MICROBIAL TREATMENT OF WEEVIL-INFESTED SWEET POTATO MEAL AS FEED TO BROILERS

A feeding trial was conducted to determine the effectivity of microbial treatment on eliminating the toxicity of weevil-infested sweet potato roots, and to assess intake level and performance of broilers fed microbiologically-treated, weevil-infested sweet potato meal. Weevil-infested sweet potato meal was treated with Aspergillus awamori (terpene-degrading fungus), dried, and mixed with other ingredients. One hundred twenty (120) broiler chicks were randomly distributed to treatment diets containing 3 types of sweet potato meal (healthy, weevil-infested, and microbiologically-treated, weevil-infested) incorporated at 2 levels (12% and 24%) in the ration, following the $2{\times}3$ factorial in CRD with 4 replicates per treatment. Voluntary intake was high with healthy sweet potato meal, even at 24% in the ration, especially at later stage of broiler development. Weevil infestation of sweet potato meal, even at 24% in the ration, especially at later stage of broiler development. Weevil infestation of sweet potato roots significantly reduced voluntary intake and broiler performance even at 12% level in the diet, much more at 24% level (p<0.01). Microbial treatment, however, was found to alleviate such problem, especially at 24% level of incorporation (p<0.01). "Toxicity" of weevil infestation, in terms of enlargement of liver and spleen, in the absence of mortality, was only apparent at 24% level of incorporation in the ration. Again, this was minimized by microbial treatment (p<0.01), and is therefore recommended at high levels of incorporating weevil-infested sweet potato meal in broiler diets. Microbial treatment constitutes an added cost, so that economic analyses should be done to find out whether increases in broiler performance, or reduction in the toxic effects of terpenoid compounds, outweigh the cost of treatment before a definite recommendation can be made for its commercial application.