Backyard Farms Research Articles

A study of Newcastle disease virus in poultry from live bird markets and backyard flocks in Kenya

A countrywide cross-sectional study was conducted to determine the presence of Newcastle disease virus (NDV) in poultry in live bird markets (LBMs) and backyard poultry farms in Kenya. A total of nine hundred and twenty two (922) poultry in backyard flocks and four hundred and fifty four (454) poultry in LBMs were examined. Overall, NDV was detected in 10.1% (46/454) of the poultry sampled in live bird markets. In backyard flocks, NDV was detected in 3.6% (33/922) of the poultry sampled. Regional variations in NDV occurrence was observed in both live bird markets and poultry flocks. Markets in major towns and cities had significantly (p<0.05) higher NDV detection rates. Higher NDV detection rates were observed in backyard farms in Lake Victoria Basin than other regions. Chicken had the highest NDV detection compared to other poultry species. The study detected NDV in apparently healthy chicken and brought forward the probable high importance of carrier birds in the circulation and transmission of NDV and in causing outbreaks. The study also points to the usefulness of reverse transcription polymerase chain reaction (RT-PCR) in screening for NDV to prevent the outbreaks and control of ND in Kenya. Key words: Backyard poultry, chicken, Kenya, live bird markets, NDV, RT-PCR.

Technical and environmental efficiency of livestock farms in China: A slacks-based DEA approach

In the wake of economic development and raised living standards, Chinese pork consumption has risen significantly. As a response to the increased demand and active government support, the national hog sector, which was traditionally dominated by small backyard farms, is featuring a quick restructuring towards large-scale breeding enterprises. With the transformation of the hog sector, environmental externalities have become a very serious concern. Foremost non-point source pollution resulting from the leakage of pig waste into surface water and groundwater resources is seen as a serious threat. Via data envelopment analysis (DEA), we approach the question of efficiency gains from both technical and environmental perspective along a 2012 sample of 371 Chinese hog farms. Our results suggest that especially mid-size hog farms in transition face low environmental efficiency and high pollution abatement costs due to limited waste disposal options. Existent policies turn out to be yet hardly effective in decreasing environmental externalities. In some provinces, projects for rural biogas production could help to improve waste management. However, especially small farms require state support towards improving storage and transportations facilities.

Determination of hematological and serum biochemical reference values for indigenous sheep (Ovies aries) in Dhaka and Chittagong Districts of Bangladesh.

Aim:The study was aimed to determine the reference values of most commonly used hematological and biochemical parameters of indigenous sheep, reared under semi-intensive backyard farms in Dhaka and Chittagong district, Bangladesh.Materials and Methods:A total of 41 blood samples were collected from indigenous sheep (Ovis aries) from June to December 2016 from Dhaka and Chittagong Districts of Bangladesh. Hematological and serum biochemical parameters such as hemoglobin (Hb), packed cell volume (PCV), erythrocyte sedimentation rate (ESR), total erythrocyte count (TEC), total leukocyte count (TLC), neutrophil, eosinophil, basophil, monocyte, lymphocyte, urea, triglyceride, cholesterol, glucose, albumin, total protein (TP), alanine aminotransferase (ALT), and aspartate transaminase (AST) were determined by biochemical analyzer. 90% reference intervals were calculated for all parameters.Results:The hematologica and serum biochemical profiles of indigenous sheep showed wide range and variation. The results were categorized according to sex and age of the sheep for comparison. Young sheep had significantly higher PCV, eosinophil, triglyceride, and TP level than that of adult (p<0.05), whereas the urea and albumin level was higher in adult than that of juvenile (p<0.05). Most of the values of the parameters are close to each other for both male and female except TEC, urea, cholesterol, triglyceride, glucose, and AST. However, a significant difference was found only for albumin and basophil level between male and female sheep.Conclusion:Hematological and biochemical parameters in Bangladeshi indigenous sheep showed a wide range and variation implicating future study for the prophylaxis of ovine diseases.

