On epizootiology and control of lymphoid leukosis in chickens

The effect of an in ovo infection with a Dutch isolate of avian leukosis virus subgroup J (ALV-J) on the growth of specific pathogen free (SPF) broiler chickens was analysed. During this study, possible immune suppressive effects of ALV-J were assessed by measuring delayed-type hypersensitivity with keyhole limpet haemocyanin (KLH), natural killer (NK) cell activity, the production of radicals of nitric oxide (NO) by macrophages, humoral immune response against Newcastle and infectious bursal disease vaccine viruses, and automated total and differential leukocyte counts. In an attempt to elucidate the underlying causal mechanisms of the induced growth retardation, 3,39 ,5-triiodothyronine (T3) concentrations in serum were measured. Four experiments were conducted. In experiment 1, ALV-J-injected birds were compared with ALV subgroup A (ALV-A)-injected and negative control chickens. In experiment 2, ALV-J-injected birds were only compared with negative controls. Finally, in experiments 3a and 3b, ALV-J-injected chickens were compared with negative controls and a group of chickens in which only 10% of birds had been injected with ALV-J. Birds were injected in ovo at day 7 of incubation with 10 4 median tissue culture infectious dose (TCID 50 ) ALV-J or ALV-A, except in experiment 3a where 10 2 TCID 50 ALV-J was injected. Significant growth suppression was found in all 100% of ALV-J-infected groups. The average growth retardation of ALV-J-infected birds compared with negative controls at 6 weeks of age was approximately 8, 11, 2.5 and 6% for the four successive experiments performed. The delayed-type hypersensitivity test against KLH of ALV-J-infected birds showed a tendency towards lower wattle thickness; however, the difference with controls was not significant (P > 0.05). The same was true for NK cell activity and NO production by macrophages, although the difference was not significant. The total and differential leukocyte counts performed on blood samples from birds at 3, 4 and 6 weeks of age as well as the humoral immune response against Newcastle and infectious bursal disease vaccine viruses did not show significant differences between treatment groups either. Only the number of basophils were significantly higher (P = 0.02) in ALV-J-infected birds at 3 weeks of age. No significant lower T 3 levels were found in ALV-J-infected birds in weeks 2 and 3 (experiment 2) and weeks 3 and 5 (experiment 3b); however, at 4 weeks (experiment 2) and 6 weeks (experiment 3b) of age, T 3 levels were significantly lower suggesting mild hypothyroidism in these broilers. In conclusion, the present experiments show the occurrence of significant growth retardation in SPF broilers after an ALV-J in ovo infection. The various studies performed to assess the immune competence of ALV-J-infected chickens did not show significant differences in immune responsiveness. The assays on cellular immunity showed a tendency to a lower response in ALV-J-infected birds, but these differences were not statistically significant.

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“…The purity and identity of the RAV-1 isolate was confirmed as described elsewhere (de Boer et al, 1978).…”

Section: Purity and Identity Of The Alv-j And Rav-1 (Alv-a) Inoculummentioning

confidence: 99%

“…The origin and further characteristics of the RAV-1 isolate have been established, as described previously (de Boer et al, 1978).…”

Section: Purity and Identity Of The Alv-j And Rav-1 (Alv-a) Inoculummentioning

confidence: 99%

Effect of an in ovo infection with a Dutch avian leukosis virus subgroup J isolate on the growth and immunological performance of SPF broiler chickens

Landman¹,

Post²,

Boonstra-Blom³

et al. 2002

Avian Pathology

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“…The data obtained in this experiment, in particular from groups 4-6, could be used for guidance in the surveillance of flocks under a programme for the control of LV as described by Rispens et al (1976), De Boer et aL (1978a and Maas (1980). Prevaccination plasma samples and WBC preparations should be free of LV and neutralising antibodies, while samples obtained at 3 weeks post-vaccination or later should be free of LV and the majority should contain neutralising antibodies to the subgroups of LV used for the inoculation (Rispens et aL, 1976 …”

Section: Discussionmentioning

confidence: 99%

Age related resistance to avian leukosis virus. III. Infectious virus, neutralising antibody and tumours in chickens inoculated at various ages

Maas

Boer²,

Groenendal³

1982

Avian Pathology

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“…In addition, by using the same technique with a chick embryo fibroblast (CEF) cell homogenate as antigen this serum demonstrated some affinity to CEF proteins. • ELISA blocking tests were performed employing chicken sera with neutralising antibody to Rous associated virus (RAV-1) and RSV (RÂV-1) collected from experimentally infected SPF birds of earlier trials (De Boer et al, 1978) and antisera prepared in goats, employing disrupted AMV, AMV-p27 and RSV-Praque C, that were kindly provided by Dr. J.W. Portwood, Becton Dickinson and Comp., Triangle Park, N.C., USA.…”

Section: Cell Cultures and Antiseramentioning

confidence: 99%

“…Recent studies have indicated that in ALV infected chickens total mortality rates are higher than in virus negative birds and egg production is reduced (Gavora et al, 1980). Previously we have described a method for the control of lymphoid leukosis (LL) which is primarily directed to the selection of hens which do not transmit ALV to their offspring (De Boer et al, 1978). This report describes a comparison of the available techniques for the identification of ALV shedding hens employing materials from four basic breeder flocks.…”

Section: Introductionmentioning

confidence: 99%

The use of Elisa for detection of exogenous and endogenous avian leukosis viral antigens in basic breeding flocks

Boer¹,

Gielkens²,

Hartog³

et al. 1983

Avian Pathology

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SUMMARYAn enzyme-linked immunosorbent assay (ELISA) for avian leukosis/ sarcoma virus (ALV) group-specific (gs) antigens was used to study the identification of hens which congenitally excrete exogenous ALV. The sensitivity of this assay was compared with that of the phenotypic mixing test (PMT) and the direct complement fixation test (CFT) by testing limiting dilutions of purified avian myeloblastosis virus (AMV), embryo homogenates and albumens. About 0.4 ng/ml of purified AMV protein could be detected by ELISA and 23.8 ng/ml of AMV protein was demonstrable by the CFT. The lowest levels of gs-antigen detection corresponded with about 100 median tissue culture infectious doses (TCID 50 ) of infectious ALV. Albumens and embryos of three White Leghorn flocks and one White Plymouth Rock flock were tested for the presence of avian leukosis virus (ALV) gs-antigens by the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA) and exogenous ALV employing the phenotypic mixing test (PMT). The highest number of ALVgs antigen positive samples of egg albumens was obtained by the ELISA. In embryo homogenates prepared from eggs of the four flocks under study 100% scores for gs-antigens were obtained by ELISA. A differentiation between gs-antigens of endogenous and exogenous ALV was made by testing of supernatant fluids after one chick embryo fibroblast passage of the C/E phenotype. Endogenous viral (ev) genes leading to the expression of endogenous ALV gs-antigens were apparently present in practically all chickens of the four flocks under study. Complete endogenous ALV (subgroup E) was detected in embryos (41%) from the White Plymouth Rock grandparent flock, but was not found in embryos of two White Leghorn basic breeder flocks. The results indicate that both flocks of White Leghorn chickens are endowed with ev 3 genes. Circumstantial evidence was obtained for the prevalence of endogenous ALV gs-antigens in albumen samples of eggs from flocks with gs + chf + and V-E + phenotype respectively.

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On epizootiology and control of lymphoid leukosis in chickens

Cited by 16 publications

References 19 publications

Effect of an in ovo infection with a Dutch avian leukosis virus subgroup J isolate on the growth and immunological performance of SPF broiler chickens

Effect of an in ovo infection with a Dutch avian leukosis virus subgroup J isolate on the growth and immunological performance of SPF broiler chickens

Age related resistance to avian leukosis virus. III. Infectious virus, neutralising antibody and tumours in chickens inoculated at various ages

The use of Elisa for detection of exogenous and endogenous avian leukosis viral antigens in basic breeding flocks

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