ABSTRACT
This study investigated the effects of pig feed contaminated with lead (Pb) on the decomposition rate of pig carrion, identified the aerobic microorganisms and necrophagous insects associated with decomposing pig (Sus scrofa) carrion (above ground), and explored their potential use in the determination of post-mortem interval (PMI). The study profiled the decomposition of Sus scrofa carrion over a period of 40â¯days to record the effects of lead during decomposition. Fungi were identified by sub-culturing on prepared solidified potato dextrose agar and microbial identification was carried out using biochemical characterization. The decomposition rate of pigs fed with lead-contaminated feed (0.18 and 0.2â¯ppm) attracted insects and increased the rate of hair fall, hence at day 35, these carrion were skeletonized. The aerobic bacterial communities identified were Staphylococcus aureus, Bacillus sp. and Salmonella paratyphiwhereas the fungi identified include Fusarium sp., Cylindrocladium sp Cephalosporium sp., Scopolariopsis sp., Aspergillus sp, Mucor sp., Circinella sp., Pythium sp., Penicillium sp., Trichoderma sp., Geotrichum sp., Phytophthora sp., and Saccharomyces sp. The necrophagous insects collected consisted of three orders: Coleoptera, Diptera, and Hymenoptera which included insects like Chrysomya chloropyga Wiedemann, 1818, Musca domesticaLinnaeus, 1758, Sarcophaga exuberansPandelle, 1896, Necrobia rufipesDe Geer, 1775, Dermestes maculatusDe Geer, 1774, Camponotus sericeusFabricius, 1798 and Camponotus perrisiiForel, 1886. The activity of insect on treatments was well matched but the decomposition rate differs. Spectrophotometric analysis of insect larvae collected from decomposing pigs revealed they had presence of lead. Insect larvae and microbes identified are good entomotoxicological tools in crimes associates with lead poisoning.