Farm Biosecurity at backyard poultry of Bangladesh and its role in spread of HPAI

Objective: We have conducted this study to characterise the movement and contact patterns of poultry in Bangladesh that could be associated with transmission of newly-introduced subtypes of avian influenza virus in two districts of Bangladesh as well as to summarise the patterns arising from the network analysis in a way that can inform the parameterisation of spatially explicit stochastic models of transmission of newly-introduced subtypes of avian influenza virus in the two types of areas.Introduction: Bangladesh is a South Asian country with large human and poultry populations which is highly affected with frequent outbreaks of both high and low pathogenic avian influenza since 2007. Very few studies have been carried out to reveal the farm biosecurity at backyard poultry that might have contributed to the spread of avian influenza in Bangladesh, specially rural areas. Therefore, we aimed to characterize biosecurity practices of poultry farm including the movement of live birds which is a well-known risk factor for the geographic dissemination of the virus among poultry flocks and personnel hygiene of poultry workers for rapid detection and effective risk management of incursion of HPAI and LPAI viruses.Methods: This cross sectional survey was carried out using pretested questionnaire in backyard Poultry holdings of Kalkini Upazila of Madaripur district in Dhaka division which has a relatively low proportion of commercial poultry farms and high proportion of backyard poultry holdings.1-mode and 2-mode social network analysis was also carried out to show the farm to farm movements. From each primarily selected farm, details of the last 2 movements of live poultry along with source/destination details was collected with pre-tested questionnaire. Later, data was stored in Epi-Info, analysed with STATA 14 and UCINET. 315 backyard HH from 2 villages of Kalkini Upazila, Madaripur District were randomly selected.Results: The study revealed that majority backyard farm owners do not maintain the standard biosecurity measures whereas a significant amount of the study included farms rear multiple poultry species. No poultry workers found to use any personal protective equipments (PPEs) while cleaning the litter/mats (Figure 2). The farms with multiple poultry species feed them in same container and keep them in same shed which is a major risk factor for disease transmission.Movement patterns differed in a number of aspects (Table 1) and this information is useful for the establishment of the movement parameter settings in a simulation model of avian influenza incursion.Conclusions: The findings on farm biosecurity practices and movement pattern from this study will support to develop risk-based surveillance and contingency policies as well as to minimize the spread between poultry units and also from poultry to people for novel AI viruses in Bangladesh.

Exploring contacts facilitating transmission of influenza A(H5N1) virus between poultry farms in West Java, Indonesia: A major role for backyard farms?

Highly pathogenic avian influenza virus (HPAIV) H5N1 has been reported in Asia, including Indonesia since 2003. Although several risk factors related to the HPAIV outbreaks in poultry in Indonesia have been identified, little is known of the contact structure of farms of different poultry production types (backyard chickens, broilers, layers, and ducks). This study aims to quantify the contact rates associated with the movement of people, and movements of live birds and products and equipment that affect the risk of HPAIV H5N1 transmission between poultry farms in Indonesia. On 124 poultry farms in 6 districts in West Java, logbooks were distributed to record the movements of farmers/staff and visitors and their poultry contacts. Most movements in backyard chicken, commercial native chicken, broiler and duck farms were visits to and from other poultry farms, whilst in layer farms visits to and from poultry companies, visits to egg collection houses and visit from other poultry farms were most frequent. Over 75% of persons visiting backyard chicken and duck farms had previously visited other poultry farms on the same day. Visitors of backyard chicken farms had the highest average contact rate, either direct contact with poultry on other farms before the visits (1.35 contact/day) or contact during their visits in the farms (10.03 contact/day). These results suggest that backyard chicken farms are most at risk for transmission of HPAIV compared to farms of the other poultry production types. Since visits of farm-to-farm were high, backyard farms could also a potential source for HPAIV transmission to commercial poultry farms.

Chlamydiosis in Backyard Chickens (Gallus gallus) in Italy.

