PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Rocha A.C.G.P., Rocha S.L.S., Lima-Rosa C.A.V., Souza G.F., Moraes H.L.S., Salle F.O., Moraes L.B. & Salle C.T.P. 2008. Genes associated with pathogenicity of avian Escherichia coli (APEC) isolated from respiratory cases of poultry. Pesquisa Veterinária Brasileira 28(3):183-186. Centro de Diagnóstico e Pesquisa em Patologia Aviária, Departamento de Medicina Animal, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS 91540-000, Brazil. E-mail: ana.crocha@terra.com.br The virulence mechanisms of avian pathogenic Escherichia coli (APEC) have been continually studied and are believed to be multi-factorial. Certain properties are primarily associated with virulent samples and have been identified in avian isolates. In this study a total of 61 E. coli, isolates from chicken flocks with respiratory symptomatology, were probed by Polimerase Chain Reation (PCR) for the presence of genes responsible for the adhesion capacity, P fimbria (papC) e F11 fimbria (felA), colicin production (cvaC), aerobactin presence (iutA), serum resistance (iss), temperature-sensitive hemagglutinin (tsh), and presence of K1 and K5 capsular antigens (kpsII). The iss gene was detected in 73,8%, tsh in 55,7%, iutA in 45,9%, felA in 39,3%, papC in 24,3%, cvaC in 23% and kpsII in18%.

• Escherichia coli virulence PCR poultry pathogenicity

Abstract in Portuguese:

ABSTRACT.- Rocha A.C.G.P., Rocha S.L.S., Lima-Rosa C.A.V., Souza G.F., Moraes H.L.S., Salle F.O., Moraes L.B. & Salle C.T.P. 2008. Genes associated with pathogenicity of avian Escherichia coli (APEC) isolated from respiratory cases of poultry. Pesquisa Veterinária Brasileira 28(3):183-186. Centro de Diagnóstico e Pesquisa em Patologia Aviária, Departamento de Medicina Animal, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS 91540-000, Brazil. E-mail: ana.crocha@terra.com.br The virulence mechanisms of avian pathogenic Escherichia coli (APEC) have been continually studied and are believed to be multi-factorial. Certain properties are primarily associated with virulent samples and have been identified in avian isolates. In this study a total of 61 E. coli, isolates from chicken flocks with respiratory symptomatology, were probed by Polimerase Chain Reation (PCR) for the presence of genes responsible for the adhesion capacity, P fimbria (papC) e F11 fimbria (felA), colicin production (cvaC), aerobactin presence (iutA), serum resistance (iss), temperature-sensitive hemagglutinin (tsh), and presence of K1 and K5 capsular antigens (kpsII). The iss gene was detected in 73,8%, tsh in 55,7%, iutA in 45,9%, felA in 39,3%, papC in 24,3%, cvaC in 23% and kpsII in18%.

Abstract in English:

ABSTRACT.- Montassier M.F.S., Brentano L., Montassier H.J. & Richtzenhain L.J. 2008. Genetic grouping of avian infectious bronchitis virus isolated in Brazil, based on RT-PCR/RFLP analysis of the S1 gene. Pesquisa Veterinária Brasileira 28(3):190-194. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Paiva 87, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

• Avian infectious bronchitis virus spike glycoprotein genotyping and RFLP

Abstract in Portuguese:

ABSTRACT.- Montassier M.F.S., Brentano L., Montassier H.J. & Richtzenhain L.J. 2008. Genetic grouping of avian infectious bronchitis virus isolated in Brazil, based on RT-PCR/RFLP analysis of the S1 gene. Pesquisa Veterinária Brasileira 28(3):190-194. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Paiva 87, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

Abstract in English:

