Response of cyclophosphamide-treated broiler chickens to challenge with velogenic Newcastle disease virus

Immunostimulant potential of Moringa Oleifera leaves alcoholic extract versus Oregano Essential Oil (OEO) against cyclophosphamide-induced immunosuppression in broilers chicks

The current study was conducted to evaluate the immunoenhancement effect of Moringa oleifera leaves alcoholic extract (MOLE) versus Oregano essential oil (OEO) against cyclophosphamide induced immunosuppression in broilers chicks. A total of a three hundred one-day-old chicks were assigned randomly into three main dietary groups, control, MOLE, and OEO for 14 days. After 14 days the three main experimental groups were subdivided into six groups, control, cyclophosphamide, MOLE, MOLE and Cyclophosphamide, OEO, and OEO and cyclophosphamide. Each group of these six groups was subdivided into three subgroups. Supplementation of broiler chicks with MOLE and OEO for 14 days significantly increased body weight compared to the control group. However, injection of broiler chicks with cyclophosphamide significantly induced body weight loss, impaired immunological response represented by decreasing total leukocytic count, differential leukocytic count, phagocytic activity, phagocytic index, and hemagglutinin inhibition titer for New Castle disease virus, lymphoid organs depletion, and increased the mortality rate. In contrast, supplementation of cyclophosphamide treated chicks with MOLE and OEO significantly reduced cyclophosphamide induced body weight loss and impaired immunological responses, as it showed significant increase in body weight, total leukocytic count, differential leukocytic count, phagocytic activity, phagocytic index, and hemagglutinin inhibition titer for New Castle disease virus, lymphoid organs proliferation, and reduced the mortality rate. This study indicated that MOLE and OEO supplementation ameliorated cyclophosphamide induced body weight loss and impaired immunological responses.

Detection and assessment of risk factors associated with Newcastle disease virus infection in birds in backyard poultry in Laichau province of Vietnam

Newcastle disease (ND) is a highly pathogenic and contagious viral infectious disease of poultry that causes a very serious problem for poultry production and economic loss worldwide. ND has been an epizootic disease in Vietnam. Information about the risk factors that are associated with virus transmission in backyard chickens in Vietnam is limited. To provide more epidemiological information about ND in Vietnam, this study was performed to estimate NDV prevalence and identify the risk factors for ND virus (NDV) infection in birds at the backyard flock level. Choanal swabs were taken from 400 randomly selected birds from 100 apparently healthy flocks from May to July 2020. Based on RT-PCR analysis, 43 of 400 swab samples (10.75%; 95% CI 8-14.17) and 21 of 100 flocks (21%; 95% CI 14.17-29.98) were positive for the fusion (F) gene of NDV. The management practice risks were: backyard flocks contacting wild birds (OR = 3.89; P = 0.030), mixed flocks with different types and species of birds (OR = 5.46; P = 0.004), and infrequency of cleaning and disinfecting poultry houses (OR (odds ratio) = 4.43; P = 0.034). The second and third risks (above) showed a positive interaction on the risk of NDV infection in birds (OR = 39.38; P = 0.001), and the first risk showed a negative interaction. Further studies on NDV surveillance in domestic waterfowl, longitudinal studies, a well-optimized RT-qPCR assay, and genetic characterization are needed. The development of handbooks, flyers, or lessons for educating poultry keepers are also needed.RESEARCH HIGHLIGHT RT-PCR was used to detect the F gene of NDV in choanal swabs.Risk factors associated with NDV-positive samples were determined.The evidence for NDV circulation in backyard healthy birds was observed.Contact with wild birds, mixed flocks, and poor hygiene were major risk factors.

Effects of dietary supplementation of Vitamins E and C on oxidative stress induced by a Nigerian velogenic strain of the Newcastle disease virus (KUDU 113) in the brain and bursa of Fabricius of broiler chickens

Background and Aim:

Newcastle disease (ND) is widely recognized as an extremely harmful and contagious disease of birds. Therefore, the present study aims to evaluate the effect of oxidative stress induced by the virulent ND virus (NDV) (KUDU 113) on the plasma, brain, bursa of Fabricius, NDV antibody response, and hematology as well as the ameliorative effect of the individual or combined use of Vitamins E and C on the clinical signs of NDV-infected chickens.