Until recently, Chlamydia psittaci was considered to be the only etiological agent of avian chlamydiosis, but two new avian species, Chlamydia gallinacea and Chlamydia avium, have recently been described in poultry and pigeons or psittacine birds, respectively. The aim of this study was to explore the occurrence of C. psittaci and C. gallinacea in backyard chickens in Italy. Cloacal swabs were taken from 160 asymptomatic chickens reared in 16 backyard farms. Samples were tested for C. psittaci and C. gallinacea by specific real-time polymerase chain reaction assays, with 24 (15%) of the 160 chickens resulting positive for C. gallinacea. To attempt chlamydial isolation, new samples were obtained from two farms harboring a high prevalence (60% and 70%, respectively) of C. gallinacea-positive chickens. In total, eight C. gallinacea and one C. psittaci isolates were successfully recovered from 13 chickens. C. gallinacea was confirmed to be the endemic chlamydial species in chickens, with a high ompA intraspecies diversity. The presence of viable C. psittaci and C. gallinacea demonstrated by isolation from chickens in backyard farms poses a potential public health problem.

Molecular Detection of Mycoplasma synoviae from Backyard and commercial Turkeys in Some Parts of Iran.

M. synoviae (MS) is an economically important pathogen and the major cause of airsacculitis and infectious synovitis in turkeys. Infection with this pathogen may remain asymptomatic but can render infected birds susceptible to secondary infections. This study was carried out for the molecular detection of MS infection in commercial and backyard turkey flocks in Tehran, Semnan, Isfahan, Qazvin, Zanjan, East Azerbaijan, Gilan, Mazandaran, and Golestan provinces of Iran. Sixty-hundred tracheal, choanal cleft or/and infraorbital sinus samples were collected from 18 commercial and 31 backyard turkey flocks. The polymerase chain reaction (PCR) technique was performed by using primers specific for detecting the 16S rRNA and vlhA genes of MS. The results showed that 51.61% of backyard and 33.33% of commercial farms were MS-positive. These findings suggested the molecular presence of MS, especially in northern and central regions of Iran. Further, the frequency of MS-positive samples was significantly lower in commercial farms than backyard farms (P&amp;lt;0.05).

Backyard Farms Represent a Source of Wide Host Range Salmonella Phages That Lysed the Most Common Salmonella Serovars

The genus Salmonella has more than 2,600 serovars, and this trait is important when considering interventions for Salmonella control. Bacteriophages that are used for biocontrol must have an exclusively lytic cycle and the ability to lyse several Salmonella serovars under a wide range of environmental conditions. Salmonella phages were isolated and characterized from 34 backyard production systems (BPSs) with a history of Salmonella infections. BPSs were visited once, and cloacal or fecal samples were processed for phage isolation. Four hosts, Salmonella serovars Enteritidis, Heidelberg, Infantis, and Typhimurium, were used for phage isolation. The host range of the phages was later characterized with a panel of 23 Salmonella serovars (serovar diversity set) and 31 isolates obtained from the same farms (native set). Genetic relatedness for 10 phages with a wide host range was characterized by restriction fragment length polymorphism, and phages clustered based on the host range. We purified 63 phages, and 36 phage isolates were obtained on Salmonella Enteritidis, 16 on Salmonella Heidelberg, and 11 on Salmonella Infantis. Phages were classified in three clusters: (i) phages with a wide host range (cluster I), (ii) phages that lysed the most susceptible Salmonella serovars (serogroup D) and other isolates (cluster II), and (iii) phages that lysed only isolates of serogroup D (cluster III). The most susceptible Salmonella serovars were Enteritidis, Javiana, and Dublin. Seven of 34 farms yielded phages with a wide host range, and these phages had low levels of genetic relatedness. Our study showed an adaptation of the phages in the sampled BPSs to serogroup D Salmonella isolates and indicated that isolation of Salmonella phages with wide host range differs by farm. A better understanding of the factors driving the Salmonella phage host range could be useful when designing risk-based sampling strategies to obtain phages with a wide lytic host range for biocontrol purposes.

Detection of Antibodies to Seven Priority Pathogens in Backyard Poultry in Trinidad, West Indies.

