中东欧的鸵鸟产品市场

通过对全球，特别是对主要生产鸵鸟肉和皮产品的欧洲的观察发现在20世纪末人们对鸵鸟产品产生的兴趣日渐浓厚。在鸵鸟产品的总收入中肉和皮产品所占份额在不同国家和不同年份有所区别。在2000-2004年间，中欧和东欧的鸵鸟肉收入在商品鸟总收入中所占的比例为51．2％～     

Viral diseases of the Ostrich (Struthio camelus var. domesticus)

The ostrich is an important animal in many livestock industries. A significant threat to this industry is losses from diseases. Newcastle disease is a notifiable, highly contagious viral infection of ostriches. Avian influenza may be transmitted from waterfowl, shorebirds and gulls to ostriches. Borna disease virus is a viral neurotropic infection spread mainly by rodents and felines. Crimean‐Congo hemorrhagic fever is a viral disease transmitted by Hyalomma ticks to humans. Avipoxvirus afflicts ostrich chicks and is transmitted by mosquitoes or by direct contact with a pox lesion. Maintenance of a healthy and profitable enterprise requires the implementation, with assistance from the local veterinary authority, of comprehensive, practical and effective methods of health management and preventative medicine.     

The combined effects of temperature and GnRHa treatment on the final stages of sexual maturation in Atlantic salmon (Salmo salar L.) females

Atlantic salmon (Salmo salar L.) females (2 SW), maturing for the first time, were reared under one of three temperature regimes (high: 14.3 ± 0.5°C; natural: 10.6 ± 1.0°C; and cold: 6.9 ± 1.0°C) in combination with one of two experimental treatments; an injection of GnRH analogue (GnRHa) contained in biodegradable microspheres, or a sham injection (microspheres only). The six experimental groups were then reared under simulated natural photoperiod for 4 weeks. Blood samples were drawn for analysis of plasma steroid levels and the fish were inspected for ovulation weekly. Batches of stripped eggs were incubated in triplicate incubators in raceways until the eyed stage. Treatment with GnRHa resulted in a substantial advancement and synchronization of ovulation at all temperatures, while exposure to cold water also appeared to advance ovulation slightly. While 75% (warm and cold) to 90% (natural) of GnRHa fish ovulated during the 4-week trial, only 30% of sham-treated females exposed to cold water, and none of the sham-treated fish held at higher temperatures, ovulated during this period. Survival rates of embryos to the eyed-stage were significantly higher for broodstock exposed to cold water. Plasma levels of testosterone (T), 17β-oestradiol (E₂), and 17α,20β-dihydroxy-4-pregnen-3-one (17,20βP) were all significantly affected by treatment with GnRHa and, to a lesser extent, temperature. The efficiency of GnRHa in counteracting the negative effects of high temperature on ovulation and the associated changes in circulating sex steroids suggest that temperature inhibition operates at least in part at the brain or pituitary.     

Impact of Honey Bee Migratory Management on Pathogen Loads and Immune Gene Expression is Affected by Complex Interactions With Environment,Worker Life History,and Season

The effects of honey bee management, such as intensive migratory beekeeping, are part of the ongoing debate concerning causes of colony health problems. Even though comparisons of disease and pathogen loads among differently managed colonies indicate some effects, the direct impact of migratory practices on honey bee pathogens is poorly understood. To test long- and short-term impacts of managed migration on pathogen loads and immunity, experimental honey bee colonies were maintained with or without migratory movement. Individuals that experienced migration as juveniles (e.g., larval and pupal development), as adults, or both were compared to control colonies that remained stationary and therefore did not experience migratory relocation. Samples at different ages and life-history stages (hive bees or foragers), taken at the beginning and end of the active season, were analyzed for pathogen loads and physiological markers of health. Bees exposed to migratory management during adulthood had increased levels of the AKI virus complex (Acute bee paralysis, Kashmir bee, and Israeli acute bee paralysis viruses) and decreased levels of antiviral gene expression (dicer-like). However, those in stationary management as adults had elevated gut parasites (i.e. trypanosomes). Effects of environment during juvenile development were more complex and interacted with life-history stage and season. Age at collection, life-history stage, and season all influenced numerous factors from viral load to immune gene expression. Although the factors that we examined are not independent, the results illuminate potential factors in both migratory and nonmigratory beekeeping that are likely to contribute to colony stress, and also indicate potential mitigation measures.     

