饲粮精氨酸与丙氨酸对环江香猪肉质、氨基酸组成及抗氧化功能的影响

本试验旨在研究饲粮精氨酸与丙氨酸对环江香猪肉质、氨基酸组成及抗氧化功能的影响,选用体重为 ２８～３３ｋｇ的环江香猪 １６头（公母各占 １／２）,按体重相近原则随机分为 ２组,每组 ４个重复,每个重复 ２头猪。丙氨酸组在基础饲粮中外源添加 １．７１％的 Ｌ－丙氨酸（等氮对照）,精氨酸组在基础饲粮中外源添加 ０．８３％的 Ｌ－精氨酸和 ０．８８％的米糠。试验期为 ４５ｄ。结果表明：与丙氨酸组相比,精氨酸组瘦肉率显著提高（Ｐ＜０．０５）,脂肪率和背最长肌中粗脂肪含量显著降低（Ｐ＜０．０５）;肝脏丝氨酸、缬氨酸、亮氨酸和异亮氨酸含量显著提高（Ｐ＜０．０５）;血浆过氧化氢酶活性显著提高（Ｐ＜０．０５）,丙二醛含量显著降低（Ｐ＜０．０５）。上述结果提示,饲粮中适宜水平的精氨酸可提高环江香猪瘦肉率,降低脂肪率,增强机体抗氧化功能,从而改善部分肉品质指标。     

饲粮ω-6/ω-3多不饱和脂肪酸比例对鹅肝脏过氧化脂质和肝细胞超微结构的影响

本试验旨在研究饲粮ω-6/ω-3多不饱和脂肪酸(PUFA)比例对鹅肝脏过氧化脂质和肝细胞超微结构的影响。选择160只同批出雏、体质健壮、体重(0.407±0.023)kg的21日龄扬州鹅,随机分成4组,每组4个重复,每个重复10只,分别饲喂ω-6/ω-3 PUFA比例为12∶1、9∶1、6∶1、3∶1的试验饲粮。饲养至42、56和70日龄时分别进行肝脏分离和过氧化脂质测定,并采用电镜观察肝细胞超微结构。结果表明:鹅肝脏丙二醛(MDA)、一氧化氮(NO)含量随日龄的增加呈上升趋势,并以70日龄较高,其中12∶1和9∶1组升高的幅度较大,而3∶1和6∶1组较小。MDA、NO含量随ω-6/ω-3 PUFA比例的降低呈现下降的趋势,各日龄基本以3∶1组最低。12∶1和9∶1组肝细胞糖原颗粒相对减少,线粒体有肿胀现象,但各组线粒体的面积没有显著变化(P>0.05)。由此可见,生长期扬州鹅肝脏抗氧化状态受饲粮ω-6/ω-3 PUFA比例的影响;较低饲粮ω-6/ω-3 PUFA比例(3∶1和6∶1)能够减少肝细胞过氧化脂质的损伤。     

饲粮维生素D添加水平对蛋雏鸭免疫及抗氧化功能的影响

本试验旨在研究饲粮维生素D添加水平对1～28日龄蛋雏鸭免疫及抗氧化功能的影响,以探讨饲粮维生素D的适宜添加量。试验选取健康、体重相近的1日龄金定蛋雏鸭180只,随机分为5组(Ⅰ～Ⅴ组),每组6个重复,每个重复6只试鸭。采用玉米-豆粕型基础饲粮,Ⅰ组(对照组)试鸭饲喂基础饲粮,Ⅱ～Ⅴ组试鸭分别饲喂在基础饲粮中添加110、220、550、1 000 IU/kg维生素D的试验饲粮,试验期4周。结果表明:饲粮添加550 IU/kg维生素D可显著提高胸腺指数、脾脏指数(P<0.05),并显著增强肝脏超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05),降低血清白细胞介素-2(IL-2)及血清和肝脏丙二醛(MDA)含量(P<0.05);饲粮添加220、550 IU/kg维生素D可显著提高血清总蛋白(TP)和白蛋白(ALB)含量(P<0.05),并显著增强血清SOD和GSH-Px活性及血清和肝脏总抗氧化能力(T-AOC)(P<0.05)。综合本试验结果,在玉米-豆粕型基础饲粮中添加适量的维生素D可提高1～28日龄蛋雏鸭的免疫及抗氧化功能。综合考虑各指标,通过二次回归模型估测得出维生素D适宜添加量为512.8～550.0 IU/kg。     

