The Effects of Different Dietary Protein Levels and Feeding Rations on Water Quality and Growth Performance of Pacific White Shrimp (Litopenaeus vannamei) Reared in Individual Biofloc Culture Systems

Abstract

Dietary protein is one of the most expensive feed components and an important determinant in the growth of the Pacific white shrimp (Litopenaeus vannamei). Therefore, understanding the interaction between dietary protein levels and daily protein intake, which drives the shrimp’s growth, is crucial. An 8-week growth trial was conducted to examine the effect of dietary protein levels offered at different percentages of standard ration on water quality and growth response of L. vannamei reared in individual biofloc systems, each containing 800 L of culture water stocked at 88 shrimp/m³. Four diets with crude protein (CP) levels of 25%, 30%, 35%, and 40% fed at the standard feeding rate (100%) were used for this experiment. Additionally, 25% CP and 30% CP diets were also fed at 140% and 116.7%, respectively, of the standard feeding rate (equivalent to 35% CP) as the other two treatments. This resulted in six treatments with four replicates per treatment, which were randomly assigned to the tanks. At the end of the trial, significant differences (p  < 0.05) in growth and feed conversion ratio (FCR) were observed. Results showed that the increase in CP content of the feed resulted in an increased final mean weight and weight gain. The shrimp fed with a 40% CP diet at 100% standard ration had the highest final mean weight (15.38 g), weight gain/week (1.61 g/week), weight gain percentage (523.63%), and the lowest FCR (1.26). Whereas feeding lower protein diets at higher rations (25% and 30% CP at 140% and 116.7% of the standard ration, respectively) did not lead to significant growth improvements but resulted in a higher FCR, indicating potential overfeeding. This trial demonstrated that shrimp raised in the biofloc system performed better in terms of growth and feed utilization as protein intake increased.