首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
A comparison is made between normal birds and birds deprived of oral taste by bilateral section of the lingual nerves. Following nerve section the birds showed a marked reduction of food intake for the first few days after operation. On presentation of a novel diet birds with sectioned nerves rejected it, the extent of rejection depending on the mode of presentation and on the degree of novelty. It is suggested that taste plays a major role in the initial selection of food and possibly in the motivation to eat. The birds preferred a diet with 2 per cent citric acid added and a rejected one with 5 per cent sodium chloride; these effects were probably oral in origin. There was rejection of a diet with 0.5 per cent quinine hydrochloride which was rapid in all birds, with or without nerve section. There was a preference in all birds for a diet with 20 per cent sucrose; this may be post‐ingestional in origin.  相似文献   

3.
The role of cell-mediated immunity (CMI) in protection of birds from Newcastle disease was investigated by two different strategies in which only Newcastle disease virus (NDV)-specific CMI was conveyed without neutralizing antibodies. In the first strategy, selected 3-wk-old specific-pathogen-free (SPF) birds were vaccinated with either live NDV (LNDV), ultraviolet-inactivated NDV (UVNDV), sodium dodecyl sulfate-treated NDV (SDSNDV), or phosphate-buffered saline (PBS) (negative control) by the subcutaneous route. Birds were booster vaccinated 2 wk later and challenged with the velogenic Texas GB strain of NDV 1 wk after booster. All vaccinated birds had specific CMI responses to NDV as measured by a blastogenesis microassay. NDV neutralizing (VN) and hemagglutination inhibition (HI) antibody responses were detected in birds vaccinated with LNDV and UVNDV. However, birds vaccinated with SDSNDV developed antibodies that were detected by western blot analysis but not by the VN or HI test. Protection from challenge was observed only in those birds that had VN or HI antibody response. That is, birds with demonstrable CMI and VN or HI antibody response were protected, whereas birds with demonstrable CMI but no VN or HI antibody response were not protected. In the second strategy, birds from SPF embryos were treated in ovo with cyclophosphamide (CY) to deplete immune cells. The birds were monitored and, at 2 wk of age, were selected for the presence of T-cell activity and the absence of B-cell activity. Birds that had a significant T-cell response, but not a B-cell response, were vaccinated with either LNDV, UVNDV, or PBS at 3 wk of age along with the corresponding CY-untreated control birds. The birds were booster vaccinated at 5 wk of age and were challenged with Texas GB strain of NDV at 6 wk of age. All birds vaccinated with LNDV or UVNDV had a specific CMI response to NDV, VN or HI NDV antibodies were detected in all CY-nontreated vaccinated birds and some of the CY-treated vaccinated birds that were found to have regenerated their B-cell function at 1 wk postbooster. The challenge results clearly revealed that CY-treated birds that had NDV-specific CMI and VN or HI antibody responses to LNDV or UVNDV were protected, as were the CY-nontreated vaccinated birds. However, birds that had NDV-specific CMI response but did not have VN or HI antibodies were not protected from challenge. The results from both strategies indicate that specific CMI to NDV by itself is not protective against virulent NDV challenge. The presence of VN or HI antibodies is necessary in providing protection from Newcastle disease.  相似文献   

