Effects of three medicinal herbs Bidens pilosa, Lonicera japonica, and Cyathula officinalis on growth and non-specific immune responses of cobia (Rachycentron canadum)

The effect of dietary administration of Saussurea lappa root on performance, blood biochemical indices, redox status, innate immune response, intestinal microbial population and resistance against A. hydrophila infections of Tilapia Fingerlings

This experiment was performed to identify the influence of dietary Saussurea lappa root (SLR) on the performance and general health status of Nile Tilapia fingerlings (O. niloticus). Four formulated diets with different SLR levels of 0.0, 2.5, 5 and 10 g/kg, respectively, were afforded to fingerling fish (15.42 ± 0.05 g) for 8 weeks. The feed efficiency ratio (FER), feed intake (FI) and feed conversion ratio varied with dietary SLR level in a linear model and a high feed efficiency rate was recorded at the 10 g/kg group, while FI and FCR exhibited an opposite trend (P < 0.001). Dietary SLR level influenced serum protein constituents, liver and renal function enzymes, triglycerides, cholesterol and glucose (P < 0.001). Serum Catalase (CAT), total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) remarkedly increased with dietary SLR level and attained a level at 10 g/kg. Furthermore, serum lysozyme, complement C3 (C3), IgA and IgD were stimulated by 10 g/kg SLR. Intestinal digestive enzymes (lipase and amylase) increased with SLR level up to 10 g/kg. As the dietary SLR level raised, the cumulative survival percentage aginst A. hydrophila challenge increased and then reached a maximum at 10 g/kg SLR group. Moreover, gene expression of pro-inflammation cytokines (TNF-2a, IL-1β, and IL-10) in liver and kidney transcriptomes demonstrated effective immunostimulant capabilities of greater SLR inclusion levels in fish diet. Meanwhile, intestinal microbial investigation, revealed that high levels of SLR in tilapia fish feed significantly suppressed total bacterial count, and pathogenic bacterial count (such as, E. coli, Coliform, Aeromonas spp, Pseudomonas spp.), and stimulated lactic acid bacteria development. Finally, it is recommended to include a high level of SLR (5 or 10 g/kg) in the diet of O. niloticus fingerlings to enhance feed efficiency, antioxidant characteristics, and immunological response against bacterial infections.

Potentials of Aloe barbadensis inclusion in fish feeds on resilience to Aeromonas hydrophila infection in freshwater fish Labeo rohita

Aquatic bacterial pathogens can cause severe economic loss in aquaculture industry. An opportunistic pathogen, Aeromonas hydrophila is responsible for Motile Aeromonas Septicemia, leading to high mortality rates in fish. The present study was focused on the efficacy of Aloe barbadensis replacing fishmeal diets on hematological, serum biochemical, antioxidant, histopathological parameters, and disease resistance against A. hydrophila infection in Labeo rohita. Isonitrogenous fishmeal replaced diets (FMR) were prepared with varying levels of A. barbadensis at D1 (0%) (control), D2 (25%), D3 (50%), D4 (75%) and D5 (100%) then fed to L. rohita. After 60 days of post-feeding, the experimental fish were challenged with A. hydrophila. Blood and organs were collected and examined at 1- and 15-days post infection (dpi). The results demonstrated that on 1 dpi, white blood cells (WBC), total protein, cholesterol and low-density lipoprotein (LDL) levels were significantly increased in D3 diet fed groups. The D2 and D3 diet fed group showed decreasing trends of serum glutamic pyruvic transaminase (SGPT) and antioxidant enzymes activity on 15 dpi. The histopathological architecture results clearly illustrated that the D3 diet fed group had given a higher protective effect by reducing the pathological changes associated with A. hydrophila infection in liver, intestine and muscle. Higher percentage of survival rate was also observed in D3 diet fed group. Therefore, the present study suggested that the dietary administration of A. barbadensis up to 50% fishmeal replacement (D3 diet) can elicit earlier antioxidant activity, innate immune response and improve survival rate in L. rohita against A. hydrophila infection.

