HI Antibody Titers Research Articles

The growth-promoting effect of water extract of Chuanminshen violaceum stem and leaf on broilers

Currently, developing non-antibiotic growth promoters is a broad consensus in broiler industry, which is one of the effective ways to reduce drug-resistant strains. Chuanminshen violaceum is a traditional Chinese medicinal herb that is commonly used for its roots, while the stems and leaves are often discarded, resulting in a huge amount of waste. This study optimized the preparation process of water extract of Chuanminshen violaceum stems and leaves (CVSLE) by response surface analysis based on the yields of polysaccharide and protein. The CVSLE and herbal powder (CVSL) were then processed into granules before being used as feed additives. The Macleaya cordata powder was used as positive control. The results showed that the addition of CVSLE (0.5% of the feed) showed the highest growth-promoting activity than other CVSLE groups (0.2% and 1%), 1% CVSL group and positive control (0.05%). CVSLE at the dosage of 0.5% could significantly increase the ADG and reduce the FCR from d 21 to 42, d 0 to 42. The HI antibody titers against Newcastle disease virus and avian influenza virus were significantly enhanced at 21, 28 and 42d. CVSLE did not affect the slaughtering performances, but could significantly elevate the spleen, thymus and bursa of Fabricius indices and the transcriptional levels of IL-2, IL-4, IL-10 and IFN-γ in spleen. The intestinal barrier function of broilers was significantly enhanced by increased levels of immune barrier (sIgA), physical barrier (ZO-1, OCL and Muc-2) and flora barrier (Lactobacillus and Bifidobacterium). These results suggest that CVSLE was a promising herbal additive candidate for broilers.

INFLUENCE OF PIGEON PARAMYXOVIRUS TYPE-1 ON CLINCOPATHOLOGICAL PROFILES IN RACING PIGEONS ASSOCIATED WITH RECENT OUTBREAKS IN IRAQ

The number of racing pigeons recently increased in Iraq accompanied by significant increases in the number of events similar to the neurotrophic velogenic group of ND viruses in different regions. Thus, this research was designed to study the influence of natural infection with PPMV-1 on clincopathological profiles in four PPMV-1-associated mortality events in racing pigeons in the southern part of Iraq. The result revealed that HI antibody titers above the positivity threshold of four events were seen in (9 out of 24) of tested pigeons in all events, and the predominant signs included polyuria followed by neural symptoms which appear in most of the affected pigeons in the flock. All events showed a high mortality rate (60% - 70%) and absence of gross abnormalities in necropsied pigeons. kidney showed widespread interstitial hemorrhage and intensive epithelial sloughing of renal tubular epithelium, marked white pulp hyperplasia and marked peri-arteriolar fibrosis with onion skin appearance in the spleen, and marked destruction of the superficial intestinal mucosa and intensive inflammation in the site of tissue destruction. This study demonstrates the role of PPMV-1 on clincopathological profiles in racing pigeons associated with recent outbreaks in Iraq, polyuria followed by neural symptoms represent the predominant symptoms in the affected pigeons.

Immunological properties of inactivated vaccines against Newcastle disease based on virus antigens VII and II the genotype

Newcastle disease (ND) is now widely spread in many countries of Eurasia, Africa and the Americas and causes significant economic damage to poultry farming. New NDinfected localities are reported in the Russian Federation every year; besides, the number of farms with vaccinated poultry demonstrating high specific antibody titres, decreased performance and survivability while being asymptomatic has increased. This is attributed to the virus evolution leading to the emergence of new genotypes represented by highly virulent strains. Since 2019, subgenotype VII-L has been isolated from Newcastle disease outbreaks in Russia. The vaccines currently available on the market do not confer appropriate protection against it due to the lack of antigenic matching between vaccine strains and this subgenotype. The development of a vaccine based on subgenotype VII -L will allow to ensure protection of poultry flocks against Newcastle disease caused by new NDV isolates. The immunological properties of emulsion inactivated vaccine against Newcastle disease based on genotype VII NDV (ARRIAH G7 strain) antigen were studied in 30-day-old Hisex Brown chickens. A similar vaccine based on genotype II NDV LaSota strain antigen was used as control. Tests of different immunizing antigen doses were carried out. The vaccines were tested for induced humoral immunity level (HI antibody titres), as well as for protective effect (protective index) after challenge with a highly virulent genotype VII NDV strain. The tests revealed that the antigenic activity and protective effect of both vaccines depended on the antigen concentration in the inoculation volume. Antibody titres were always higher when homologous antigens were used in HI tests. The vaccine based on the antigen of ARRIAH G7 strain (homologous to the challenge strain) was more effective than the control vaccine. Less ARRIAH G7 strain antigen was required to protect 50% of vaccinated poultry, compared with LaSota strain antigen. The comparative assessment of the same doses of the antigens showed that the vaccine based on ARRIAH G7 strain antigen had better immunological properties. The tested antigens demonstrated 18.3% bilateral affinity.