Materials and Methods:

In this study, a total of 150 broiler chickens were included and divided into five groups: Group 1, nonsupplemented and unchallenged chickens (UCC); Group 2, nonsupplemented and challenged chickens (ICC); Group 3, Vitamin C-supplemented + challenged chickens; Group 4, Vitamin E-supplemented + challenged chickens; and Group 5, Vitamins E and C-supplemented + challenged chickens. Groups 3, 4, and 5 were supplemented with Vitamins E and C (33 and 400 mg/kg/day, respectively). Virus challenge was done with 0.1 ml of KUDU 113 7 days after the start of vitamin inclusion in their diet. Concentrations of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT) were analyzed in the plasma, brain, and bursa on days 0, 3, and 7 post-infection (pi) using the biochemical method. The blood samples were randomly collected from five chickens in each group for antibody response and hematological analyses on day 0 previtamin treatment and at 0, 3, 7, 10, 14, and 21 days pi (dpi).

Results:

A significant increase in the concentrations of MDA and NO in the NDV-challenged chickens was observed when compared with the UCCs. Moreover, a significant decrease in GSH concentration was observed in the NDV-challenged chickens when compared with the UCCs. The activities of CAT and SOD were reduced markedly in the NDV-challenged chickens. Increases in the mean antibody titers were observed in the NDV-challenged group when compared with the UCCs from days 3 to 21 pi. The mortality rates of groups 1, 2, 3, 4, and 5 were 0%, 30%, 3.3%, 3.3%, and 26.6%, respectively.

Conclusion:

The findings of this study suggest that KUDU 113 causes oxidative stress in the brain and bursa of Fabricius of chickens. Individual supplementation with Vitamin E or C was found to be more effective in ameliorating oxidative stress, improving the immune response, and reducing mortality in KUDU 113 infections than the combined supplementation of Vitamins C and E.

Ascaridia galli challenge model for worm propagation in young chickens with or without immunosuppression

With the continued growth of free-range egg production, the importance of the chicken roundworm Ascaridia galli is increasing. Investigations into this parasite would be facilitated by the availability of characterised strains and clear guidelines on optimal methods of multiplication and maintenance. Currently, there is lack of well-defined in vivo models for maintaining A. galli and the potential of using host immunosuppression to boost parasite development and worm egg output has not been investigated. To determine the most efficient way of propagating A. galli in young chickens an experiment with a 2 × 3 × 4 × 2 factorial design involving age of chicken at infection (day-old or 14 days old), immunosuppression (dexamethasone (DEX), cyclophosphamide (CY) or sham), infective egg dose (0, 100, 300 or 900 embryonated eggs/bird) and time of worm recovery after infection (8 or 10 weeks post-infection) was conducted. The experiment used a total of 384 layer cockerel chicks. Infection was delivered orally in 3 split doses over one week and immunosuppressants were administered by intramuscular injection concurrently with the infections. Body weight, excreta egg counts, intestinal worm count and worm establishment rate were assessed. The only sign of ascaridiosis noted was mild diarrhoea at the time of slaughter in some birds with a significant- positive association with worm count. Infection caused a significant dose dependent reduction in body weight in non-immunosuppressed birds but this effect was ameliorated by immunosuppression. Age at infection had no significant effect on the studied variables although both worm and egg counts were numerically higher in the day-old infected groups. Egg dose significantly influenced the prevalence of infection, worm establishment rate, worm egg production and mean worm count. The 300 and 900 egg doses resulted in significantly higher worm count and egg production than the 100 egg dose. A significant negative correlation was observed between egg dose and worm establishment rate indicating an inverse relationship. Immunosuppression with DEX, but not CY resulted in significantly higher mean worm burden than in control chickens with excreta egg counts also considerably higher in DEX treated birds. Our results suggest that trickle infection at day-old with infective doses of 300 eggs coupled with immunosuppression with DEX would provide the most efficient way to propagate A. galli worms in vivo, as using older birds or a higher egg dose did not provide any advantage.

Prevalence of Newcastle disease virus in feces of free-range turkeys in Enugu, Nigeria

Background and Aim:

Newcastle disease (ND) virus of free-range turkeys may be linked to outbreaks of ND in backyard chickens seen during Harmattan in Enugu State in Southeast Nigeria. This study aimed to determine the prevalence of ND virus and (NDV) detect NDV in the feces of free-range, domestic turkeys in Enugu, Nigeria.

