Mortality Rate Of Chickens Research Articles

Construction, molecular characterization, and safety assessment of purB mutant of Salmonella Gallinarum

This study involves the development and molecular characterization of the isogenic markerless knockout mutant SG ΔpurB, a genetically engineered live attenuated strain aimed at controlling Salmonella Gallinarum (SG) infection in poultry. The mutant was generated by deleting the purB gene using λ-Red recombination technology, impairing adenylosuccinate lyase, necessary for purine biosynthesis. An 1,180 bp deletion was engineered within the purB gene, leaving a residual 298 bp genomic scar resulting in a purine auxotrophic mutant. Phenotypically, SG ΔpurB showed a 66.5% reduction in growth in LB broth compared to the wild-type strain and failed to grow in minimal media without adenosine. Growth was restored to near wild-type levels with 0.3 mM adenosine supplementation, demonstrating the strain’s conditional attenuation. In vivo pathogenicity assessments revealed that oral inoculation of SG ΔpurB into 3-day-old chickens at a dose of 2 × 108 CFU resulted in zero mortality, compared to an 80% mortality rate in chickens challenged with the wild-type strain. The SG ΔpurB strain exhibited significantly reduced clinical signs and lesion scores, with clinical sign scores dropping from 2.5/3 with the wild-type to 0.4/3 with the ΔpurB mutant, and lesion scores decreasing from 2.9/3 to 0.3/3. Additionally, the mutant was efficiently cleared from liver and spleen tissues by 14 days post-inoculation, unlike the wild-type strain, which persisted until the experiment’s end on day 21. The SG ΔpurB mutant shows potential as a safe alternative for preventing fowl typhoid, highlighting the promise of targeted genetic attenuation in developing effective vaccines for poultry diseases.

Reduced Nitric Oxide Synthase Involvement in Aigamo Duck Basilar Arterial Relaxation.

The basilar arterial endothelium mediates blood vessel relaxation partly through the release of nitric oxide (NO). Apoptosis of cerebrovascular endothelial cells is linked to a high mortality rate in chickens infected with the highly pathogenic avian influenza virus, but interestingly, ducks exhibit a greater resistance to this virus. In this study, we examined the responsiveness of duck basilar arteries (BAs) to various vasoactive substances, including 5-hydroxytryptamine (5-HT), histamine (His), angiotensin (Ang) II, noradrenaline (NA), acetylcholine (ACh), and avian bradykinin ornithokinin (OK), aiming to characterize the receptor subtypes involved and the role of endothelial NO in vitro. Our findings suggest that arterial contraction is mediated with 5-HT1 and H1 receptors, while relaxation is induced with β3-adrenergic and M3 receptors. Additionally, OK elicited a biphasic response in duck BAs, and Ang II had no effect. Endothelial NO appears to be crucial in relaxation mediated with M3 and OK receptors but not β3-adrenergic receptors in the duck BA. The reduced endothelial NO involvement in the receptor-mediated relaxation response in duck BAs represents a clear difference from the corresponding response reported in chicken BAs. This physiological difference may explain the differences in lethality between ducks and chickens when vascular endothelial cells are infected with the virus.

IMPLEMENTATION OF CORPORATE SOCIAL RESPONSIBILITY (CSR) PT. SARIWIGUNA BINASENTOSA, THROUGH THE BROILER CHICKEN CULTIVATION PROGRAM, TO IMPROVE CAPACITY BUILDING AND COMMUNITY WELFARE IN SAMPIK BACKWOODS, AIR BARA VILLAGE

One of the concrete steps for change to contribute to the society and environment where the company locates is through the Corporate Social Responsibility (CSR) program. The CSR program aims to improve the company's good name, maintain good relations between the company and stakeholders, help with problems in the surrounding environment, and improve community welfare. PT. Sariwiguna Binasentosa is a tin smelting, processing, and marketing company spread across several areas in Bangka Belitung Islands, one of which is in Air Bara Village. This type of CSR program conducts in Sampik backwoods, Air Bara Village. It is through community empowerment for broiler chicken farming. The selection of program activity type is where broiler chickens are economical livestock compared to other livestock. In addition, the growth is fast, and meat production is relatively short is 5-7 weeks. However, there are some drawbacks of this broiler cultivation or livestock, such that they are susceptible to disease, easily stressed, and selling prices are relatively fluctuating. The success of broiler farming is seeable from various aspects, including feed, body weight, etc. The results of cultivating twice the period showed a decrease in the mortality rate of chickens by 2.17%. In the first period, the death rate was 7.77% (39 of the 502-population died). While in the second period, the mortality rate was 5.60% (28 of the 500 population). The group succeeded in reducing the death rate of chickens by controlling the causal factors