Protective effectiveness of two vaccination schemes against the prevalent Egyptian strain of Newcastle disease virus genotype VII.

Despite the strict preventive immunization used in Egypt, Newcastle disease remained a prospective risk to the commercial and backyard chicken industries. The severe economic losses caused by the Newcastle disease virus (NDV) highlight the importance of the trials for the improvement and development of vaccines and vaccination programs. In the present study, we evaluated the effectiveness of two vaccination schemes for protection against the velogenic NDV (vNDV) challenge. Four groups (A-D) of commercial broiler chickens were used. Two groups (G-A and G-B) were vaccinated with priming live HB1 GII simultaneously with inactivated GVII vaccines at 5 days of age, then boosted with live LaSota GII vaccine in group A and live recombinant NDV GVII vaccine in group B on day 16. Groups A to C were challenged with NDV/Chicken/Egypt/ALEX/ZU-NM99/2019 strain (106 Embryo infective dose 50/0.1 ml) at 28 days of age. Two vaccination schemes achieved 93.3% clinical protection against NDV with body gain enhancement; whereas, 80% of the unvaccinated-challenged birds died. On day 28, the mean HI antibody titers were 4.3 ± 0.33 and 5.3 ± 0.33 log2 in groups A and B, respectively. As well as both programs remarkably reduced virus shedding. The two vaccination schemes displayed close protection efficacy against the vNDV challenge. Therefore, using the combination of a live attenuated vaccine with an inactivated genetically matched strain vaccine and then boosting it with one of the available live vaccines could be considered one of the most effective programs against current field vNDV infection in Egypt.

A single immunization with H5N1 virus-like particle vaccine protects chickens against divergent H5N1 influenza viruses and vaccine efficacy is determined by adjuvant and dosage

ABSTRACT The H5N1 subtype highly pathogenic avian influenza virus (HPAIV) reveals high variability and threatens poultry production and public health. To prevent the spread of H5N1 HPAIV, we developed an H5N1 virus-like particle (VLP) vaccine based on the insect cell-baculovirus expression system. Single immunization of the H5N1 VLP vaccines induced high levels of HI antibody titres and provided effective protection against homologous virus challenge comparable to the commercial inactivated vaccine. Meanwhile, we assessed the relative efficacy of different adjuvants by carrying out a head-to-head comparison of the adjuvants ISA 201 and ISA 71 and evaluated whether the two adjuvants could induce broadly protective immunity. The ISA 71 adjuvanted vaccine induced significantly higher levels of Th1 and Th2 immune responses and provided superior cross-protection against antigenically divergent H5N1 virus challenge than the ISA 201 adjuvanted vaccine. Importantly, increasing the vaccine dose could further enhance the cross-protective efficacy of H5N1 VLP vaccine and confer completely sterilizing protection against antigenically divergent H5N1 virus challenge, which was mediated by neutralizing antibodies. Our results suggest that the H5N1 VLP vaccine can provide broad-spectrum protection against divergent H5N1 influenza viruses as determined by adjuvant and vaccine dose.

