Joined: 2008-12-30 8:27:00 Source: China Poultry Diseases Network
Of Beijing, Tianjin, Hebei, Shandong, Ningxia, and other 14 provinces, municipalities and autonomous regions, more than 100 farmers conducted a survey of some new characteristics of poultry.
1, popular characteristics and pathological changes
The region covered by the survey, there are two different levels of disease were distributed to 180 ~ 300-day-old chicken main peak of the egg, the spread of faster, the course of 40 days about the serious decline in egg production, production can resume after rehabilitation to the original 90%, the mortality rate in the 5% ~ 30%.
Tracheal mucosal hyperemia, hemorrhage; subcutaneous, abdominal, fat Xinguantong bleeding points; Proventriculus unusual bleeding, common disease mainly concentrated in the reproductive system; follicle hyperemia, hemorrhage, deformation, or variability, following a breakdown in the formation of yolk peritonitis, intrafallopian jelly-like white cheese-like objects.
Monitoring the incidence of antibody levels before and after the chickens and found that just when the incidence of Newcastle disease or avian influenza H9 subtypes of low levels of antibodies, the majority of chickens in the protection of the value of antibody levels following antibody titers dispersion, dispersion in more than five. Condition at the time of the resumption of increased antibody titers 3 to 5 above, and higher than that produced by the immune antibody.
2, Analysis
From the popular features of clinical symptoms and pathological changes of analysis, the disease may have occurred as a "low pathogenic avian influenza subtype h9" or "atypical Newcastle." The reasons are as follows: a "low pathogenic avian influenza H9 subtypes" due to the neglect of the immune H9. Some farmers only H5 subtype of avian influenza-free, can not help but H9 subtypes that immunization of H5N1, it has been immune H9; or less immune H9 subtypes, only in laying before the immunization 1 or 2 times, while laying scared is no longer immune to the impact of production, resulting in antibody levels enough protection force.
Secondly, the countries of highly pathogenic avian influenza (H5N1) attaches great importance to and vigorously publicized, so that some farmers have a misconception that the immune H9 unimportant. In addition, some areas can not buy single-H9 avian flu vaccine, but also caused the disease occurred in one of the factors.
Newcastle disease caused by atypical reasons are: inadequate understanding, I do not know Newcastle protection needs of humoral immune + local immune.
Secondly, many fish farmers not to antibodies or antibodies to monitor the timely monitoring, immunization method shall not be treated, only drinking water, eye or intravenous immunoglobulin. Although the humoral immune better, but local mucosal antibodies is not high, that is, against Newcastle disease virus infection in the first line of defense is not solid.
In addition, the immune excessive immune time interval is too short causing immune paralysis.
Newcastle local immune best way is immune aerosol.
3, prevention and control measures
Immunization to produce uniform flocks effective antibody levels.
Bird flu prevention, to no H9 subtype of avian influenza vaccine or antibody While a relatively low level of immunization but emergency fill-free chickens. Reference immunization procedures: 2 ~ 4-week-old first-free; 8 to 10 weeks of age 2 free; 120 ~ 130-day-old three-free; egg after every 3 to 4 months once immune.
Prevention of disease, we must attach importance to the role of local mucosal antibodies, which is pathogenic to resist the invasion the first line of defense in anti-infection plays an important role. Thus the cycle of humoral antibody with the same close attention. Mucosal antibodies mainly rely on the live vaccine produced, mainly by humoral antibody produced inactivated vaccine, which in the chickens immunized two most important stage - rearing period and pre-laying, to do the combined effects of two vaccines. After entering the egg production period, in order to maintain a relatively high level of local mucosal antibodies, we must ensure that 2 to 3 months time Newcastle disease live vaccine immunization.
4, immunization method
Three weeks before the best use of intranasal, eye method; three weeks after the use of aerosol methods; the immune effect of poor drinking water, preferably not be adopted; if the problem can not be used because the equipment aerosol immunization methods, preferably intranasally, eye method replace the reference to immunization procedures are as follows:
The first free 1 ~ 3-day-old seedlings of living eye; Second-free 7 ~ 10-day-old seedlings of living eye; three free 17 ~ 21-day-old live MILLER + inactivated vaccine; four free 8 to 10 weeks of age living Miao (aerosol Law) ; five free 16 ~ 18-week-old live Miao + inactivated vaccine (aerosol Act); laying period of 2 to 3 months a live vaccine.
These two diseases, we must attach importance to antibody detection. Of chickens to Newcastle disease and avian influenza after immunization, antibody levels in vivo immunization as time gradually decreased to protect the value of the following. To the timely monitoring of the antibody level of chickens to determine the timing of immunization, the immune blood checks after the completion of timely rise in antibodies to confirm that the immune effect.
At the same time, experts recommend: before vaccination, and even drink Diamond Circle 3-5 days, which can effectively enhance the immune effect and reduce immune stress, while adding METALOR Kerry, can reduce the vaccine-induced respiratory disease.
No comments:
Post a Comment