Backyard poultry farms in Trinidad and Tobago (T&T) play a vital role in providing food and income for rural communities. There is currently no information on the presence and circulation of pathogens in backyard poultry farms in T&T, and little is known in relation to the potential risks of spread of these pathogens to the commercial poultry sector. In order to address this, serum samples were collected from 41 chickens on five backyard farms taken from selected locations in Trinidad. Samples were tested for antibodies to seven priority pathogens of poultry by enzyme-linked immunosorbent assay (ELISA). Antibodies were detected in 65% (CI 95%: 50–78%) of the sampled birds for Infectious bronchitis virus (IBV), 67.5% (CI 95%: 52–80%) for Infectious bursal disease virus (IBDV), 10% (CI 95%: 4–23%) for Newcastle disease virus (NDV), 0% (CI 95%: 0–0%) for Avian influenza virus (AIV), 0% (CI 95%: 0–0%) for West Nile virus (WNV), 31.7% (CI 95%: 20–47%) for Mycoplasm gallisepticum/synoviae and 0% (CI 95%: 0–0%) for Salmonella enterica serotype Enteritidis. These results reveal the presence and circulation of important pathogens of poultry in selected backyard farms in Trinidad. The results provide important information which should be taken into consideration when assessing the risks of pathogen transmission between commercial and backyard poultry farms, as well as between poultry and wild birds.

Backyard pigs are a reservoir of zoonotic hepatitis E virus in southern Brazil.

Hepatitis E virus (HEV) is the causative agent of acute hepatitis worldwide. There is no seroprevalence study in backyard farms, which are characterized by suboptimal hygienic conditions in Brazil. We aimed to determine the seroprevalence and genetic diversity of HEV in backyard pigs in Brazil. Swine serum samples collected in 2012 (n=731) and 2014 (n=713) were analysed. The presence of anti-HEV immunoglobulin G in pig serum was evaluated by indirect enzyme-linked immunosorbent assay. Reverse transcription polymerase chain reaction was performed and phylogenetic analyses were carried out based on the partial ORF1 and ORF2 coding regions. Anti-HEV antibodies were detected in 77.6% (567/731; 95% confidence interval [CI] 74.5 to 90.6%) of serum samples in 2012 and 65.5% (467/713; 95% CI 62.0 to 69.0%) in 2014. The herd seroprevalence was 91.7% (187/204; 95% CI 91% to 99%) in 2012 and 83.7% (164/196; 95% CI 78% to 89%) in 2014. Further, HEV RNA was detected in 0.8% (6/713) of samples from 2014. Phylogenetic analysis showed three different genotype 3 subtypes with high similarity to human HEV strains. This study showed that backyard pigs are a reservoir of HEV and alerts us to the need to control infection and spillover from backyard farms. MF438128-MF438135.

Microbiological identification and analysis of waterfowl livers collected from backyard farms in southern China.

In total, 985 livers were collected from 275 backyard waterfowl farms distributed in seven provinces of southern China. The virus that was most commonly isolated was avian influenza virus, with a 12.1% positivity rate. Of the other positive samples, 10.6% tested positive for avian Tembusu virus, 6.8% for duck hepatitis A virus, 3.8% for duck plague virus, 3.4% for Muscovy duck parvovirus, 3.1% for goose parvovirus, 1.0% for mycoplasma and 0.9% for respiratory enteric orphan virus. The bacterium that was most commonly isolated was Escherichia coli, with a 47.1% positivity rate. This survey suggests that backyard waterfowl in southern China could be an important vector for the storage, variation, and transmission of various pathogens.

Effects of Highly Pathogenic Avian Influenza H5N1 Outbreak in Nepal from Financial and Social Perspectives: A Case Study

The outbreaks of highly pathogenic avian influenza (HPAI) H5N1 have serious public health, economic and social implications. After the first two report of HPAI H5N1 outbreak in Nepal in Jhapa in 2009, a third outbreak was reported in Pokhara the following year where more than 11,000 birds were culled to control the disease. However, the financial and social effects of the Pokhara bird flu outbreak were never assessed. The objectives of this study were to evaluate the local financial and social effects of HPAI H5N1 outbreak in Pokhara and to understand farmers and consumers perceptions on bird flu and the control measures implemented by the government. A total of 200 people including poultry farmers, butchers, veterinary drug dealers, feed suppliers, and consumers were interviewed using the semi-structured questionnaire. The result showed that the direct loss of Pokhara bird flu outbreak from the culling of birds was more than 4.5 million Nepali rupees. The small scale commercial and backyard farmers and the butchers were the most affected from this outbreak. A large proportion of the consumers temporarily stopped to consume chicken meat and shifted to other meat sources. Most of the participants in this study had at least heard about the bird flu. The farmers were unhappy by the compensation provided by the government and perceived that the government control efforts were not satisfactory and were provided little assistance for their rehabilitation. In conclusion, there was a momentary local financial and social effect of the Pokhara bird flu outbreak which may not very important from the macroeconomic point of view but is important for the affected small-scale farmers and the butchers. It is recommended that the government review their policy and provide small scale commercial and backyard farmer a compensation that is closer to the market price and promote largescale poultry farmers to go for insurance.