Evaluating the effect of Spirulina platensis on the immune response of broiler chickens to various vaccines and virulent Newcastle disease virus challenge

This study investigated the efficacy of co-administration of Spirulina platensis (SP) with vaccines on the immune response to Avian influenza (AI), Infectious bronchitis (IB), and Newcastle disease (ND), along with I/M challenging by virulent ND virus (vNDV) genotype VII. 126 one-day-old broiler chicks were allocated into six groups (21 birds/group with three replicates): G1: negative control; G2: positive control; G3: vaccinated, non-SP-supplemented; G4: vaccinated, SP-supplemented (0.1%); G5: vaccinated, SP-supplemented (0.3%); and G6: vaccinated, SP-supplemented (0.5%). G2–6 were challenged with a velogenic NDV genotype VII virus. Dietary SP administration prevented the ND-induced mortality compared to G2 (52.4%) and G3 (14.3%), in addition to alleviating the clinical disease. G3–6 showed significant improvement in body weight loss% and FCR during two weeks post vNDV challenge (pc), and the overall FCR (2.64 ± 0.28, 1.56 ± 0.03, 1.60 ± 0.05, 1.53 ± 0.04, and 1.54 ± 0.03 for G2, 3, 4, 5 and 6, respectively) (P<0.05). On the challenging day, the ND-HI titer (log2) of G3 (5.44 ± 0.24) was numerically higher than G6 (4.20 ± 0.55) and lower than G4 (6.10 ± 0.34) and G5 (6.00 ± 0.28). On the 10th day pc, ND-HI titer in G4–6 was numerically lower in a dose-dependent manner than that of G3, suggesting an antiviral efficacy of SP. G4–6 had lower viral shedding titer than G2 and G3 (P<0.05). In G3–6, viral shedding was reduced by 15, 27, 24, and 33.6%, respectively. In addition, the histopathological lesions in the trachea, lung, and spleen were severe in G2, moderately reduced in G3, and more relieved in G4–6. At three weeks after vaccination, the HI antibody titer of AIH5 was significantly higher after SP administration, especially at the 0.3% level, compared to the vaccine alone (P<0.05), demonstrating an immune-stimulating effect. In conclusion, dietary administration of SP, particularly a dose of 0.3%, for vaccinated chickens against NDV exerted an antiinflammatory and antiviral effects by preventing deaths, alleviating clinical disease and weight loss, and decreasing viral shedding post heterologous NDV challenge.

Immunomodulatory effects of aqueous extracts of Azadirachta indica and Piper Guineense on Newcastle disease vaccination in cockrels

The increased incidence of Newcastle disease (ND) outbreaks in the country even amongst vaccinated flocks, has given rise to the search for other means of boosting the immune system besides vaccination alone. A lot of plants have been shown to possess antimicrobial, antipyretic and anticoccidial effects. This study was designed to evaluate the immunomodulatory effect of the aqueous extracts of the leaves of Piper guineense and Azadirachta indica (Neem) on immune response to Newcastle vaccination in birds. A total of 110 cockrels were used in this study (30 for acute toxicity test and 80 for immuonomodulatory effects of extracts). The 80 cockerels were divided into four groups (A, B, C and D), each consisting 20 birds. Group A and B were treated with 100mg/kg of the aqueous extracts of Azadirachta indica and Piper guineense respectively for the first three weeks. All the birds in groups A to C were vaccinated with Newcastle disease vaccine Lasota (NDV-L) at day 21, while Group D was given distilled water only. Blood samples were taken from all groups on day 1, 7, 14 and 21 post-vaccination. Serum antibody level against ND virus were measured by HI test and antibody titre was found to be significantly (p≤0.05) higher in the group treated with Azadirachta indica but low in those treated with Piper guineense. There was no significant (p≥0.05) difference in the immune response seen in Group A compared to the positive control (Group C), but significantly (p≤0.05) higher compared to the negative control (Group D). It was therefore concluded that the aqueous extract of Azadirachta indica may enhance immunomodulatory effects against Newcastle disease virus, unlike that of Piper guineense.

