共查询到20条相似文献，搜索用时 171 毫秒
1.
Erysipelas was diagnosed in a layer breeder flock in Sweden in 2002. Although vertical transmission of Erysipelothrix rhusiopathiae has not been previously described in chickens, the potential of erysipelas infection to adversely affect hatching eggs was of concern. To clarify the possible impact of erysipelas on hatching eggs and their progeny, an experiment was done using 200 hatching eggs collected from the infected flock. The eggs were incubated for 21 days, and the egg shells, infertile eggs, dead-in-shell embryos, and a sample of day-old hatched chicks and blood samples from 5-day-old chicks were cultured for E. rhusiopathiae. In addition, after 28 days of grow-out, the male chickens were euthanatized and cultured for the bacterium, and the remaining female chickens were placed as a backyard flock and observed over a 4-mo period. Bacteriological test results of the above-mentioned samples were negative for E. rhusiopathiae. Mortality rates were not excessive, and no clinical symptoms of erysipelas were observed during the period of observation. The result of the investigation suggests that in layer breeder chickens, E. rhusiopathiae is not vertically or egg transmitted and that the disease outbreak in the parent stock had no adverse impact on the quality of hatching eggs in terms of increased embryo mortality. 相似文献
2.
Branton SL Roush WB Lott BD Evans JD Dozier WA Collier SD Bearson SM Bearson BL Pharr GT 《Avian diseases》2005,49(1):147-151
Vaccination of commercial layer chickens is labor intensive and often results in poor rates of seroconversion, which, in turn, generally correlate with decreased flock uniformity and performance. Attempts to improve the vaccination process include numerous variations of individual shop-built vaccinators in use by the layer sector of the poultry industry. Each of these vaccinators has limitations that contribute to poor vaccinations. Major problems include the nonuniform speed of the applicator system and pressure fluctuations at the spray nozzles, which contribute to sporadic dispersion of the vaccine as the vaccinator is pushed or carried past the cages. A battery-powered, self-propelled, constant-speed vaccinator was designed and constructed that operates with constant nozzle pressure. In field use, this vaccinator has resulted in both labor savings (reduction of manpower from five to one to vaccinate 75,000 chickens) and time savings (from 45 min to 7.5 min/poultry house) as well as improved vaccination results (higher positive seroconversion rates) against the poultry pathogen Mycoplasma gallisepticum (MG), a bacterium associated with losses of 15.7 eggs/hen over a 45-wk laying period in MG-infected layers as compared with layers maintained free from infection with MG. 相似文献
3.
舍饲与林地放养混合模式下寿光鸡、固始鸡和罗曼蛋鸡蛋品质及肉品质的比较 总被引：1，自引：0，他引：1
本试验旨在比较寿光鸡、固始鸡和罗曼蛋鸡在舍饲与林地放养混合模式下蛋品质及肉品质的差异。选取90日龄寿光鸡、固始鸡和罗曼蛋鸡母鸡各120只,每个品种鸡设4个重复,每个重复30只,在舍饲与林地放养混合模式下采用常规基础饲粮饲喂至180日龄。结果表明:罗曼蛋鸡与寿光鸡、固始鸡相比,蛋重显著升高(P0.05),而蛋黄颜色、蛋白高度和哈氏单位显著降低(P0.05)。寿光鸡和固始鸡的蛋中锌、硒、钙、蛋白质和脂肪含量较罗曼蛋鸡显著升高(P0.05),肌肉中脂肪和蛋白质含量也较罗曼蛋鸡显著升高(P0.05)。寿光鸡、固始鸡肌肉的滴水损失率、剪切力显著低于罗曼蛋鸡(P0.05),肉色显著高于罗曼蛋鸡(P0.05)。寿光鸡和固始鸡肌肉中甘氨酸、谷氨酸、异亮氨酸和鲜味氨基酸含量显著高于罗曼蛋鸡(P0.05)。总之,寿光鸡和固始鸡的蛋具有大蛋黄、高蛋白,且营养元素丰富,而罗曼蛋鸡的蛋含水量较高,蛋白质品质较差;寿光鸡和固始鸡的肌肉较罗曼蛋鸡具有较长货架期,且肌苷酸和氨基酸含量高,肉质鲜嫩,营养丰富;3个品种鸡中,寿光鸡和固始鸡的蛋品质和肉品质更佳。 相似文献
4.
