Identifying and managing pathways of AI transmission by wild birds on meat chicken farms in eastern Australia

Abstract Conjecture surrounds the reservoir and bridge species potentially involved in introducing, maintaining and transmitting avian influenza (AI) on Australian meat chicken farms. This is mainly due to a lack of AI prevalence data and in-depth understanding of wild bird ecology on farms and across regions. For risk assessment purposes, we identified candidate species likely to be involved in AI maintenance and transmission during 68 bird surveys conducted across ten commercial meat chicken farms from Winter 2016 to Summer 2018 in southeastern Queensland. Using an AI-risk classification processes described in this paper, we speculate that 57 of the 139 species recorded in and around production facilities and nearby water bodies pose a medium to high risk, particularly on free range farms. On the farms with permanent waterbodies, resident and semi-resident dabbling ducks (Genus Anas ) could maintain AI indefinitely on-site, creating opportunities for these species and several bridge species to potentially infect poultry by being a vector between the dam/water habitat and poultry facilities. We suggest that other types of wild birds that may be involved in AI transmission including nomadic waterfowl, grazing ducks (Australian Wood Ducks and Plumed Whistling-duck), Waterhens, Lapwings, resident scavengers (corvids, ibis), birds of prey and mud nests builders (e.g. Fairy Martins). Disrupting AI maintenance cycles on farm dams would reduce the chances of transmission of environmental AI by potential bridge species. This may be achievable by proactively preventing higher risk waterfowl becoming resident and habituated on farms and deterring potential bridge species from accessing poultry houses. Targeted AI surveillance of suspected bridge species is required to determine the real risk. Ideally, this should occur on non-commercial poultry farms where AI transmission to poultry can be objectively investigated.

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Potential reverse spillover of infectious bursal disease virus at the interface of commercial poultry and wild birds

Virus Genes ◽

10.1007/s11262-020-01793-x ◽

2020 ◽

Vol 56 (6) ◽

pp. 705-711

Author(s):

Rania F. El Naggar ◽

Mohammed A. Rohaim ◽

Muhammad Munir

Keyword(s):

Disease Virus ◽

Infectious Bursal Disease Virus ◽

Potential Role ◽

Wild Birds ◽

Infectious Bursal Disease ◽

Free Living ◽

Bean Goose ◽

Bursal Disease ◽

Commercial Poultry

AbstractRecently, multiple spillover events between domesticated poultry and wild birds have been reported for several avian viruses. This phenomenon highlights the importance of the livestock-wildlife interface in the possible emergence of novel viruses. The aim of the current study was to investigate the potential spillover and epidemiological links of infectious bursal disease virus (IBDV) between wild birds and domestic poultry. To this end, twenty-eight cloacal swabs were collected from four species of free-living Egyptian wild birds (i.e. mallard duck, bean goose, white-fronted goose and black-billed magpie). Genetic and phylogenetic analysis of three positive isolates revealed that the IBDV/USC-1/2019 strain clustered with previously reported very virulent IBDV (vvIBDV) Egyptian isolates. Interestingly, two other wild bird-origin isolates (i.e. IBDV/USC-2/2019 and IBDV/USC-3/2019) grouped with a vaccine strain that is being used in commercial poultry. In conclusion, our results revealed the molecular detection of vaccine and vvIBDV-like strains in Egyptian wild birds and highlighted the potential role of wild birds in IBDV epidemiology in disease-endemic regions.

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Reassortment and persistence of influenza A viruses from diverse geographic origins within Australian wild birds: evidence from a small, isolated population of Ruddy turnstones

Journal of Virology ◽

10.1128/jvi.02193-20 ◽

2021 ◽

Author(s):

