摘要：An experiment was conducted to improve the nutrient content of tapioca by product to produce β carotene rich feed as alternative poultry feed through fermentation by using carotenogenic fungi ( Neurospora crassa ) as inoculums. The experiment was determination of substrate composition ( carbon source and nitrogen source) based on nutrient quality and quantity of these fermented products. The study was conducted in experimental methods, using the completely randomize design in factorial with 2 treatment were : 1. A factor, ( tapioca by product as carbon source with nitrogen sources: A 1 = tapioca by product+tofu waste, A 2 = tapioca by product + palm kernel cake and A 3 = tapioca by product + rice bran. 2. B factor (Percentage of composition of carbon source with nitrogen source), B 1 = 90% : 10%, B 2 = 80% : 20%, B 3 = 70% : 30% and 60% : 40%). Results of study showed that optimum substrate composition of the fermentation by Neurospora crassa was the mixture 60% tapioca by product with 40% tofu waste. This conditions can increase β carotene and crude protein and also decrease crude fiber which made the nutritional value of the product based on dry-substance was 295.16 μg/g, β carotene 20.44% crude protein , 2.75% crude fat, 11.96% crude fiber, 0.24% calcium, 0.17% phosphor, metabolic energy 2677 Kcal/kg, 67.05% nitrogen retention and 35.44% fiber digestion.