Optimizing the lighting regime for Alstroemeria with respect to photoperiod and fluence rates

The Alstroemeria cultivars Diamond, King Cardinal and Libelle were grown for 18 months under five lighting regimes with, and without, soil cooling. The aim was to optimize the daily investment of light energy from artificial sources with respect to photoperiod and photosynthetic fluence rates and to elucidate possible links between reactions to photoperiod and root-zone temperature. The more photons (photosynthetically active radiation, PAR) that were supplied to the plants per day (8, 11 and 13 mol m⁻²), the higher was the total production of flowering stems. The total yield from regimes with 13 mol m⁻² day⁻¹ was higher when the light was spread over 20 and 16 h compared to 12 h. In treatments with soil cooling, the plants flowered continuously under all combinations of photoperiods and photosynthetic fluence rates, and the summer and autumn recession in flower production that occurred for non-cooled ‘King Cardinal' and ‘Diamond' was the same under all lighting regimes. It is concluded that it might be more cost-effective to spread the daily investment of light over 20 rather than 16 or 12 h when the total energy budget and CO₂ costs are taken into consideration.     

Photoperiod and temperature affects seasonal ovarian gene expression of p450 aromatase and gonadotropin receptors in Atlantic Salmon (Salmo salar L.) broodstock

Photoperiod and temperature modulated the seasonal pattern of ovarian gene expression of P450 aromatase, Follicle-Stimulating Hormone receptor and Luteinizing Hormone receptor in Atlantic salmon broodstock.     

Addition of bacteria bioencapsulated in Artemia metanauplii to a rearing system for halibut larvae

Theaim of this study was to determine whether it is possible to influence thespecies composition of the gut microflora in 70-days old halibut larvae(Hippoglossus hippoglossus L.) by addition of bacteriabioencapsulated in Artemia franciscana in two shortpulses.Two Vibrio strains, PB 1-11 and PB 6-1 were used. Twotreatments received each strain alone, a third treatment received the twobacterial strains in mixture, whereas in a control treatment no bacteria wereadded. Five fish tanks were included in each treatment. The bacteria werebioencapsulated in Artemia franciscana metanauplii duringashort-term incubation in bacterial suspensions of the specific strains, andwereadded in two pulses, on day 1 and day 10 of the experiment. Addition ofbacteriadid not increase the total number of colony-forming units (CFU) in the larvalgut. The total CFU in the water was lower in tanks added bioencapsulatedbacteria than in the control treatment (p < 0.05). Animmunocolony blot assay was used to measure the numbers of the specificbacteriaadded in samples of water, A. franciscana, and fishlarvae.At the end of the experiment on day 13, the strain PB 1-11 reached on average10% of the total CFU when added alone and 25% when added in mixture with PB6-1.Strain PB 6-1 reached at the end of the experiment 26.8% of the total CFU whenadded alone and 24.2% when added in mixture with PB 1-11, whereas thepercentages of PB 1-11 and PB 6-1 in the control fish were 12.7% and 10.8% ofthe total CFU, respectively. However, the differences between the experimentaltreatments compared with the control group were not significant(p > 0.05). The addition of bioencapsulated bacteria intwo pulses within a ten days period was therefore not sufficient to influencethe species composition of the microflora of the halibut larvae.     

Changes in arterial PO₂, physiological blood parameters and intracellular antioxidants in free-swimming Atlantic cod (Gadus morhua) exposed to varying levels of hyperoxia

Free-swimming Atlantic cod (Gadus morhua) were exposed to water oxygen pressures (P _wO₂) ranging from 18.1 to 41.5 kPa and sampled for blood using an indwelling caudal artery cannula. Arterial blood oxygen pressure (P _aO₂) increased with increasing P _wO₂, from 12.0 kPa in normoxia (18.1 kPa) to 34.2 kPa in the highest hyperoxic level tested (41.5 kPa). Blood CO₂ pressure and plasma bicarbonate concentration increased with P _wO₂, indicating reduced ventilation with increased P _wO₂. Plasma glucose, sodium and potassium were not affected by water oxygen level. Blood oxidative stress biomarkers, reduced glutathione, oxidized glutathione and the oxidative stress index (ratio between oxidized and total glutathione) differed intermittently between normoxia and hyperoxia. The oxidative stress index was higher in the blood of exposed compared to unexposed control cod. Together with elevated P _aO₂, these findings suggest increased production of reactive oxygen species and increased oxidative stress in Atlantic cod exposed to hyperoxia.     

Serological Investigations of Leptospiral Deoxyribonucleases

Enzymoserological comparison of a selection of leptospira strains tested with sera from rabbits immunized with unpurified DNase of Leptospira interrogans, serotype canicola, indicates the production of DNase of serologically very similar properties by the serotypes canicola, autumnalis, icterohemorrhagiae and pomona. The DNase produced by serotype hyos was serologically different from the others, while the serotypes grippotyphosa and bataviae did not produce DNases at all. The method used made it possible to differentiate between leptospiral DNase and normally occurring DNases in the serum samples. Neither leptospira DNase nor specific leptospira-DNase-antibodies could be detected in dog sera with high agglutinationlysis titres after natural infection.