A Dynamic Model For Poultry Supply Chain In West Java


 
 
 
 This paper analyzes the constraints on supply chain processes within the poultry industry in West Java, Indonesia after COVID-19 pandemic. During the upstream process, poultry feed costs fluctuates greatly and lacks of storage which causing feed supply constraint, the mortality rate of chickens often surpasses 5% due to several factors including stocking density. Another identified problem adversely affecting the upstream process is the inability of small-scale farmers to procure their own Grand Parent Stock (GPS) since they remain dependent upon corporations to supply it, leading to inefficiency and increased production costs. Meanwhile, in downstream processes, the lack of a cold supply chain system and adequate storage capacity presents other challenges with regard to product durability. Consumer awareness regarding the relationship between food safety and health, and shifting in consumer preferences, especially during COVID-19 pandemic is also considered as a constraint in West Java poultry supply chain. To cope with those problems, several solutions such as technology and policy were offered to improve and solve problems in the supply chain process. Technology can be a powerful tool in addressing challenges in the poultry supply chain by providing efficient, accurate, and scalable solutions. While policy play a crucial role in addressing problems in the poultry supply chain by setting standards, promoting best practices, and providing a framework for action, regulate the behavior of the actors, promote transparency and hold actors accountable for their actions. A causal loop diagram is also made to assess the relationship between technology and policy in poultry supply chain process
 
 
 
 

HPAI-resistant Ri chickens exhibit elevated antiviral immune-related gene expression

Highly pathogenic avian influenza viruses (HPAIVs) is an extremely contagious and high mortality rates in chickens resulting in substantial economic impact on the poultry sector. Therefore, it is necessary to elucidate the pathogenic mechanism of HPAIV for infection control. Gene set enrichment analysis (GSEA) can effectively avoid the limitations of subjective screening for differential gene expression. Therefore, we performed GSEA to compare HPAI-infected resistant and susceptible Ri chicken lines. The Ri chickens Mx(A)/BF2(B21) were chosen as resistant, and the chickens Mx(G)/BF2(B13) were selected as susceptible by genotyping the Mx and BF2 genes. The tracheal tissues of HPAIV H5N1 infected chickens were collected for RNA sequencing followed by GSEA analysis to define gene subsets to elucidate the sequencing results. We identified four differentially expressed pathways, which were immune-related pathways with a total of 78 genes. The expression levels of cytokines (IL-1β, IL-6, IL-12), chemokines (CCL4 and CCL5), type interferons and their receptors (IFN-β, IFNAR1, IFNAR2, and IFNGR1), Jak-STAT signaling pathway genes (STAT1, STAT2, and JAK1), MHC class I and II and their co-stimulatory molecules (CD80, CD86, CD40, DMB2, BLB2, and B2M), and interferon stimulated genes (EIF2AK2 and EIF2AK1) in resistant chickens were higher than those in susceptible chickens. Resistant Ri chickens exhibit a stronger antiviral response to HPAIV H5N1 compared with susceptible chickens. Our findings provide insights into the immune responses of genetically disparate chickens against HPAIV.

Genomics and pathogenesis of the avian coronavirus infectious bronchitis virus.

