نتایج جستجو برای: flock level risk factors

تعداد نتایج: 2641362  

2005
M. Clay Green Paul L. Leberg

It has been hypothesized that white plumage facilitates flock formation in Ardeidae. We conducted four experiments using decoys to test factors involved in attracting wading birds to a specific pond. The first three experiments tested the effects of plumage colouration, flock size, and species-specific decoys on flock formation. The fourth experiment examined intraspecific differences in flock ...

2008
Ádám Zoltán Lendvai

Animals often use alternative strategies when they compete for resources, but it is unclear in most cases what factors determine the actual tactic followed by individuals. Although recent models suggest that the internal state of animals may be particularly important in tactic choice, the effects of state variables on the use of alternative behavioural forms have rarely been demonstrated. In th...

2006
Ádám Zoltán Lendvai

Animals often use alternative strategies when they compete for resources, but it is unclear in most cases what factors determine the actual tactic followed by individuals. Although recent models suggest that the internal state of animals may be particularly important in tactic choice, the effects of state variables on the use of alternative behavioural forms have rarely been demonstrated. In th...

2014
Saskia Luttikholt Anouk Veldhuis René van den Brom Lammert Moll Karianne Lievaart-Peterson Klaas Peperkamp Gerdien van Schaik Piet Vellema

In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for ...

Journal: :BMC Veterinary Research 2009
Glenda Dexter Sue C Tongue Lindsay Heasman Susan J Bellworthy Andrew Davis S Jo Moore Marion M Simmons A Robin Sayers Hugh A Simmons Danny Matthews

BACKGROUND Although the epidemiology of scrapie has been broadly understood for many years, attempts to introduce voluntary or compulsory controls to eradicate the disease have frequently failed. Lack of precision in defining the risk factors on farm has been one of the challenges to designing control strategies. This study attempted to define which parts of the annual flock management cycle re...

Hosna Safari Maryam Ansari-Lari, Samira Mehrshad Shahram Shekarforoush

Salmonella spp. are important food borne pathogens worldwide that frequently infect poultry flocks. This cross-sectional study was conducted to determine the prevalence of Salmonella spp. colonization in broiler flocks in Shiraz (southern Iran) and to find the possible association of infection status with some potential risk factors including vaccination program and use of ant...

2013
Sema Nickbakhsh Louise Matthews Jennifer E. Dent Giles T. Innocent Mark E. Arnold Stuart W.J. Reid Rowland R. Kao

The importance of considering coupled interactions across multiple population scales has not previously been studied for highly pathogenic avian influenza (HPAI) in the British commercial poultry industry. By simulating the within-flock transmission of HPAI using a deterministic S-E-I-R model, and by incorporating an additional environmental class representing infectious faeces, we tracked the ...

2013
Endrias Zewdu Gebremedhin Abebe Agonafir Tesfaye Sisay Tessema Getachew Tilahun Girmay Medhin Maria Vitale Vincenzo Di Marco Eric Cox Jozef Vercruysse Pierre Dorny

Toxoplasmosis is a global zoonosis caused by Toxoplasma gondii, an intracellular apicomplexan parasite. The objectives of this study were to estimate the animal and flock level seroprevalence and risk factors associated with toxoplasmosis in goats of Central Ethiopia. In Ethiopia, goats are economically important animals used for meat and milk production. The study was cross-sectional and 927 b...

Journal: :The Journal of general virology 2005
Clara Díaz Zulma G Vitezica Rachel Rupp Olivier Andréoletti Jean Michel Elsen

Data from 4049 Romanov sheep belonging to a flock affected by natural scrapie were analysed by using survival-analysis techniques. Failure time was defined as the period of time between first exposure to infection and the date that animals left the flock with scrapie signs. Four hundred and forty-seven sheep were identified as 'scrapie animals'. Several models, including level of exposure as a ...

Journal: :PLoS ONE 2008
K. Marie McIntyre Simon Gubbins Wilfred Goldmann Nora Hunter Matthew Baylis

BACKGROUND Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics be...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید