Effect of difference doses of Newcastle disease vaccine immunization on growth performance, plasma variables and immune response of broilers

Newcastle disease virus infection remodels plasma phospholipid metabolism in chickens

Newcastle disease is a global problem that causes huge economic losses and threatens the health and welfare of poultry. Despite the knowledge gained on the metabolic impact of NDV on cells, the extent to which infection modifies the plasma metabolic network in chickens remains unknown. Herein, we performed targeted metabolomic and lipidomic to create a plasma metabolic network map during NDV infection. Meanwhile, we used single-cell RNA sequencing to explore the heterogeneity of lung tissue cells in response to NDV infection in vivo. The results showed that NDV remodeled the plasma phospholipid metabolism network. NDV preferentially targets infected blood endothelial cells, antigen-presenting cells, fibroblasts, and neutrophils in lung tissue. Importantly, NDV may directly regulate ribosome protein transcription to facilitate efficient viral protein translation. In conclusion, NDV infection remodels the plasma phospholipid metabolism network in chickens. This work provides valuable insights to further understand the pathogenesis of NDV.

Effects of anti-stress agents on the growth performance and immune function in broiler chickens with vaccination-induced stress

The aim of this study was to evaluate the effects of anti-stress agents on the growth performance and immune function of broilers under immune stress conditions induced by vaccination. A total of 128, 1-day-old Arbor Acres broilers were randomly divided into four groups. Group normal control (NC) was the control group. Group vaccination control (VC), T 0.5%, and T 1% were the treatment groups, which were nasally vaccinated with two doses of the Newcastle disease virus (NDV) vaccine. The chicks in groups T 0.5% and T 1% were fed conventional diets containing 0.5% and 1% anti-stress agents. Thereafter, these broilers were slaughtered on 1, 7, 14, and 21 days post-vaccination. The results indicated that anti-stress agents could significantly reduce serum adrenocorticotropic hormone (ACTH) (P < 0.01) and cortisol (CORT) (P < 0.05) levels, and improve the growth performance (P < 0.05) and immune function of broilers (P < 0.05); However, the levels of malondialdehyde (MDA) (P < 0.05) were decreased, and the decreased total antioxidant capacity (T-AOC) (P < 0.01) levels mediated by vaccination were markedly improved. In addition, anti-stress agents could attenuate apoptosis in spleen lymphocytes (P < 0.01) by upregulating the ratio of Bcl-2 to BAX (P < 0.01) and downregulating the expression of caspase-3 and -9 (P < 0.01), which might be attributed to the inhibition of the enzymatic activities of caspase-3 and -9 (P < 0.05). In conclusion, anti-stress agents may improve growth performance and immune function in broilers under immune-stress conditions.RESEARCH HIGHLIGHTS Investigation of effects and mechanism of immune stress induced by vaccination.Beneficial effect of anti-stress agents on growth performance, immune function, oxidative stress, and regulation of lymphocyte apoptosis.Demonstration of the effects of apoptosis on immune function in the organism.

Serological evaluation of Newcastle disease protection among broilers at a live bird market in Kano, Northwest Nigeria, and its epidemiological significance

Vaccination is a tool of Newcastle disease (ND) control among broilers. This study aimed at determining the immunity status of sampled broilers against ND at a live bird market in Kano, Northwest Nigeria, and its epidemiological implication. A cross-sectional study of antibodies against Newcastle disease virus (NDV) was carried out among broiler chicken in a live bird market in Kano State, Northwest Nigeria. A total of 471 samples was tested successfully. NDV antibody titer was assayed using hemagglutination-inhibition test (HI) and ND indirect enzyme-linked immunosorbent assay (ELISA). Serological levels of NDV antibodies were 67.9% (ELISA) and 78.1% (HI). Also, 67 (20.9%) samples tested positive for ELISA but negative for HI, whereas 115 (31.3%) samples tested negative for ELISA but positive for HI. There is strong association between the immune status obtained from both tests (P < .05), significant difference exists between the immune titer obtained from both tests (P < .05). Protective antibody titer among the test subjects suggests individual protection against virulent NDV (vNDV) strain; however, protective levels ≥85% that confers herd immunity were not attained. This report emphasizes the need for farmers to be more compliant to ND vaccination schedule and best practices in their poultry farm to enhance ND control in Live Bird Markets (LBMs).

Prevalence of Newcastle Disease Virus in Commercial and Backyard Poultry in Haryana, India

Newcastle disease virus (NDV) causes Newcastle disease (ND) in poultry. The ND is a highly contagious disease, which is endemic in several countries despite regular vaccination with live or killed vaccines. Studies on NDV in India are mostly targeted toward its detection and characterization from disease outbreaks. A surveillance study was undertaken to determine NDV prevalence throughout the state of Haryana from March 2018 to March 2020 using a stratified sampling scheme. The state was divided into three different zones and a total of 4,001 choanal swab samples were collected from backyard poultry, commercial broilers, and layers. These samples were tested for the M gene of NDV using real-time RT-PCR. Of the 4,001 samples tested, 392 were positive (9.8% apparent prevalence; 95% CI: 8.9–10.8%) for the M gene. Of these 392 M gene positive samples, 35 (8.9%; 95% CI: 6.4–12.3%) were found to be positive based on F gene real-time RT-PCR. Circulation of NDV in commercial and backyard poultry highlights the importance of surveillance studies even in apparently healthy flocks. The information generated in this study should contribute to better understanding of NDV epidemiology in India and may help formulate appropriate disease control strategies for commercial and backyard birds.