Infectious bronchitis virus (IBV) is a member of the family Coronaviridae, together with viruses such as SARS-CoV, MERS-CoV and SARS-CoV-2 (the causative agent of the COVID-19 global pandemic). In this family of viruses, interspecies transmission has been reported, so understanding their pathobiology could lead to a better understanding of the emergence of new serotypes. IBV possesses a single-stranded, non-segmented RNA genome about 27.6 kb in length that encodes several non-structural and structural proteins. Most functions of these proteins have been confirmed in IBV, but some other proposed functions have been based on research conducted on other members of the family Coronaviridae. IBV has variable tissue tropism depending on the strain, and can affect the respiratory, reproductive, or urinary tracts; however, IBV can also replicate in other organs. Additionally, the pathogenicity of IBV is also variable, with some strains causing only mild clinical signs, while infection with others results in high mortality rates in chickens. This paper extensively and comprehensibly reviews general aspects of coronaviruses and, more specifically, IBV, with emphasis on protein functions and pathogenesis. The pathogenicity of the Australian strains of IBV is also reviewed, describing the variability between the different groups of strains, from the classical to the novel and recombinant strains. Reverse genetic systems, cloning and cell culture growth techniques applicable to IBV are also reviewed.

Dual Host and Pathogen RNA-Seq Analysis Unravels Chicken Genes Potentially Involved in Resistance to Highly Pathogenic Avian Influenza Virus Infection.

Highly pathogenic avian influenza viruses (HPAIVs) cause severe systemic disease and high mortality rates in chickens, leading to a huge economic impact in the poultry sector. However, some chickens are resistant to the disease. This study aimed at evaluating the mechanisms behind HPAIV disease resistance. Chickens of different breeds were challenged with H7N1 HPAIV or clade 2.3.4.4b H5N8 HPAIV, euthanized at 3 days post-inoculation (dpi), and classified as resistant or susceptible depending on the following criteria: chickens that presented i) clinical signs, ii) histopathological lesions, and iii) presence of HPAIV antigen in tissues were classified as susceptible, while chickens lacking all these criteria were classified as resistant. Once classified, we performed RNA-Seq from lung and spleen samples in order to compare the transcriptomic signatures between resistant and susceptible chickens. We identified minor transcriptomic changes in resistant chickens in contrast with huge alterations observed in susceptible chickens. Interestingly, six differentially expressed genes were downregulated in resistant birds and upregulated in susceptible birds. Some of these genes belong to the NF-kappa B and/or mitogen-activated protein kinase signaling pathways. Among these six genes, the serine protease-encoding gene PLAU was of particular interest, being the most significantly downregulated gene in resistant chickens. Expression levels of this protease were further validated by RT-qPCR in a larger number of experimentally infected chickens. Furthermore, HPAIV quasi-species populations were constructed using 3 dpi oral swabs. No substantial changes were found in the viral segments that interact with the innate immune response and with the host cell receptors, reinforcing the role of the immune system of the host in the clinical outcome. Altogether, our results suggest that an early inactivation of important host genes could prevent an exaggerated immune response and/or viral replication, conferring resistance to HPAIV in chickens.

Immunogenicity and protective efficacy of irradiated Salmonella Gallinarum against homologous challenge infection in Bovans brown chickens

Fowl typhoid is a systemic poultry disease caused by Salmonella Gallinarum (SG). It is responsible for significant economic loss, due to its severe morbidity and mortality. An irradiated vaccine is one of the possible alternatives to prevent and control fowl typhoid. This study aimed to evaluate the safety, immunogenicity, and protective efficacy of irradiated SG using a randomized control trial in chicken. A field strain of SG was exposed to different doses of gamma irradiation to determine its effect on the viability of SG. Safety and immunogenicity were assessed by administering irradiated SG orally to 3 groups (5 each) of 5 weeks old Bovans brown chickens at 2400, 2500, and 2600 gray (Gy). The protective efficacy of 108colony forming units (CFU) of SG irradiated at 2400 Gy administered orally and subcutaneously was then evaluated using homologous challenge infection and compared with SG 9R commercial vaccine using 40, 5-week old Bovans brown chickens where the chickens were randomly assigned to 4 groups. Chickens in Group 1were exposed to 108 CFU of irradiated SG orally; Group 2 to the same dose subcutaneously; Group 3 to SG 9R strain commercial vaccine subcutaneously, Group 4 to phosphate-buffered saline (PBS) orally. Data related to survival, antibody response, and pathological lesions were recorded. Mann-Whitney U-test, Kruskal-Wallis test, and Fisher’s exact tests were used to examine for statistical significance. Irradiation at 2600 Gy caused complete inactivation of SG whereas SG exposed to 2400 Gy showed better immunogenicity and was safe for chickens. Antibody response in a group of chickens vaccinated with irradiated SG administered subcutaneously (SC) was significantly higher than those vaccinated with the SG 9R vaccine on day 7 (p=0.003) and day 14 (p=0.002) post-immunization. Comparative evaluation of the protective efficacy based on the mortality rate of chickens after challenge showed that 2400 Gy irradiated SG vaccine administered SC and SG 9R vaccine-induced equal protection of 50% while the irradiated vaccine administered orally protected only 10% of chickens against homologous challenge infection. SG was not isolated from the liver, spleen, and feces of chickens that survived challenge infection until the end of the experiment. Irradiated SG administered SC is shown to be a promising vaccine against fowl typhoid. Further studies using a large sample size involving tuning of irradiation dose to improve immunogenicity and use of booster vaccination are recommended.
 Keywords: Chicken; Fowl typhoid; Gamma irradiation; Salmonella Gallinarum; Vaccine

