This study was funded by the Ministry of of Higher Education, Malaysia through the research grants ERGS/1/2013/STG 03/UKM/01/02 (MOHE) and # 04-0102-SF1208 (MOSTI) and UKM Research Grant GUP-2015025. We would like to thank the anonymous reviewers for their worthwhile comment. We also would like to thank Dr. Mike Rimmer, Faculty of Veterinary Science, University of Sydney, Prof. Dr. Wickneswari Ratnam Faculty of Science and Technology, Universiti Kebangsaan Malaysia and Dr. Shelby E. Temple, University of Bristol, UK for their very useful comment that greatly improved the quality of the manuscript. All field sampling and laboratory protocols followed and complied with the current laws of Malaysia.