ABSTRACT.- Parizzi R.C., Miglino M.A., Maia M.O., Souza J.A., Santos J.M., Oliveira M.F. & Santos T.C. 2007. [Morphology of the ovary in rhea (Rhea americana).] Morfologia do ovário da ema (Rhea americana). Pesquisa Veterinária Brasileira 27(3):89-94. Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, USP, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270. E-mail: tcsantos@usp.br The ovarian morphology of the sexually mature rhea (Rhea Americana) is described. Ovaries from 24 adult rheas in their reproductive age were collected in the slaughterhouse. Follicular diameters (n = 18) were measured and samples (n = 6) were fixed in 10% formaldehyde with 0.1M phosphate buffer at pH 7.4 for light microscopy. Results showed that the left ovary occupied the dorsal portion of the celomatic cavity in contact with the cranial portion of the left kidney and the suprarenal gland, being supported in the cavity through the mesovary. On the free surface of the ovary 72.4±17.09 follicles in different phases of development and 30.4±3.65 atretic follicles were observed. The follicles were linked to the ovarian surface by the follicular stalk and had a wide band surrounding its surface, the Stigma folliculare. Histologically, the ovary is constituted by a medulla, composed by connective tissue and vessels, and by a cortex with oocytes and follicles. The follicular wall is composed by the Theca externa and Theca interna, Stratum granulosum and the Zona radiata. The ovary surface is covered by a cubic epithelium, the germinal epithelium, on the connective tissue of the Tunica albuginea. The morphologic characteristics of the ovary of the rhea are due to the egg size in this species and generally similar to other birds.

• Ovary follicle morphology avian anatomy rhea Rhea americana

Abstract in Portuguese:

ABSTRACT.- Parizzi R.C., Miglino M.A., Maia M.O., Souza J.A., Santos J.M., Oliveira M.F. & Santos T.C. 2007. [Morphology of the ovary in rhea (Rhea americana).] Morfologia do ovário da ema (Rhea americana). Pesquisa Veterinária Brasileira 27(3):89-94. Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia, USP, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270. E-mail: tcsantos@usp.br The ovarian morphology of the sexually mature rhea (Rhea Americana) is described. Ovaries from 24 adult rheas in their reproductive age were collected in the slaughterhouse. Follicular diameters (n = 18) were measured and samples (n = 6) were fixed in 10% formaldehyde with 0.1M phosphate buffer at pH 7.4 for light microscopy. Results showed that the left ovary occupied the dorsal portion of the celomatic cavity in contact with the cranial portion of the left kidney and the suprarenal gland, being supported in the cavity through the mesovary. On the free surface of the ovary 72.4±17.09 follicles in different phases of development and 30.4±3.65 atretic follicles were observed. The follicles were linked to the ovarian surface by the follicular stalk and had a wide band surrounding its surface, the Stigma folliculare. Histologically, the ovary is constituted by a medulla, composed by connective tissue and vessels, and by a cortex with oocytes and follicles. The follicular wall is composed by the Theca externa and Theca interna, Stratum granulosum and the Zona radiata. The ovary surface is covered by a cubic epithelium, the germinal epithelium, on the connective tissue of the Tunica albuginea. The morphologic characteristics of the ovary of the rhea are due to the egg size in this species and generally similar to other birds.

Abstract in English:

