Garbage Management: An Important Risk Factor for HPAI-Virus Infection in Commercial Poultry Flocks

Utilization of Eggshell Waste Calcite as a Sorbent for Rare Earth Element Recovery

The green energy transition requires rare earth elements (REE) for the permanent magnets used in electric cars and wind turbines. REE extraction and beneficiation are chemically intensive and highly damaging to the environment. We investigated the use of eggshell waste as a sustainable alternative sorbent for the capture and separation of REE from aqueous solutions. Hen eggshell calcite was placed in multi-REE (La, Nd, Dy) solutions at 25 to 205 °C for up to 3 months. A pervasive diffusion of the REE inside the eggshell calcite was observed along pathways formed by the intracrystalline organic matrix and calcite crystal boundaries. At 90 °C, kozoite (REECO3OH, orthorhombic) spherulites precipitate on the surface of the dissolving calcite. At 165 and 205 °C, an interface-coupled dissolution-precipitation mechanism is observed, resulting in the complete dissolution of the calcite shell and its pseudomorphic replacement by polycrystalline kozoite. At 205 °C, kozoite is slowly replaced by hydroxylbastnäsite (REECO3OH, hexagonal), the stable form of the rare earth hydroxycarbonate polymorphs. Our results demonstrate two potential applications of eggshell waste for the uptake of rare earth elements in solution: at low temperatures, as a mixed organic-inorganic adsorbent and absorbent, given sufficient sorption time; and at higher temperatures, as an efficient sacrificial template for the precipitation of rare earth hydroxycarbonates.

Modeling long-distance airborne transmission of highly pathogenic avian influenza carried by dust particles

Highly pathogenic avian influenza (HPAI) is continuously causing significant economic losses with massive poultry depopulations. Airborne transmission of HPAI was suspected, as initial bird mortalities were reported near air inlets of poultry houses. In addition, infected farms were distant, indicating that the viruses carried by dust particles might help the viruses travel for long distances in the environment. The objective of this study focused on simulating the airborne transmission of HPAI by using computational modeling to assess the risk of airborne and deposited avian influenza (AI) carried by poultry-litter dust particles. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modeling was used in this study. Data from 168 infected cases in the Mid-Western area of U.S. were obtained from the Animal and Plant Health Inspection Service (APHIS) and Watt Poultry. The concentration simulation modeling was performed to estimate the airborne and deposited AI concentration carried by PM2.5 dust particles. Results showed that concentrations of airborne AI, deposited AI, and combined AI transmitted to other farms in a day were lower than the minimal infective dose for poultry. In most of the scenarios, the predicted probability of infection showed that Iowa-infected farms and turkey poultry houses had the highest infection probability. The findings may provide an understanding of the risk of airborne HPAI virus carried by dust particles and suggest the factors that influence long-distance airborne transmission.

Village and farm-level risk factors for avian influenza infection on backyard chicken farms in Bangladesh

A cross-sectional study was conducted with 144 small-scale poultry farmers across 42 Bangladeshi villages to explore risk factors associated with avian influenza H5 and H9 seropositivity on backyard chicken farms. Using mixed-effects logistic regression with village as random effect, we identified crow abundance in garbage dumping places and presence of migratory wild birds within villages to be associated with higher odds of H5 and H9 seropositivity. At farm-level, garbage around poultry houses was also associated with higher odds of H5 and H9 seropositivity. In addition, specific trading practices (such as, purchase of chickens from live bird markets (LBM) and neighboring farms to raise them on their own farms, frequency of visits to LBM, purchase of poultry at LBM for consumption) and contact of backyard chickens with other animals (such as, feeding of different poultry species together, using pond water as drinking source for poultry, access of feral and wild animals to poultry houses) were associated with higher odds of H5 or H9 seropositivity. Resource-constrained small-scale poultry farmers should be able to address risk factors identified in this study without requiring large investments into poultry management, thereby reducing the likelihood of avian influenza virus transmission and ultimately occurrence of avian influenza outbreaks.

