Effects of Curcuma longa rhizome on growth, skin pigmentation, and stress tolerance after transport of Trichogaster labiosa

ABSTRACT We aimed to evaluate the effects of Curcuma longa as growth promoter, skin pigmentation enhancer, and stress reducer in diets of Trichogaster labiosa after transport. We used five diets containing 0.0, 1.0, 5.0, 10.0, and 25.0 g kg−1 of turmeric rhizome powder. We observed quadratic effects of turmeric supplementation for feed intake, weight gain, final length, and specific growth rate. The estimated amount of turmeric that decreased these variables ranged from 15.53 to 16.39 g kg−1. Quadratic effects of supplementation of turmeric for cyan and black dorsal skin coloring indices were observed, with estimated values that increased these variables equal to 15.03 and 17.44 g kg−1, respectively. After fish transport, quadratic effects of turmeric were observed for the cyan and black dorsal skin depigmentation indices, with estimated values that increased these variables equal to 13.29 and 17.04 g kg−1, respectively. These results demonstrate that supplementation with turmeric at levels up to 17 g kg−1 causes further reduction in skin color due to the stress of transport. Thus, Curcuma longa acts neither as a growth promoter nor as a stress reducer for Trichogaster labiosa. Curcuma longa does not improve the orange pattern of skin pigmentation in the strain of T. labiosa orange thick-lipped gourami.

摘要 本研究旨在评估日粮中添加姜黄（Curcuma longa）对运输后拉利毛足鲈（Trichogaster labiosa，橙色厚唇丽丽鱼）的生长促进、皮肤色素增强及应激缓解效果。本实验设置5组日粮，分别添加0.0、1.0、5.0、10.0及25.0 g·kg⁻¹的姜黄根茎粉。结果显示，姜黄添加量对采食量、增重、终末体长及特定生长率均存在二次效应。经估算，上述指标达到最优值的姜黄添加量区间为15.53~16.39 g·kg⁻¹。研究同时发现，姜黄添加对背侧青蓝色、黑色皮肤着色指数存在二次效应，使该两项指标达到峰值的姜黄添加量分别为15.03 g·kg⁻¹和17.44 g·kg⁻¹。经运输应激后，姜黄添加对背侧青蓝色、黑色皮肤脱色指数仍存在二次效应，使该两项指标得到提升的姜黄添加量分别为13.29 g·kg⁻¹和17.04 g·kg⁻¹。上述结果表明，当姜黄添加量高达17 g·kg⁻¹时，反而会因运输应激进一步加剧皮肤色素流失。因此，姜黄对拉利毛足鲈既无生长促进作用，也无法起到应激缓解效果。姜黄亦无法改善该品系橙色厚唇丽丽鱼的皮肤橙色色素沉着模式。