肠道气泡堆积对银鲳组织抗氧化能力与溶菌酶活力的影响#br#

为研究肠道气泡堆积对银鲳(Pampus argenteus)组织抗氧化能力及溶菌酶活力的影响,采集了15尾肠道气泡堆积的银鲳为病鱼组,15尾健康银鲳为对照组,分别采集各组样品的肝脏、肾脏、肌肉和鳃组织,并对这4种组织的超氧化物歧化酶活力、过氧化氢酶活力、丙二醛含量、总抗氧化能力以及两种组织(鳃和肾脏)溶菌酶活力进行测定和比较。结果显示,相比对照组,病鱼组肝脏、鳃和肾脏的总抗氧化能力都有下降,其中肝脏和肾脏显著下降(P<0.05);而肌肉中总抗氧化能力病鱼组显著高于对照组(P<0.05)。对照组肝脏和肌肉的超氧化物歧化酶和过氧化氢酶活力显著高于病鱼组(P<0.05);丙二醛含量对照组肝脏和肌肉中显著低于病鱼组(P<0.05),但鳃和肾脏显著高于病鱼组(P<0.05);溶菌酶活力病鱼组鳃显著高于对照组(P<0.05),但肾脏与对照组间无显著性差异。结果表明,肠道气泡堆积对银鲳组织抗氧化能力及其溶菌酶活力影响较大,导致肝脏与肌肉中的超氧化物歧化酶、过氧化氢酶活力显著降低,鳃溶菌酶活力显著升高。     

Dietary supplementation with biofloc promotes growth,improves immune and antioxidant status,and upregulates NF‐κB/Nrf2 signalling molecules and stress resistance in Rhynchocypris lagowskii Dybowski

Bioflocs are rich in a variety of probiotics and bioactive compounds, which have been documented to promote growth, regulate antioxidant status and enhance the immune system. A 60‐day experiment was conducted to investigate the effects on growth, antioxidant and immune status, NF‐κB/Nrf2 signalling molecules and stress resistance in juvenile Rhynchocypris lagowskii Dybowski fed different dietary biofloc supplementations. Four hundred fifty R. lagowskii were fed five experimental diets containing graded levels of biofloc from 0 to 160 g/kg (referred to as B0, B4, B8, B12 and B16, respectively). The results showed that biofloc supplementation markedly promoted growth performance (weight gain rate, specific growth rate); improved amylase, lipase and protease activity; and enhanced the activities of glutathione peroxidase, catalase, total superoxide dismutase, total antioxidant capacity, lysozyme, complement C3, complement C4 and immunoglobulin M in the gill, hepatopancreas, kidney, gut and serum. The malondialdehyde content was significantly reduced with treatment B12. In addition, the levels of heat shock protein 70, heat shock protein 90, interferon‐γ and insulin‐like growth factor I were substantially increased with treatment B12 compared to those with the control treatment. Furthermore, biofloc assisted in regulating the expression of NF‐κB/Nrf2 signalling molecule genes, including NF‐κB, TNF‐α, IL‐1β, IL‐8, IL‐10, TGF‐β, Nrf2, Keap1, Maf, HO‐1, CAT, GPX, GCLC and CuZn‐SOD. Overall, our results suggest that dietary supplementation with biofloc can promote growth, improve immune and antioxidant status, and enhance NF‐κB/Nrf2 signalling molecule expression and stress resistance in juvenile R. lagowskii. A suitable supplementation level of approximately 120 g/kg biofloc is recommended in the present study.     

Effects of dietary carbohydrate level on growth performance,innate immunity,antioxidant ability and hypoxia resistant of brook trout Salvelinus fontinalis

Juvenile brook trout were fed on six isonitrogenous and isolipidic diets, containing graded levels of gelatinized corn starch (50, 100, 150, 200, 250, 300 g/kg diet) for 81 days. Cellulose was used to compensate carbohydrate loss. The weight gain, specific growth rate and protein efficiency ratio increased as the dietary carbohydrate level increased from 50 to 150 g/kg, but decreased thereafter (p < .05). Quadratic regression analysis revealed that the optimum dietary carbohydrate level was in the range of 187.1–194.1 g/kg. In addition, serum alanine transaminase and aspartate transaminase activities, as well as glucose content, were highest in the group fed on 300 g/kg carbohydrate (p < .05). The hepatic malondialdehyde level increased with dietary carbohydrate levels (p < .05). The hepatic lysozyme activity increased as dietary carbohydrate level increased from 50 to 150 g/kg and decreased thereafter (p < .05). The overall survival rate after hypoxia challenge (45 min; dissolved oxygen content: 2.2 mg L^?1) decreased with dietary carbohydrate levels (p < .05). Taken together, these results suggested that optimal level of dietary carbohydrate could improve growth performance. However, excessive dietary carbohydrate intake (> 250 g/kg) may decrease innate immunity status, increase oxidative stress and reduce resistance to hypoxia stress in brook trout.     