Manajemen Risiko Penyakit Unggas pada Peternak dan Pedagang Ayam Broiler di Jawa Barat

Livestock products are an important commodity in Indonesia. Broiler chickens are one of the main consumption commodities in the community. The high demand for broiler chickens needs to be accompanied by supervision of product quality. Product quality control is one of them is the management of poultry disease risk. The research objective is to determine the behavior of breeders and traders in mitigating the spread of poultry disease. This study was conducted by mapping the supply chain of live broiler chickens to find out the distribution channel, analyzing the behavior of breeders and traders to determine optimal disease mitigation, and multiple linear regression analysis to determine the causes of death. Research locations were conducted in four regions, namely Ciamis Regency, Tasikmalaya Regency, Subang Regency, and Sukabumi Regency. The results of the study show that the supply chain of broiler chickens is different for each region. The longer the distribution channel, the higher the risk of spreading the disease. breeders and traders generally know poultry diseases and the symptoms of chickens infected with the disease. Knowledge of breeders and traders about bird flu symptoms that are better proven to reduce the risk of death of broiler chickens during handling. More than 64% breeders chose to separate sick chickens form healthy chickens, 22% chose to treat sick chikens, 11%sold all si hicens, and 3% destroyed sick chikens. The majority of traders mitigate the disease only by cleaning vehicles and baskets without disinfectants. The mortality rate of chickens in traders significantly increased along with the increase in the number of purchases and the distance of transportation.

Role of Pigeons in the Transmission of Avian Avulavirus (Newcastle Disease-Genotype VIId) to Chickens.

Simple SummaryNewcastle disease is an acute fatal disease of poultry. All broiler chickens and 8/15 pigeons were killed when infected intramuscularly (IM), while 7/10 chickens and only 1/15 pigeons were killed when infected intranasally (IN) with the virus in an experimental setting. Chickens in contact with infected pigeons developed severe respiratory, digestive and nervous signs. The mortality rates in chickens in contact with IM and IN infected pigeons were 2/5 and 3/5, respectively. Chickens in contact with IM infected pigeons had higher viral shedding titres than those in contact with IN infected pigeons. Free-range pigeons are considered an efficient carrier and transmitter of NDV-VIId to commercial broiler chickens raised in open houses.Newcastle disease is an acute fatal disease of poultry. The aim of this study was to determine the dynamics of the transmission of avian avulavirus (velogenic viscerotropic Newcastle disease-genotype VIId) from either intramuscularly (IM)- or intranasally (IN) infected 8-week-old Egyptian Baladi pigeons in contact with commercial Arbor Acres broiler chickens (4 weeks of age). The mortality of IM infected chickens and pigeons was 10/10 for chickens and 8/15 for pigeons, while the mortality of IN infected chickens and pigeons was 7/10 for chickens and only 1/15 for pigeons. The concentration of viral shedding in the oropharynx was higher than that in the cloaca for both IN and IM infected pigeons. Pigeons infected IN continued shedding the virus from the oropharynx from the 4th day post-infection (dpi) up to the 16th dpi, while IM infected pigeons stopped oropharyngeal shedding at the 11th dpi. Chickens in contact with infected pigeons developed severe respiratory, digestive and nervous signs. The mortality rates in chickens in contact with IM and IN infected pigeons were 2/5 and 3/5, respectively. Chickens in contact with IM infected pigeons showed higher viral shedding titres in both the oropharynx and cloaca than chickens in contact with pigeons infected IN. In conclusion, free-range pigeons are considered an efficient carrier and transmitter of NDV-VIId compared to commercial broiler chickens raised in open houses.