Pig mange in Ossha Umuahia Southern Nigeiria – A case report

The increased incidence of Newcastle disease (ND) outbreaks in the country even amongst vaccinated flocks, has given rise to the search for other means of boosting the immune system besides vaccination alone. A lot of plants have been shown to possess antimicrobial, antipyretic and anticoccidial effects. This study was designed to evaluate the immunomodulatory effect of the aqueous extracts of the leaves of Piper guineense and Azadirachta indica (Neem) on immune response to Newcastle vaccination in birds. A total of 110 cockrels were used in this study (30 for acute toxicity test and 80 for immuonomodulatory effects of extracts). The 80 cockerels were divided into four groups (A, B, C and D), each consisting 20 birds. Group A and B were treated with 100mg/kg of the aqueous extracts of Azadirachta indica and Piper guineense respectively for the first three weeks. All the birds in groups A to C were vaccinated with Newcastle disease vaccine Lasota (NDV-L) at day 21, while Group D was given distilled water only. Blood samples were taken from all groups on day 1, 7, 14 and 21 post-vaccination. Serum antibody level against ND virus were measured by HI test and antibody titre was found to be significantly (p≤0.05) higher in the group treated with Azadirachta indica but low in those treated with Piper guineense. There was no significant (p≥0.05) difference in the immune response seen in Group A compared to the positive control (Group C), but significantly (p≤0.05) higher compared to the negative control (Group D). It was therefore concluded that the aqueous extract of Azadirachta indica may enhance immunomodulatory effects against Newcastle disease virus, unlike that of Piper guineense.

Immunological effect of Lactic acid bacteria adjuvant on in ovo injection of Newcastle disease vaccine

In ovo immunization of chicken embryos with live vaccines is an effective strategy to protect chickens against various viral pathogens. The immunogenic efficacies of in ovo administration of lactic acid bacteria (LAB) in combination with live Newcastle disease (ND) vaccine were investigated in this study. Four hundred healthy 1-day-old fertilized specific pathogen-free (SPF) eggs of similar weights were randomly assigned to one of four treatments, with five replicates of each treatment and a total of 20 for each replicate. On day 18.5 of incubation, in ovo injections were given. The treatment groups are as follows: (I) no injection, (II) 0.9% physiological saline injection, (III) ND vaccine injection, and (IV) LAB as an adjuvant for ND vaccine injection. The ND vaccine adjuvanted with LAB significantly increased the daily weight gain, immune organ index, and small intestine histomorphological development in layer chicks while decreasing the feed conversion ratio (FCR). The results suggested that the LAB-adjuvant group significantly affected the relative expression of mucosal mucin protein (mucin-1) and zoccluding small circle protein-1 (ZO-1) (P < 0.05), whereas the relative expression of occludin mRNA was not significantly affected (P > 0.05) compared with the non-injected group. Meanwhile, we indicated that intra-amniotic synbiotic injection significantly maintained the balance of flora (P < 0.05). Compared with the non-injected group, the ND vaccine adjuvanted with the LAB group exhibited significant promotion of the HI and SIgA antibody titers in serum on day 21 (P < 0.05), induction of higher production of cytokines (IL-2, IL-4, IL-6, IFN-γ) in serum. In summary, in ovo injection of ND vaccine adjuvanted with LAB has a positive impact on the growth performance, immune function, and microbiome of growing chicks.

Effects of dietary supplementation with antibiotic, organic acid, probiotic and prebiotic on the intestinal morphology and Newcastle disease virus titers of broilers in commercial farms

This experiment was carried out to survey the antibody levels against Newcastle disease virus (NDV) and the morphology of ileal villi of broilers in commercial farms. Based on antibiotics and feed additives used, farms were classified in 3 groups as follows (1) Group I was supplied with antibiotic, probiotics and prebiotics; (2) Group II were supplemented with antibiotic, probiotics, prebiotics and organic acids; and (3) Group III was supplied with antibiotic and probiotics. In each farm, ten chicks were sacrificed at day 1, and five chicks were sacrificed at 7, 14, and 28 days old. A total number of 225 Ross 308 broilers at 1, 7, 14 and 28 days of age were selected randomly from nine farms for the titration of antibody against NDV by using Hemagglutination inhibition assay (HI). Furthermore, total 54 ileum samples of chickens on 14 and 28 days old were also collected for measurement of intestinal morphology. The present study showed there were significant differences about the body weights of broilers across farms within the same antibiotics, feed additives and vaccination programs or among different groups at 7, 14 and 28 days of age. However, at the age of 28 days, except Farm 1, 9 (Group I); 4 (Group II) and 3 (Group III), the remaining farms did not meet the criterion of chicken’s body weight. After ND vaccination for broilers at one day old, the mean value of HI antibody titers gradually declined in the first two weeks. Except for Farm 7 and 8, at 14 days old, the remaining farms showed the low antibody titers under 3log2. No significant differences about the antibody titers against ND virus were found in broilers at 28 days of age (P &gt; 0.05) among farms. The findings suggested that the supplementation of antibiotics, probiotics and/or prebiotics and/or organic acids did not have any consistent effects on immune response to NDV and body weights of broilers. However, the morphometric parameters of ileal villi were improved and the positive correlations between body weight and villi height or villi area in ileum segment were found in these chickens.

