RESUMEN
AIM: The objective of this study was to evaluate the potential of Gabing San Fernando (Xanthosoma spp.) corms as partial carbohydrate replacement for maize in finisher broiler production. MATERIALS AND METHODS: The completely randomized design was utilized to investigate the effects of three finisher poultry diets prepared in varying amounts of cocoyam-corm meal set at 0% (control), 25%, and 50% (experimental) replacement levels. RESULTS: There were no significant differences (p≥0.05) as to mortality and body weight measurements between control and experimental groups. Similarly, the mean weights of selected internal organs and condemnable carcasses among treatment groups did not show any significant differences (p≥0.05). In terms of the average feed intakes, birds from 50%-cocoyam group had the highest mean value and were found to be statistically different (p≥0.01) from both control and 25%-cocoyam groups. However, feed conversion ratio did not significantly differ (p≥0.05) among three groups. Higher feed costs were associated with the 50%-cocoyam treatment diet, which was only consistent with higher feed inputs. Thus, the group fed with 50%-cocoyam meal had significantly higher total mean production costs (p<0.005) per bird, when other expenses were taken into account. The production costs for the group given 25%-cocoyam meal did not significantly differ (p≥0.05) from the control group. CONCLUSION: Partial replacement of maize with cocoyam-corm meal at 25% level was acceptable since inclusion at this level did not adversely affect the production performance of finisher broilers in terms of growth rate, mortality rate, and feeding efficiency. The use of cocoyam meal as nonconventional and alternative carbohydrate source in poultry diet presents positive economic implications, especially to smallhold farmers from the developing countries, like the Philippines.
RESUMEN
The potential use of acanthocephalans as bioindicators of Lead (Pb) pollution in Sampaloc Lake, Laguna, Philippines was investigated. Nile tilapias (Oreochromis niloticus) were collected and Pb concentrations were determined in fish tissues and in their acanthocephalan parasites, Acanthogyrus sp. Significantly higher levels of Pb were detected in the parasites relative to the fish host tissues (p = 0.001). Bioaccumulation capacity of the parasites against fish tissues were 102, 119, and 147 times higher than the fish intestine, liver, and muscles, respectively. Pb sensitivity of the parasites was quantified by exact logistic analysis showing higher odds of Pb detection ranging from 18 to 45 folds (p = 0.001-0.009). Interestingly, infected fish showed significantly lower Pb concentration in their tissues compared to uninfected fish (p = 0.001), suggesting parasites were able to sequester Pb and served as active biosinks. The Pb levels in the parasites were also hundred folds higher (988 times) relative to the ambient waters, indicating a potential role of fish parasites as metal biosinks in aquatic ecosystems.