Bethany J. Hoye ◽

Celeste M. Donato ◽

Simeon Lisovski ◽

Yi-Mo Deng ◽

Simone Warner ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Wild Birds ◽

Influenza Viruses ◽

Low Density ◽

Isolated Population ◽

Influenza A Viruses ◽

Geographic Origins ◽

Eastern Australia

Australian lineages of avian influenza A viruses (AIVs) are thought to be phylogenetically distinct from those circulating in Eurasia and the Americas, suggesting the circulation of endemic viruses seeded by occasional introductions from other regions. However, processes underlying the introduction, evolution and maintenance of AIVs in Australia remain poorly understood. Waders (Order Charadriiformes, Family Scolopacidae) may play a unique role in the ecology and evolution of AIVs, particularly in Australia, where ducks, geese and swans (Order Anseriformes, Family Anatidae) rarely undertake intercontinental migrations. Across a five-year surveillance period (2011–2015), Ruddy turnstones (Arenaria interpres) that ‘overwinter’ during the Austral summer in south eastern Australia showed generally low levels of AIV prevalence (0–2%). However, in March 2014 we detected AIVs in 32% (95% CI; 25–39%) of individuals in a small, low-density, island population 90km from the Australian mainland. This epizootic comprised three distinct AIV genotypes, each of which represent a unique reassortment of Australian, recently introduced Eurasian, and recently introduced American-lineage gene segments. Strikingly, the Australian-lineage gene segments showed high similarity to H10N7 viruses isolated in 2010 and 2012 from poultry outbreaks 900–1500km to the north. Together with the diverse geographic origins of the American and Eurasian gene segments, these findings suggest extensive circulation and reassortment of AIVs within Australian wild birds over vast geographic distances. Our findings indicate that long-term surveillance in waders may yield unique insights into AIV gene flow, especially in geographic regions like Oceania where Anatidae do not display regular inter- or intracontinental migration. IMPORTANCE High prevalence of avian influenza viruses (AIVs) was detected in a small, low-density, isolated population of Ruddy turnstones in Australia. Analysis of these viruses revealed relatively recent introductions of viral gene segments from both Eurasia and North America, as well as long-term persistence of introduced gene segments in Australian wild birds. These data demonstrate that the flow of viruses into Australia may be more common than initially thought and that, once introduced, these AIVs have the potential to be maintained within the continent. These findings add to a growing body of evidence suggesting Australian wild birds are unlikely to be ecologically-isolated from the highly pathogenic H5Nx viruses circulating among wild birds throughout the northern hemisphere.

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Electromagnetic induction sensing of soil identifies constraints to the crop yields of north-eastern Australia

Soil Research ◽

10.1071/sr11199 ◽

2011 ◽

Vol 49 (7) ◽

pp. 559 ◽

Cited By ~ 19

Author(s):

Y. P. Dang ◽

R. C. Dalal ◽

M. J. Pringle ◽

A. J. W. Biggs ◽

S. Darr ◽

...

Keyword(s):

Grain Yield ◽

Electromagnetic Induction ◽

Crop Production ◽

Crop Yields ◽

Yield Potential ◽

Management Options ◽

Soil Constraints ◽

Eastern Australia ◽

North Eastern ◽

On Farm

Salinity, sodicity, acidity, and phytotoxic concentrations of chloride (Cl–) in soil are major constraints to crop production in many soils of north-eastern Australia. Soil constraints vary both spatially across the landscape and vertically within the soil profile. Identification of the spatial variability of these constraints will allow farmers to tune management to the potential of the land, which will, in turn, bring economic benefit. For three cropping fields in Australia’s northern grains region, we used electromagnetic induction with an EM38, which measures apparent electrical conductivity of the soil (ECa) and soil sampling to identify potential management classes. Soil Cl– and soluble Na+ concentrations, EC of the saturated extract (ECse), and soil moisture were the principal determinants of the variation of ECa, measured both at the drained upper limit of moisture (UL) and at the lower limit (LL) of moisture extracted by the crop. Grain yield showed a strong negative relation with ECa at both UL and LL, although it was stronger for the latter. We arrive at a framework to estimate the monetary value of site-specific management options, through: (i) identification of potential management classes formed from ECa at LL; (ii) measurement of soil attributes generally associated with soil constraints in the region; (iii) grain yield monitoring; and (iv) simple on-farm experiments. Simple on-farm experiments suggested that, for constrained areas, matching fertiliser application to realistic yield potential, coupled to gypsum amelioration, could potentially benefit growers by AU$14–46/ha.year (fertiliser) and $207/ha.3 years (gypsum).

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Do spring cover crops rob water and so reduce wheat yields in the northern grain zone of eastern Australia?