Immunological, biochemical and pathological effects of vitamin C and Arabic gum co-administration on H9N2 avian influenza virus vaccinated and challenged laying Japanese quails

AimThis study evaluated the effect of co-administration of vitamin C and Arabic gum (AG) supplements on the response of vaccinated (VAC) and challenged laying Japanese quails with avian influenza virus (AIV) H9N2.Materials and methodsOne hundred and fifty 49-day-old laying Japanese quails were divided into 5 groups (G1-G5): the G1 group was a negative control, G2 group was unvaccinated + H9N2 challenged (Ch), G3 group was unvaccinated + supplements + Ch, G4 group was VAC + Ch, and the G5 group was VAC + supplements + Ch. The supplements (vitamin C, 1 g/liter of drinking water and AG, 1% ration) were given for 5 weeks post-vaccination (PV). The birds were injected subcutaneously with an inactivated H9N2 vaccine at 49 days of age. The quails were then challenged intranasally with AIV H9N2 at the 3rd week PV. Blood, tracheal swab and tissue samples were collected at the 1st, 2nd, and 3rd weeks PV, and at different time points post-challenge (PC).ResultsGrowth performance, egg production (%), egg and eggshell weights, HI antibody titers, clinical signs, lesions, mortality, virus shedding rates, leukogram, biochemical and immunological parameters and histopathological lesions PC showed significant differences (P < 0.05) between the vaccinated-unsupplemented (G4) group and the vaccinated-supplemented (G5) group. G5 showed the highest (P < 0.05) growth performance, egg production, HI antibody titers, and heterophil phagocytic activity and the lowest heterophil/lymphocyte (H/L) ratio, mortality, virus shedding rates, creatinine level and histopathological lesion scores in the lungs.ConclusionThe co-administration of vitamin C and AG for 5 weeks can improve growth performance, egg production and the immune response in vaccinated laying quails challenged with AIV H9N2.

Deficiency of C-reactive protein or human C-reactive protein transgenic treatment aggravates influenza A infection in mice.

C-reactive protein (CRP) has been shown to be a potential candidate target in the immunotherapy of severe influenza A infection. However, it is unclear on the pathogenesis associated with CRP in influenza infections. Here, we used influenza A H1N1 CA04 to infect human CRP transgenic mice (KI), CRP knockout mice (KO), and wild-type mice (WT), respectively, and compared the viral pathogenicity and associated immune response in those mice. The results showed that CA04 infection resulted in 100%, 80%, and 60% death in KO, KI, and WT mice, respectively. Compared to WT mice, CA04 infection resulted in higher TCID50 in lungs on day 3 after infection but lowered HI antibody titers in sera of survivors on day 21 after infection in KI mice. ELISA assay showed that IFN-γ concentration was significantly increased in sera of WT, KI, or KO mice on day 7 after infection, and IL-17 was remarkably increased in sera of WT mice but decreased in sera of KI mice while no significant change in sera of KO mice on day 3 or 7 after infection. Quantitative RT-PCR showed that the relative expression levels of immune checkpoint CTLA-4, LAIR-1, GITR, BTLA, TIM-3, or PD-1 mRNA in the lung presented decreased levels on day 3 or 7 after infection in KI or KO mice. The correlation analysis showed that mRNA expression levels of the 6 molecules positively correlated with viral TICD50 in WT mice but negatively correlated with viral TCID50 in KI or KO mice. However, only LAIR-1 presented a significant correlation in each lung tissue of WT, KI, or KO mice with CA07 infection statistically. IHC results showed that LAIR-1 positive cells could be found in WT, KO, or KI mice lung tissues with CA04 infection, and the positive cells were mainly distributed in an inflammatory dense area. Our results suggested that deficiency of CRP or human CRP transgenic treatment aggravates influenza A virus infection in mice. CRP is a double sword in immune regulation of influenza infection in which IL-17 and immune checkpoint may be involved.