Clinical effects, virological and serological responses in chickens following in-ovo inoculation of reticuloendotheliosis virus 总被引：1，自引：0，他引：1
M X Motha 《Veterinary microbiology》1987,14(4):411-417
Six-day-old embryonated specific pathogen free chicken eggs were inoculated with reticuloendotheliosis virus (REV) into the yolk sac and were incubated until they hatched. The hatchability of eggs inoculated with REV was significantly less (P less than 0.025) than that of media-inoculated controls. Although there were no significant differences in the body weights of these chickens at hatching, there were differences (P less than 0.001) at 6, 25 and 51 days of age between the infected and control chickens. Six of 10 chickens hatched from eggs inoculated with REV had feathering defects at 6 days of age. All chickens hatched from infected eggs had cell-free viraemia and antigenaemia, but not precipitating antibodies. Some of these chickens had very low neutralising antibody titres (less than 45) when examined at 25 and 37 days of age, as did all 10 chickens at 51 days of age. A low rate of horizontal transmission was indicated by the detection of antibodies at 37 and 51 days of age in chickens running in contact with the chickens hatched from eggs inoculated with REV. 相似文献
5.
为研究输氧对拉萨白鸡种蛋和藏鸡种蛋孵化效果的影响,选用5世代拉萨白鸡种蛋、尼木藏鸡种蛋、山南藏鸡种蛋进行孵化,于孵化过程及孵化结束时测定各品种鸡种蛋的相关孵化指标。结果表明:与输氧条件下相比,拉萨白鸡种蛋和尼木藏鸡种蛋在不输氧条件下的蛋重、初生重和初生重占入孵蛋重的百分比均更高,而山南藏鸡种蛋在不输氧条件下的蛋重、初生重和初生重占入孵蛋重的百分比均较低;拉萨白鸡种蛋、尼木藏鸡种蛋、山南藏鸡种蛋在输氧时的入孵蛋孵化率比不输氧时分别高29.40%、35.01%、14.72%;拉萨白鸡种蛋、尼木藏鸡种蛋、山南藏鸡种蛋在输氧时的受精蛋孵化率比不输氧时分别高31.55%、39.49%、11.91%。综上表明,缺氧是高原优良种质资源鸡种蛋孵化率低的最主要的因素,该研究为今后提高高原环境下种蛋的孵化效果提供了参考。 相似文献
6.
G.F de Boer J van Vloten J.E Groenendal H.J.L Maas A Hoogerbrugge 《Comparative immunology, microbiology and infectious diseases》1978,1(1-2)
Sera and organ extracts from ten different commercial stocks of layer chickens were examined for the presence of lymphoid leukosis (LL) viruses. Virus was recovered from 40.8% of the cockerels between three and six weeks of age. Their female hatch mates were examined at the age of 20 months. A mean of 11.3% of these laying hens was positive in the NP activation test. Lymphoid leukosis was successfully controlled in three inbred strains of White Leghorn chickens and in a commercial White Plymouth Rock line. All flocks were kept in a filtered air positive pressure (FAPP) house during the first two months of life and thereafter transferred to a conventional environment. The control method is based on three elements:
- • —from an infected flock, hens are selected in whose eggs no avian lymphoid leukosis viruses can be detected by examination of pooled extracts of groups of embryos;
- • —only eggs from hens that are shown not to shed congenitally virus in their eggs are used for the production of progeny. The offspring are reared in isolation until two months of age at which time the age-related resistance against tumour formation appears to be sufficiently developed;
- • —the chickens are subsequently intramuscularly inoculated with lymphoid leukosis viruses of subgroups A and B and transferred to a conventional chicken house. The inoculated birds become persistently viremic and resist horizontal virus exposure and intramuscular challenge infections.
7.
Branton SL Bearson SM Bearson B Lott BD Maslin WR Collier SD Pharr GT Boykin DL 《Avian diseases》2002,46(2):423-428
In each of two trials, 80 commercial leghorn-type pullets were separated into two treatments with four replicates of 10 chickens in each treatment. Forty pullets were designated as controls and received no inoculation, whereas the remaining 40 pullets received the 6/85 vaccine strain of Mycoplasma gallisepticum (MG) at 10 wk of age. Hen-day egg production, egg weight, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded weekly in each trial through an entire laying cycle of 43 wk. Further, eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. No significant difference was observed between the treatments for 43-wk means for hen-day egg production, for any of the monitored egg or eggshell quality parameters, or for the number of extra large, large, medium, small, pee wee, or undergrade egg sizes. A significant (P < or = 0.05) difference was observed for the number of jumbo-sized eggs between the two treatments. Results of this study suggest that vaccination of commercial layer chickens at 10 wk of age with 6/85 strain MG does not detrimentally impact egg production, egg size distribution, or ovary/oviduct function as evidenced by selected egg parameters monitored in this study. 相似文献
8.