Molecular detection of Marek's disease virus in feather and blood samples from young laying hens in Colombia.

Marek's disease virus (MDV) is an immunosuppressive pathogen that can cause low production efficiency and high mortality rates in chickens. There is no current information on the MDV serotypes and pathotypes circulating in vaccinated commercial farms in Colombia where the birds are vaccinated in the incubator with Gallid herpesvirus (GaHV-2) and Meleagrid herpesvirus 1 (MeHV-1). Based on that, the main focus of this study was to understand the MDV's infection dynamics for the three known serotypes and to detect wild-virus pathogenic strains in 4-layer poultry farms in Antioquia. Samples of blood, feathers and spleens were collected from three randomly chosen animals according to age category: 1, 15, 30, 60, 90, and 120 days. Quantitative real-time PCR (qPCR) that differentiates between the three serotypes of MDV was used to assess viral loads over time, and phylogenetic analysis of the Meq oncogene was done to compare the strains of MDV with those of known pathogenicity. Meleagrid herpesvirus 1 (MeHV-1) was detected in all blood and feather follicle samples with an average number of genome copies (per 10,000 cells) of 31.44 in blood as expected as a result of vaccination. GaHV-2 was also detected in almost 100% of the blood and feather follicle samples throughout all defined age categories, with an average of 10.65 genome copies in blood samples. Gallid herpesvirus 3 (GaHV-3) was detected in 72% of blood and 84.61% of feather samples, with less than 1 copy per 10,000 cells. Based on the number of 132 bp repeats of the BamHI-H and BamHI-D regions in pooled feather samples, there were 70% (8/25) of attenuated MDV and 30% (17/25) of virulent MDV strains circulating in the farms. Virus isolation was performed successfully from every farm. In conclusion, different strains of MDV are circulating for up to 120 days in layers in Antioquia-Colombia and could be of major impact in poultry health. Keywords: Marek's disease virus (MDV); Antioquia-Colombia; qPCR; PCR; Meq gene phylogeny.

RISK ASSESSMENT FOR EXPERIMENTAL WASTE CONDEMNATION FROM CHICKEN CHALLENGED WITH VARIANT IB VIRAL STRAIN

infectious bronchitis virus is an acute and economically important viral disease of chickens. IB is a member of the Coronaviridae family it is an acute disease of respiratory and urogenital tract of chickens. Some IBV strains can cause acute nephritis and urolithiasis associated with the high mortality rate in chickens; considering (IBV) which can affect avian and represent a risk for public health, classified as risk group 2. This study, take place in isolators to detect of experimental waste condemnation after challenge variant IB strain in 3 weeks specific pathogen-free vaccinated birds and non-vaccinated control. Samples (kidneys and lungs) were collected for the detection of pathological changes. No Histopathological lesions were observed, nor virus was detected in the following challenge. This work was designed to apply biosecurity and biosafety parameter which including biological waste decontamination and disinfection in order to judge about any residual living virus after challenge test

A comparative pathogenicity analysis of two adenovirus strains, 1/A and 8a/E, isolated from poultry in Poland