4.
Abstract The development of disease following oral challenge with Yersinia pseudotuberculosis (serotype 11) was compared in four groups of five birds treated with a parenteral dose of 10 mg iron dextran (Imferon), 10 mg of iron dextran plus 10 mg of the chelating agent desferrioxamine (Desferal), 10 mg of desferrioxamine or 10 mg of dextran 2 days before the experiment. Four groups of two birds received the above treatment regimens but no bacterial challenge. In iron dextran treated birds, oral challenge resulted in faecal shedding for the 10 day duration of the experiment, whereas in those birds which received dextran or desferrioxamine alone, the duration of faecal shedding was significantly less. Serological titres to the lipopolysaccharide antigen of the challenge bacteria were also lower in the groups not pretreated with iron dextran. The birds pretreated with iron dextran had diarrhoea and were clinically unwell 2 days following the initial oral challenge. Birds not given iron dextran showed no clinical signs of disease. Histological examination of five selected areas in the liver, spleen and intestine of each bird indicated that birds in the groups treated with iron dextran prior to bacterial challenge had significantly more intestinal lesions than birds in the groups not treated with iron. In contrast, there were significantly more lesions in the spleens of birds not pretreated with iron dextran. There was no evidence of stainable iron in the livers of birds challenged with Y pseudotuberculosis 10 days after an injection of 10 mg of iron dextran. This is in contrast to birds given iron dextran and no bacteria. It was concluded that pretreatment of birds with iron dextran resulted in more severe clinical disease, prolonged faecal shedding with associated intestinal lesions and higher serological titres to bacterial antigen. The number of lesions in the spleen and liver was not necessarily correlated with the severity of clinical disease, and in all infected birds the hepatic iron levels were significantly lower than in the non-infected control birds 10 days after oral challenge. It seems probable that the chicken has a high requirement for iron during infection with Y pseudotuberculosis and mobilises stored and exogenously supplied iron for tissue repair and immunological function.  相似文献   

5.
OBJECTIVES: This study aimed to characterise tick species responsible for avian tick infestations in the UK, to analyse various risk factors for tick-related syndrome in tick-infested birds and to test samples for the presence of certain tick-transmitted pathogens. METHODS: Ticks, blood, splenic tissue and tick attachment site tissue from birds with attached ticks were requested from veterinarians and wildlife sanctuaries around the UK. Ticks were identified according to standard keys, and samples were analysed via DNA PCR test for Borrelia burgdorferi sensu lato, Babesia species, Bartonella species and Ehrlichia species. RESULTS: Ixodes frontalis was the most commonly identified tick, and an association of adult female I frontalis with tick-related syndrome in birds was demonstrated. Tick infestation was markedly seasonal. I frontalis was found on 32 species of birds. DNA PCR testing was uniformly negative. Of the birds known to have been treated, 75 per cent (nine of 12) survived. CLINICAL SIGNIFICANCE: Tick-related syndrome is a poorly understood syndrome, with sporadic distribution, both geographically and seasonally. This study confirms I frontalis as the most common cause of this syndrome in the UK and identifies some features of the tick life cycle in this country. The benefit of treatment in affected birds is highlighted. Risk factors for tick-related syndrome are examined and preventive strategies discussed.  相似文献   

6.
在2002~2005年对吉林西部游禽资源进行了考察,共记录到游禽49种,隶属于4目4科17属。其中国家重点保护鸟类7种,皆为二级,占我国重点保护鸟类的1.22%,占吉林省西部地区鸟类总数的13%。同时对吉林省西部游禽的区系组成、生态类群及数量进行了研究,并对游禽的资源保护和管理提出了建议。  相似文献   

7.
The development of disease following oral challenge with Yersinia pseudotuberculosis (serotype 11) was compared in four groups of five birds treated with a parenteral dose of 10 mg iron dextran (Imferon), 10 mg of iron dextran plus 10 mg of the chelating agent desferrioxamine (Desferal), 10 mg of desferrioxamine or 10 mg of dextran 2 days before the experiment. Four groups of two birds received the above treatment regimens but no bacterial challenge. In iron dextran treated birds, oral challenge resulted in faecal shedding for the 10 day duration of the experiment, whereas in those birds which received dextran or desferrioxamine alone, the duration of faecal shedding was significantly less. Serological titres to the lipopolysaccharide antigen of the challenge bacteria were also lower in the groups not pretreated with iron dextran. The birds pretreated with iron dextran had diarrhoea and were clinically unwell 2 days following the initial oral challenge. Birds not given iron dextran showed no clinical signs of disease. Histological examination of five selected areas in the liver, spleen and intestine of each bird indicated that birds in the groups treated with iron dextran prior to bacterial challenge had significantly more intestinal lesions than birds in the groups not treated with iron. In contrast, there were significantly more lesions in the spleens of birds not pretreated with iron dextran. There was no evidence of stainable iron in the livers of birds challenged with Y pseudotuberculosis 10 days after an injection of 10 mg of iron dextran. This is in contrast to birds given iron dextran and no bacteria. It was concluded that pretreatment of birds with iron dextran resulted in more severe clinical disease, prolonged faecal shedding with associated intestinal lesions and higher serological titres to bacterial antigen. The number of lesions in the spleen and liver was not necessarily correlated with the severity of clinical disease, and in all infected birds the hepatic iron levels were significantly lower than in the non-infected control birds 10 days after oral challenge. It seems probable that the chicken has a high requirement for iron during infection with Y pseudotuberculosis and mobilises stored and exogenously supplied iron for tissue repair and immunological function.  相似文献   