Effects of heat stress on the immune responses of chickens subjected to thermal manipulation in the pre-hatch period

Heat stress affects the performance of poultry species and also induces immunosuppression. Chickens can be treated by thermal conditioning to have better heat stress tolerance. Our purpose was to determine the effect of acute heat stress on the immune response, i.e. antibody production against Newcastle disease virus (NDV) and change in the proportion of leukocyte components, in chicks subjected to prenatal heat conditioning. Eighty as-hatched broiler chicks from the same parent stock were used: control (40 chicks incubated at 36.7 °C from days 18-20 of embryonic life) and thermally manipulated (TM) (40 chicks incubated at 38.4 °C from day 18-20 of embryonic life; 4 h/day). The chickens were exposed to heat stress: at day 19 (31 °C/8 h) and at day 35 (32 °C/10 h). The first heat stress (day 19) decreased the lymphocyte counts and significantly increased the heterophil counts (P < 0.05) in both treatments (from 34.25 to 55% in the controls and from 37 to 60.06% in the TM chicks). The second heat stress (day 35) did not alter the heterophil and lymphocyte profiles of the chickens. Before the heat stress, all of the chickens (control and TM) presented the same positive antibody titres to NDV vaccination. After the first heat stress, 50% of the control samples and 40% of samples from the TM chickens were negative. After the second heat stress, 80% of the TM samples were negative.

Effects of ND vaccination combined LPS on growth performance, antioxidant performance and lipid metabolism of broiler

Newcastle Disease Virus (NDV) is the important pathogen of Newcastle Disease (ND) attacking chicken, turkey and other birds. Therefore, the purpose of this study was to assess the effects of immune stress induced by ND vaccination and lipopolysaccharide (LPS) on growth performance, antioxidant ability, and lipid metabolism of broilers. In total, 128 one-day-old broilers were randomly assigned to the following four groups and were treated as indicated: normal control (NC); vaccinated with live LaSota ND vaccine (CV); administered ND vaccine and 0.25 mg/kg body weight (BW) LPS (L-LPS); and administered ND vaccine and 0.5 mg/kg BW LPS (H-LPS). The results demonstrated that broiler feed conversion ratio (FCR) was increased in the groups CV, L-LPS and H-LPS from d 0 to 42 days compared with the group NC. The antioxidant function of broilers was decreased as indicated by the malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) levels in the serum of the treated groups. ND vaccination combined LPS increased the concentration of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), but decreased the concentration of high-density lipoprotein cholesterol (HDLC) compared with the group NC. The reverse transcription (RT)-PCR results revealed that the mRNA expression of acetyl-CoA carboxylase gene (ACC) and 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR) in the liver were downregulated, whereas the mRNA expression of carnitine palmitoyltransferase-1 (CPT-1) and peroxisome proliferator-activated receptor (PPAR)-α were upregulated compared with the group NC. These results suggest that ND vaccination combined LPS reduced broiler growth performance and antioxidant ability, whereas it activated AMPK-mediated lipid metabolism.

Do different vaccination regimes affect the growth performance, immune status, carcase characteristics and meat quality of broilers?

1. A vaccination regime is a schedule for the administration of vaccines which may vary according to country or even by farm. This study aimed to measure the production and health performance of broilers treated with different vaccination regimes. 2. A total of 108 Cobb 500 broiler birds were randomly divided into three treatment groups, with six replicates consisting of six birds per replicate. Each treatment group was administered with different vaccination regimes against Newcastle Disease (ND), Infectious Bronchitis (IB) and Infectious Bursal Disease (IBD). Treatment 1 (T1) broilers were vaccinated against ND+IB and IBD on days 7 and 14 of age, respectively (control); Treatment 2 (T2) broilers were vaccinated against ND+IB on days 3 and 7 of age, and IBD on day 14; and Treatment 3 (T3) broilers were vaccinated against ND+IB on days 7 and 21 and IBD on day 14. Throughout the 42-day study period, data and samples were collected to determine the growth performance, immune status, carcase characteristics and meat quality. 3. There were significant differences (P < 0.05) on growth performance (body weight, body weight gain, feed intake and cumulative feed conversion ratio), white blood cell count (heterophils percentage, lymphocytes percentage and heterophils to lymphocytes ratio), carcase characteristics (kill-out weight, de-feathered weight, dressing percentage, drumsticks and gastrointestinal tract weight) and meat quality (cooking loss and drip loss) between treatments. T1 broilers showed better growth, white blood cell count, carcase characteristics and meat quality compared to T2 and T3 broilers. 4. Based on findings from the current work, vaccination against ND+IB and IBD on days 7 and 14 proved to be the best vaccination regime for broiler production, due to the better production performance and health status of broilers.

