MODERN APPROACHES TO THE PREVENTION OF REO-VIRUS BIRD INFECTION

Currently, reo-virus infection causes significant economic damage to industrial poultry worldwide. Losses as a result of the disease consist of: 1) direct losses - death of chickens (5-30 %), increased culling due to lameness, low weight gain (up to 40 %), reduction of carcass categories, reduction of laying by 6-20 %; in breeding farms, a decrease in the sexual activity of poultry is observed, which is the reason for the decrease in fertilization - derivability; 2) indirect losses associated with the cost of eliminating the effects of primary losses, as well as the immune-suppressive effect of reo-viruses, which increase the risk of other infections and inhibit the formation of post-vaccine immunity. Reo-virus has an immune-suppressive effect on the sick bird, which may be the cause of such diseases as small absorption syndrome and syndrome of increased bird death. Small absorption syndrome, which can be caused by reo-virus, is characterized by slowing growth, low feed conversion index and damage to the bones of the bird, which becomes apparent until 2 weeks of age and later. The syndrome of absorption is characterized by an increase in glandular stomach, sometimes with necrosis and signs of catarrhal hemorrhagic enteritis. The incidence is on average 5 to 15 %, but can reach up to 40 %. In studying the pathogenesis of reo-virus infection, it was found that the intestine is the main target of the virus, regardless of the method of its introduction. After oral or aerogenic infection, the pathogen enters the bloodstream and, as a result of viremia, is rapidly spread to various organs and tissues. In particular, the virus can be isolated from the intestines, bursa of Fabricius, liver, pancreas, heart, kidneys, joints and tendons. When conducting serological studies in ELISA (test system company IDvet, France), the presence of antibodies in the blood of broilers to reo-virus level ranged from 40-52 days in the range from 1125 to 5138 indicates the circulation of the field virus of reo-virus infection. In the study of broiler sera for 2, 3, 7 days, the cultivation of specific antibodies to reo-virus was not detected. Starting from the 14th day, the mean titer of AO to reo-virus was 1989 and their levels ranged from 3478 to 4825 at 21, 28, 35 and 45 days. 2.3 times (35 days) and 45 days 2.4 times. These data indicate the circulation of a field strain of reo-virus infection. It was inserted that at completion of broiler fattening with reo-virus lesion, body weight was lower than the technological norm by 9.8%. When determining specific BP for reo-virus in sera from different age groups of broilers of 11 batches, including from poultry: 9 batches of non-vaccinated against reo-virus infection and 2 batches of vaccinated poultry have determined the number of BPs in serum among the 9 batches received from the unvaccinated parent stock, there is evidence of field strain circulation. The percentage of specific AOs in 2 batches received from parental herds vaccinated against reo-virus infection ranged from 87.5-100, indicating the effectiveness of the vaccination. To control reo-virus infection, serological monitoring in poultry farms should be carried out.

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SIGNIFICANCE OF SEROLOGICAL MONITORING FOR POULTRY ORNITOBACTERIOSIS THERAPY

Scientific and Technical Bulletin оf State Scientific Research Control Institute of Veterinary Medical Products and Fodder Additives аnd Institute of Animal Biology ◽

10.36359/scivp.2021-22-1.02 ◽

2021 ◽

Vol 22 (1) ◽

pp. 30-37

Author(s):

I. K. Avdosieva ◽

O. I. Chajkovska ◽

O. B. Basarab ◽

V. V. Regenchuk

Keyword(s):

