Evaluation of extruded feeds with no or low inclusion of fishmeal on growth performance of Pacific white shrimp Penaeus vannamei in clear water and biofloc systems

Shrimp research has been focused on the development of feeds with minimal levels of fishmeal, as well as using alternative, lower cost protein sources. The study objective was to evaluate the performance of the Pacific white shrimp Penaeus vannamei fed with four different protein-based extruded diets [plant-based (AP), 8% poultry by-product meal (PM8), 8% fishmeal (FM8) and 12% fishmeal (FM12)] while cultured in two independent trials with clear water and biofloc type systems. Additionally, the pellet durability index (PDI) and hardness of these diets were determined. Results from the clear water experiment showed that the shrimp fed with PM diet had the lowest final individual weight, biomass (g) and weight gain (g), and the poorest feed conversion ratio (FCR). It was observed that the shrimp fed with AP, FM8 and FM12 diets had significantly higher weight gain than shrimp offered the PM8 diet. Results from the biofloc experiment showed that shrimp fed with AP diet had the lowest biomass (g), weight gain (g) and thermal growth coefficient and the poorest FCR. No significant differences in survival rate were observed among the four diets in both experiments. The extruded diets showed high PDI when measured using the tumbling box and the Holmen tester. Additionally, the pellet hardness showed no significant differences among the four diets. The low inclusion of fishmeal, as well as the use of alternative protein sources in these diets, did not adversely affect the final weight, weight gain and percent weight gain of P. vannamei.