Materials and Methods:

A total of 569 serum and 569 cloacal swab samples were collected from adult turkeys in selected households that keep turkeys and chickens together in the study area. The serum samples were assayed for antibodies against NDV using the hemagglutination inhibition (HI) test, whereas the cloacal samples were subjected to virus detection using a hemagglutination (HA) test.

Results:

A total of 186 serum samples (32.7%) were positive for NDV and 383 (67.3%) were negative. Of the 186 NDV-positive serum samples, 138 (74.2%) had HI titers ≥ 8. The remaining 48 (25.8%) serum samples had HI titers <8. NDV was detected from the cloacal swabs of turkeys with NDV -positive serum samples.

Conclusion:

The turkeys in this study were not previously vaccinated with the NDV vaccine; thus, those with NDV -positive serum samples and virus shedding in their feces may be potential risks to chickens reared in the same households as well as on commercial farms in the area. Those turkeys with sera negative for NDV are regarded to be at risk if they encounter a virulent strain of NDV. Regular vaccination of turkeys against the NDV is advised, especially in backyard farms, where turkeys are reared together with chickens and other species of poultry.

Effect of omega-3 rich diet on the response of Japanese quails (Coturnix coturnix japonica) infected with Newcastle disease virus or avian influenza virus H9N2

This study was performed to evaluate the effects of omega-3 supplementation on growth performance, clinical signs, post-mortem lesions, haemagglutination inhibition (HI) antibody titres, gene expression and histopathology in quails (Coturnix coturnix japonica) infected with Newcastle disease virus (NDV) and avian influenza virus (AIV) H9N2. One hundred, 40-day-old male quails were divided into 5 groups: G1, fed a control basal diet; G2A, infected with NDV; G2B, infected with H9N2; G3A, infected with NDV and given omega-3, and G3B, infected with H9N2 and given omega-3. The dietary omega-3 supplementation was continued for 4 weeks: two weeks before infection and two weeks after intranasal infection with virulent NDV and AIV H9N2. Our results revealed significant differences (P < 0.05) in growth performance, HI antibody titres, clinical signs, post-mortem lesions, mortality, viral shedding rates, immunological parameters, and histopathological lesions between the treated (G3A and G3B) and untreated (G2A and G2B) groups. In conclusion, dietary omega-3 supplementation for 4 weeks can improve growth performance and alleviate the deleterious immunological and pathological effects of NDV and AIV H9N2 infection in quails.

Pullets had higher bursal and thymic weight indices and more antibody response to La Sota vaccination than broiler chickens (Gallus gallus domesticus)

This study investigated the immune responses to La Sota vaccination, used in protection of chickens against Newcastle disease, in light weight type breeds of chickens (pullets) and heavy weight type breeds of chickens (broilers) used in commercial poultry production. Seven-week-old 50 White Marshall broilers (Br) and 50 Isa Brown pullets (Pu) were randomly divided into four groups: vaccinated broilers chickens; (VBr), unvaccinated broiler chickens (UBr), and vaccinated pullet chickens (VPu) and unvaccinated pullet chickens (UPu). Chickens in groups VBr and VPu were vaccinated with La Sota vaccine, whereas groups UBr and UPu were not vaccinated. On day 0 post vaccination (PV), six chickens from group Br and Pu, and on day 4 PV, three chickens from each four groups were sacrificed and the bursa weight index (BWI), thymus weight index (TWI) and the splenic weight index (SWI) were obtained. The chickens were observed for clinical signs and lesions. Serum samples were collected from the chickens in all the groups on days 0, 7, 14, 21, 28 PV and assayed for haemagglutination inhibition (HI) antibodies. The BWI, TWI and SWI were 0.37 ± 0.05, 0.35 ± 0.17, 0.65 ± 0.26 for pullets and 0.11 ± 0.04, 0.13 ± 0.02, 0.36 ± 0.17 for broilers on day 0 PV. On day 4 PV there was no significant difference (p < .05) between the indices of the vaccinated and unvaccinated chickens. The geometrical mean antibody titres (GMT) of the pullets were 2 to 3 times higher than those of the broilers on days 7 to 28 PV. Vaccination did not produce clinical signs or lesions. The above observations show that naturally pullets produce higher antibodies than broilers because of their higher BWI.