Fowl adenoviruses (FAdVs) are the causative agents of multietiological syndromes and diseases in poultry flocks. During a routine diagnostic examination, two FAdVs strains were isolated. Molecular typing of these isolates based on the partial loop L1 HVR1-4 region of the hexon gene sequence revealed the presence of different FAdV isolates: 1/A-61/11z (GenBank accession number KX247012, APP94082), and 8a/E-6/12j (GenBank accession number: KP890032, ALB00550), and comparative genome analysis indicated small differences between these two viruses. The next step of the study was the estimation of the pathogenicity of these isolates in specific-pathogen-free (SPF) chickens. Chickens were divided into three groups, with 20 chickens per group infected intraperitoneally on the first day after hatching. Group I consisted of chickens infected with strain FAdV-1/A-61/11z, group II consisted of chickens infected with strain FAdV-8a/E-6/12j, and group III consisted of uninfected birds. Clinical signs observed in infected chickens included poor growth, apathy, prostration, ruffled feathers, crouching position, and huddling behavior. The mortality rate in chickens infected with FAdV-1/A-61/11z was 10% at 10 days postinfection (dpi), and no mortality was observed in chickens infected with the FAdV-8a-6/12j strain. The mean real-time PCR threshold cycle (Ct) value was 39.70%. The detection limit of these assays was 8 copies, with an efficiency of 91.03% and 95.17% and regression square (R2) values of 0.991 and 0.997, respectively, with a mean pathogen load of 4.8 × 106.0 copies/µl. The assays did not demonstrate cross-reactivity between types 1/A and 8a/E and non-targeted poultry viruses. Adenoviral DNA was detected in the liver, spleen, kidney, gizzard, intestine, bursa of Fabricius, and thymus of every examined dead and euthanized chicken from groups I and II between the third and fourth week postinfection. This is the first study conducted on the pathogenic and apathogenic strains FAdV-1/A and FAdV-8a/E, showing the presence of the virus in multiple tissues in chickens in Poland. This study revealed that it is very likely that the FAdV-1/A-61/11z strain is able to cause clinical inclusion body hepatitis (IBH) in chickens and that it is slightly more virulent than the FAdV-8a/E-6/12j strain, although both are primary pathogens of the disease.

PATHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY OF P. MULTOCIDA CAPSULAR TYPE A IN TISSUES OF CHICKENS AND DUCKS INFECTED WITH FOWL CHOLERA

Sixteen chickens' flocks and six ducks᾿ flocks were surveyed for presence of fowl cholera (FC) during the period from July 2013 to November 2016. A total of 81 freshly dead birds (51 chickens of average age 50 to 180 days and 30 ducks of average age 30-100 days) were received from different farms and house breeding in Dakahlia Governorate at Mansoura Laboratory of Animal Health Research Institute for further laboratory examination. FC was diagnosed based on case history, postmortem lesions, bacteriological isolation, polymerase chain reaction (PCR), capsular typing, virulence factor detection (Tox A gene), and immunohistochemistry (IHC). In this study, Pasteurella multocida (P. multocida) were bacteriologically isolated from 22 chickens and 16 ducks. The infection occurred in 4 layer chickens flocks, 2 breeder flocks and 3 broiler flocks. Meanwhile, all affected flocks of ducks were broiler. Age susceptibility in chickens varied as the age ranged from 30-54 days in broiler flocks, 45-150 days in layer flocks during the rearing period and before start egg production, 70-150 days in breeder flocks during the rearing period. In ducks the susceptible age ranged from 30-100 days. The most affected cases of chickens were from farm housing and the most affected cases of ducks were from back yard housing. Mortality rate in chickens was 0.03 to 0.36 and in ducks was 33.3 to 46.6%. Main gross findings in affected chickens and ducks were corn meal liver, fibrinous perihepatitis and fibrinous pericarditis. Swollen hock joint and thickened foot pad were grossly detected in ducks only. The histopathological lesions in the infected ducks were more severe than those detected in the infected chickens that characterized by multiple granulomata in most examined organs. Therefore, the IHC positive reaction against antigen of P. multocida serotype A were more intensely stained and widely distributed in all examined organs of infected ducks than in chickens.