Egg Production ◽

Early Stage ◽

Age Groups ◽

Clinical Signs ◽

Live Weight ◽

Suppressive Effect ◽

Field Strain ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Tests ◽

Tissue Samples

One of the main problems of poultry diseases is respiratory diseases. Among them a special place is occupied by ornithobacteriosis (ORT). Losses from ORT consist of: direct losses as a result of the disease - death of chickens, increased culling due to lameness, low live weight gain (up to 40%), reduction of carcass categories, reduction of egg production by 6-20%; indirect losses associated with the immune-suppressive effect of ornithobacteria, which increase the risk of other infections and prevent the formation of post-vaccination immunity. The diagnosis is established on the basis of epizootological data, clinical signs, pathological and anatomical changes, bacteriological and serological tests, positive bioassay. In most cases, infections caused by ornithobacteria are not diagnosed in time, the pathogen is difficult to isolate due to complications of other pathogens, or because experts are currently insufficiently aware of the ability of ORT to cause disease. ORT can be isolated by bacteriological method only at an early stage of the disease. The most relevant method of diagnosis is PCR. The advantage of the method is not only the isolation of DNA of individual cells of the pathogen in the sample, but also the ability to detect all serotypes. In addition, PCR is a successful diagnosis in the detection of ORT nucleic acid not only in tissue samples, but also in feces, eggs, dust, which is important for timely diagnosis. Enzyme-linked immunosorbent assay (ELISA) is used to control the presence of ornithobacteriosis in bird. The presence of antibodies to this pathogen in poultry of many species indicates its wide circulation. Thus, when conducting serological monitoring of blood serum from different age groups of broilers aged 1-44 days, the percentage of positive samples ranged from 40 to 100, which indicates the circulation of the field strain of the pathogen ornithobacteriosis. The percentage of positive serum from broilers to ORT was: from 1 to 5 days - from 88 to 50, from 6 to 10 days serum were negative, while at 17, 21 days and from 32 days to the end of cultivation (44 days) – 100 %. The percentage of positive batches at the end of fattening ranged from 42-53 days in the range from 75 to 100%, indicating the circulation of the field strain of the ornithobacteriosis pathogen antibiotic therapy against this disease.

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IMMUNOLOGIC RESPONSE OF NEONATAL AND OLDER RABBITS TO ANTIGENS OF RABBIT LEUCOCYTES

Journal of Experimental Medicine ◽

10.1084/jem.116.5.575 ◽

1962 ◽

Vol 116 (5) ◽

pp. 575-588 ◽

Cited By ~ 2

Author(s):

T. N. Harris ◽

Susanna Harris ◽

Miriam B. Farber

Keyword(s):

Lymph Node ◽

Age Groups ◽

Suppressive Effect ◽

Test System ◽

Active Immunization ◽

Adult Rabbit ◽

Immunologic Response ◽

Splenic Cells ◽

Lymph Node Cells ◽

Transplantation Antigens

The immunologic response of neonatal and of older rabbits to the tissue (transplantation) antigens of pooled rabbit leucocytes was studied, the test system being the suppression of formation of agglutinin to Shigella paradysenteriae by transferred lymph node cells which had been incubated with Shigella antigen. In the active induction of the suppressive effect on the transferred cells it was found that neonatal rabbits reacted as vigorously as 1 kg rabbits to the prior injection of a given number of rabbit leucocytes pooled from prospective donors of lymph node cells. The suppressive effect was dose-related, and within the range of number of leucocytes used was similar for both age groups of recipients. An attempt to detect a difference in the response during the first few days after leucocyte injection, before the full suppressive effect is reached, failed to show any difference between rabbits of the two age groups. Since it had been found possible to transfer the suppressive effect passively with sera obtained from older rabbits injected with rabbit leucocytes, attempts were made to do so with sera obtained from neonatal rabbits injected with similar numbers of pooled adult rabbit leucocytes. No consistent suppression of transferred lymph node cells was observed with sera from neonatal rabbits, even with relatively large amounts of such serum. In sera of rabbits which had been injected with rabbit leucocytes at the age of 4 to 6 weeks, suppressive antibody could be detected. When anti-rabbit-leucocyte serum obtained in adult rabbits was injected into neonatal and 1 kg recipients at a given volume per gram of animal weight the suppressive effect of the serum was of similar extent in the two groups of recipients. In the adoptive transfer of the lymph node cell suppressive effect, by cells of lymph nodes draining the sites of injection of pooled rabbit leucocytes, it was found that the popliteal lymph node cells of neonatal rabbits were as effective as those of 1 kg rabbits. Splenic cells of neonatal rabbits were also effective, when an adequate number of rabbit leucocytes had been injected intravenously. Thus, in conferring adoptive immunologic response, as in active immunization, the neonatal rabbits were as effective as the older rabbits in their response to homotransplantation antigens, in contrast to the considerable difference in concentration of the suppressive antibody in sera of neonatal and older rabbits injected with rabbit leucocytes.