8.
丹顶鹤、黑鹳等属世界珍稀鸟类物种,为我国I级保护动物,现已确认鹤、鹳等可以患鸟类的烈性、毁灭性传染病——新城疫。鉴于国内外鹤、鹳新城疫防疫与检测没有系统的研究报道,尚没有一个完整可靠的科学依据来指导防疫程序。本研究采用血凝抑制试验(HI)测定接种新城疫疫苗前后的鹤、鹳,观察其血清抗体效价的消长规律,认定其免疫能力。支持和指导鹤、鹳防疫程序的建立。  相似文献   

9.
1. Poultry are usually transported in crates which provide the birds with very limited space. Slaughter transport of male turkeys is often carried out using crates that are 40?cm or less in height where it is not possible for them to stand up. There is little information on how this physical restriction over many hours affects the birds.

2. The aim of the study was to compare the welfare of male turkeys transported in crates 40?cm and 55?cm in height. Observations on the birds’ behaviour during lairage, carcass damage and meat quality were carried out after four commercial slaughter transport journeys.

3. Birds in 40?cm crates panted more and lay down more than birds in 55?cm crates during lairage. A large percentage of the carcasses had some damage. Significantly more birds from the 55?cm crates had scratches on their backs than birds from the 40?cm crates. There was no significant difference in meat quality between birds transported in the two crate heights.

4. Both positive and negative effects of increased crate height were established and there is no evidence from this study that merely increasing crate height improves turkey welfare. Other solutions should therefore be sought in order to improve the welfare of birds during transport.  相似文献   

10.
鸟类,特别是濒危鸟类同工酶的分析,长期以来一直受到组织学样品来源上的限制。因为在分析实验中普遍采用血液和各种新鲜组织为分析材料,这常常要损伤或杀死动物,对濒危鸟类的保护是不利的。本文以生长羽毛的羽髓组织为材料,进行了乳酸脱氢酶(LDH)同工酶的凝胶电泳分析。所得谱带清晰,重复性好,且对鸟体无伤害,是濒危鸟类同工酶分析的理想方法。  相似文献   

11.
Bolivia has a total of 47 species of Psittacidae, seven of which have been identified in our study site, the semiarid Gran Chaco of the Isoso. One species, the blue-fronted parrot (Amazona aestiva), is frequently captured by local Isose?o Guaraní Indians for exploitation on the national and international market. These birds are often temporarily housed in small villages under unhygienic conditions with poultry and other domestic species. On occasion, these parrots escape back to the wild. Additionally, many of these birds are kept as pets or are used to lure wild. parrots within slingshot range for subsequent capture. In this study, we evaluated the health status, including the level of exposure to selected infectious agents, in the wild-caught captive birds and free-ranging birds. Physical examinations were performed, and blood was collected, from 54 live birds (20 captive and 34 free-ranging). Feces were collected from 15 birds (seven captive and eight free-ranging). Necropsies were also performed on four recently dead wild-caught birds. On serologic testing, no birds were found to have antibodies to avian influenza virus, Chlamydophila psittaci, infectious bronchitis virus, infectious bursal disease virus, infectious laryngotracheitis virus, Marek's disease virus, paramyxovirus-1, paramyxovirus-2, paramyxovirus-3, polyomavirus, eastern equine encephalitis virus, western equine encephalitis virus, or Venezuelan equine encephalitis virus. Positive antibody titers were found for psittacine herpesvirus (8/44, 18.2%), Aspergillus spp. (3/51, 5.9%), and Salmonella pullorum (33/49, 67.3%). All three of the birds that tested antibody positive for Aspergillus spp. were captive, whereas six of the eight and 15 of the 33 birds that tested positive for psittacine herpesvirus and S. pullorum, respectively, were wild.  相似文献   