Mycoplasma synoviae (M. synoviae) can cause respiratory disease, synovitis, or result in a silent infection in chickens and turkeys. The importance of M. synoviae is well established in broilers but only a few studies have been conducted in layers. In the present study, the prevalence of M. synoviae in commercial layer flocks was estimated using ELISA. For this study, 19 commercial layer flocks were selected randomly from New South Wales and Queensland region of Australia from producers who were willing to participate in the survey. Sixty eggs per flocks were randomly collected, out of these 30 eggs were used for ELISA and remaining 30 eggs were used to estimate various egg shell quality parameters. Subsequently, association between the serological status of eggs for M. synoviae and egg shell quality was studied. In the flocks under study, seroprevalence of M. synoviae was found to be high at 69% (95% confidence interval (CI)=41.3-89.0). Statistical analysis showed an association between serological status for M. synoviae and egg quality parameters such as translucency, shell breaking strength, % shell reflectivity and shell deformation. On the other hand, there was no significant association between serological status for M. synoviae and other egg quality parameters such egg weight, egg shell weight, % egg shell or shell thickness. 相似文献
9.
《畜牧与生物技术杂志(英文版)》2017,(4)
Background: Among various feed additives currently used in poultry nutrition, an important role is played by bioactive substances, including prebiotics. The beneficial effect of these bioactive substances on the gastrointestinal tract and immune system give rise to improvements in broiler health and performance nutrition, thus increasing the productivity of these birds. An innovative method for introducing bioactive substances into chickens is the in ovo injection into eggs intended for hatching. The aim of the study was to evaluate the development of histomorphological parameters of the duodenum and productivity in chickens injected in ovo with the prebiotic DiNovo~?(extract of Laminaria species of seaweed, BioA tlantis Ltd., Ireland) on d 12 of incubation, under large-scale, high density poultry production conditions.Results: There was no significant impact of the injection of DiNovo~? prebiotic on the production parameters of broiler chickens(body weight, FCR, EBI and mortality) obtained on d 42 of rearing. No significant impact of the DiNovo~? injection on the duodenum weight and length was observed, as wel as on the CSA, diameter and muscular layer thickness of the duodenum. The in ovo injection of DiNovo~? significantly increased the width of the duodenal vil i(P 0.05) and crypt depth(P 0.01) of chickens on d 21 of rearing. Other histomorphological parameters of duodenal vil i at d 42 of chickens rearing such as: the height, width, and cross section area of vil i were significantly greater in chickens from the control group compared to those from the DiNovo~? group(P 0.05 and P 0.01).Conclusions: In conclusion, this study demonstrates that injection of DiNovo~? prebiotic into the air chamber of egg significantly influences the histomorphological parameters on d 21 of rearing without negatively affecting productivity in chickens at the end of rearing. 相似文献
10.
11.
12.
Myeloblastosis-associated virus type 1 (MAV-1) is an exogenous avian retrovirus with oncogenic potential. MAV-1 was detected in young chicks hatching from eggs produced by an experimental genetic line of egg-type chickens. Transmissibility of MAV-1 had not been documented previously. This investigation was intended to partially characterize the virus involved and to study its transmissibility and oncogenicity in naturally and contact-infected chickens. Commercially produced white and brown layer pullets free of exogenous avian leukosis viruses were commingled at hatch with naturally MAV-1-infected chickens. The original MAV-1-infected chickens were discarded after approximately 8 wk, and the contact-exposed chickens were maintained in isolation for 36 wk. Young specific-pathogen-free (SPF) single comb white leghorn chickens were added to the group to study possible horizontal transmission of MAV-1 in young chickens. Upon weekly virus isolation attempts, MAV-1 was readily isolated from the contact-exposed white layers but not from the brown layers between 36 and 53 wk of age (18 wk in total). Three-week-old SPF chickens were readily infected with MAV-1 by contact as early as 1 wk postexposure. Throughout 22 hatches derived from the white and brown MAV-1-contact-exposed layers (between 36 and 53 wk of age), MAV-1 was frequently detected in the white layer progeny, whereas the virus was seldom isolated from the progeny produced by the brown layers during the same 18-wk period. MAV-1 induced a persistent infection in some of the SPF chickens that were exposed by contact at 3 wk of age. Gross tumors were not detected in any of the originally infected experimental chickens at 8 wk of age, in the contact-exposed brown or white layers at the termination of the study at 53 wks of age, or in the contact-exposed SPF chickens at the end of the study at 12 wk of age. Exogenous avian leukosis-related viruses may still be detected in egg-type chickens, emphasizing the importance of thorough screening before incorporation of experimental genetic material into commercial genetic lines of egg-type chickens. 相似文献
13.