The effects of açaí oil addition in tilapia diets on performance,hepatic energy metabolism enzymes and antioxidant responses

The aim of the present study was to determine whether açai oil (Euterpe oleraceae) addition in the diets of juvenile Nile tilapia (Oreochromis niloticus) in biofloc system would stimulate hepatic energy metabolism and antioxidant responses. Treatments are as follows: T0 (6%‐soybean oil), T1 (1%‐AÇAI; 5%‐SOY), T3 (3% AÇAI; 3%‐SOY) and T6 (6%‐AÇAI). In the liver, reactive oxygen species levels were significantly lower in T1, T3 and T6 than in T0, lipid peroxidation levels were significantly lower in T3 and T6, and nitric oxide levels were significantly lower in the T6 than in T0. Glutathione peroxidase activity was significantly higher in the T3 and T6 than in T0, while superoxide dismutase activity and total antioxidant capacity levels were significantly higher in the T6 than in T0. Adenylate kinase activity was significantly lower in the T6 than in T0. These results suggest that the açai oil addition in Nile tilapia diets stimulated antioxidant responses.     

连翘提取物抗氧化活性的研究进展

诸多因素可引起动物氧化应激,破坏体内自由基的动态平衡,从而产生一系列的氧化危害。添加天然抗氧化剂能保持动物机体内自由基的动态平衡。传统中药连翘具有抗菌、抗病毒、抗炎症、抗内毒素等药理活性。近年来的研究表明,连翘提取物具有良好的抗氧化活性。本文对连翘提取物抗氧化活性的研究做一综述。     

高温高湿对不同品种(系)现蕾期辣椒(Capsicum annuum L.)抗氧化性的影响

选用10个具有代表性辣椒品种(系),于人工气候室内分别在正常和高温高湿条件下,研究了现蕾期辣椒抗氧化系统生理生化性状的变化以及不同品种(系)的抗氧化性差异。结果表明:10个辣椒品种(系)抗坏血酸(AsA)、花青素含量下降,而谷胱甘肽(GSH)、花色苷含量增加;超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)4个酶活性一致增强。根据8个生理生化指标的相对值,通过坐标综合评定法对活性氧的抑制和清除进行分析,抗氧化剂类的贡献大于抗氧化酶类;系统聚类法将10个辣椒品种(系)的抗氧化性强弱分为3类:06591、115-5-5-12-9-1-2、B04-99-5-1-1-2、06597、06590为强抗氧化性品种(系);B04-51-4-2-1-2-1和43-5-1-1-1为中等抗氧化性品种(系);06592、B04-114-1-1-1-1-1、B04-512-4-1(系)为弱抗氧化性品种。     

铅胁迫对芦竹抗氧化酶活性的影响

研究了在不同浓度Pb2+胁迫下,芦竹(Arund donax Linn.)体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)3种抗氧化酶活性随时间的变化情况。结果显示,芦竹遭受Pb2+胁迫初期,3种酶活性较对照值有明显增高;随着污染浓度加大和时间延长,3种酶活性又出现下降,降低程度与受污染浓度和时间有关。Pb2+胁迫初期,芦竹幼苗体内的抗氧化能力增强,表现出对抗氧化酶的激活效应,但随着植物生长,Pb2+在植物体内迁移,其叶片内抗氧化能力降低,表现出对抗氧化酶的抑制效应。抗氧化酶活性产生的效应强弱及维持期长短与Pb2+胁迫浓度有关,胁迫初期一般是Pb2+浓度高,抗氧化酶活性升高明显;胁迫后期Pb2+浓度低,活性维持期长。Pb2+胁迫对过氧化氢酶和过氧化物酶的影响没有超氧化物歧化酶的影响显著,但3种酶活性的变化趋势基本一致。