Assessing the efficacy of three methionine sources in low protein and low fish meal diet for Chinese soft-shelled turtle, Pelodiscus sinensis

Autor: Qing-Hui Meng, Wang Dingnan, Bei Yijiang, Xue-Yan Ding, Shiyan Li, Fan Zhou, Ya-Qin Wang, Wing-Keong Ng
Rok vydání: 2017
Předmět:
Zdroj: Aquaculture International. 26:15-26
ISSN: 1573-143X
0967-6120
DOI: 10.1007/s10499-017-0193-3
Popis: An 8-week feeding trial was conducted to evaluate the effects of three dietary methionine (Met) sources [dl-Met, coated-Met, and a methionine hydroxy analogue calcium salt (MHA-Ca)] for Chinese soft-shelled turtle (Pelodiscus sinensis). Triplicate groups of juvenile turtles (initial weight 3.48 ± 0.03 g) were fed twice per day at 3% of body weight with positive control diet (T1, 46% protein and 46% fish meal, FM), negative control diet (T2, 43% protein and 23% FM), or three other test diets supplemented with either 0.2% coated-Met (T3), 0.125% MHA-Ca (T4), or 0.1% dl-Met (T5) to the T2 basal formulation, respectively. The feeding trial was conducted in 15 350-L plastic containers with three replicates per dietary treatment. The results showed that the highest and lowest percentage weight gain (1023.5 ± 18.2 versus 882.1 ± 14.5%) and feed efficiency (87.2 ± 0.94 versus 81.4 ± 0.4%) were observed in turtles fed the T1 and T2 diet (P 0.05). Protein utilization efficiency was significantly higher in turtles fed T4 or T5 diet compared to the T2 diet. Whole body protein content (17.0 to 17.4% on a wet weight basis) in turtles fed with Met-added diets was comparable to those of turtles fed the T1 diet which were significantly higher compared to T2-fed turtles. Antioxidant defense system enzymes, superoxide dismutase, and glutathione peroxidase showed the highest activity, 658.8 ± 17.9 U/mL and 642.8 ± 17.5 μmol/L, respectively, in the serum of turtle fed the MHA-Ca supplemented diet and was significantly higher compared to turtles fed the T2 or T3 diet. The present results showed that P. sinensis are able to effectively use added MHA-Ca and dl-Met in low protein and low FM diets to enhance growth, feed utilization efficiency, nitrogen retention, and antioxidant defense system enzyme activities.
Databáze: OpenAIRE
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