Complete replacement of fishmeal by soybean and poultry meals in Pacific whiteleg shrimp feeds: Growth and tolerance to EMS/AHPND and WSSV challenge

Abstract

Corresponding to projected global population growth, the world's food production systems must likewise enlarge substantially if current levels of dietary protein intake are to be maintained. The anticipated growth curve for global aquaculture, and especially for shrimp farming, which is forecast to double production by 2030, will inevitably result in shortfalls in currently favored dietary ingredients: fishmeal (FM) and fish oil (FO). Servicing the projected FM-FO shortfall with marine products would be a formidable task as economic, social, moral, safety and environmental issues have forced the feed sector to examine the use of alternative, non-marine, ingredients. Herein, various alternative protein and lipid sources were evaluated as substitutes for FM-FO in Pacific whiteleg shrimp diets. Growth trials were coupled to challenges with viral and bacterial pathogens to assess potential benefit or disadvantage of ingredient switching. No differences (P > .05) were observed between control and test diets regarding growth or survival, Average Daily Gain (g d−1) or Specific Growth Rate (% d−1) over a 56-day period. Moreover, response to post-feeding trial challenge with EMS/AHPND or WSSV also did not differ between diets (P > .05). However, there was a difference in size/age responsiveness to bacterial challenge, with younger animals succumbing to infection more rapidly (P ≤ .035). Similar responses were observed for shrimp exposed to WSSV over the first 5-days post-challenge (P ≤ .02) after which survival rates equalized. Overall, the results support the sustained belief that FM-FO constituents of Pacific whiteleg shrimp diets can be totally replaced by non-marine ingredients that are nutritionally equivalent. Improvement in responsiveness to substitute proteins and oils might be further gained with more judicious blending of ingredients and use of other additives. Such manipulations could also result in less expensive sustainable feeds.