12.
The goal of this study was to localize antigen presenting cells (APC), which may play roles in defense against pathogens and fertility, and examine the effects of age and gonadal steroids on their population in the rooster epididymis. Healthy White Leghorn male birds (immature 60-day-old birds; matured 150-, 330-, and 550-day-old), and immature birds treated with testosterone propionate (TP) or estradiol benzoate (EB) for 3 or 6 days were used. Cryostat sections of the epididymis and ductus deference were immunostained for Ia to identify APC. RT-PCR was performed to confirm the expression of major histocompatibility complex class II (MHC class II) mRNA in the epididymis. Ia+ cells were localized in the surface epithelium and subepithelial layer of the ductules and occasionally in the luminal content of the epididymis and ductus deference. RT-PCR analysis confirmed expression of MHC class II mRNA in the epididymis, ductus deferens, testis, and spleen. The frequency of Ia+ cells in the subepithelial layer was significantly greater in the proximal efferent ductules than in the other two types of ductules in the epididymis of 550-day-old birds. Although there were no significant differences in the frequencies in the subepithelial layer of the proximal efferent ductules between 60- and 150-day-old birds, the frequencies were significantly greater in 330- and 550-day-old birds than in 60-day-old birds. The frequencies of Ia+ cells in the ductus deferences was increased in the 150-day-old birds compared with the 60-day-old birds, with a larger increase in 330- and 550-day-old birds. The Ia+ cell frequency was significantly increased by EB-injection, but not by TP-injection, on Days 3 and 6 of injection compared with Day 0. These results suggest that the population of APC in the epididymis increases with age after sexual maturation, and estrogen may be one of the factors involved in induction of Ia+ cells.  相似文献   

13.
Erysipelas was diagnosed in 1998 from 34-wk-old laying hens in a free range flock in Germany. Erysipelothrix rhusiopathiae of serotype 1 was cultured from internal organs of the affected birds. This article describes the pathogenicity of the field isolate of E. rhusiopathiae in experimentally infected specific pathogen-free (SPF) laying hens. Three experiments were performed with SPF chickens inoculated at 17, 27, and 37 wk of age by either intramuscular (IM) or oral route. Inoculated birds were observed for 14 days. The highest mortality rates occurred in older birds, with 100% mortality observed in the 37-wk-old birds inoculated IM, 60% mortality reported in the younger 27-wk-old birds, and no mortality in the 17-wk-old age group. In the orally infected 27-wk-old birds, 40% mortality was detected, whereas no mortality was observed in the oldest birds by the same route. The results of the experiments support the contention that older birds are more sensitive to infection than younger birds and that mortality in laying hens is age related and dependent on the route of infection.  相似文献   

14.
During an epornitic of velogenic viscerotropic Newcastle disease (VVND) in southern California, free-flying wild birds, captive and free-ranging semidomestic birds, and exotic birds were collected from the quarantine area to determine their role in the epizootiology of the disease. The VVND virus was isolated from 0.04% of 9,446 free-flying wild birds, 0.76% of 4,367 semidomestic birds, and 1.01% of 3,780 exotic birds examined. Three house sparrows and 1 crow directly associated with infected poultry flocks were the only free-flying wild birds from which VVND virus was isolated. Among semidomestic species, ducks, quail, chukars, pheasants, peafowl, pigeons, and doves were found to be infected. Psttacines, pittas, and toucans accounted for 92% of the VVND virus isolations from exotic birds. In addition, domestic Newcastle disease virus (NDV) was isolated from 0.29% of the free-flying wild birds, from 1.65% of the semidomestic birds, and from 0.19% of the exotic birds collected. Hemagglutination-inhibition against domestic NDV was demonstrated in 0.24% of 3,796 wild bird serums, 8.28% of 2,004 semidomestic bird serums, and 3.90% of 231 exotic bird serums tested. Although few free-flying wild birds were infected with VVND virus in this epornitic, the isolation of domestic NDV strains from free-flying wild ducks and mourning doves suggests the potential for transportation of NDV over long distances by migratory birds.  相似文献   