Chin RP 《Avian diseases》2002,46(2):447-452
Thirty-eight cases were identified in which a nonfermentative, gram-negative, rod-shaped bacterium was isolated from the respiratory system of turkeys and chickens. Cases were submitted from various parts of the country. Preliminary assessment of phenotypic characteristics indicated this bacterium was different from common pathogenic or opportunistic bacteria isolated from the avian respiratory tract. Most cases reported a history of respiratory distress and/or increased flock mortality. Lesions seen in infected birds included tracheitis and pneumonia, which correlate with the sites of isolation. Sixty-one percent of the isolations were made from the trachea and 25% from the lung. Age of infected birds ranged from 35 to 315 days in turkeys and 53 days to 3 yr in chickens. In most instances (90%), other bacteria were also isolated from affected sites. The significance of this organism in respiratory disease in birds is unknown. 相似文献
14.
15.
16.
Two experiments were conducted to compare the effect of chickens' age on resistance to primary and secondary infections with Ascaridia galli. In Experiment I, three groups, each of 80 female Lohman Brown chickens, aged one day, one month, or four months were compared. Within each group, 54 chickens were infected orally with 500 embryonated eggs and 26 were kept as non-infected controls. Weights were recorded weekly and five chickens in each group were slaughtered every 2 weeks for worm counts. At week 10 post-infection, 17 of the infected chickens and 18 of the controls were challenged with 500 eggs. In a replicate experiment (Experiment II), 35 one-day-old and 53 one-month-old female Lohman Brown chickens were infected orally with 500 A. galli eggs. Weights and fecal egg counts were recorded every week and infected chickens were necropsied every two weeks for determination of the worm burden. Chickens infected at one month of age excreted significantly fewer A. galli eggs when measured at 14 weeks of inoculation. The worms recovered from the one-month-old age group were significantly shorter than those from the chickens infected at one day of age in the first experiment. Worm burden and female fecundity values, however, were not significantly different between age groups in both Experiments I and II. Weight gains of infected chickens were not significantly different from the controls' and only a few chickens exhibited occasional slight diarrhea in both experiments. The results from these experiments demonstrate that the chickens' age only partially influences resistance to A. galli infection. 相似文献
17.
18.
19.
Chicken kidney cells, derived from the eggs of white leghorn chickens that had serological evidence of prior exposure to both adenovirus and the adeno-associated virus (AAV), produced AAV antigenic proteins upon challenge with purified adenovirus. Antigen was detected by indirect immunofluorescence using monoclonal antibody to AAV. The number of fluorescent cells were few and did not increase during the course of adenovirus infection. Similar results were obtained using cells prepared from specific-pathogen-free chicks with no previous exposure to adenovirus or AAV. It is postulated that the avian AAV can exist as a latent infection in the germ line of chickens. 相似文献
20.
Humoral responses and salmonellosis protection in chickens given a vitamin-dependent Salmonella typhimurium mutant 总被引：2，自引：0，他引：2
Humoral responses in chickens inoculated with an aromatic vitamin dependent (Aro-) Salmonella typhimurium mutant (STM) were studied to ascertain the efficacy of the organism as a vaccine for salmonellosis and possibly as a delivery system for antigens from enteric pathogens of chickens. Serum antibody responses in chickens that were given oral or subcutaneous inoculations of the bacterium followed the classic order of antibody production, with IgM being detected first, followed by IgG and IgA. Antibody responses in the gut of orally inoculated chickens were restricted to IgG and IgA. Weight gain measured in chickens given high doses of STM (up to 5 x 10(9)) orally, revealed that the bacterium did not adversely affect the chickens; in fact, inoculated chickens had significantly higher body weights than controls at the same age. Salmonellosis protection of chickens by oral vaccination with STM was examined in a vaccination/challenge experiment. The experiment revealed that oral vaccination reduced excretion of a virulent S. typhimurium used as the challenge organism. 相似文献