ABSTRACT.- Peres M.F., Carrijo A.S., Higa A.H. & Oliveira J.M. 2006. [Serological evidence of avian pneumovirus infections in broiler flocks in counties of Mato Grosso do Sul.] Evidência sorológica de Pneumovírus aviário em lotes de frangos de corte em municípios de Mato Grosso do Sul. Pesquisa Veterinária Brasileira 26(4):254-258. Departamento de Zootecnia, Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul (UFMS), Av. Filinto Müller 2443, Campo Grande, MS 79070-900, Brazil. E-mail: acarrijo@nin.ufms.br Avian pneumovirus (APV) is an important respiratory pathogen of hens and broilers. Although it was not clearly elucidated whether APV may cause economical losses in broiler flocks, it is known that APV infection can induce specific antibody production on these birds, and these serological reactions may provide some information about the epidemiological status of the APV infections. This work was carried out in search for antibodies to APV in broiler flocks in counties of Mato Grosso do Sul. Five hundred and thirty six serum samples from 54 broiler flocks at 42 and 51 days of age were tested with a commercially available enzyme-linked immunosorbent assay (ELISA). The results showed that 330 samples (61.6%) were negative, 108 (20.1%) were suspect and 98 (18.3%) were considered positive for the presence to APV antibodies. Of all the flocks analyzed, 49 (90.7%) were considered either positive or suspect. The ELISA test demonstrated that there was a similar percentage of positive or suspect flocks among those flocks between 42 and 46 days of age, and among those between 47 and 51 days. No seasonal differences were observed, since the percentages of positive or suspect flocks either in summer or in winter months were similar. Most of the flocks were considered positive despite the type of broiler housing (conventional, environmental controlled or semi-controlled). It is concluded that there are strong evidences indicating circulation of APV in Mato Grosso do Sul. The percentages of positive flocks were similar regardless of the age groups of the birds examined, the type of broiler housing and the season when sampling was performed.

• Antibody diagnosis epidemiology avian pneumovirus PVA swollen head syndrome

Abstract in Portuguese:

ABSTRACT.- Peres M.F., Carrijo A.S., Higa A.H. & Oliveira J.M. 2006. [Serological evidence of avian pneumovirus infections in broiler flocks in counties of Mato Grosso do Sul.] Evidência sorológica de Pneumovírus aviário em lotes de frangos de corte em municípios de Mato Grosso do Sul. Pesquisa Veterinária Brasileira 26(4):254-258. Departamento de Zootecnia, Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul (UFMS), Av. Filinto Müller 2443, Campo Grande, MS 79070-900, Brazil. E-mail: acarrijo@nin.ufms.br Avian pneumovirus (APV) is an important respiratory pathogen of hens and broilers. Although it was not clearly elucidated whether APV may cause economical losses in broiler flocks, it is known that APV infection can induce specific antibody production on these birds, and these serological reactions may provide some information about the epidemiological status of the APV infections. This work was carried out in search for antibodies to APV in broiler flocks in counties of Mato Grosso do Sul. Five hundred and thirty six serum samples from 54 broiler flocks at 42 and 51 days of age were tested with a commercially available enzyme-linked immunosorbent assay (ELISA). The results showed that 330 samples (61.6%) were negative, 108 (20.1%) were suspect and 98 (18.3%) were considered positive for the presence to APV antibodies. Of all the flocks analyzed, 49 (90.7%) were considered either positive or suspect. The ELISA test demonstrated that there was a similar percentage of positive or suspect flocks among those flocks between 42 and 46 days of age, and among those between 47 and 51 days. No seasonal differences were observed, since the percentages of positive or suspect flocks either in summer or in winter months were similar. Most of the flocks were considered positive despite the type of broiler housing (conventional, environmental controlled or semi-controlled). It is concluded that there are strong evidences indicating circulation of APV in Mato Grosso do Sul. The percentages of positive flocks were similar regardless of the age groups of the birds examined, the type of broiler housing and the season when sampling was performed.

Abstract in English:

Abstract.- Brocchi M., Ferreira A., Lancellotti M., Stehling E.G., Campos T.A., Nakazato G., Pestana de Castro A.F. & Silveira W.D. 2006. Typing of avian pathogenic Escherichia coli strains by REP-PCR. Pesquisa Veterinária Brasileira 26(2):69-73. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade de Campinas, Cx. Postal 6109, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.

• Avian Escherichia coli typing REP-PCR.

Abstract in Portuguese:

Abstract.- Brocchi M., Ferreira A., Lancellotti M., Stehling E.G., Campos T.A., Nakazato G., Pestana de Castro A.F. & Silveira W.D. 2006. Typing of avian pathogenic Escherichia coli strains by REP-PCR. Pesquisa Veterinária Brasileira 26(2):69-73. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade de Campinas, Cx. Postal 6109, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.

