Shrimp farming is a significant global industry which in 2021 was estimated to be worth US$ 38 billion and is expected to grow to an estimated 6m mt in 2023. However, the industry continues to face a number of challenges including higher feed costs, lower farm gate prices, and increasing demand for diets with reduced capture marine resources and lower nutrient input. Balancing these competing demands is critical to ensure the long-term profitability and sustainability of shrimp farming. The use of low-cost inputs may seem attractive, but it often negatively impacts animal health and performance, reducing yields, harvest animal quality, and water quality, which in turn affects nutrient output from the farm.
In light of these challenges, commercial-scale farm trials were conducted at Australian Prawn Farms’ Ilbilbie facility with Black Tiger Shrimp (Penaeus monodon) to assess the performance of a diet using zero marine resources, as well as the protein and nutrient input into the farming environment and return on investment for the farm in connection with the use of the diet. The inclusion of a microbial biomass called NovaqPro® allowed for flexible formulation and the reduction of protein and marine resources in the diet it was included in.
Results from the first commercial trial showed that a diet containing NovaqPro®, and zero marine resources, performed as well as a diet containing a high level of marine resources, indicating that marine protein and oil was not necessary for commercially farmed P. monodon. To the knowledge of the authors, this was the first reported commercial production of P. monodon grown on a diet completely devoid of marine resources.
In the second trial, the use of NovaqPro® enabled the formulation of a diet for P. monodon that allowed for the reduction of protein and fishmeal inclusion while, as compared to the diet containing a high level of marine resources, improving growth by ~5%, increasing harvestable yield by 2.5t/ha, and increasing survival rates by ~10%. Furthermore, there was a reduction of feed conversion ratio by ~6% and total ammonia nitrogen production per tonne of biomass harvested of ~40%. Importantly, the net revenue on the ponds fed low protein diets containing NovaqPro® increased by ~16%, while the nutrient output decreased, as compared to the ponds fed a diet containing a high level of marine resources.
Overall, these trials demonstrate that the use of NovaqPro® microbial biomass can help farmers balance competing demands and reduce marine inputs, while maintaining or improving yields and profitability. By reducing reliance on marine resources and improving water quality, this approach may also contribute to the long-term sustainability of the shrimp farming industry.