Distinct effects of dietary Chitosan, ZnO, and Chitosan–ZnO nanocomposite on the performance and diet economic efficiency of Pacific white shrimp (Penaeus vannamei)

Abstract

Abstract This study investigated the effects of dietary supplementation with chitosan, zinc oxide (ZnO), and chitosan–ZnO nanoparticles (NPs) on the growth, survival, body composition, digestive enzymes activities, and hemato-immunity of Pacific white shrimp (Penaeus vannamei), alongside its impact on diet economic efficiency. Shrimps with an initial weight of 3.27 ± 0.11 g were exposed to eight diets: a control basal diet without additives, and experimental diets containing 36 mg kg− 1 chitosan, 10, 20, and 40 mg kg− 1 ZnO, and chitosan–ZnO NPs over a 90-day period. All experimental diets led to enhancements in final weight, specific growth rate, weight gain (%), survival rate, and feed conversion ratio. The most significant improvements in growth performance and survival rate were observed with chitosan–ZnO NPs at the 10 mg kg− 1 dosage. Furthermore, experimental treatments resulted in elevated whole-body lipid and protein contents, as well as heightened activities of protease, amylase, and lipase enzymes compared to the control group. Substantially increased digestive enzymes activities were noted in shrimps fed chitosan–ZnO NPs at 10 mg kg− 1 concentration (P < 0.05). In addition, shrimp fed with chitosan–ZnO NPs at 10 mg kg− 1 exhibited lower levels of serum aspartate transaminase, alanine transaminase, and alkaline phosphatase, along with higher levels of acid phosphatase (P < 0.05). Notably, total and differential hemocyte counts showed a gradual increase from the control group to experimental treatments, peaking with chitosan–ZnO NPs at the 10 mg kg− 1 concentration. The findings highlight the potential of bionanocomposites, specifically chitosan–ZnO NPs, in improving shrimp nutrition and subsequently its diet economic efficiency. This study provides valuable insights into sustainable approaches for optimizing the performance of Penaeus vannamei in aquaculture systems.