Abstract in English:

Beltrão N., Furian T.Q., Leão J.A., Pereira R.A., Moraes L.B. & Canal C.W. 2004. [Detection of infectious laryngotracheitis virus in chickens in Brazil.] Detecção do vírus da laringotraqueíte das galinhas no Brasil. Pesquisa Veterinária Brasileira 24(2):85-88. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária, UFRGS, Porto Alegre, RS 91540-000, Brazil. E-mail: nilzaneb@hotmail.com A study was carried out in search for evidences of infectious laryngotracheitis virus (ILTV) infections in some Brazilian chicken flocks. Tracheal tissues and swabs were collected from 10 different flocks of layers and broilers displaying respiratory signs of disease. Samples were processes for virus isolation in embryonated eggs and the membranes examined by histopathology. In addition, specimens were examined by polymerase chain reaction (PCR). Three flocks had ILTV positive chickens by virus isolation and PCR. These results confirm the occurrence of ILTV in chickens in Brazil.

• Infectious laryngotracheitis virus PCR virus isolation avian pathology.

Abstract in Portuguese:

Beltrão N., Furian T.Q., Leão J.A., Pereira R.A., Moraes L.B. & Canal C.W. 2004. [Detection of infectious laryngotracheitis virus in chickens in Brazil.] Detecção do vírus da laringotraqueíte das galinhas no Brasil. Pesquisa Veterinária Brasileira 24(2):85-88. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária, UFRGS, Porto Alegre, RS 91540-000, Brazil. E-mail: nilzaneb@hotmail.com A study was carried out in search for evidences of infectious laryngotracheitis virus (ILTV) infections in some Brazilian chicken flocks. Tracheal tissues and swabs were collected from 10 different flocks of layers and broilers displaying respiratory signs of disease. Samples were processes for virus isolation in embryonated eggs and the membranes examined by histopathology. In addition, specimens were examined by polymerase chain reaction (PCR). Three flocks had ILTV positive chickens by virus isolation and PCR. These results confirm the occurrence of ILTV in chickens in Brazil.

Abstract in English:

Canal C.W., Ferreira D.J., Macagnan M., Fallavena L.C.B., Moraes H.L.S. & Wald V.B. 2004. Prevalence of antibodies against chicken anaemia virus (CAV) in broiler breeders in Southern Brazil. Pesquisa Veterinária Brasileira 24(2):89-92. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br Chicks infected during the first two weeks of life with chicken anaemia virus (CAV) manifest clinical disease that can be avoided if the breeder hens transfer enough antibodies to their progeny. The objective of the present work was to establish the prevalence and titer of anti-CAV antibodies in some Brazilian broiler hen breeder flocks and verify in which phase of life the birds were infected. A total of 1,709 serum samples from 12 broiler hen flocks vaccinated against CAV and 64 unvaccinated flocks were analyzed for CAV antibodies with an enzyme-linked immunosorbent assay (ELISA). All non-vaccinated breeder flocks were found to be infected with CAV, with 89% of the hens tested presenting antibodies, 52% of these with titers considered high enough to protect their progeny against CAV infection. Likewise, all vaccinated hens had antibody titer to CAV capable of conferring protection to their progeny. Thus, vaccination of hens seems capable of conferring protection to chicks against clinically apparent CAV-associated disease.

• Antibodies avian pathology chicken anemia virus CAV epidemiology prevalence.

