Use of ovotransferrin on a turkey farm to reduce respiratory disease
- Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent BE-9000, Belgium;
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We performed a clinical trial on a Belgian turkey farm administering ovotransferrin (ovoTF) as a natural antimicrobial protein against respiratory disease. OvoTF is present in egg white and avian serum. Its antibacterial activity involves iron sequestration (Valenti and others 1982, Giansanti and others 2012) and selective ion permeation (Aguilera and others 2003), and the N-terminal antimicrobial peptide OTAP-92 damages the bacterial membrane (Ibrahim and others 2000).
OvoTF aerosols were administered daily from the age of 2 to 3.5 weeks, and again from the age of 8 to 9.5 weeks. The concept of the field trial was based on former observations: (i) Chlamydia psittaci plays a key role in respiratory disease on Belgian turkey farms in association with Ornithobacterium rhinotracheale and the avian metapneumovirus (aMPV) (Van Loock and others 2005), (ii) respiratory disease in Belgian turkeys occurs at 3–6 and 8–12 weeks of age (Van Loock and others 2005), (iii) OvoTF kills extracellular C psittaci and inhibits bacterial internalisation into host cells through interference with the bacterial type III secretion system (Beeckman and others 2007), (iv) specific pathogen-free turkeys receiving an ovoTF aerosol prior to an experimental C psittaci infection, followed by a repeated daily ovoTF aerosol (during 12 days) of 5 mg ovoTF/turkey were significantly protected against C psittaci-induced respiratory disease (Van Droogenbroeck and others 2008) and finally, (v) a single ovoTF administration period (2–3.5 weeks) on a turkey farm in West-Flanders could not prevent the foreseen respiratory disease outbreak …