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51.
52.
Between 2006 and 2009, seven strains of infectious bronchitis (IB) virus (IBV) were isolated from vaccinated chicken flocks on different chicken farms in China. The pathogenic characters of seven IBV strains were assessed. Each of the seven strains was infective to the test chickens and could induce an immune response. The results from chicken embryo cross-neutralization assays showed that these strains were antigenically distinct from classic IBV strains of H120, M41, Conn, and Gray. Compared to H120 vaccine strain, point mutation, short insertion, and deletion occurred at many positions in the S1 protein of the seven strains. Five of the seven strains had the motif (HRRRR), which was identical to that of the epidemic IBV strains in China. Two new motifs (HRLRR and RRIRR) emerged in the isolated strains. The homology of the nucleotide and amino acid sequences of the S1 gene among the seven isolates was 81.7%-99.7% and 79.0%-99.4%, respectively. These seven strains were also genetically different from the vaccine strains and non-China IBV strains but closely related to large numbers of Chinese strains. The seven isolates and 36 reference IBV strains were clustered into six distinct groups (I-VI). The seven strains were categorized into groups I, II, and III, forming a big phylogenetic branch, which is closely related to Chinese IBVs, whereas the vaccine strains belonging to group VI are genetically distant from groups I, II, and III. The results from this study indicate that different IBV strains cocirculate in the chicken population in China. 相似文献
53.
Ronald W Hardy 《中国水产》2014,(11):81-82
五.鲑鳟饲料中目前的大豆产品用量
如前所讨论,大豆粕在鳟鱼饲料中的使用已有60年的历史,不过仅使用于鱼苗后的阶段,且用量很少。其它在鲑鳟饲料中曾被评估过的大豆产品包括大豆浓缩蛋白、大豆分离蛋白、全脂大豆与大豆油。溶剂萃脂之去皮大豆粕(48%粗蛋白)在鲑鳟饲料中使用较普遍。 相似文献
54.
55.
Wittig W Hoffmann K Müller H Johne R 《Berliner und Münchener tier?rztliche Wochenschrift》2007,120(3-4):113-119
Between 2000 and 2004 a disease occurred in an aviary in Germany affecting various bird species belonging to the order Passeriformes including Collared Grosbeaks (Mycerobas affinis), Eurasian Bullfinches (Pyrrhula pyrrhula griseiventris), Brown Bullfinches (Pyrrhula nipalensis), Grey-headed bullfinches (Pyrrhula erythaca) and Yellow-bellied Tits (Periparus venustulus).The major clinical signs included increased mortality of fledglings and young birds, as well as feather disorders and feather loss in adult birds. In addition, adult Eurasian Bullfinches showed in one year a disease course, in which the major symptom was inflammation of the skin beginning on the basis of the beak and spreading over the head occurring a few days before death. Bacteriological and parasitological investigations did not reveal any consistent findings. Using a newly developed polymerase chain reaction protocol, DNA of the recently discovered finch polyomavirus (FPyV) was demonstrated in several affected birds. Because of the consistent detection of FPyV-DNA and the similarity of the symptoms with those observed during infection with the closely related avian polyomavirus in other bird species, an etiological role of FPyV in the observed disease is assumed. 相似文献
56.
Gómez Alvarez CB Wennerstrand J Bobbert MF Lamers L Johnston C Back W van Weeren PR 《Equine veterinary journal》2007,39(3):197-201
REASONS FOR PERFORMING STUDY: Lameness has often been suggested to result in altered movement of the back, but there are no detailed studies describing such a relationship in quantitative terms. OBJECTIVES: To quantify the effect of induced subtle forelimb lameness on thoracolumbar kinematics in the horse. METHODS: Kinematics of 6 riding horses was measured at walk and at trot on a treadmill before and after the induction of reversible forelimb lameness grade 2 (AAEP scale 1-5). Ground reaction forces (GRF) for individual limbs were calculated from kinematics. RESULTS: The horses significantly unloaded the painful limb by 11.5% at trot, while unloading at walk was not significant. The overall flexion-extension range of back motion decreased on average by 0.2 degrees at walk and increased by 3.3 degrees at trot (P<0.05). Changes in angular motion patterns of vertebral joints were noted only at trot, with an increase in flexion of 0.9 degrees at T10 (i.e. angle between T6, T10 and T13) during the stance phase of the sound diagonal and an increase in extension of the thoracolumbar area during stance of the lame diagonal (0.7degrees at T13, 0.8 degres at T17, 0.5 degres at L1, 0.4 degrees at L3 and 0.3 degrees at L5) (P<0.05). Lameness further caused a lateral bending of the cranial thoracic vertebral column towards the lame side (1.3 degrees at T10 and 0.9 degrees at T13) (P<0.05) during stance of the lame diagonal. CONCLUSIONS: Both range of motion and vertebral angular motion patterns are affected by subtle forelimb lameness. At walk, the effect is minimal, at trot the horses increased the vertebral range of motion and changed the pattern of thoracolumbar motion in the sagittal and horizontal planes, presumably in an attempt to move the centre of gravity away from the lame side and reduce the force on the affected limb. POTENTIAL RELEVANCE: Subtle forelimb lameness affects thoracolumbar kinematics. Future studies should aim at elucidating whether the altered movement patterns lead to back and/or neck dysfunction in the case of chronic lameness. 相似文献
57.