Amino acid substitution at position 44 of matrix protein 2 of an avirulent H5 avian influenza virus is crucial for acquiring the highly pathogenic phenotype in chickens

The pathogenicity of highly pathogenic avian influenza (HPAI) viruses is dependent on multiple factors, but the sequence at the HA cleavage site plays the most important role. To better understand the mechanism of virulence of HPAI virus, an avirulent H5 avian influenza virus, A/teal/Tottori/150/02 (H5N3, teal/150), was passaged in respiratory organs of chickens to generate a virus with a highly pathogenic phenotype. After 12 consecutive passages, the virus (strain 12a) became highly pathogenic, with a 100 % mortality rate in chickens. Sequence analysis of the highly pathogenic variant revealed an amino acid change from aspartic acid (Asp) to asparagine (Asn) at position 44 of matrix protein 2 (M2). To investigate the role of M2 in the pathogenicity of HPAI virus, we generated reassortant viruses possessing a polybasic HA cleavage site and either Asp or Asn at position 44 of M2 using the highly pathogenic strain 12a and the avirulent strain 7a, which has Asp at position 44 of M2 derived from isolate teal/150, and we compared their pathogenicity in chickens. Experimental infections demonstrated that the pathogenicity of viruses possessing Asp in M2 was dramatically decreased, and the mortality rate of inoculated chickens was 0 %, in contrast to viruses with Asn, which showed 70 to 100 % mortality. Our findings indicate that M2 protein of the avirulent H5 avian influenza virus is important for acquiring high virulence and that Asn at position 44 of M2, in addition to the polybasic HA cleavage site, is crucial for high pathogenicity in chickens.

SUBSTITUSI TEPUNG DAUN MENGKUDU DALAM RANSUM MENINGKATKAN KINERJA AYAM BROILER

An experiment was conduted to evaluate the effectiveness level of corn substituted by Morinda citrifolia leaf meal in broiler ration. The use of Morinda citrifolia leaf meal substituted for corn in ration is expected to improve feed conversion in broiler chickens and produce chicken meat that safe for consumption and free of chemical antibiotics residues . Completely Randomized Design (CRD) was used to analyze data obtained from this research. One hundred and sixty chicleas (7 days aged) divided into 5 (five) treatments with 4 (four) replications and each replication consisted of 8 (eight) chicleas. Ration of treatments were a negative control diet (R0), 1% Morinda citrifolia leaf meal (R1), 2% Morinda citrifolia leaf meal (R2), 3% Morinda citrifolia leaf meal (R3) and commersial ration (R4). All treatments rations were added a natural feed additive that consist of 0,125% Curcuma and.0,075% Turmeric meal. Measured parameters were feed intake, weight gain, feed conversion ratio, mortality, percentages of carcas and abdominal fat. Results showed that feed consumption, weight gain, and feed conversion ratio were significantly (p <0.05) influenced by treatments. Mortality, percentage of carcas and abdominal fat were not significantly (p >0.05) influenced by ration treatments. Mortality rates in chickens using a ration of treatment was 0%, while using the control diet 0,78% (1 bird). The counclusion showed that the substitution of 1-2% Morinda citrifolia leaf meal in ration has better performance compared to the control diet, with improvement of feed conversion ratio was 7.57 and 9.2% respectively was more efficient than the control diets

Glycogen production by different Salmonella enterica serotypes: contribution of functional glgC to virulence, intestinal colonization and environmental survival

In enteric bacteria, the contribution of endogenous energy sources to survival both inside and outside the host is poorly understood. The contribution of glycogen production to the virulence, colonization and environmental survival of different Salmonella enterica serotypes was assessed. Of 19 serotypes (339 strains) tested for glycogen production, 17 (256 strains) were positive. The avian-specific serovars S. Gallinarum (62 strains) and S. Pullorum (21 strains) did not produce glycogen. The sequence of glgC in three S. Gallinarum strains tested revealed an identical deletion of 11 consecutive bases, which was not present in S. Pullorum, and a CCC insertion after position 597. Transduction of S. Gallinarum and S. Pullorum to a glycogen-positive phenotype did not change the ability to colonize the intestine or affect virulence in the chicken. Mortality rates in chickens following oral infection with a S. Typhimurium glycogen mutant (glgC : : km) were not significantly reduced, although colonization of the intestine was reduced over the first 4 weeks of the trial. Growth and yield of the glgC : : km mutant were comparable to the parent. The glgC mutant survived less well in faeces and in water at 4 degrees C when the strain was grown in LB broth containing 0.5 % glucose, and in saline it died off more rapidly after 7 days. The data suggest that glycogen has a complex but comparatively minor role in virulence and colonization, but a more significant role in survival.