Abstract in Portuguese:

Canal C.W., Ferreira D.J., Macagnan M., Fallavena L.C.B., Moraes H.L.S. & Wald V.B. 2004. Prevalence of antibodies against chicken anaemia virus (CAV) in broiler breeders in Southern Brazil. Pesquisa Veterinária Brasileira 24(2):89-92. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br Chicks infected during the first two weeks of life with chicken anaemia virus (CAV) manifest clinical disease that can be avoided if the breeder hens transfer enough antibodies to their progeny. The objective of the present work was to establish the prevalence and titer of anti-CAV antibodies in some Brazilian broiler hen breeder flocks and verify in which phase of life the birds were infected. A total of 1,709 serum samples from 12 broiler hen flocks vaccinated against CAV and 64 unvaccinated flocks were analyzed for CAV antibodies with an enzyme-linked immunosorbent assay (ELISA). All non-vaccinated breeder flocks were found to be infected with CAV, with 89% of the hens tested presenting antibodies, 52% of these with titers considered high enough to protect their progeny against CAV infection. Likewise, all vaccinated hens had antibody titer to CAV capable of conferring protection to their progeny. Thus, vaccination of hens seems capable of conferring protection to chicks against clinically apparent CAV-associated disease.

Abstract in English:

ABSTRACT.- Soares C.O., lshikawa M.M., Fonseca A.H. & Yoshinari, N.H. 2000. [Borrelioses, agents and vectors: a review.] Borrelioses, agentes e vetores. Pesquisa Veterinária Brasileira 20(1):1-19. Depto Epidemiologia e Saúde Pública, Instituto de Veterinária, Univ. Fed. Rural do Rio de Janeiro, Km 47, Seropédica, RJ 23851-970, Brazil. Borrelioses are infectous diseases caused by spirochaetes of the genus Borrelia. They are born mainly through ticks at animals and/or human beings. In this review are shown and discussed five groups of diseases determined by borrelia, general characteristics of the spirochaetes, aspects related to transmission by arthropods, biological and pathological aspects of the diseases in domestic and wild animals, Lyme disease as an important zoonosis, the association of borrelia with other hematozoa agents, the diagnostic methods and the comparative epidemiologywith data obtained from Brazil and other countries. The borrelioses have pathological, clinical and epidemiological characteristics which vary according to physiographic regions due to the existence of different species, genospecies and strains of borrelia, of arthropod vectors, vector-agent relationship and of different ecocystems.

• Borreliosis ticks Borrelia spp. relapsing fever avian borreliosis bovine borreliosis Lyme disease epizootic bovine abortion Borreliose carrapatos febrerecurrente borreliose aviária borreliose bovina doença de Lyme aborto epizoótico bovino.

Abstract in Portuguese:

RESUMO.- Soares C.O., lshikawa M.M., Fonseca A.H. & Yoshinari, N.H. 2000. [Borrelioses, agents and vectors: a review.] Borrelioses, agentes e vetores. Pesquisa Veterinária Brasileira 20(1):1-19. Depto Epidemiologia e Saúde Pública, Instituto de Veterinária, Univ. Fed. Rural do Rio de Janeiro, Km 47, Seropédica, RJ 23851-970, Brazil. As borrelioses são enfermidades infecciosas determinadas por espiroquetas do gênero Borrelia, agentes transmissíveis, principalmente, por carrapatos aos animais e/ou ao homem. Nesta revisão são apresentadas e discutidas as enfermidades determinadas por borrélias, bem como as características gerais das espiroquetas, os aspectos relacionados a transmissão por artrópodes, as enfermidades nos animais domésticos e silvestres, quanto aos aspectos biológicos e patológicos, a doença de Lyme como principal zoonose do grupo, a associação de borrélia com outros agentes hematozoários e os métodos diagnósticos e a epidemiologia comparativa entre dados obtidos no Brasil com os de outros países. Estas borrelioses possuem características patológicas, clínicas e epidemiológicas variadas de acordo à região fisiográfica, devido à existência de distintas espécies, genoespédes e cepas; estes aspectos variam ainda em função dos artrópodes vetores, da interação vetor-patógeno e dos ecossistemas distintos.

