Effect of Soybean Meal Substitution Using Raintree (Samanea saman) Seed Meal on the Physical Quality of Feed and Growth Performance of the Juvenile White Shrimp, Litopenaeus vannamei

Efforts to find alternative raw materials to replace soybean meal in Litopenaeus vannamei feed are ongoing. Feed plays a critical role in promoting growth and survival and directly impacts production costs. The use of raintree seed meal as a protein source to replace soybean meal in L. vannamei feed has not yet been extensively studied. This study assessed the feasibility of using raintree seed meal fermented with a combination of different microorganisms as a replacement for soybean meal in feed, with the goal of improving the growth performance of L. vannamei. The research was conducted in two stages. First, Fourier transform infrared (FT-IR) analysis was performed to compare the functional groups of unfermented and fermented raintree seed meal. The fermentation process involved using a mixture of microbes at a concentration of 1.5 mL/100g and a fermentation time of 72 hours. Second, the study evaluated the replacement of soybean meal with fermented raintree seed meal at five different levels of substitution (0%, 25%, 50%, 75%, and 100%) in L. vannamei feed. The results showed an increase in intramolecular N-H amines and carboxylic acids and a decrease in O-H functional groups in the fermented raintree seed meal. The inclusion of 50% fermented raintree seed meal with mixed microbes significantly improved the feed's physical characteristics and shrimp growth performance, surpassing the effects observed in other treatments. The physical properties of the feed included a breaking speed of 64.73 minutes and a solids' dispersion of 10.86%. The growth performance metrics for L. vannamei included a feed consumption rate of 117.87g, feed efficiency of 81.44%, body glycogen content of 20.27%, absolute growth of 4.09g, and a survival rate of 89.16%. In conclusion, fermented raintree seed meal can effectively replace 50% of soybean meal in feed, enhancing the growth performance of L. vannamei.