Multiple introductions of reassorted highly pathogenic avian influenza viruses (H5N8) clade 2.3.4.4b causing outbreaks in wild birds and poultry in Egypt

Recently, an increased incidence of outbreaks of highly pathogenic avian influenza (HPAI) H5N8 in poultry linked to infected migratory birds has been reported from different European, Asian and African countries.In Egypt, incursion of HPAI H5N8 virus of clade 2.3.4.4b has been recently registered. Full genomic characterization of 3 virus isolates from wild birds and poultry (backyard and commercial farm sectors) showed high nucleotide similarity among the HA, NA, M, and NS gene segments of the three Egyptian HPAI H5N8 viruses, indicating that they are descendants of a common ancestral virus. However, the analyzed Egyptian H5N8 viruses revealed distinct genotypes involving different origins of the PB2, PB1, PA and/or NP segments. In genotype-1 represented by strain A/common-coot/Egypt/CA285/2016 the PB2 and NP segments showed closest relationship to H5N6 and H6N2 viruses, recently detected in Italy. The second is replacement of PB1 and NP genes A novel reassortant, represented by strain A/duck/Egypt/SS19/2017, showed an exchange of PB1 and NP genes which might have originated from H6N8 or H1N1 and H6N2 viruses. Finally, replacement of PA and NP genes characterized strain A/duck/Egypt/F446/2017. Bayesian phylogeographic analyses revealed that Egyptian H5N8 viruses are highly likely derived from Russian 2016 HPAI H5N8 virus (A/great_crested_grebe/Uvs-Nuur_Lake/341/2016 (H5N8)) and the reassortment likely occurred before incursion to Egypt.

A targeted investigation to demonstrate the freedom of West Timor from HPAI H5N1

In early 2004 highly pathogenic avian influenza (HPAI) H5N1 virus caused major outbreaks of disease in poultry in Indonesia. The disease was first reported in West Timor in eastern Indonesia in the same year, resulting in the death of approximately one hundred chickens from both commercial and backyard farms; however no evidence of disease has subsequently been reported in West Timor since 2007.A targeted survey was undertaken in 2013 in 2 districts of West Timor. Three hundred village and commercial poultry (292 chickens and 8 Muscovy ducks) from 10 villages and 5 live bird markets (LBMs) were sampled between August and October 2013. Swabs of the cloaca and trachea of the sampled birds were tested using the Anigen® Rapid Test (Bionote). All samples were negative on testing (0%; 95%CI: 0.0–1.2%). From these results it was concluded with a high level of confidence (100%, 95%CI: 99.988, 100) that this population is not infected, and these results, along with a lack of clinical evidence of disease, support the conclusion that West Timor was free from HPAI infection at the time of the survey.

Allocation of responsibility among pork supply chain players

Purpose The purpose of this paper is to investigate the responsibility that should be taken by different pork supply chain participants to ensure pork quality and safety, with the aim of providing some guidance for strengthening the supervision of pork quality and safety. Design/methodology/approach The pig farmer survey and the pork consumer survey were conducted in Funing County, Jiangsu Province, using the best-worst scaling (BWS) and a mixed logit model. Findings The results showed that the designation of responsibility for ensuring pork quality and safety was of, in descending order, feed producers and suppliers, backyard farmers and farms of designated size, pork processing workshops and companies of and above designated size, slaughterhouses, supermarkets, farmer’s markets, pig transporters, and consumers. Both pig farmers and pork consumers believed that those involved in the initial pork supply chain should take greater responsibility for pork quality and safety. Originality/value Allocation of responsibilities across the entire pork industry chain was investigated from the perspective of pig farmers and pork consumers using the BWS and a mixed logit model. The results of this study might explain the unique problems that occur in pork supply chain management in large developing countries like China.