Abstract in English:

Blood samples were obtained at slaughter from sixty 43 to 56 day old broilers, from each of 60 healthy flocks located in a region of high density poultry production. The flocks tested corresponded to approximately 10% of the total number existing in the region and were located within a radius of 50 km. All broilers had been vaccinated against Marek's disease atone day of age. Sera were tested in the immunodiffusion test for antibodies to avian reovirus (ARV), infectious bursal disease vírus (IBDV), fowl poxvirus (FPV), herpes virus of turkeys (HVT), avian adenovirus of groups 1 (AAV-1) and 2 (AAV-2). The sarne sera were tested in the micro serum neutralization test in plates for antibodies to infectious bronchitis virus (IBV) and infectious laryngotracheitis virus (ILTV), and for hemagglutination inhibition antibodies to Newcastle disease virus (NDV). Antibodies to ARV, detected in 2172 (63.6%) of 3418 sera, and to AAV-1, in 2701 (78.2%) of 3456 sera, were found in all 60 flocks, while antibodies to IBDV, in 3086 (89.4%) of 3452 sera, were found in only 57 of the sarne flocks. These results indicated that the three viruses are ubiquitous in broilers. Antibodies to FPV in 14 (0.5%) of 2935 sera, and to NDV in 6 (0.2%) of 3320 sera, were demonstrated in five of 59 and in one of 60 flocks, respectively, indicating that these two viruses occur only rarely. Antibodies to HVT, in 315 (9.0%) of 3384 sera, were detected in 39 of 60 flocks tested, suggesting poor serological response to vaccination and low field exposure to MDV. Antibodies to IBV, in 61 (2.1 %) of 2925 sera, were found in 12 of 57 flocks tested. However, in only one flock was the percentage of reactors significant (41 %); in the 11 flocks the percentage of broilers with antibody ranged from 1.7 to 16.1 %. Finally, no antibodies were found in 3491 sera from 60 flocks tested for AAV-2, nor in 3035 sera from 59 flocks when tested for ILTV, indicating that these two viruses do not exist in the geographical area tested. The significance of these findings is discussed.

• Antibodies broilers reovirus Gumboro Fowl pox Marek's disease adenoviruses infectious bronchitis infectious laryngotracheitis Newcastle disease

Abstract in Portuguese:

Amostras de sangue foram obtidas ao abate de 60 frangos de corte, de 43 a 56 dias de idade, de cada uma de 60 granjas sem problemas sanitários aparentes localizadas em uma região de alta densidade de produção avícola. As granjas correspondiam a 10% do número total que existe na região e estavam localizadas em um raio de 50 km. Todos os frangos tinham sido vacinados contra a doença de Marek no primeiro dia de vida. Os soros foram avaliados no teste de imunodifusão para anticorpos para reovírus aviário (R V A), vírus da doença infecciosa da bursa (VDIB), vírus da bouba aviária (VBA), vírus herpes de perus (HVT), adenovírus aviário do grupo 1 (AVA-1) e do grupo 2 (A VA-2). Os mesmos soros foram examinados no microteste de soroneutralização em placas para anticorpos para o vírus da bronquite infecciosa (VBI) e o vírus da laringotraqueíte infecciosa (VLTI), bem como anticorpos inibidores da hemoaglutinação para o vírus da doença de Newcastle (VDN). Anticorpos para RVA, detectados em 2172 (63,6%) de 3418 soros, e para AVA-1, em 2701 (78,2%) de 3456 soros, foram demonstrados em todas as 60 granjas, enquanto que, anticorpos para o VDIB, em 3086 (89,4%) de 3452 soros, foram encontrados em somente 57 destas granjas. Estes resultados indicam que os três vírus são ubíquos em frangos de corte da região estudada. Anticorpos para o VBA em 14 (0,5%) de 2935 soros, para o VDN em seis (0,2%) de 3320 soros, foram encontrados em cinco de 59 e em uma de 60 granjas, respectivamente, indicando que esses dois vírus ocorrem apenas raramente. Anticorpos para HVT, em 315 (9,0%) de 3484 soros, foram detectados em 39 de 60 granjas testadas, sugerindo resposta sorológica pobre à vacinação e baixa exposição de campo ao vírus da doença de Marek. Anticorpos para o VBI, em 61 (2,1%) de 2925 soros, foram encontrados em 12 de 57 granjas testadas. Porém, em apenas uma granja a percentagem de reagentes era significativa (41 %); nas outras 11 granjas a percentagem de frangos com anticorpos variava de 1,7 a 16,1%. Finalmente, não foram detectados anticorpos em 3491 soros de 60 granjas testada para A VA-2, nem em 3035 soros de 59 granjas testadas para o VLTI, indicando que esses vírus não existem na área geográficas estudada. O significado de todos os achados é discutido.

