Effects of Assam tea extract on growth, skin mucus, serum immunity and disease resistance of Nile tilapia (Oreochromis niloticus) against Streptococcus agalactiae. Issue 93 (October 2019)

• Record Type: Journal Article
• Authors: Van Doan, Hien; Hoseinifar, Seyed Hossein; Sringarm, Korawan; Jaturasitha, Sanchai; Yuangsoi, Bundit; Dawood, Mahmoud A.O.; Esteban, Maria Ángeles; Ringø, Einar; Faggio, Caterina
• Is Part Of: Fish & shellfish immunology. Issue 93(2019)
• Page Start: 428
• Page End: 435
• Publication Date: 2019-10
• Subjects: Assam tea extract -- Growth performance -- Mucosal immunity -- Humoral immunity -- Disease resistance -- Nile tilapia -- S. agalactiae; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.07.077
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: The present study aimed to assess the possible effects of Assam tea ( Camellia sinensis ) extract (ATE) on growth performances, immune responses, and disease resistance of Nile tilapia, Oreochromis niloticus against Streptococcus agalactiae . Five levels of ATE were supplemented into the based diet at 0, 1, 2, 4, and 8 g kg −1 feed of Nile tilapia fingerlings (10.9 ± 0.04 g initial weight) in triplicate. After four and eight weeks of feeding, fish were sampled to determine the effects of the tea supplements upon their growth performance, as well as serum and mucosal immune responses. A disease challenge using S. agalactiae was conducted at the end of the feeding trial. Fish fed ATE revealed significantly improved serum lysozyme, peroxidase, alternative complement (ACH50), phagocytosis, and respiratory burst activities compared to the basal control fed fish ( P < 0.05). The mucus lysozyme and peroxidase activities were ameliorated through ATE supplementation in the tilapia diets. Supplementation of ATE significantly ( P < 0.05) enhanced final body weight, weight gain, and specific growth rate; while a decreased feed conversion ratio was revealed at 2 g kg −1 inclusion level, after four and eight weeks. Challenge test showed that the relative percent survival (RSP) of fish in each treatment was 33.33%, 60.00%, 83.33%, 76.68%, and 66.68% in groups fed 0, 1, 2, 4, and 8 g kg −1, respectively. In summary, diets supplemented with ATE especially at 2 g kg −1 increased the humoral and mucosal immunity, enhanced growth performance, and offered higher resistance against S. agalactiae infection in Nile tilapia. Highlights: DietaryAssam tea extract (ATE) significantly improved growth rate and reduced the FCR. Significant enhances in the skin mucus and serum immunity were found in tilapia fed ATE. Significant reduction in mortality was observed in tilapia fed ATE against Streptococcus agalactiae. Supplementation of ATE at 2 g kg −1 is recommended for better growth, immune response and resistance against S. agalactiae .