The effects of combined inclusion of Malvae sylvestris, Origanum vulgare, and Allium hirtifolium boiss for common carp (Cyprinus carpio) diet: Growth performance, antioxidant defense, and immunological parameters

The present study aimed to investigate the effects of a mixture of three medicinal plants extracts (COP: common mallow (Malvae sylvestris), oregano (Origanum vulgare), and Persian shallot (Allium hirtifolium boiss)) on growth, hematological indices, immunological parameters, liver antioxidant, and digestive enzyme activity of common carp (Cyprinus carpio). Accordingly, 540 common carp fingerlings were randomly allotted to 18 fiberglass tanks, including six treatments each in triplicate. Fish were fed with experimental diets supplemented with 0, 0.5, 1, 2, 3, and 5% of the herbal mixture. After 60 days, the effects on growth performance, antioxidant, and immunological parameters were evaluated. According to the results, the highest final weight was observed in the fish fed 2 and 3% of the herbal mixture. Also, the feed conversion ratio (FCR) showed a significant decrease in fish treated with the herbal mix, so that the lowest FCR was observed in the treatment 1%. Hematological examinations such as red blood cells (RBC), white blood cell (WBC), and hemoglobin showed significant changes between different parameters compared to the control group. The highest protein content was observed in the fish supplemented with 2, 3, and 5% herbs. Besides, in contrast to glucose, the cortisol level showed a significant decrease compared to the control group. The digestive enzymes (Amylase, Lipase, and Protease) were significantly higher in 2 and 3% treatments than in the control group. Also, a significant difference was found in Superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) activity, and malondialdehyde (MDA) content between the experimental and control treatments. Examination of liver enzymes (and alanine aminotransaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP)) showed a significant difference in herbal mixture treatments with the control group, according to which the lowest amount of these enzymes was recorded in 2 and 3% herb supplemented fish. Herbal mix resulted in higher mucosal and intestinal immunity parameters, including total immunoglobulin (total Ig), lysozyme, alternative complement activities (ACH50), protease, and ALP. According to the results, supplementing the diet with a mixture of the COP can significantly improve growth parameters, stimulate the innate immune system, and improve antioxidant defenses and liver health of common carp.

Dietary Cinnamon Successfully Enhanced the Growth Performance, Growth Hormone, Antibacterial Capacity, and Immunity of European Sea Bass (Dicentrarchus labrax)

Simple Summary

Optimum aquafeed formulations should consider incorporating both nutritional and non-nutritional substances to fulfill the basal requirements and achieve the welfare of aquatic animals. In this context, medicinal plants are validated for their functionality as non-chemical derived materials. This study evaluated dietary cinnamon at varying levels on the growth performance and health status of European sea bass. The results showed the positive influence of the inclusion of cinnamon powder in the diets for European sea bass on the growth performance, feed utilization, blood analysis, and intestinal microbial community. Therefore, it can be concluded that 10–15 g/kg of cinnamon powder is suggested with no adverse effects for better performance of European sea bass.

Abstract

Dietary cinnamon has several bioactive compounds with growth-promoting and immunomodulation potential and is suggested for finfish species. This study evaluated the inclusion of cinnamon at 0, 10, 15, and 20 g/kg in European sea bass (Dicentrarchus labrax) diets. After 90 days, the highest final weight, weight gain, specific growth rate, protein efficiency ratio, and the lowest feed conversion ratio were seen in fish treated with 10 g/kg (p < 0.05). Further, the measured growth hormone in the blood indicated that fish treated with 10 g/kg had a higher level than fish 0 and 20 g/kg. After the feeding trial, fish treated with cinnamon at varying levels had higher lipid content than fish before the feeding trial (p < 0.05). Lower Vibrio spp. and Faecal Coliform counts were observed in fish treated with cinnamon than fish fed a cinnamon-free diet (p < 0.05). The hematocrit level was markedly (p < 0.05) increased in fish fed cinnamon at 10 g/kg compared to the control without significant differences with fish fed 15 and 20 g/kg. Hemoglobin was significantly increased in fish treated with cinnamon at 10, 15, and 20 g/kg compared to fish fed a cinnamon-free diet (p < 0.05). Red and white blood cells (RBCs and WBCs) were meaningfully (p < 0.05) increased in fish treated with cinnamon compared with the control. Markedly, fish treated with cinnamon had higher serum total lipids than the control with the highest value in fish treated with 15 g/kg (p < 0.05). The lysozyme activity was markedly higher in fish treated with 15 g cinnamon/kg than fish fed 0, 10, and 20 g/kg (p < 0.05). Moreover, phagocytic activity was significantly higher in fish treated with cinnamon at 10, and 15 g/kg than fish fed 0 and 20 g/kg (p < 0.05). In conclusion, dietary cinnamon is suggested at 10–15 g/kg for achieving the high production and wellbeing of European sea bass.