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Results of Surveillance Studies of Infectious Fish Diseases in Freshwater Aquaculture of Ukraine

Agricultural science and practice ◽

10.15407/agrisp2.02.032 ◽

2015 ◽

Vol 2 (2) ◽

pp. 32-38 ◽

Cited By ~ 4

Author(s):

N. Matvienko ◽

A. Vashchenko ◽

I. Tsiganok ◽

L. Buchatsky

Keyword(s):

Rainbow Trout ◽

Infectious Diseases ◽

Cell Cultures ◽

Standardized Test ◽

Age Groups ◽

Infectious Pancreatic Necrosis Virus ◽

Test System ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Freshwater Aquaculture ◽

Pancreatic Necrosis Virus

Aim. To investigate the epizootic state of fi sheries in Ukraine; to study the biological specifi cities of viral and bacterial isolates of fi sh in freshwater aquaculture. Methods. The epizootic state of fi sheries was defi ned ac- cording to the surveillance plan for fi sheries, virological (biosampling of sensitive fi sh species, virus isolation on sensitive passaged cell cultures), serological (enzyme immunoassay, virus neutralization test using sensitive passaged cell cultures) and molecular-biological (reverse transcriptase polymerase chain reaction − RTPCR) methods of investigation were used. The pathogenicity of the isolated bacteria was studied in the biosample. The identifi cation was performed using Bergey’s Manual. The express-identifi cation of bacteria was performed using the standardized test-system API 20E Bio Merieux (France). Results. The IPNV isolates of rainbow trout were fi rst isolated in the fi sheries of different forms of ownership in the western regions of Ukraine (Volyn, L’viv, Transcarpathian, Chernivtsi regions). It was demonstrated that different age groups of carp are infested with the virus in the fi sheries of L’viv, Donetsk, Chernihiv, Kyiv, and Odesa regions which testifi es to a wide spread of the virus in Ukraine. Out of fi sh infectious diseases the red spot-like disease and the swim bladder infl ammation of carp, the diseases of young trout and sturgeon were detected in the investigated fi sheries of Ukraine. Conclusions. The epizootic data were used to estimate the condition of the fi sheries in Ukraine in terms of fi sh infectious diseases. An infectious pancreatic necrosis virus, new for Ukraine, was revealed. It was found to affect rainbow trout (Oncorhynchus mykiss , Walbaum, 1792) and the spread of SVCV in carp fi sheries was demonstrated. As for bacterial fi sh diseases, the decrease in the epizootic situation was described along with considerable extension of the range of species of bacterial pathogens of fi sh. Annual systematic monitoring and measures of preventing the introduction of the agents of infectious diseases are the guarantee of protection of the specialized fi sheries of Ukraine.

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Efficacy of Live Vaccines and Specific Prevention in Chicken Infectious Bronchitis

International Journal of Veterinary Science ◽

10.37422/ijvs/20.042 ◽

2020 ◽

Keyword(s):

Egg Production ◽

Live Weight ◽

Economic Damage ◽

Feed Conversion ◽

Local Immunity ◽

Effective Prevention ◽

Live Vaccines ◽

Infectious Bronchitis ◽

Variant Strain

Infectious bronchitis of chickens (IBC) is a highly contagious disease characterized by damage to the respiratory tract. Adult chickens exhibit respiratory symptoms, a 10-50% decrease in egg production, discoloration of the eggshell, deformation of the shell, and a deterioration in the marketability and breeding quality of eggs. The circulation of variant strains in poultry farms of the Russian Federation causes a significant decrease in egg production and the quality of the eggs obtained, causing significant economic damage to industrial poultry farming. The study aimed to presents materials and methods for the industrial and efficient use of live-vaccines against infectious bronchitis of hens from a variant strain. After the use of a live vaccine against infectious bronchitis of chickens from a variant strain, the development, live weight of chickens, and feed conversion during the rearing period were within the standard parameters. in present study, the safety for the growing period with a planned 97.6% was 98.8-98.9%. The uniformity of the herds when transferred to hen - hen was 94-95%. When carrying out immunoprophylaxis of IBS, local immunity is important, which can be ensured using a live spray vaccine - a method starting from the day old. When establishing circulation in the economy of variant strains of IBC virus, it is necessary to introduce vaccination against the variant strain into the scheme of treatment and preventive measures. The research results allow us to conclude that, for the effective prevention of chicken infectious bronchitis, immunization against IBS from variant strains should be introduced into the vaccine prevention scheme.

