Nannochloropsis spp. as Feed Additive for the Pacific White Shrimp: Effect on Midgut Microbiology, Thermal Shock Resistance and Immunology

Abstract

This work aimed to evaluate Nannochloropsis spp. as feed additive in the diet of Pacific white shrimp for their effect on midgut microbiology, thermal shock resistance and immunological parameters. Initially, the digestibility of the microalgae meal was assessed, and the apparent digestibility coefficient (ADC) was determined. The ADC was, in general, high in lipids (78.88%) and eicosapentaenoic fatty acid (73.86%). Then, Nannochloropsis spp. were included in diets at four levels (0, 0.5, 1 and 2% inclusion). The shrimp were reared in 500 L clear water tanks containing 20 shrimp per tank with an initial weight of 6.05 ± 0.06 g and fed four times a day. Shrimp fed with supplemented diets containing Nannochloropsis spp. (0.5 and 2%) presented higher resistance to thermal shock when compared to the non-supplemented group (control). Shrimp fed with 1 and 2% of algae inclusion had a higher production of reactive oxygen species (ROS) when compared to other treatments. No statistical difference was observed in the immunological parameters and microbiology of the intestinal tract. Thus, the inclusion of Nannochloropsis spp. in shrimp diets at 0.5 and 2% levels increases resistance to thermal shock and ROS production in shrimp.

Immunostimulatory effects of Nannochloropsis oculata supplementation on Barki rams growth performance, antioxidant assay, and immunological status

“…Furthermore, microalga dosage directly associated with BwtGKg and negatively with FCR as determined by PCA could support this finding. Nannochloropsis has been used in nutraceuticals and feed enrichments [ 11 , 38 ]; as a rich source of a wide variety of essential and non-essential amino acids as noted in the chemical composition. Amino acids supplementation, especially branched-chain amino acids, exerts a unique capability to recruit signal transduction pathways that up-regulate protein biosynthesis, in skeletal muscle, therefore, increasing BwtGKg [ 39 , 40 ].…”

“…Consequently, incorporating microalgae in ruminant diets had encouraging outcomes [ 10 ]. Nannochloropsis microalgae are well recognized in aquaculture nutrition and play a significant role in live feed enrichment due to their high amounts of eicosapentaenoic fatty acid [ 11 ]. As a result, they can be used to promote ruminal fermentation and feed digestion [ 12 ].…”