Crop and Pasture Science ◽

10.1071/cp08397 ◽

2009 ◽

Vol 60 (6) ◽

pp. 517 ◽

Cited By ~ 9

Author(s):

J. P. M. Whish ◽

L. Price ◽

P. A. Castor

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Wheat Yield ◽

Soil Surface ◽

Farming System ◽

Simulation Modelling ◽

Wheat Crop ◽

Research Approach ◽

Eastern Australia ◽

On Farm

During the 14-month-long fallow that arises when moving from summer to winter crops, stubble breakdown can denude the soil surface and leave it vulnerable to erosion. Cover crops of millet have been proposed as a solution, but this then raises the question, how often is there sufficient water in the system to grow a cover crop without reducing the soil water reserves to the point of prejudicing the following wheat crop? An on-farm research approach was used to compare the traditional long fallow (TF) with a millet fallow (MF) in a total of 31 commercial paddocks over 3 years. Each treatment was simulated using the simulation-modelling framework (APSIM) to investigate the outcomes over a longer timeframe and to determine how often a millet fallow could be successfully included within the farming system. The on-farm trials showed that early-sown millet cover crops removed before December had no effect on wheat yield, but this was not true of millet cover crops that were allowed to grow through to maturity. Long-term simulations estimated that a spring cover crop of millet would adversely affect wheat yields in only 2% of years if planted early and removed after 50% cover had been achieved.

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Implications of Ammonia Production and Emissions from Commercial Poultry Facilities: A Review

The Journal of Applied Poultry Research ◽

10.1093/japr/13.4.684 ◽

2004 ◽

Vol 13 (4) ◽

pp. 684-692 ◽

Cited By ~ 77

Author(s):

C.W. Ritz ◽

B.D. Fairchild ◽

M.P. Lacy

Keyword(s):

Ammonia Production ◽

Poultry Facilities ◽

Commercial Poultry

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Assessment of Newcastle and infectious bronchitis pathogens, and Salmonella spp. in wild birds captured near poultry facilities

Arquivo Brasileiro de Medicina Veterinária e Zootecnia ◽

10.1590/s0102-09352010000100031 ◽

2010 ◽

Vol 62 (1) ◽

pp. 219-223 ◽

Cited By ~ 3

Author(s):

E. Sousa ◽

K. Werther ◽

A. Berchieri Júnior

Keyword(s):

Wild Birds ◽

Salmonella Spp ◽

Infectious Bronchitis ◽

Poultry Facilities

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Decreasing the mob size but not stocking rate of ewes at lambing increases the survival of twin lambs born on farms across southern Australia

Animal Production Science ◽

10.1071/an19632 ◽

2020 ◽

Vol 60 (16) ◽

pp. 1949 ◽

Cited By ~ 1

Author(s):

A. Lockwood ◽

J. Trompf ◽

L. Kubeil ◽

A. Thompson ◽

G. Refshauge ◽

...

Keyword(s):

Resource Allocation ◽

Stocking Rate ◽

South Eastern ◽

Factorial Combination ◽

Eastern Australia ◽

Context Data ◽

Lamb Survival ◽

On Farm ◽

Stocking Rates ◽

South Eastern Australia

Context Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates <4 ewes/ha. Methods Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of <4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P < 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival.

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A CFD approach to assess the effects of different opening combinations in poultry houses

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n12p852-857 ◽

2017 ◽

Vol 21 (12) ◽

pp. 852-857 ◽

Cited By ~ 1

Author(s):

Jairo A. O. Saraz ◽

Keller S. O. Rocha ◽

Flavio A. Damasceno ◽

Ilda F. F. Tinoco ◽

Robinson Osorio ◽

...

Keyword(s):

Cfd Model ◽

Temperature Level ◽

Computational Fluids Dynamics ◽

Air Inlet ◽

Poultry Houses ◽

Poultry Facilities ◽

Computational Fluids ◽

Building Typology ◽

Commercial Poultry ◽

Reduce Energy Consumption

ABSTRACT The aim of this study was to use computational fluids dynamics (CFD) to evaluate hygiene and comfort conditions in function of temperature level and ammonia (NH3) concentration during the night in commercial poultry houses used in Brazil and countries with tropical and subtropical climates. Four models with different curtain heights and different air inlet and outlet positions were used, adopting the open building typology without thermal insulation. The validated CFD model did not present statistical differences from the experimental data, making it possible to use this model to predict the behavior in the four proposed cases. This model can be used to improve the internal conditions of the poultry facilities during the night and could be an important tool to reduce energy consumption and generate better conditions for animal production of chicks over 21 days old.

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