Economic impacts of avian influenza outbreaks in Kerala, India.

This study assessed the short-run impact to poultry farmers, duck hatcheries, control costs, compensation paid to stakeholders (transfer payments) and market reactions on own and substitute product prices and backwater tourism (boat operators) due to avian influenza (AI) outbreaks in Kuttanad region of Kerala, India, during 2014. The primary data from 91 poultry farms (duck farms, broiler chicken and backyard poultry), four hatcheries and 90 backwater boat owners were collected through pre-tested schedules. The secondary data on transfer payments and expenditure incurred to control AI were collected from developmental departments and were analysed. The estimated loss (culling live birds, eggs and feed destruction) per duck farm was USD 9,181, USD 3,889 and USD 156 in case of commercial farms reared for meat, dual-purpose and backyard farms, respectively. The loss incurred by small-scale broiler and backyard poultry farms was USD 453 and USD 40, respectively. The loss incurred by large and small duck hatcheries was USD 11,963 and USD 5,790, respectively, due to culling of hatchlings, young birds and destroying eggs. The government invested USD 744,890 to contain the disease spread through massive culling, surveillance and monitoring of poultry and humans due to zoonotic nature of the disease. A sharp market reaction on own and substitute product prices and eight weeks' time lag in price recovery was observed. The consequential impact on tourism especially for the backwater boat operators amounted to a loss of USD 2,280/boat due to fall in tourist inflow. Since, control measures are post-incidence, it is necessary to adopt appropriate preventive bio-security measures at the farm level besides periodical screening of domestic birds in migratory birds' flyway locations like Kuttanad to reduce the AI burden on various stakeholders including government.

Case of syngamosis in partridges of a backyard farm

Sick and dead 2-months-old partridges (Alectoris chukar) were presented to the unit of Avian Medicine, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Greece. The birds were reared at a specially constructed wire cage, which covered 600 m2 of the ground, including self-growing flora, in the region of Diavata, in the countryside of Thessaloniki. The farm consisted of young partridges, adult pheasants and wild passerines. Two months after placing the birds, 5 partridges were found dead. During the clinical examination of the submitted sick partridges, severe respiratory distress was observed, while some birds had anemic combs and others were breathing with open beaks and had their necks stretched. The necropsy revealed the presence of numerous gapeworms in the lumen of the trachea, forming the typical " Y" shape, since male and female Syngamus trachea are locked in copulation. The mucosa of trachea was, also, thickened, irritated and congested. No lesions to other organs were observed and the microbiological examination of liver, spleen and air-sacs samples was negative. Meanwhile, faecal samples were collected from the farm for parasitological examination. A sedimentation method was used and eggs of S. trachea were found. Syngamosis was determined to be the cause of the partridges' death. The gapeworms are considered potentially dangerous, especially for backyard, game-birds and free-living birds, while the control of the disease is complicated. This fact, along with the selective appearance of the clinical signs and the mortality only in the partridges of the farm are the remarkable points discussed in this article.

The role of backyard farms in two West African urban landscapes

Urban and peri-urban agriculture (UPA) is a well-researched landscape component, but there is a need to extend the quantitative database on West Africa as well as to explain how UPA contributes to food systems differently across locations. We therefore performed a quantitative survey of Tamale, Ghana, and Ouagadougou, Burkina Faso, using a spatially randomised sampling frame to identify farms in peri-urban villages, open-space farming zones and isolated spaces. This was complemented with focus group discussion data. After preliminary analysis, further interviews were performed to explain trends observed. Rainy season production dominated in both cities. In Ouagadougou, commercial production was concentrated in open-space farming sites, whereas in Tamale it was more dispersed, with isolated space farms playing an unexpectedly important market role. This was attributed to Tamale's recent rapid expansion, combined with more relaxed planning implementation and a permissive legislative context. In both cities, leafy vegetables were important commercial crops. Irrigation and soil fertility management were areas where resource use efficiency could be improved. Untreated well water was a major irrigation source in Ouagadougou, as was potable water in Tamale, raising queries over sustainability. Inorganic fertiliser use was more common in Tamale than Ouagadougou, and the opposite was the case for compost and manure, ascribed to the existence of manure markets in Ouagadougou. Urban agriculture's contribution to urban food systems is thus shaped by its historical and geographical context. Attention to planning trajectories, irrigation and soil fertility management issues could help it contribute further.