Efficacy of recombinant Newcastle disease virus expressing HA protein of H9N2 Avian influenza virus in respiratory and intestinal tract

H9N2 subtype avian influenza virus (AIV) is a low pathogenic AIV, which is widely prevalent all over the world. The infection of H9N2 AIV often leads to secondary infection with other pathogens, causing serious economic losses to poultry industry. Up to now, several recombinant Newcastle disease viruses (NDV) expressing H9N2 AIV hemagglutinin (HA) protein had been developed. However, the efficacy of recombinant virus on tracheal and intestinal injury caused by H9N2 AIV was rarely reported. The aim of this study was to evaluate the efficacy of recombinant NDV expressing H9N2 AIV HA protein in respiratory and intestinal tract. In this study, based on Red/ET homologous recombination technology, H9N2 AIV HA gene was embedded into the genome of NDV LaSota vaccine strain to obtain the recombinant virus rNDV-H9. The recombinant virus rNDV-H9 showed similar replication kinetic characteristics with the parent LaSota strain and had good genetic stability. The immunization result showed that rNDV-H9 induced high HI antibody titer against H9N2 AIV. In the H9N2 AIV challenge experiment, rNDV-H9 could significantly reduce the virus shedding in trachea and cloaca. In addition, rNDV-H9 protected the barrier function of chicken intestinal mucosal epithelial cells and reduced the virus-induced inflammatory response to a certain extent, so as to inhibit the abnormal proliferation of E. coli. This study suggests that rNDV-H9 is a promising vaccine candidate against H9N2 AIV.

Supplementation of H7N9 Virus-Like Particle Vaccine With Recombinant Epitope Antigen Confers Full Protection Against Antigenically Divergent H7N9 Virus in Chickens.

The continuous evolution of the H7N9 avian influenza virus suggests a potential outbreak of an H7N9 pandemic. Therefore, to prevent a potential epidemic of the H7N9 influenza virus, it is necessary to develop an effective crossprotective influenza vaccine. In this study, we developed H7N9 virus-like particles (VLPs) containing HA, NA, and M1 proteins derived from H7N9/16876 virus and a helper antigen HMN based on influenza conserved epitopes using a baculovirus expression vector system (BEVS). The results showed that the influenza VLP vaccine induced a strong HI antibody response and provided effective protection comparable with the effects of commercial inactivated H7N9 vaccines against homologous H7N9 virus challenge in chickens. Meanwhile, the H7N9 VLP vaccine induced robust crossreactive HI and neutralizing antibody titers against antigenically divergent H7N9 viruses isolated in wave 5 and conferred on chickens complete clinical protection against heterologous H7N9 virus challenge, significantly inhibiting virus shedding in chickens. Importantly, supplemented vaccination with HMN antigen can enhance Th1 immune responses; virus shedding was completely abolished in the vaccinated chickens. Our study also demonstrated that viral receptor-binding avidity should be taken into consideration in evaluating an H7N9 candidate vaccine. These studies suggested that supplementing influenza VLP vaccine with recombinant epitope antigen will be a promising strategy for the development of broad-spectrum influenza vaccines.

Comparative efficacy of LaSota, B1 and Mukteswar Strain vaccines for Newcastle Disease Virus (NDV) in layer chickens

The control of Newcastle Disease (ND) relies on the use of safe and effective vaccines. Live vaccines which are prepared with lentogenic strains of Newcastle Disease Virus (NDV) are now more frequently used in broilers and layers than vaccines prepared from chemically inactivated strains of NDV mixed with adjuvant. This is because live freeze-dried vaccines can be produced on a large scale at a relative low cost. The vaccines are easy to administer on large scale, and rapidly stimulate cell-mediated and mucosal surface immunity. The present study was designed to compare the efficacy of LaSota, B1 and Mukteswar Strain vaccines for NDV in layer chickens. Findings of our present study indicated that production of HI-antibody titre was higher in birds of group A (512) vaccinated with ND LaSota, compared to those of group B (256) vaccinated with RDV (Mukteswar strain); group C (128) vaccinated with ND B1 (B1 strain) Hitchner at six weeks after vaccination. Thus, the ND LaSota vaccine was found to be superior to some extent than ND B1 Hitchner. However, as regards vaccination of chicks against NDV in earlier days, the use of lentogenic strains are recommended although it should be kept in mind that vaccination with LaSota strains would cause greater problems in young susceptible birds than Hitchner B1 strain and even though LaSota induces stronger immune response Asian J. Med. Biol. Res. 2021, 7 (4), 332-338

