Laboratory of Fish Nutrition, School of Marine Sciences, Ningbo University, Ningbo, 315211, China.
Fish Shellfish Immunol. 2020 Jun;101:168-175. doi: 10.1016/j.fsi.2020.03.037. Epub 2020 Mar 21.
The present study was aimed to compare and evaluate the impacts of supplemented diets with different yeast hydrolysate (YH) levels on growth performance, body composition, hematological characteristics, antioxidant enzyme activities, and non-specific immunity (intestinal cytokines) of juvenile Nile tilapia (Oreochromis niloticus). Three isonitrogenous (protein, 33%) and isolipidic (lipid, 6%) experimental diets supplemented graded levels of YH (0% for control; 1% and 3% as tested diets) were fed to juvenile Nile tilapia. A total of 240 fish with initial body weight averaging 3.5 ± 0.02 g were randomly divided into three groups with four replicates per group and 20 fish for each replicate. For apparent satiation, the fish were fed twice daily during eight weeks. The results showed no significant difference in survival among all treatments. The fish fed the diet containing 1% yeast hydrolysate had significantly elevated weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) compared to the control group and lower feed conversion ratio (FCR). The fish fed 1% and 3% YH showed higher glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) activity and a significantly lower malondialdehyde (MDA) level in the liver than the control group, indicating enhancement of the anti-oxidant status. Serum lysozyme activity was significantly increased in the diet having 1% and 3% yeast hydrolysate supplementation groups, suggesting an improvement influence on the non-specific immune response. The expression of IL-1β, IL-10, TNF-α, TGF-β2, ALP and TLR2 was significantly elevated in fish fed the diet containing 1% YH. In conclusion, dietary supplementation with 1% yeast hydrolysate improves growth performance, and feed utilization enhances the antioxidant status and exerts an adequate stimulus on the non-specific immunity (intestinal cytokines) of Nile tilapia.
本研究旨在比较和评估不同酵母水解物（YH）水平补充饲料对幼尼罗罗非鱼（Oreochromis niloticus）生长性能、体组成、血液学特性、抗氧化酶活性和非特异性免疫（肠道细胞因子）的影响。三种等氮（蛋白质，33%）和等脂（脂质，6%）实验饲料补充了不同水平的 YH（对照组为 0%；测试组为 1%和 3%）。将平均初始体重为 3.5±0.02g 的 240 条鱼随机分为三组，每组四个重复，每个重复 20 条鱼。为了达到明显的饱食状态，鱼在八周内每天喂食两次。结果表明，所有处理组的存活率无显著差异。与对照组相比，摄食含 1%酵母水解物的饲料的鱼的增重（WG）、特定生长率（SGR）和蛋白质效率比（PER）显著提高，饲料转化率（FCR）降低。摄食 1%和 3% YH 的鱼的肝组织谷胱甘肽过氧化物酶（GPx）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性较高，丙二醛（MDA）水平较低，表明抗氧化状态增强。血清溶菌酶活性在添加 1%和 3%酵母水解物的饲料组中显著增加，表明对非特异性免疫反应有改善作用。摄食含 1% YH 的饲料组的鱼的 IL-1β、IL-10、TNF-α、TGF-β2、ALP 和 TLR2 的表达显著升高。综上所述，日粮中添加 1%酵母水解物可提高生长性能，改善饲料利用效率，增强抗氧化状态，对尼罗罗非鱼的非特异性免疫（肠道细胞因子）产生适当的刺激作用。