Streptococcus iniae: an aquatic pathogen of global veterinary significance and a challenging candidate for reliable vaccination 总被引:1,自引:0,他引:1
Streptococcus iniae has become one the most serious aquatic pathogens in the last decade causing high losses in farmed marine and freshwater finfish in warmer regions. Although first identified in 1976 from a captive Amazon freshwater dolphin, from which it derives its name, disease outbreaks had most likely been occurring for several decades in marine aquaculture in Japan. S. iniae is globally distributed throughout warm water finfish aquaculture. In common with other encapsulated beta-haemolytic streptococci and in direct contradiction to the phenomenal success story of bacterial vaccines in finfish aquaculture, control of S. iniae by vaccination has met with limited success. Thus, antibiotic usage is the current practice for reducing mortality and consequent economic loss. Vaccine failure appears to result in part from serotypic variation and, whilst 2 serotypes have been named, variation would appear to be more complex. S. iniae also has zoonotic potential, with human infections identified in the USA, Canada, and throughout Asia. In humans, infection is clearly opportunistic with all cases to date associated with direct infection of puncture wounds during preparation of contaminated fish, and generally in elderly or immunocompromised individuals. Significant progress has been made in terms of research into pathogenic mechanisms of S. iniae, with recent research elucidating the role of capsule in virulence for fish through antiopsonic activity. In light of this recent coverage in the literature, the present review centres on areas of direct veterinary interest including identification, epidemiology, therapy and prevention in farmed finfish. Clearly as the prevalence of S. iniae and associated economic losses continue to increase, further work towards developing a reliable vaccine is essential. This would appear to require a much better understanding of cell-surface variability amongst S. iniae isolates. 相似文献
58.
Post-weaning multisystemic wating syndrome (PMWS) associated with PCV2 was one of the most costly diseases currently faced by the swine industry. In order to develop a vaccine to control this disease, we previously constructed a recombinant adenovirus expressing the capsid of PCV2. Here, we examined the protection of swine against PMWS by the recombinant adenovirus. Eighteen 32-day-old pigs were assigned to three groups each with six. Group 1 was vaccinated subcutaneously with rAd-Cap and boosted 2 weeks later. Thirty-seven days after first vaccination, Groups 1 and 2 were oronasally challenged with virulent PCV2 isolate, 4 and 7 days later, intramuscularly exposed to keyhole limpet hemocyanin (KLH). Group 3 remained unchallenged but with KLH. The results showed that high level of PCV2-specific ELISA antibody and neutralizing antibody could be induced at 37 days after first vaccination. After challenge, pigs in vaccinated group had no clearly clinical signs, although some of them had increased rectal temperatures (>/=40 degrees C) for short time. The pyrexic phase in vaccinated group was significantly lighter than that in challenge-control group (P<0.05). The relative daily weight gain in vaccinated-challenged group was similar to that in empty control group. But it was significantly high compared to the challenge-control group (P<0.05). Mean while the pathological lesions and virema presented in vaccinated group were milder than those in control group. It indicated that the recombinant adenovirus was able to confer significant protection against clinical disease and reduce pathogenic lesions induced by PCV2 challenge, even though it could not provide complete virological protection. The recombinant adenovirus might be an attractive candidate vaccine for preventing the disease associated with PCV2 infection. 相似文献
59.
The objective of this study was to test for correlations between alopecia and ruminal drinking in young calves. 331 calves up to an age of 31 days were tested for evidence of generalized hair loss daily during their stay in the clinic. Incidence of diarrhoea and the results of ruminal fluid and blood analysis were compared between the groups with and without alopecia. Calves with alopecia showed a significantly higher incidence of diarrhoea and of ruminal acidosis persisting for at least 24 hours. Blood analysis revealed significant differences in degree of acidosis, in concentrations of D-lactate, urea, and creatinine in serum as well as in the activities of glutathione peroxidase, aspartate amino transferase, and creatine kinase. Alopecia in calves is correlated to longer periods of diseases, which are known to be accompanied by the production of D-lactate in the gastrointestinal tract, such as diarrhoea and ruminal drinking. The question, whether alopecia is due to formation of toxic substances or to deficiency of essential substances can not be answered. 相似文献
60.
Previously, we reported the construction and characterization of a genetically defined Actinobacillus pleuropneumoniae (A. pleuropneumoniae) apxIIC gene mutant, HB04C(-), which conferred protection to mice against infection with A. pleuropneumoniae. In this study, we further evaluated HB04C(-) for safety and its ability to elicit protective immunity in pigs. It was demonstrated that a dose of 2 x 10(8) CFU HB04C(-) was safe to the pigs via intranasal or intramuscular injection. Immunization with a dose of 2 x 10(8) HB04C(-) by both intranasal and intramuscular routine could yield equal protective efficacy and elicited significant protection against experiment challenge with homologous or heterologous serotypes of a virulent A. pleuropneumonia. Taken together, HB04C(-) might serve as a promising vaccine candidate against infection with A. pleuropneumoniae. 相似文献