Germination and Drying as a Traditional Processing Method for Soybean Incorporation in Fish Feed in Togo

The effects of germination (fresh germinated soybean [SG1F]) and post-germination drying (dried germinated soybean [SG1S]) on the crude protein (CP) levels, aflatoxin content, survival, and growth performance of Nile tilapia fry (Oreochromis niloticus) were evaluated. Raw soybean (SC) and roasted soybean (ST) served as controls. Laboratory analyses revealed CP contents of 11.74%, 38.72%, 38.42%, and 34.72% for SG1F, SG1S, RT, and RS, respectively. Aflatoxin levels were 2.3 µg/kg for SG1S, 1.66 µg/kg for RS, 1.60 µg/kg for RT, and 0.00 µg/kg for SG1F. Experimental diets, formulated to be isoproteic (35.44%) and isolipidic (8.73%), were prepared using flour from these soybean treatments and tested on tilapia fry with an average initial weight of 11.86 ± 2.15 g. The study was conducted in a completely randomized design with three replicates in 1 m3 tanks stocked at 35 fry per tank over 56 days. Weight gains were 23.40 ± 10.21 g, 18.93 ± 8.67 g, 16.30 ± 9.92 g, and 16.07 ± 5.55 g for RT, RS, SG1S, and SG1F, respectively. Survival rates were 100%, 90.67%, 89.33%, and 88% for SG1F, RS, RT, and SG1S, respectively. Daily growth rates showed a consistent upward trend for all diets from the start to the end of the experiment.