Efficacy evaluation of herbal preparations and antioxidants on the growth, immunity, antioxidant status and Escherichia coli counts of broilers under heat stress

The present experiment was conducted to evaluate the efficacy of different herbal preparations on the performance of broilers. For this, 250-day-old male broiler chicks were randomly divided into 5 treatment groups with 10 replicates of 5 birds each. The experimental design consisted of T1: control diet, T2: Herbal powder I, T3: Herbal powder II, T4: Herbal powder III, T5: vit E and Se. The results indicated that T4 and T5 had significantly higher body weight gain compared to other treatments at 42 d of age. However, among other test diets, cumulative body weight gain was comparable with vit E and Se. Feed intake was not influenced by different herbal supplementation, but significantly better feed conversion ratio was noticed in all the test diets. Lipid peroxidation, alkaline phosphatase, blood urea nitrogen, cholesterol, blood glucose levels and E. coli counts in small intestine were significantly low in treatment groups compared to control and at par with vit E and Se. All herbal preparations did not have any significant effect on various carcass parameters, total protein, albumin and HI antibody titer. From the results, it could be concluded that poly herbal preparations improved the overall performance of broilers.

Health Status and Stress in Different Categories of Racing Pigeons

Simple SummaryCorticosterone is the most important “stress” hormone in birds. Stress response is influenced by different factors, such as phylogeny, feed supply, age, body condition, health status, climate, predators. Pigeon races over long distances, 500 km or more, can lead to the “exploitation” of animals if not strictly regulated and observed, jeopardizing their welfare status. Animals should be in good health and body condition, and health monitoring must be implemented. In stressful situations such as races, the possibility of infection increases. Clinically asymptomatic infections can flare up later in the breeding season and can cause high offspring mortality. For example, infections with circoviruses are particularly important because of their ability to weaken the immune system. The purpose of this work is to identify the critical stress points during the active training season of racing pigeons for the improvement of their condition and the preservation of their welfare during races. The aim of our study was to determine the serum corticosterone levels in different categories of racing pigeons exposed to severe stress factors. At the time of racing, some parameters of stress, including environmental factors, or the presence of infectious diseases or parasites, were recorded. It was found that participation in the race significantly increased serum corticosterone levels and remained high even one month after the race. Therefore, training and races should be properly managed and planned.The influence of different stress parameters in racing pigeon flocks, such as the presence of diseases and environmental conditions at the time of the races, were described. A total of 96 racing pigeons from 4 pigeon flocks were examined, and health monitoring was carried out. No helminth eggs and coccidia were found. Trichomonas sp. was confirmed in subclinical form. Paramyxoviruses and avian influenza viruses were not confirmed, but circovirus infections were confirmed in all flocks. Chlamydia psittaci was confirmed in one flock. Blood samples were collected, and HI antibody titers against paramyxoviruses before and 25 days after vaccination were determined. To improve the conditions during racing and the welfare of the pigeons, critical points were studied with regard to stress factors during the active training season. Serum corticosterone levels were measured in the blood serum of four different categories of pigeons from each flock. Corticosterone levels were almost twice as high in pigeons from the category that were active throughout the racing season, including medium- and long-distance racing, compared to the other three categories that were not racing actively. Within five hours of the finish of a race, the average serum corticosterone level was 59.4 nmol/L in the most physically active category. The average serum corticosterone level in this category remained at 37.5 nmol/L one month after the last race.

Generation and Evaluation of Recombinant Thermostable Newcastle Disease Virus Expressing the HA of H9N2 Avian Influenza Virus.

