Effect of l-theanine on the growth performance, immune function, and jejunum morphology and antioxidant status of ducks. (31st October 2018)

• Record Type: Journal Article
• Authors: Zhang, C.; Chen, K. K.; Zhao, X. H.; Wang, C.; Geng, Z. Y.
• Is Part Of: Animal. Volume 13:Number 6(2019)
• Page Start: 1145
• Page End: 1153
• Publication Date: 2018-10-31
• Subjects: feed additive, -- intestine, -- amino acid, -- interleukin, -- immunoglobulin; Animal breeding -- Periodicals; Animal genetics -- Periodicals; Animal nutrition -- Periodicals; Animal physiology -- Periodicals; Environmental sciences -- Periodicals; 636.005
• DOI: 10.1017/S1751731118002884
• Languages: English
• ISSNs: 1751-7311

Abstract

Abstract : l -theanine is a unique nonproteinogenic amino acid found in tea, and has recently received considerable attention because of its various biological activities. However, there is no available research report on the use of l -theanine as a feed additive in ducks. This study was conducted to investigate the potential benefits and appropriate dosages of l -theanine on the growth performance, immune function, serum biochemical parameters, and jejunum morphology and antioxidant capacity of ducks. A total of 600 1-day-old Chaohu ducks were randomly allocated into five dietary treatment groups supplemented with 0 (control group), 300, 600, 900 and 1500 mg/kg of l -theanine. Each group included five replicates of 24 birds each. Body weight at day 28 was increased ( P <0.05) by l -theanine. From days 15 to 28, l -theanine elevated cumulative BW gain (BWG) and cumulative feed intake (FI), and decreased feed to gain ratio. From days 1 to 28, l -theanine elevated ( P <0.05) cumulative BWG and cumulative FI. l -theanine elevated ( P <0.05) the relative weight of bursa of Fabricus (day 14), thymus (day 14), spleen (day 28) and liver (day 28). On day 28, l -theanine decreased ( P <0.05) serum glucose, uric acid, triacylglycerol, total cholesterol, low-density lipoprotein cholesterol, insulin, interleukin-2 (IL-2) and IL-6 contents, and elevated ( P <0.05) serum total protein, globulin (GLB), immune globulin A (IgA) and IgG contents, but only serum insulin, interferon- γ, tumor necrosis factor- α and IL-6 contents was decreased ( P <0.05) and serum GLB and IgM content was elevated ( P <0.05) by l -theanine on day 14. On day 14, l -theanine decreased ( P <0.05) jejunum crypt depth, and elevated ( P <0.05) jejunum villus height, villus height to crypt depth ratio (V/C), goblet cell number and total superoxide dismutase (T-SOD) activity. On day 28, l -theanine decreased ( P <0.05) jejunum malondialdehyde content, and elevated ( P <0.05) jejunum villus height, V/C, goblet cell number, and T-SOD, catalase and glutathione peroxidase activities. l -theanine levels caused quadratic effect on the growth performance, relative organ weight, serum parameters, jejunum morphology and antioxidant capacity. In conclusion, l -theanine can be used as a promising feed additive for ducks, and its optimal supplementation level was 600 to 900 mg/kg based on the current experimental condition.