Effects of dietary Bergamot ( Citrus bergamia ) peel oil on growth, haematology and immune response of European sea bass ( Dicentrarchus labrax ) juveniles

Abstract

The aim of the present study was to evaluate the effects of essential oil extracted from bergamot (Citrus bergamia) peel on growth performance and health status of European sea bass juveniles (5.10 + 0.05 g). Test diets supplemented with 0.0%, 0.5%, 1.0% and 2.0% bergamot peel oil (BPO0, BPO0.5, BPO1 and BPO2) were fed to experimental fish for 60 days. At the end of the experiment, the best growth performance was obtained in the BPO0.5 and BPO1 groups (p < .05). No significances were found for haematological parameters including red blood cell count, haematocrit and haemoglobin concentration at the end of the feeding experiment. There were significant differences between the total protein, cholesterol, alkaline phosphatase and glutamic oxaloacetic transaminase (p < .05) between the BPO0.5 and BPO1 supplemented groups and the control group with no BPO addition. The addition of BPO showed significant differences in immune parameters such as lysozyme activity, total myeloperoxidase content, superoxide dismutase and glutathione peroxidase activity between BPO0 and BPO supplemented groups (p < .05). It might be concluded that dietary addition of 0.5%‐1% BPO could increase the growth performance and feed utilization with improved health status in sea bass juveniles.

Dietary essential oil extract from sweet orange (Citrus sinensis) and bitter lemon (Citrus limon) peels improved Nile tilapia performance and health status

“…The results from the present study revealed that Nile tilapia fed diets supplemented with different inclusion levels of EOs extract from sweet orange and/or lemon peels revealed improved growth (final fish weight, BWG, WG%, SGR and TGC) and reduced FCR compared with CG, and the proper growth and feed utilization being directed towards the fish fed OEO × LEO in a dose‐dependent effect. Similar findings are observed in European sea bass ( Dicentrarchus labrax ) juveniles (Acar et al., 2019), Mozambique tilapia ( Oreochromis mossambicus ) (Acar et al., 2015), Rainbow Trout ( Oncorhynchus mykiss ) juveniles (Gültepe, 2018), silver catfish ( Rhamdia quelen ) (Lopes et al., 2019), Juvenile Labeo victorianus fingerlings (Ngugi et al., 2017) and Nile tilapia ( Oreochromis niloticus ) fingerlings (Salem & Abdel‐Ghany, 2018).…”

“…This was accompanied by an increase in the secretion of pancreatic digestive enzymes (trypsin and amylase) and intestinal enzymes (maltase, alkaline phosphatase and leucine amino peptidase) (Jang et al., 2007). Furthermore, EOs may improve the beneficial microbial population (Acar et al., 2019; Jang et al., 2007) and reduce bacterial count of undesirable and/or pathogenic microorganisms (Salem et al., 2019) in the digestive tract that increases the absorption of essential nutrients (Holst & Williamson, 2008). The reduced pathogenic microorganisms may be attributed to the presence of citral and terpinene as active components of OEO and LEO that have antimicrobial activities (Kumar et al., 2020).…”

“…The reduced pathogenic microorganisms may be attributed to the presence of citral and terpinene as active components of OEO and LEO that have antimicrobial activities (Kumar et al., 2020). Consequently, EOs may enhance the growth rate of fish (Acar et al., 2019; MacLennan et al., 2002). In addition, Aanyu et al.…”

“…The erythrogram (Hb, RBCs and PCV) of Nile tilapia fed OEO and/or LEO supplemented diets showed non‐significant difference and was within the normal range of tilapia (Mohamed et al., 2017). It indicated that OEO and/or LEO had no negative effect on health status of cultured fish (Acar et al., 2019; Vicente et al., 2019). Dissimilar, RBC and PCV are increased with increasing dietary supplementation of EO extract from Citrus limon fruit peels from 1% to 5% (Ngugi et al., 2017).…”

Chemical composition, cytotoxicity and antimicrobial activity of selected plant‐derived essential oils against fish pathogens

“…In addition to reducing resistance phenomenon (Dugo & Di Giacomo, 2002) and broad‐spectrum antimicrobial activity against fish pathogens, they are considered safe substances with several potential benefits for fish farming, which include the improvement of fish welfare, health and zootechnical performance indices, such as growth performance, feed conversion rate and protein efficiency rate (Acar et al., 2019; De Souza et al., 2019; Sutili et al., 2018). The antibacterial (Vaseeharan et al., 2013), antiparasitic (Da Costa et al., 2017; Metin et al., 2015; Soares et al., 2016) and immunomodulatory (Acar et al., 2019; Sutili et al., 2018; Valladão et al., 2017) effects of EOs help to prevent outbreak of disease in fish farming, therefore minimizing economic loss due to disease and help combat the indiscriminate use of antimicrobials and therefore the emergence of antimicrobial resistance. Moreover, the reduction of antimicrobial utilization in aquaculture has the potential to improve the quality of aquaculture products by reducing antimicrobial residue in both the environment and animals intended for human consumption (Liu et al., 2017).…”