Molecular and pathological characterisation of genotype VII Newcastle disease virus on Egyptian chicken farms during 2016-2018

Newcastle disease virus (NDV) remains a constant threat to the poultry industry even with intensive vaccination programmes. In the present study, 40 samples were collected from farms showing high mortalities in some Egyptian governorates between 2016 and 2018. Tracheal samples were collected for virus isolation and confirmed by real-time RT-PCR. Molecular characterisation was performed by sequencing, followed by phylogenetic analysis of the novel sequences. Histopathological and immunohistochemical examinations were performed on different organs from NDV-infected broilers. The phylogenetic analysis revealed that the NDV isolates from different areas of Egypt were genetically closely related and all belonged to genotype VII. The histopathological hallmarks included haemorrhagic tracheitis, interstitial pneumonia with syncytia formation, haemorrhagic proventriculitis, necrotising pancreatitis, pan-lymphoid depletion, non-suppurative encephalitis and nephritis. Immunological detection of NDV antigen clarified the widespread presence of viral antigen in different organs with severe lesions. The present study confirmed that a virulent NDV of genotype VII became the predominant strain, causing severe outbreaks in poultry farms in Egypt. The presence of viral antigen in different organs indicates the pantropic nature of the virus. Immunohistochemistry was a very useful diagnostic tool for the detection of NDV antigen.

Effects of induced stress from the live LaSota Newcastle disease vaccination on the growth performance and immune function in broiler chickens

This study was conducted to assess the growth performance and immunological effects of vaccination-induced stress on broilers. The chickens were administered 0, 2, 4, 8, and 16 doses of live LaSota Newcastle disease (ND) vaccine and slaughtered on the 1st, 7th, 14th, and 21st day post vaccination. The results showed that the serum antibody titers after Newcastle disease virus (NDV) vaccination were elevated at day 7 post vaccination, peaked at day 14, then declined by day 21. Interestingly, the antibody titers peaked at 2 doses, and no further dose-dependent titer increases were observed. This study demonstrated that vaccination-induced stress increased serum adrenocorticotropic hormone and cortisol, affected growth performance (average daily gain, average daily feed intake, and feed conversion ratio), and triggered apoptosis in spleen lymphocytes by downregulating the ratio of Bcl-2 to BAX and upregulating the gene expressions of caspase-3 and -9, which was concordant with the activation of the enzymatic activities of caspase-3 and -9. This study suggests that NDV vaccine doses in broilers must be controlled judiciously because increasing the number of doses resulted in increased lymphocyte apoptosis while the peak of the antibody titer and optimal growth performance were achieved at a low number of doses (2 doses).

A review of virulent Newcastle disease viruses in the United States and the role of wild birds in viral persistence and spread

Newcastle disease is caused by virulent strains of Newcastle disease virus (NDV), which causes substantial morbidity and mortality events worldwide in poultry. The virus strains can be differentiated as lentogenic, mesogenic, or velogenic based on a mean death time in chicken embryos. Currently, velogenic strains of NDV are not endemic in United States domestic poultry; however, these strains are present in other countries and are occasionally detected in wild birds in the U.S. A viral introduction into domestic poultry could have severe economic consequences due to the loss of production from sick and dying birds, the cost of control measures such as depopulation and disinfection measures, and the trade restrictions that would likely be imposed as a result of an outbreak. Due to the disease-free status of the U.S. and the high cost of a potential viral incursion to the poultry industry, a qualitative risk analysis was performed to evaluate the vulnerabilities of the U.S. against the introduction of virulent strains of NDV. The most likely routes of virus introduction are explored and data gathered by several federal agencies is provided. Recommendations are ultimately provided for data that would be useful to further understand NDV on the landscape and to utilize all existing sampling opportunities to begin to comprehend viral movement and further characterize the risk of NDV introduction into the U.S.

Pathology and immunohistochemistry study of Newcastle disease field case in chicken in Indonesia

AIM

The aim of the study was to examine pathology and the distribution pattern of Newcastle disease virus (NDV) in internal organs of chickens from a field case using immunohistochemical staining.

MATERIALS AND METHODS

10 groups of broiler, layer, and domestic chicken were collected from necropsy room Division of Pathology, Bogor Agricultural University. These chickens were originated from West Java and collected based on pathologist diagnosis as suspect of Newcastle disease (ND). They were subsequently confirmed positive of ND with real-time-reverse transcription polymerase chain reaction assay. The respiratory, circulatory, digestive, lymphoreticular and central nervous systems were collected for histopathology examination.

RESULTS

The gross pathology and histopathology changes were tracheitis, pneumonia, pericarditis, myocarditis, catarrhal proventriculitis, catarrhal enteritis, typhlitis, perihepatitis, pancreatitis, nephritis interstitial, splenitis, atrophy of Bursa Fabricius, and encephalitis.

CONCLUSION

The distribution pattern of NDV in internal organs of chickens from a field case in this study is similar with a previous reported pattern in systemic cases of the internal chicken organs. High intensity of immunohistochemistry stain result was detected in trachea, lung, proventriculus, duodenum, cecal tonsil, kidney, and brain.