H9N2 avian influenza virus (AIV) has become endemic in many countries, causing great economic losses when co-infected with other pathogens. So far, several live vaccines based on Newcastle disease virus (NDV) vectors expressing influenza hemagglutinin (HA) have been developed. However, the thermostable recombinant NDV is rarely reported. In this study, using a thermostable NDV rAHR09 strain as the vector, three recombinant NDVs expressing native HA, chimeric HA ectodomain with transmembrane domain/C-terminal cytoplasmic tail domain from fusion protein of NDV, and HA ectodomain were generated, designated rAHR09-HA, rAHR09-HAF, and rAHR09-HAE. The MDT value of three recombinant NDVs was above 120 h, their ICPI value was about 0.03, and the recombinant NDVs were still infectious when treated for 100 min under 56 °C, which demonstrated that the recombinant NDVs kept the lentogenic and thermostable nature of rAHR09. The immunization data showed that rAHR09-HA and rAHR09-HAF induced a higher HI antibody titer against H9N2 AIV and NDV. After being challenged with H9N2 AIV, the rAHR09-HA and rAHR09-HAF could significantly reduce the virus shedding in cloacal and tracheal swab samples. Our results suggest that rAHR09-HA and rAHR09-HAF might be vaccine candidates against H9N2 AIV.

KEMAMPUAN POLISAKARIDA MANNAN SEBAGAI ORAL ADJUVAN VAKSIN AVIAN INFLUENZA PADA AYAM BROILER

Polysaccharides contain mannan (PM) from palm kernel meal (PKM) potential as leader pathogen microorganism and enhancing the immune responses. The objective of the study was to evaluate efficacy of PM as oral adjuvant in increasing AI H5N1 antibody titer and immunoglobulin A (IgA) in serum of broiler thirty chickens age 1 - 6 weeks were divided onto five groups and assigned randomly to five vaccine treatments i.e : un-vaccinated birds (R0A), birds vaccinated with antigen H5N1 + 0 µg PM (R0B), birds vaccinated with antigen H5N1 + 50 µg PM (R1), birds vaccinated with antigen H5N1 + 100 µg PM (R2) and birds vaccinated with antigen H5N1 + 200 µg PM (R3). The results showed the treatment did not reduce broiler body weight (PM is not toxic). AI H5N1 antibody titer increased significantly (P0.05) one week after the first vaccination, serum IgA of broiler also increased significantly (P0.05) two weeks after the second vaccination. R3 treatment (200 μg PM) produce higher HI antibody titer ≤ 5 log2 and serum IgA 1.6 fold higher compared with those of broiler received R0A and R0B. It can be concluded that PM can increase the immune response in broiler chickens and can be used as an adjuvant for inactive AI vaccine.

Effect of Newcastle disease and infectious bronchitis live vaccines on the immune system and production parameters of experimentally infected broiler chickens with H9N2 avian influenza

H9N2 Avian influenza (AI) is an infectious disease which considered to have low pathogenic virulence, but in the case of coinfection with other pathogens it has the potential to become a major threat to the poultry industry. Infectious bronchitis (IB) and Newcastle diseases (ND) are other common problems to the poultry industry, which there are an extensive vaccination program against these viral pathogens. To investigate the effects of administration of infectious bronchitis and Newcastle disease live vaccines (IBLVs and NDLVs) in the presence of H9N2 AI infection on the immune system and some production parameters, 180 one-day-old broiler chicks were randomly allocated into six groups with different vaccination programs including H120 IBLV, 4/91 IBLV, B1 NDLV and LaSota NDLV. At the age of 20 days, all birds of the experimental groups except the negative control group, were inoculated intra-nasally (at dose of 106 EID50) with H9N2 AIV. After the inoculation, gross and microscopic lesions of the immune organs, serological changes and some production parameters were examined. The findings of this study showed that coinfection of H9N2 AI with NDLVs exacerbated the gross and microscopic injuries in the immune organs; especially the bursa of Fabricius. LaSota + AIV group had the most severe lesion in the bursa of Fabricius, spleen and thymus. Furthermore, the birds of LaSota + AIV group consumed the least amount of feed and water and their final body weight were significantly (P ≤ 0.05) lower in comparison with the other groups. Interestingly, in the context of this experiment both 4/91 and H120 IB live vaccines enhanced the HI antibody titers against H9N2 AIV, but the 4/91 showed the most significant (P ≤ 0.05) increase compared to the other experimental groups.