• Anticorpos frangos de corte reovírus Gumboro bouba Marek adenovírus bronquite infecciosa laringotraqueíte infecciosa Newcastle

Abstract in English:

White Leghorn hens of two lines, selected as non-shedders of the group-specific antigen (gs-ag) of àvian lymphoid leukosis viroses (LLV) in the albumen of their fresh unincubated eggs, produced significantly more eggs (p < 0.01) during seven consecutive-laying periods of 28 days each, than hens of the sarne lines that had been selected as consistent shedders of the gs-ag of LLV. Eggs were obtained from all dams, incubated, and various parameters of productivity compared. Eggs obtained from non-shedder dams had better fertility (p < 0.01) than eggs obtainedfrom shedder dams of the sarne line. Superior embryo viability was observed in only one of the non-shedder lines. Fertile eggs of both non shedder lines had better hatchability (p < 0.01) and yielded a higher percentage of good quality chicks (p < 0.01) than eggs from correspondig shedder hens. Progeny obtained from non-shedder dams had lower non-specific mortality (p < 0.01) anda higher rate of body weight gain (p < 0.01) than the progeny obtained from shedder dams. It is concluded that inapparent infection of White Leghorn dams with avian LLV reduces egg production and affects the productivity of their progeny. Since the methodology available for reducing infection rates or eradicating LLV is relativiely simple, it is recommended that Brazilian poultry suppliers start programs to control exogenous LLV in thefr grandparental stocks.

• Avian lymphoid leukosis vírus productivity eradication

Abstract in Portuguese:

Matrizes Leghorn brancas de duas linhagens que tinham sido selecionadas como não eliminadoras do antígeno específico de grupo (ag-gs) dos vírus da leucose linfóide (VLL) aviária na albumina de ovos frescos não incubados, produziram um maior número de ovos (p < 0,01) durante sete períodos consecutivos de postura de 28 dias cada um, que as matrizes das mesmas linhagens selecionadas como eliminadoras constantes de ag-gs dos VLL aviária. Ovos foram obtidos de todas as matrizes, incubados e vários parâmetros de produtividade foram comparados. Os ovos obtidos das matrizes não eliminadoras de ag-gs tiveram maior fertilidade (p < 0,01) que os ovos obtidos de matrizes eliminadoras da mesma linhagem. Uma melhor viabilidade embrionária foi somente observada em uma das linhagens não eliminadoras de ag-gs. Os ovos férteis derivados das duas linhagens não eliminadoras tiveram uma eclosão superior (p < 0,01) e percentagem maior de pintos eclodidos de boa qualidade (p < 0,01) que os ovos das matrizes eliminadoras correspondentes. As progênies obtidas das linhagens não eliminadoras acusaram menor mortalidade (p < 0,01) e maior ganho de peso corporal (p < 0,01) que as progênies obtidas das linhagens· eliminadoras. Conclui-se que a infecção inaparente de matrizes Leghorn brancas com os VLL aviária afeta tanto a produção de ovos, como a fertilidade, viabilidade e eclodibilidade dos mesmos, assim como o crescimento e a mortalidade observada durante as primeiras semanas de vida. Desde que, a metodologia disponível para reduzir as taxas de infecção ou erradicar os VLL aviária é relativamente simples, recomenda-se que as firmas fornecedoras de aves matrizes operando no Brasil, iniciem programas de controle dos VLL aviária nos seus plantéis de avós.

• Leucose linfóide aviária vírus produtividade erradicação