首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9篇
  免费   0篇
  2篇
水产渔业   1篇
畜牧兽医   6篇
  2018年   1篇
  2012年   1篇
  2010年   1篇
  2009年   1篇
  2008年   1篇
  2006年   1篇
  1998年   1篇
  1997年   2篇
排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
Objective To examine whether sub-optimal temperature induced stress and immunosuppression in farmed saltwater crocodile (Crocodylus porosus) hatchlings. Design A clinico-pathological study. Animals A total of 140 hatchlings were used. Procedure Body weight and length, plasma corticosterone and immunoglobulin concentrations and total and differential white blood cell counts were measured in 140 hatchlings from five clutches divided between five water temperature treatment groups. Initially all groups were housed at 32°C for 10 weeks, then two groups (L, LC) were changed to low temperature (28°C) and two groups (H, HC) to high temperature (36°C), while one group (C) remained at 32°C. The LC and HC groups were maintained at these temperatures for 10 days, after which the water temperature of both groups was returned to 32°C. Blood samples were collected twice (at 6 and 9 weeks of age) before the initial temperature change, and at 10 days and 4 weeks after the initial temperature change (at 11.5 and 14 weeks of age). Results Except for an increase in plasma corticosterone in the HC group and a decrease in the L group when the temperature change was first introduced, changes in plasma corticosterone were not significant. There were no significant changes in immunoglobulin concentrations. There were, however, significant decreases in the total white cell and lymphocyte counts in the LC group after the temperature was decreased to 28°C, and an increase in these counts after water temperature was returned to 32°C. Clutch of origin had significant effects on body weight and length gains, and there were negative relationships between body weight and corticosterone concentrations and between body weight and immunoglobulin concentrations. Conclusions As haematological changes indicative of stress were not associated with significant changes in serum corticosterone, immunosuppression in young crocodiles may be independent of the hypothalamic-pituitary-adrenal cortical axis.  相似文献   
2.
Proximate compositions of dorsal, ventral, leg, and tail cuts of farmed spectacled caiman (Caiman crocodilus) were determined. The water, protein, fat, and ash contents of muscle were 77–78%, 19–23%, 0.3–1.2%, and 1.0%, respectively. The dominant nucleotide-related compound in the tissues was inosine monophosphate (IMP) (68.6–84.9%). The predominant free amino acids (FAAs) in the muscle of spectacled caiman were taurine (Tau), glycine (Gly), alanine (Ala), and histidine (His), along with a dipeptide of anserine (Ans) (80–183 mg/100 g) and carnosine (Car) (35–103 mg/100 g) being detected in each sample. The major fatty acid composition included palmitic (16:0), oleic (18:1 cis-9), linoleic (18:2n-6), and stearic (C18:0) acids. The amount of docosahexaenoic acid (4.27–8.76%) was higher than that of eicosapentaenoic acid (0.99–2.24%). The ratio of polyunsaturated fatty acid/saturated fatty acid in spectacled caiman (0.83–1.19) was higher than that in other commonly consumed meat. Meat from the spectacled caiman can be characterized as a valuable food for human consumption in terms of these nutritional features.  相似文献   
3.
近年来,国内兴起建鳄鱼养殖场的热潮,而指导新养殖户们如何进行鳄鱼养殖场选址的相关研究尚未见报道。为此,笔者于2007年6月至2008年7月深入鳄鱼养殖场进行调查,探讨鳄鱼场选址时的主要考虑因素:温度、饲料、市场与交通、水质和安全等,并认为在实际操作过程中,其他的一些因素,如土地权属和水电供应等也不可忽略。  相似文献   
4.
Commercial trade is a major driver of over-exploitation of wild species, but the pattern of demand and how it responds to changes in supply is poorly understood. Here we explore the markets for snakes from Tonle Sap Lake in Cambodia to evaluate future exploitation scenarios, identify entry points for conservation and, more generally, to illustrate the value of multi-scale analysis of markets to traded wildlife conservation. In Cambodia, the largest driver of snake exploitation is the domestic trade in snakes as crocodile food. We estimate that farmed crocodiles consume between 2.7 and 12.2 million snakes per year. The market price for crocodiles has been in decline since 2003, which, combined with rising prices for their food, has led to a reduced frequency of feeding and closure of small farms. The large farms that generate a disproportionate amount of the demand for snakes continue to operate in anticipation of future market opportunities, and preferences for snakes could help maintain demand if market prices for crocodiles rise to pre 2003 levels. In the absence of a sustained demand from crocodile farms, it is also possible that alternative markets will develop, such as one for human snack food. The demand for snakes, however, also depends on the availability of substitute resources, principally fish. The substitutability and low price elasticity of demand offers a relatively sustainable form of consumerism. Given the nature of these market drivers, addressing consumer preferences and limiting the protection of snakes to their breeding season are likely to be the most effective tools for conservation. This study highlights the importance of understanding the structure of markets and the behaviour of consumer demand prior to implementing regulations on wildlife hunting and trade.  相似文献   
5.
