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排序方式: 共有133条查询结果,搜索用时 406 毫秒
1.
JaroslawOlavHorbaczuk 《中国家禽》2004,26(11):35-37
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%~ 相似文献
2.
Ross Gordon COOPER Jaroslaw Olav HORBANCZUK Noboru FUJIHARA 《Animal Science Journal》2004,75(2):89-95
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. 相似文献
3.
4.
Vikingstad E Andersson E Norberg B Mayer I Klenke U Zohar Y Stefansson SO Taranger GL 《Fish physiology and biochemistry》2008,34(3):289-298
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. 相似文献
5.
Aluminum (Al) distribution among several cellular fractions was investigated in root tips of seedlings of one Al-resistant and one Al-sensitive family of slash pine (Pinus elliottii Engelm.) and loblolly pine (Pinus taeda L.) grown in nutrient solution containing 100 microM AlCl3 (pH 4) for 167 h. Aluminum present in 5-mm-long root tips was fractionated into cell-wall-labile (desorbed in 0.5 mM citric acid), cell-wall-bound (retained after filtering disrupted cells through 20-microm mesh) and symplasmic (filtrate following cell disruption) fractions. When averaged across both species, 12% of Al absorbed by root tips appeared in the symplasmic fraction and 88% in the apoplasmic fraction (55% as cell-wall-labile, and 33% as cell-wall-bound). On a fresh mass basis, total Al in root tips was lower in loblolly pine than in slash pine, lower in the Al-resistant slash pine family than in the Al-sensitive slash pine family, and lower in the Al-resistant families than in the Al-sensitive families across species. Although the data support the hypothesis that Al-resistant plants limit Al uptake to root apices, they do not exclude other mechanisms of Al resistance. Differential Al resistance between the species and between slash pine families may also be associated with the size of the total non-labile and cell-wall-labile Al fractions, respectively. We were unable to identify the basis for differential Al resistance in loblolly pine. 相似文献
6.
Eva Andersson Sampath R. Kumar Jared Ackers Geir Lasse Taranger Sigurd Olav Stefansson John M. Trant 《Fish physiology and biochemistry》2003,28(1-4):411-411
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. 相似文献
7.
Karlsson A Heier LS Rosseland BO Salbu B Kiessling A 《Fish physiology and biochemistry》2011,37(1):249-258
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. 相似文献
8.
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. 相似文献
9.
10.
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. 相似文献