Biology of the Malaysian Strain of Plasmodium juxtanucleare Versiani and Gomes, 1941. I. Description of the Stages in the Vertebrate Host

Plasmodium juxtanucleare was first described from domestic fowl in Brazil. Since that time similar parasites have been reported from Mexico, Uruguay, and Ceylon. Recently a morphologically similar form has been found widely distributed in the domestic fowl of Malaysia. The Malaysian strain of P. juxtanucleare is described and illustrated. The Asian strains are morphologically quite similar. However, some differences are noted between the Malaysian and the Brazilian strains. Versiani and Gomes (1941) described a malarial parasite from the domestic fowl (Gallus gallus) in Minas Gerais, Brazil which they named Plasmodium juxtanucleare. In the same year Beltran isolated a similar parasite from the same genus of fowl in Huixtla, Chiapas, Mexico. More detailed descriptions of this parasite along with observations on the frequently fatal course of experimental infections in chickens were published by the same authors 2 years later (Versiani and Gomes, 1943; Beltran, 1943). In 1945 Cassamagnaghi reported this parasite from domestic chickens in Uruguay. Ishiguro (1957) described a new species of malaria from Japanese domestic fowl which he named Plasmodium japonicum. This parasite had morphological characters similar to P. juxtanucleare but it was relatively nonpathogenic. Later, Dhanapala (1962) reported what he considered to be P. juxtanucleare from Ceylonese chickens. This latter parasite also produced a low mortality rate in chickens. Recently a parasite, indistinguishable from Dhanapala's Ceylon strain of P. juxtanucleare, has been found widely distributed as a generally nonlethal infection in the domestic fowl of the Malay states. This parasite has also been identified as P. juxtanucleare. The present paper describes and illustrates the Malaysian strain of this parasite. MATERIALS AND METHODS Source of the parasite During March-April of 1963, mosquitoes caught in monkey-baited net traps in the canopy of the Received for publication 1 March 1966. * Present address: Ontario Research Foundation, 43 Queen's Park, Toronto 5, Ontario, Canada. coastal mangrove swamp near Rantau Panjang, approximately 5 miles NW of Klang, State of Selangor, Malaysia, were examined for malarial parasites. In April, a Culex (Culex) sitiens Wiedmann, caught in one of the traps, was dissected and the salivary glands found to contain numerous sporozoites. Approximately one-half of the sporozoites were inoculated subcutaneously into a canary, the remainder intravenously into a chick. The former inoculation failed to produce an infection. The latter produced a patent parasitemia at 14 days. This parasite has subsequently been maintained in this laboratory by a succession of blood and sporozoite transfers. In June 1963 a Culex (Culex) annulus Theobald, taken in a hill forest region (Ulu Gombak) near Kuala Lumpur, was found to be infected with sporozoites morphologically similar to those mentioned above. When injected into a chick a patent infection resulted on day 12. The blood parasites were morphologically indistinguishable from those obtained at Rantau Panjang. On further study, various aspects of the biology of this parasite were found to be identical with those of the Rantau Panjang isolate and both isolations were considered to be the same parasite. Hatchery-reared chickens from the local market were used throughout the study. All birds were housed in mosquito-proof cages for a period of at least 2 weeks prior to their use. Their parasitefree status was confirmed by blood examinations prior to use. No natural infections with malaria were found in chickens from this source. Blood films were taken daily from either the brachial artery or vein. Routine preparations were stained with Giemsa stain at pH 7.2, and all descriptions, unless specifically noted, were made from these films. Pigment granules were more readily observed by staining alcohol-fixed films with thiazine red (5% thiazine red, 1% acetic acid in distilled water) for 3 min. Nuclear elements of both the host cell and the parasite remained unstained whereas the c toplasm of both stained light red. Pigment granules stood out clearly as blackish brown clumps. Measurements in the text are presented in the following way: average (range)/number of measurements. For example, the length of the schizonts is presented as 2.7 u (2 to 4)/39.