young bulls born and reared under extensive conditions, 2 replicates of a transport from an assembly centre to a growing-finishing farm were studied. Journeys lasted 27 h, involving a total of 62 young bulls. Variables under study included haematocrit, red blood cell count (RBC), total white blood cell count (WBC), differential WBC counts, serum haptoglobin (Hp), cortisol, glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total protein, and albumin at loading, at the end of an intermediate market stop, and at the unloading. Before the beginning of the journey elevated WBC and neutrophil counts, and high Hp values were detected, reflecting high stress levels probably as a consequence of previous procedures associated with the grouping at the assembly centre. Some stress was also detected at the end of the market stop, with cortisol increasing from 6.5 to 12.6 ± 2.0 ng/mL (P < 0.001), although a change in Hp concentration was not observed. Neither CPK and LDH activities, related to muscular tissue damage, nor haematocrit and RBC count, related to dehydration revealed a significant effect of this first stage of the journey on the physical stress of the young bulls. Subsequent 13 h transport to the growing-finishing farm induced an increase in Hp levels from 0.48 to 0.78 ± 0.16 mg/mL (P < 0.001), reflecting an onset of the acute stress response, although cortisol levels immediately after the unloading were similar to those found before loading at the market, suggesting that calves got accustomed to transport. At the end of the journey some dehydration and physical stress were also detected. Overall, our study provides new information to the discussion of the effect of temperatures during cattle transport. Although an improvement in pre-transport conditions is essential if the welfare of assembled and transported cattle is to be improved, the stress-related alteration of cattle physiology under Spanish summer commercial transport conditions is similar to that observed under colder conditions.     

金佛山方竹竹笋幼竹生长节律

笔者在不同立地条件下和竹林类型中选择３０株竹笋观测其生长节律发现,金佛山方竹高生长开始与出笋期同步,始于九月上中旬,结束于十一月中下旬,历时６０－７０天;地径生长与高生长同步,结束于十月上旬。分析表明,高生长受竹笋出土期、竹笋径级,林分密度的制约,是制订年度经营措施的重要影响依据。     

侧柏人工幼林年生长动态及其与水热关系研究初报

侧柏人工幼林年生长动态及其与水热关系研究初报薄颖生韩恩贤罗伟祥（陕西省林业科学研究所杨陵７１２１００）关键词侧柏,人工幼林,生长动态,水分,热量,回归分析侧柏是黄土高原造林的优良树种之一［１～３］。过去由于对该树种的生物学、生态学及造林学特性等方面...     

生长季修剪对库尔勒香梨生长的影响

库尔勒香梨3年生幼树在5月12日、6月8日、7月6日三个时期进行生长季修剪能够开张枝条角度,降低树冠高度,扩大树冠,缓和树势,促进花芽分化,以7月6日进行修剪效果最好,发育枝生长量、背上枝生长量最短,干径和花芽量最大都达到显著水平,为早期丰产奠定基础。