In part 1, This study was to investigate the carotenoids composition and toxic
substances in local Thai feedstuffs a byproducts from agricultural harvest namely; tea,
mulberry and cassava leaves. Results of the studies showed that feedstuffs consisted
mainly of lutein and β - carotene, and indicate that tea and mulberry leaves have
similarly proportion of lutein and β-carotene about 1:1. In contrast, cassava leaves
comprise the lutein more than β-carotene and has a proportion of lutein and
β-carotene about 2:1. For aquatic animal safety, this results suggested that both tannin
and hydrocyanic acid in dried tea and cassava leaves could be used not more than 10
and 60%, respectively. This study might be of use for the raw materials as the
carotenoid sources for lowering the production cost of the fancy carp and ornamental
fishes diet including adding value to agricultural byproducts.