Effects of endocrine disrupting chemicals (EDCs) in mallard ducks (Anas platyrhynchos).

Professorial Chair Lecture

Southeast Asia Regional Center for Graduate Students and Research in Agriculture (SEARCA) Professorial Chair Lecture

Date

6-2009

Abstract

The declining total duck meat and egg production by 7.68% and 6.06%, respectively and the presence of several reproductive and liver abnormalities are signs of alarm for the future of duck industry in the Philippines. Aside from understanding the effects of EDCs in the duck production of egg and meat, a national program on developing duck breeding program for commercialization of genetically improved meat and egg-type ducks must be accomplished as soon as possible, to save the dwindling duck industry. The molecular characterization of various ducks raised in the Philippines may help a lot as an input to duck breeding program. The presence of lindane residues (41 to 130 ppb) in commercial pellet and mashed feed is a cause for alarm not only for the duck farmers but also for the whole livestock sector. These imply possible inclusion in our food, eventually posing human health risks. Lindane is not ban in Canada and USA by the Food and Drug Authority although U.S.EPA banned its use in 2006 (Evans, 2007). Some researches have found that lindane causes cancer (Wong and Matsumura, 2007; Rafnsson, 2006; Purdue et al 2007). Lindane and organochlorine residues are detected in amniotic fluid (Luzardo et al, 2009), in human breast milk in Asia (Tanabe and Kunisue, 2007) and blood samples of young males in Southern Spain (Carreño et al, 2007). Knowing the health risk involved of lindane in human tissues, the origin/source of the contaminated feed must be identified and banned for use in commercial duck production. Laguna Lake shellfish resources should also be banned for livestock and human consumption due to the dangerous presence of cadmium residue. This is the first report on the detection of liver mRNA and 240 kDa VTG from liver and plasma of ducks in Asia. The liver VTG mRNA utilizing chicken primer was accomplished using Reverse Transcription Polymerase Chain Reaction (RTPCR). Results have shown that the RT-PCR protocol needs more laboratory improvement although the chicken primer was found useful for duck mRNA determination. The duck VTG mRNA was not yet cloned and published as of the moment. The putative 240 kDa VTG from liver and plasma was determine using Sodium Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis (SDS-PAGE). Results have shown that almost all male ducks of completely confined production system were postive for EDCS exposure as shown by the presence of putative 240 kDa VTG peptide using SDS-PAGE. Plasma samples diluted 10x the homogenization buffer is recommended. Further confirmation of putative VTG can be accomplished by Electroblotting system procedure. The established SDS PAGE laboratory protocol is a cheap and effective biomarker of recognizing animals or humans exposed to EDCs and it is hereby recommended for use in environmental and health risk assessment and management. Briefly, the presence of several abnormalities found in the liver and ovary of ducks can be linked to cadmium heavy metal found in freshwater clams and or lindane residue detected from commercial feeds. Positive detection of putative VTG using SDS - PAGE from plasma and liver of ducks strengthens our assumption. Experiments for bioaccumulation, physiological as well as organ dysfunction due to heavy metal cadmium and lindane residues are recommended. Related to this, commercial feeds and diet ingredients should be analyzed for the presence of lindane residue and the ingredient source should be banned for use in commercial feed formulation. It is recommended that lindane residue analysis should be included in the regulation of commercial feed industry. Lastly, alternative production of commercial feed ingredient raised in an organic production system should be considered a viable option if we consider life and human health our utmost concern.

Location

UPLB Main Library Special Collections Section (USCS)

College

College of Agriculture and Food Science (CAFS)

Language

English

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