The American crocodile is widely distributed in coastal and lowland wetlands in the northern Neotropics. As a result of commercial skin hunting in the 20th century, populations were greatly diminished, but in many areas have initiated a period of recovery since hunting and trade controls were enacted in the 1980s and 1990s. While a great deal of attention has been devoted to regulated commercial use as a management strategy for recovering crocodilian populations, these approaches are limited in their efficacy to deal with issues of habitat loss and fragmentation. Because habitat limitations are expected to be the most critical issue for crocodile conservation in the 21st century, there is an unfulfilled need for alternative strategies that prioritize habitat conservation. Here, we present results of an international effort to identify and prioritize the most critical habitats for this wide ranging species. We quantified information of a group of American crocodile experts and classified 69 areas in eight distinct crocodile bioregions as Crocodile Conservation Units (CCU), the most important areas for the conservation of this species. The relative importance of the CCUs in each bioregion was quantified using an algorithm that weighted factors that the experts considered to be most important for the long term conservation of viable populations of crocodiles. This effort is the initial step in the development of a regional conservation plan for the American crocodile. We identified two bioregions in particular where the creation of protected areas should be given a high priority, the Dry Pacific South America (northern Peru and southern Ecuador) and the Northwest and Central Pacific Mexico.  相似文献   
6.
Objective To determine reference ranges for healthy yearling farmed saltwater crocodiles by performing routine biochemical and haematological laboratory tests on blood samples.
Design A clinico-pathological study.
Procedure Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm).
Results Reference ranges for biochemical and haemato-logical values were determined for farmed yearling saltwater crocodiles in the Northern Territory.
Conclusion The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors.  相似文献   
7.
A survey-based study was carried out to assess the state of crocodile farming in Botswana. A prepared, structured questionnaire was dispatched to crocodile farmers based on a directory provided by the Fisheries section of the Department of Wildlife and National Parks in the Ministry of Environment, Wildlife and National Parks. The oldest farm was established in 1986. An average of three farms have been in operation since then, all of which obtained their stock from the Okavango and Thamalakane rivers in Botswana. The current stock averages 5 419 animals as follows: breeders 4%, hatchlings 56%, and growers 40%. The average clutch size and average hatchability were 47 eggs/clutch and 67% respectively. Mortality among hatchings and growers averaged 8.3% up to 12 weeks of age. Only one farm encountered some problems with Salmonella and fungal infections of the belly. Raw skins are sold to South Africa as a result of the absence of a tannery. Crocodile farming should be encouraged in Botswana since a good market for crocodile products already exists.  相似文献   
8.
在某鳄鱼养殖场抽检的60份泰国进口鳄鱼肛拭子样品中,有12份检出霍乱弧菌。通过生化试验和血清学分型等鉴定,确认12株霍乱弧菌均为非O1非O139群霍乱弧菌。采用18种抗菌药物进行药敏试验,结果显示所有菌株对大多数抗菌药物高度敏感,对四环素等药物中度敏感,对氨苄青霉素和氧呱嗪青霉素不敏感。  相似文献   
9.
Pathology of skin diseases in crocodiles   总被引:2,自引:0,他引:2  
Objective To establish which skin diseases occur in crocodiles, particularly those on farms, to indicate the relative frequency of each particular disease and to provide information on pathogenesis, especially in regard to lesions with two or more pathogens present.
Design A gross and microscopic retrospective (period of 1989 to 1995) and current (1996 to 1997) examination of skin lesions in crocodiles in Queensland and the Northern Territory.
Result Skin lesions were obtained from crocodiles on nine farms, from a group of experimental animals and from one adult found dead in the wild. A total of 203 lesions from 180, mostly young, crocodiles was examined; 119 lesions were from retrospectively examined cases and 84 were recent. The relative frequencies of four presumed primary pathogens in lesions were Dermatophilus s p 28.1 %, fungi 14.8%, poxvirus 3.4% and probable Mycobacterium s p 2.5%. In addition, other bacteria of unknown significance were present in many lesions, and there was one case of presumed Paratrichosoma crocodilus infection. In 32.5% of lesions, multiple pathogens were identified.
Conclusion Dermatophilosis is the most common and probably the most important skin disease of crocodiles in Australia, but it is frequently complicated by concurrent infection with fungi or other microorganisms.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号