Optimal dietary L-glutamine level improves growth performance and intestinal histomorphometry of juvenile giant trahira (Hoplias lacerdae), a Neotropical carnivorous fish species
Optimal dietary L-glutamine level improves growth performance and intestinal histomorphometry of juvenile giant trahira (Hoplias lacerdae), a Neotropical carnivorous fish species
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DOI：
10.1016/j.aquaculture.2021.737469
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发表时间：
2022-01
期刊：
影响因子：
4.5
通讯作者：
A. R. Palomino Ramos;D. A. Campelo;Cristiana Carneiro;J. Zuanon;S. L. P. da Matta;W. M. Furuya;A. L. Salaro
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文献类型：
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作者：
A. R. Palomino Ramos;D. A. Campelo;Cristiana Carneiro;J. Zuanon;S. L. P. da Matta;W. M. Furuya;A. L. Salaro
尽管谷氨酰胺是一种非必需氨基酸，但其在饮食中的加入可用作优化鱼类肠道健康和生长的工具，这就是为什么它被认为是一种功能性氨基酸的原因。因此，本研究的目的是评估饲料中添加不同水平的L-谷氨酰胺的幼年巨鲈（Hoplias lacerdae），新热带区的肉食性鱼类。为此目的，采用了完全随机化设计，包括6个处理（添加0.0、2.0、4.0、6.0、8.0或10.0 g/kg L-谷氨酰胺的饲料）和5个重复。将510尾体重为1.69 ± 0.10 g，体长为4.67 ± 0.10 cm的巨角鲨幼鱼置于30个20 L的圆形水槽中，置于循环水系统中。饲养12周后，对鱼的生长性能参数（存活率、增重和体长、饲料转化率、特定生长率、蛋白质效率比、体长、最终体重均匀度、胴体产量和肠长）、体细胞指数（内脏体细胞、肝体细胞和内脏体细胞）、全身化学成分和肠组织形态计量学进行了评价。根据所应用的多项式回归，L-谷氨酰胺水平对鱼增重、体长增加和体长均匀性具有二次效应（p< 0.05）。这些参数的最高值的L-谷氨酰胺水平估计值分别为4.83 g/kg、4.92 g/kg和4.97 g/kg。补充L-谷氨酰胺不会影响全身化学成分。肠中段绒毛高度和肠中后部肌膜厚度也呈二次曲线趋势（p< 0.05）。此外，5.42 g/kg、5.16 g/kg和5.21 g/kg是使这些指标最大化的相应L-谷氨酰胺水平。试验结果表明，饲料中添加L-谷氨酰胺能提高巨鲶幼鱼的生长性能和肠道形态计量学指标，其适宜添加量为4.83 ~ 5.42g/kg。
Even though glutamine is a non-essential amino acid, its inclusion in diets can be used as a tool to optimize the intestinal health and growth of fish, reason why it has been considered as a functional amino acid. Thus, the aim of this study was to evaluate the dietary supplementation with different levels of L-glutamine for juvenile giant trahira (Hoplias lacerdae), a Neotropical carnivorous fish species. For this purpose, a completely randomized design with six treatments (diets supplemented with 0.0; 2.0; 4.0; 6.0; 8.0 or 10.0 g/kg of L-glutamine) and five replicates was used. Five hundred ten juveniles of giant trahira (1.69 ± 0.10 g and 4.67 ± 0.10 cm) were divided into 30 circulars tanks (20 L) arranged in a water recirculating system. After 12 weeks of feeding, fish growth performance parameters (survival rate, weight and length gain, feed conversion, specific growth rate, protein efficiency ratio, length, final weight uniformity, carcass yield and intestine length), somatic indices (viscerossomatic, hepatosomatic and intestinesomatic), whole-body chemical composition and intestinal histomorphometry were evaluated. According to the polynomial regression applied, there was a quadratic effect (p< 0.05) of L-glutamine levels on fish weight gain, length gain and length uniformity. The L-glutamine levels that yielded the highest values for these parameters were estimated at 4.83 g/kg, 4.92 g/kg, 4.97 g/kg, respectively. Whole-body chemical composition was not affected by the L-glutamine supplementation. The villi height in the median portion and the muscular tunic thickness in the median and posterior portion of the intestine also exhibited a quadratic trend (p< 0.05). Furthermore, 5.42 g/kg, 5.16 g/kg and 5.21 g/kg, are the respective L-glutamine levels that maximized these metrics. It has been concluded that dietary supplementation with L-glutamine can improve growth performance and intestinal histomorphometry of juvenile giant trahira and at the same time, the optimal level in the diet is between 4.83 and 5.42 g/kg.