High seroprevalence of Toxoplasma gondii and probability of detecting tissue cysts in backyard laying hens compared with hens from large free-range farms

Serological assays are commonly used to determine the prevalence of Toxoplasma gondii infection in livestock, but the predictive value of seropositivity with respect to the presence of infective tissue cysts is less clear. The present study aimed at the identification of seropositive and seronegative free-range laying hens from organic and backyard farms, and the relationship with the presence of viable tissue cysts. In addition, potential risk and protective factors on the selected farms were investigated. An in-house T. gondii surface antigen (TgSAG1, p30, SRS29B) ELISA was validated with sera from experimentally infected chickens and used to examine 470 serum samples collected from laying hens from large organic and small backyard farms at the end of their laying period. A total of 11.7% (55/470) of all chickens tested positive, and another 18.9% (89/470) of test results were inconclusive. The highest seroprevalences were observed on small backyard farms with 47.7% (41/86) of chickens being seropositive while another 20.9% (18/86) of test results were inconclusive. Twenty-nine seropositive, 20 seronegative and 12 laying hens which yielded inconclusive ELISA results, were selected for further examination. Hearts and limb muscles of these hens were examined for T. gondii tissue cysts in a bioassay with IFNɣ-knockout or IFNɣ-receptor-knockout mice. Viable T. gondii was isolated from 75.9% (22/29) of the seropositive, 25.0% (3/12) of the inconclusive, and 5.0% (1/20) of the seronegative chickens. All 26 chickens tested positive in heart samples, while drumstick muscles (i.e. limb muscles) tested positive only in three. Data on putative risk and protective factors were collected on the farms using a standard questionnaire. Generalised multilevel modelling revealed farm size, cat related factors (‘cats on the premise’, ‘cats used for rodent control’), hen house/hall related factors (‘size category of hen house/hall’, ‘frequency category of cleaning hen house/hall’, ‘service period’) as significantly associated with seropositivity to T. gondii in hens. The final model, which included the age of the birds as an effect modifier and farm as a random effect variable, revealed that the use of cats for rodent control and an area available per hen in the chicken run of ≥10sqm were statistically significant risk factors for T. gondii seropositivity. Overall this study showed that exposure to T. gondii is common in small backyard farms but is rare on large organic farms with a high density of free-range hens, even when cats were present on the premises.

PHYLOGENETIC ANALYSIS OF NP AND HN GENE OF NEWLY ISOLATED NDV/Badung-02/AK/14

virus was isolated from suspected Newcastle disease (ND) chicken in backyard farm at Sibang Village, Badung Regency, Bali Province. The isolates were then propagated and confirmed for NDV serologically. RNA isolation was performed by standard Trizol method. Phylogenetic tree analysis of NP gene (nt1020-1561) and HN gene (nt7019-7754) were performed using sequence of Badung-02/AK/14 and selected NDV strains from GenBank. Based on the NP gene sequence, the newly isolate closely related with other NDV strains belong to genotype VII that previously isolated such as Banjarmasin-010/10, Bali-1/07, and Cockatoo/90 with genetic distance 0.2%, 12.6%, and 18.0% respectively. The genetic distance with LaSota/46 virus (genotype II) is 19.6%. Based on HN gene sequence, genetic distance of the Badung-02/AK/14 with other viruses belong to genotype VII such as Banjarmasin-010/10, Bali-1/07, and Cockatoo/90 are 0.4%, 3.7%, and 4.2% respectively. The genetic distance with LaSota/46 virus (genotype II) is 9.0%. There were no difference between the result of nucleotide and amino acid sequence analysis, both in NP and HN gene (P&gt;0.05).