Backyard poultry flocks in France: A diversity of owners and biosecurity practices

Over the past few years, the number of backyard poultry flocks has been increasing in France. A mandatory step to improve backyard poultry management is to assess health risks by characterizing the flocks and understanding the owners' motivations for keeping poultry and their husbandry practices. A survey of backyard poultry owners was conducted in France to gather information about their motivations for owning poultry, flock characteristics, and breeding and biosecurity practices. The survey was completed by 1,160 owners. The major motivations for owning poultry flocks were egg consumption (93.3 %), recycling (72.4 %) and having pet animals (53.2 %). Most owners had already heard about avian influenza (96.7 %), but were less aware about other diseases such as Newcastle Disease (41.6 %), salmonellosis (79.1 %), or campylobacteriosis (18.6 %). Owners mainly kept only egg-layers (78.4 %), and the median size flock was five egg-layers. Owners gave eggs to their relatives, occasionally or regularly, in 86.6 % of the cases. Contacts with other family poultry owners were frequent (68.9 %) and biosecurity practices were poorly implemented: 50 % of owners did not wash their hands systematically after visiting the flock and more than 60 % of owners did not wear specific shoes. Drawing from the survey data, five profiles of family poultry flocks were identified with multiple correspondence analysis and hierarchical cluster analysis. The profiles, based on flock characteristics and owners' practices and motivations, illustrate the heterogeneity of the backyard poultry sector: 1) urban poultry, 2) traditional poultry, 3) student poultry, 4) pet poultry and 5) hobby poultry. Urban poultry consisted of recently constituted (< 2 years old), small (< 3 birds) flocks of layers, and traditional poultry of older, medium-sized flocks belonging to retired and older people. These two profiles were characterized by limited contacts (direct or indirect) with other flocks and owners. Student poultry consisted of younger owners (<30 years old) with flocks over 5 years old. Pet poultry consisted of recently established, medium-size flocks of layers located in both rural or urban environments. Hobby poultry consisted of dedicated owners who breed and sell poultry and participate in exhibitions and poultry shows. Pet and hobby poultry profiles were characterized by greater knowledge of diseases and biosecurity practices, more bird movements, and reported more frequent clinical signs. The observation of different profiles can help target veterinary and public health education messages to prevent disease transmission in backyard poultry flocks in France.

The role of farm business type on biosecurity practices in West Java broiler farms

Biosecurity is important to prevent introduction and spread of infectious diseases, including Highly Pathogenic Avian Influenza (HPAI). HPAI is currently endemic in Indonesia and it has triggered the adoption of a biosecurity policy. Although there is anecdotal evidence about the level of biosecurity on Indonesian broiler farms, formal evidence is lacking, as well as knowledge about determinants of low biosecurity levels. This paper has two main objectives: 1) to assess the levels of biosecurity measures across different farm business types, and (2) to analyze the determining factors, with a special reference to farm business type, for the level of biosecurity and the availability of biosecurity infrastructure in the West Java poultry farms. A multi-stage sampling procedure was applied to collect data from approximately 400 broiler farmers in four districts in West Java province, namely Ciamis, Tasikmalaya, Subang and Sukabumi. Data were collected through farmer interviews and direct observation at the farms. The Biosecurity Control Score (BCS), consisting of 16 practice indicators, and the Farm Infrastructures for Biosecurity (FIB) list consisting of 16 building or physical set-ups as biosecurity facilities were used to assess the level of biosecurity. Determinants of biosecurity measures were analyzed via tobit regression analysis. The results show that the BCS was associated with the total number of birds per cycle, and risk perception (P < 0.05). The BCS was significantly (P < 0.05) higher for the farm business types 'independent farming', 'price contract farming' and 'company' compared to the 'makloon contract farming' business type (farming for a fee). Physical set-ups as farm infrastructure for biosecurity (FIB) were associated with the total number of birds per cycle, and with risk perception (P < 0.05). FIB was significantly (P < 0.05) higher for the farm business types 'independent farming', 'price contract farming' and 'company' compared to makloon contract farming. The results of this study suggest that business types play a significant role in determining biosecurity practices; a makloon contract farm (farming for a fee) tends to have a lower level of biosecurity than other business types due to lack of incentives. Consequently, in developing incentives for improved biosecurity measures. policymakers should encourage farm registration, and at the same time develop incentives that support the independent and price contract farming.