There is a growing need to use alternative, sustainable protein ingredients in animal feeds to relieve mounting demands for traditional protein sources such as fish meal and soya meal. Insect meal is one such protein ingredient and has been shown to be a viable alternative in aquaculture feeds. This study aims to evaluate the impact of insect meal on the following parameters in white shrimp (Litopenaeus vannamei): 1. growth performance and indications on health (histology and microbial composition of the gut and hepatopancreas) starting with small shrimp (PL12), 2. Survival and anatomy on 1.5-2 g shrimp when challenged against Vibrio parahaemolyticus, and 3. protein digestibility on 3-5 g shrimp.
Five experimental groups, each with four replicates, were studied as follows: 2% Insect meal, 5% Insect meal, 10% Insect meal, 2% Insect meal + 2% Insect oil, and a control (without the inclusion of insect meal or insect oil),
After 45 days of feeding, shrimp fed 2% Insect meal +2% insect oil, and 10% Insect meal had a significantly higher average survival rate than other groups. At the same time, shrimp provided 2% Insect meal +2% Insect oil, 10% Insect meal, and 5% Insect meal had a significantly higher average body weight and lower feed conversion ratio than other groups. Regarding the immunological study, shrimp from all groups that provided insect meal had significantly higher immune responses (the total hemocyte count, phagocytosis activity, phenoloxidase activity, superoxide dismutase activity, and bactericidal activity) than the control group. Shrimp from all groups that provided insect meal had fewer Vibrio spp in the hepatopancreas and intestine of shrimp than other groups. Those shrimp also showed a significantly higher percentage survival and better condition of the hepatopancreas than the control group after being challenged with bacteria causing White faeces syndrome. And finally, after the 14 day digestibility trial, shrimps provided with 2% Insect meal +2% Insect oil had the best apparent digestibility of nutrients, including a percent dry matter digestibility, percent organic matter digestibility, percent protein digestibility, percent lipid digestibility, and percent nitrogen-free extract.
These results show that including insect meal up to 10% in a shrimp feed formulation can have a positive impact on growth and survival, and including both 2% insect meal and 2% insect oil improved the growth, survival and digibility in shrimp the most.