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Effect of age on feed efficiency and carcass yield characteristics of indigenous bull

Bangladesh Journal of Animal Science ◽

10.3329/bjas.v46i1.32171 ◽

2017 ◽

Vol 46 (1) ◽

pp. 17-23 ◽

Cited By ~ 1

Author(s):

N Sultana ◽

KS Huque ◽

MZ Rahman ◽

NG Das

Keyword(s):

Age Groups ◽

Live Weight ◽

Conversion Ratio ◽

Feed Conversion Ratio ◽

Feed Conversion ◽

Carcass Yield ◽

Concentrate Mixture ◽

Retail Cuts ◽

Daily Gain ◽

Effect Of Age

The study was conducted with the objectives to understand the effect of age of native Pabna bulls on feed conversion ratio (FCR), digestibility and carcass yield characteristics. Fifteen Pabna bulls having five in each age groups of 6 to12, 13 to 24 and 25 to 36 months were fed ad libitum mix silages of Splendida (Setaria splendida) and Andrpogan (Andropogon gyunus) grasses (1:1 fresh) and supplemented with a concentrate mixture at 1% of live weight (LW) for a period of 72 days. With the increase of age, and subsequently LW (initial LW: 98.2, 182.6 and 288 kg, respectively), there was significant decrease in dry matter (DM) intake as % LW (<0.05; 2.94, 2.61 and 2.36, respectively) and increased daily gain (<0.01; 294, 519 and 597 g/d, respectively). However, the feed conversion ratio (FCR) (>0.05; 10.88, 10.10 and 12.24, respectively) and DM digestibility (>0.05; 51.0, 48.1 and 49.1 %, respectively) of bulls were remained unchanged. In case of carcass yield characteristics, significantly lower yield grade (<0.01; 1.79, 1.27 and 0.20, respectively) of bulls of 25 to 36 years produced higher closely trimmed boneless retail cuts (CTBRC) (<0.01; 50.47, 51.64 and 54.14 %, respectively), retail cut (<0.01; 76.14, 78.55 and 83.48 %, respectively) and meat quality index (MQI) (<0.01; 67.28, 67.89 and 69.07, respectively) compared to younger bulls. It may, therefore, be recommended that beef cattle farming with native Pabna bulls of 24 to 36 months will give more daily LW gain and produce more CTBRC at a similar FCR compared to younger ones.Bang. J. Anim. Sci. 2017. 46 (1): 17-23

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Evaluation of the best vaccination regimen against Gumboro disease, based on the histopathologic lesions of bursa of Fabricius, in broilers

Journal of the Hellenic Veterinary Medical Society ◽

10.12681/jhvms.15417 ◽

2018 ◽

Vol 52 (2) ◽

pp. 135

Author(s):

B. BOUYIOUKLIS (Π. ΜΠΟΥΓΙΟΥΚΛΗΣ) ◽

S. LEKKAS (Σ. ΛΕΚΚΑΣ) ◽

I. GEORGOPOULOU (Ι. ΓΕΩΡΓΟΠΟΥΛΟΥ) ◽

P. IORDANIDIS (Π. ΙΟΡΔΑΝΙΔΗΣ)

Keyword(s):

Drinking Water ◽

Disease Virus ◽

Vaccine Strain ◽

The Other ◽

Field Strain ◽

Bursa Of Fabricius ◽

Control Group ◽

Vaccination Regimen ◽

Experimental Animals ◽

Gumboro Disease

For the evaluation of the best vaccination regimen against Gumboro disease using the vaccine strain D-78, based on the histopathologic lesions of bursa of Fabricius, 5 groups of experimental animals (A, B, C, D, E) of 15 chicks each were used. The chicks of group Β received the D-78 vaccine strain with the drinking water at the age of 14 days, those of C at the age of 8 and 11 days, and those of D at the age of 8 and 16 days, while the chicks of the other groups (A and E) remained unvaccinated. In the following, the chicks of the A, B, C and D groups were infected with a field strain of Gumboro disease virus, while those of E remained unvaccinated and uninfected as a control group. After 10 days, all chicks were killed and their bursae examined histological. It was established that the histopathologic lesions to the bursae of group C chicks were of a slighter degree than those of all the other challenged groups and therefore the protection to bursa of Fabricius against the disease is better with this vaccination regimen.

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