Effect of a phytogenic feed additive on survival and performance of shrimps receiving a fish meal reduced diet

Nutrient sparing concepts in aquatic diets are recognized as reasonable approach to support sustainable and efficient use of marine resources and thereby contribute against overfishing. Simultaneously, the reduction in marine protein source (MPS) often causes reduced health status and thus increased mortality of animals grown in aquaculture. The objective of the current study was to investigate the impact of a phytogenic feed additive (PFA) on shrimp performance in a nutrient sparing concept over a period of 57 days. A total of 240 white-leg shrimps Litopenaeus vannamei (1.5 – 2.0 g body weight (BW)) were randomly allocated to 12 tanks (RAS system with appropriate water quality parameters) which were divided into two experimental groups (n=6). Both groups received a diet based on soybean meal, wheat and corn, including 15% MPS. One group additionally received 0.2 g/kg feed of the PFA, an encapsulated blend of essential oils with thymol as major component. Shrimp health was monitored through observation and water quality parameters were recorded daily. BW as well as feed consumption were determined at day 0, 28 and 57. Hepatopancreas weight was measured at trial end. Statistical analysis comprised Student’s t-test and Kolmogorov-Smirnov test. Over the entire trial period, the PFA group showed increased biomass (p<0.001) and weight gain per tank (p<0.001), survival (p=0.004) and decreased feed conversion ratio (FCR, p=0.001). Especially the improved FCR demonstrates how PFAs can promote a better efficacy in nutrient utilization which ultimately yields an improved health status, increased survival whilst contributing to improved sustainability through reduced effluents.

Publication History

Article published online:
13 December 2021