Chemical, Biological and Agricultural Pluridisciplinary Research Center (CPQBA), Campinas State University (UNICAMP), Paulínia, SP, Brazil.
Joint Graduate Program in Physiological Sciences, Federal University of São Carlos-UFSCar/São Paulo State University, UNESP Campus Araraquara, 13565-905, São Carlos, SP, Brazil.
Fish Shellfish Immunol. 2021 Jul;114:293-300. doi: 10.1016/j.fsi.2021.05.010. Epub 2021 May 15.
Functional additives of natural origin included as dietary supplements have become an alternative to synthetic antibiotics to improve health and resistance to ecologically correct pathogenic diseases in fish farming. We tested whether incorporating a mixture of phytobiotics such as volatile oils of thyme, red thyme and pepper rosemary into the diet improves growth performance, oxidative stress, immune and hematological responses and resistance of juvenile Nile tilapia when subjected to a challenge with Aeromonas hydrophila compared to a synthetic antibiotic (enrofloxacin). The experimental design was completely randomized with three experimental groups: control diet, diets containing a mixture of thyme phytobiotic essential oils, red thyme and pepper rosemary (FTB) and the synthetic antibiotic enrofloxacin (ATB), with four replicates (14 fish per repetition/experimental unit). Plasma glucose levels, leukocyte respiratory activity, serum lysozyme levels, number of circulating erythrocytes and leukocytes, levels of lipid peroxidation (LPO), catalase (CAT) and glutathione S-transferase (GST) activity at the end of 20 days of feeding (phase) were evaluated and 24 h after exposure to bacteria (phase II). The supplementation of FTB and ATB did not change the performance parameters, but it was sufficient to increase lysozyme, leukocytes, neutrophils and monocytes after the bacterial challenge, reduction of CAT and LPO activity and the highest GST activity (P < 0.05). The results of the present study suggest that FTB as a dietary supplement has benefits and can replace synthetic ATB, including supplementation with FTB for 20 days to provide greater antioxidant protection in Nile tilapia, mitigate the impacts of stressors and modulate immunity, providing to fish greater resistance and protection against diseases.
天然来源的功能性添加剂作为膳食补充剂已成为替代合成抗生素的方法，用于改善水产养殖中鱼类的健康和抵抗力，以对抗生态正确的致病性疾病。我们测试了在饮食中加入植物抗生素混合物（如百里香、红百里香和胡椒迷迭香的挥发油）是否可以提高幼年尼罗罗非鱼的生长性能、氧化应激、免疫和血液学反应以及对嗜水气单胞菌的抵抗力，与合成抗生素（恩诺沙星）相比。实验设计完全随机，有三个实验组：对照组、含有百里香植物抗生素精油、红百里香和胡椒迷迭香混合物的饮食（FTB）和合成抗生素恩诺沙星（ATB），每个处理组有四个重复（每个实验单位 14 条鱼）。在 20 天的喂养期结束时（第 I 阶段）和暴露于细菌后 24 小时（第 II 阶段）评估了血浆葡萄糖水平、白细胞呼吸活性、血清溶菌酶水平、循环红细胞和白细胞数量、脂质过氧化（LPO）水平、过氧化氢酶（CAT）和谷胱甘肽 S-转移酶（GST）活性。FTB 和 ATB 的补充并没有改变性能参数，但足以在细菌挑战后增加溶菌酶、白细胞、嗜中性粒细胞和单核细胞，降低 CAT 和 LPO 活性，并提高 GST 活性（P<0.05）。本研究的结果表明，FTB 作为膳食补充剂具有益处，可以替代合成抗生素 ATB，包括补充 FTB 20 天，为尼罗罗非鱼提供更大的抗氧化保护，减轻应激源的影响并调节免疫，为鱼类提供更高的抵抗力和疾病保护。