15.
An ELISA using lipopolysaccharide antigens prepared from Salmonella gallinarum and S enteritidis was developed for the serological diagnosis of fowl typhoid and S enteritidis infection in poultry. There was good agreement between the results of the ELISA and conventional serological tests when samples from naturally infected birds and S enteritidis immunised birds were tested. Some cross reactions were observed when serum samples from S typhimurium infected birds were tested by ELISA. Subsequently a disc ELISA, using filter paper discs, was developed to facilitate sampling and testing of poultry. There was good correlation between the results of the disc and serum ELISAs and the test is recommended for the field testing of birds.  相似文献   

16.
In order to evaluate the effects of habituation to handling on the Doppler-derived velocity of diastolic ventricular inflow and systolic aortic outflow, falcons that were accustomed to regular handling were compared with falcons that had been handled very little. The mean heart rate of the frequently handled birds was 111 beats per minute less than the non-habituated birds. All the mean blood flow velocities recorded were much higher in the non-habituated birds than those accustomed to handling. Taking into account the difficulty of objectively quantifying the level of stress suffered by any individual bird, the question is, if meaningful clinical or reference values for Doppler-derived blood flow velocities may be obtained in unsedated or non-anaesthetized birds?  相似文献   

17.
Two experiments were conducted in which the spontaneous physical behaviour, spontaneous electroencephalogram (EEG) and somatosensory evoked potentials were examined in chickens stunned with a handheld, head-only stunner operating at 117 v. Thirteen of 14 birds lost their evoked potentials after stunning, and when they were exsanguinated within 15 seconds they did not regain them before they died. The remaining bird appeared to have evoked potentials after stunning but there was a movement artifact in its EEG and it is possible that they were not genuine responses. When head-only stunning was applied to 50 birds for one second the birds appeared to be stunned instantaneously, in terms of their spontaneous physical behaviour. However, they recovered more rapidly than 40 birds which were stunned for seven seconds. It was concluded that the handheld stunner can stun a bird effectively, and provided that the bird's neck is cut promptly, can kill it humanely.  相似文献   

18.
The ostrich is an important animal in many livestock industries and in the developing world ostrich production is a valuable source of foreign currency netted from the export of meat and skins. Its successful growth and reproductive performance is dependent upon good nutrition. In Zimbabwe, one of the greatest costs involved in the upkeep of ostrich breeder birds is purchased feed (US$4555.45/10 birds p.a.). In order to cover these costs, the producer needs to ensure an adequate throughput of birds for slaughter. The energy provided by a particular feed source is important for growth and development of the bird. More research is required in ostrich nutrition.  相似文献   

19.
Chicks were handled for 5 min twice daily for five consecutive days per week over a three-week period. The control birds were not handled once they had been allotted to their brooders. The growth rate of the treated birds was significantly decreased. There was no adrenal hypertrophy; the concentration, but not the content, of adrenal cholesterol was significantly increased. Plasma glucose, FFA and cholesterol concentrations were similar in the groups at the end of the experiment. The lipolytic response of the handled birds to a further stimulus of handling was significantly greater than that of unhandled birds experiencing novel handling stimulus. There was also a significant decrease in the concentration of corticosterone in the plasma of the handled birds but not in the unhandled group. There was thus no evidence of habituation.  相似文献   

20.
The heart of the bird is characterized by its enormous efficiency. Racing pigeons are bred for a long time for their flight performance. In the present study therefore the heart of 108 racing pigeons of the breed Bricoux were examined by means of echocardiography. The birds were either kept in aviaries (untrained) or as racing birds. The aim was to find out whether differences in the heart dimensions and/or the heart work occur between untrained and trained birds, like it is described already in humans and mammals (so-called athletic's heart). Significant differences between the two groups could be determined with different parameters, in particular with parameters, which affect the heart work. Thus it was for the first time possible to prove the formation of a athletic's heart in birds, and by that the adaptation of the avian heart to appropriate performance requirements.  相似文献   

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