日粮中添加发酵黄芩对断奶仔猪生长性能的影响

选用64头28日龄(长大二元)断奶仔猪,随机分为4个处理组,每组4个重复,每个重复4头猪。各处理组分别在基础日粮基础上添加0(对照组)、0.1%、0.15%、0.2%的发酵黄芩。试验期为28 d。结果表明,日粮中添加发酵黄芩能增强断奶仔猪食欲,提高采食量,降低料肉比、腹泻率,提高饲料报酬。通过对不同水平的比较,发现发酵黄芩添加水平为0.15%效果最优,日采食量、日增重较对照组提高12.9%(P<0.05)、33.0%(P<0.05),料肉比、腹泻率较对照组降低15.0%(P<0.05)、30.6%(P<0.05)。     

低聚糖对断奶羔羊小肠黏膜免疫相关细胞的影响

选用陶赛特F2代断奶公羔40只,随机分成4组,研究低聚糖对断奶羔羊小肠黏膜免疫相关细胞的影响。结果表明:日粮中添加低聚果糖FOS(0.3%)、低聚异麦芽糖IMO(0.3%)和复合低聚糖(0.1%FOS+0.2%IMO)均可提高断奶羔羊胸腺指数和脾脏指数(P>0.05)及小肠黏膜上皮内sIEL数量(P<0.05);FOS可提高小肠黏膜上皮GC的数量I,MO和复合低聚糖可降低GC数量(P>0.05)I;MO和复合低聚糖可提高断奶羔羊小肠黏膜中MC细胞的数量(P>0.05)。提示断奶羔羊日粮中添加低聚糖可增加其小肠黏膜免疫相关细胞的数量,增强断奶羔羊小肠黏膜免疫功能,提高其免疫力。     

Tolerable upper intake level of iron damages the liver of weaned piglets

Iron is one of the essential trace elements, which is often supplemented as an additive to meet the growing needs of toddlers and young animals. Recommended nutrient intake (RNI) and tolerable upper intake levels (UL) are always set when the iron is supplemented. The purpose of this study was to evaluate the subacute (28 days) toxicity of UL iron to weaned piglet liver. Thirty 23-day-old weaned piglets were divided into three groups and, respectively, supplemented with 100, 300 or 3000 (UL) mg/kg iron. UL iron caused significant weight loss in 4th week (p < 0.05). Divalent metal transporter 1(DMT1) decreased significantly, ferroportin 1 and ferritin increased significantly in the liver of UL iron group (p < 0.05). Although there was no significant effect on liver morphology, UL iron significantly increased hepatic iron, reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (p < 0.05). UL iron significantly reduced glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and total anti-oxidation capacity (T-AOC) in the liver (p < 0.05). Nuclear factor erythroid 2-related factor 2 (Nrf2) activated subunits of glutamate cysteine ligase (Gclc) and glutathione S-transferase A1 (Gsta1) upregulation in the UL iron group liver, thereby increasing resistance to oxidative stress. In conclusion, UL iron supplementation altered iron metabolism, generated free radicals, reduced antioxidant enzyme activity and activated Nrf2 signalling pathway in the weaned piglet liver.     

Significant changes in caecal microbial composition and metabolites of weaned piglets after protein restriction and succedent realimentation

The present study aimed to investigate the effects of protein restriction and subsequent realimentation on caecal barrier function, caecal microbial composition and metabolites in weaned piglets. Thirty-six 28-day-old weaned piglets were randomly assigned to a control group and a treatment group. The piglets were fed diets containing 18.83% (normal) or 13.05% (low) of crude protein from the 1st to 14th day, after which all piglets were fed diets containing 18.83% of crude protein from the 15th to 28th day. The results showed that protein restriction increased caecal bacterial diversity and richness as well as the abundance of Ruminococcus 2, Faecalibacterium and Lachnospiraceae_uncultured, but reduced the abundance and the gene copies of Lactobacillus in the treatment group compared with the control group on day 14. Protein restriction also decreased the concentrations of isovaleric acid and total branched-chain fatty acids. During the succedent protein realimentation stage, the abundance of Ruminococcaceae UCG-014 and the concentrations of lactic acid, acetic acid, butyric acid and total short-chain fatty acids were increased in the treatment group on day 28. Furthermore, the ammonia concentration was reduced, while the gene mRNA levels of caecal barrier function were increased in the treatment group both on days 14 and 28. In conclusion, dietary protein restriction and realimentation could change caecal microbial composition and metabolites, and eventually influence caecal barrier function. The present study may provide a new insight into protein restriction and realimentation in weaned piglets.     

妊娠母羊饲喂竹酢粉对羔羊生长性能、血液生理生化指标、免疫与抗氧化能力的影响

试验旨在研究妊娠母羊饲喂竹酢粉对羔羊生长性能、血液生理生化指标、免疫与抗氧化能力的影响。选择初产、妊娠约120 d的健康湖羊50只,随机分为2组,分别饲喂基础日粮（对照组）和基础日粮+2%竹酢粉（试验组）,饲喂3周,预饲期1周。分娩后,选择单羔母羊所产、3周龄左右、产期相近（1~4 d）羔羊20只（对照组和试验组各10只）测定其生长性能、血液生理生化、免疫与抗氧化能力等指标。结果表明：试验组羔羊的初生重（BW）、平均日增重（ADG）与对照组相比差异不显著（P>0.05）,但日增重提高4.74%。与对照组相比,试验组羔羊血液中白细胞、红细胞、血小板数量和血红蛋白浓度均无显著差异（P>0.05）;血清谷草转氨酶（GOT）活性显著降低（P<0.05）,总蛋白（TP）、白蛋白（ALB）、球蛋白（GLB）含量和白蛋白/球蛋白（A/G）有一定程度提高,总胆固醇（TC）含量、丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性和总抗氧化能力（T-AOC）均有降低趋势（P>0.05）;试验组羔羊免疫球蛋白IgA、IgM和IgG含量高于对照组,但均无显著差异（P>0.05）。综上所述,在妊娠母羊日粮中添加2%竹酢粉可在一定程度上提高羔羊日增重,同时羔羊血清总蛋白、白蛋白、球蛋白、IgA、IgM和IgG含量也有一定程度提高。     

益生菌补充剂对断奶仔兔饲料效率、生长性能和微生物种群的影响

本研究旨在探讨单株或双株益生菌补充剂对断奶仔兔饲料效率、生长性能和微生物数量的影响。试验选择64只28 d断奶(公母各半)新西兰白兔,随机分为4组,每组4个重复,每个重复4只。对照组饲喂基础日粮,试验组分别在基础日粮中添加1×10^6 cfu/g枯草芽孢杆菌(BS组)、1×10^7 cfu/g乳酸菌(LA组)及0.5×106枯草芽孢杆菌+0.5×10^7 cfu/g乳酸菌(BL组)。结果显示:LA组在42 d时体重显著增加(P<0.05),BL组较对照组显著提高日增重和饲料转化率(P<0.05)。LA组和BL组的干物质、有机质、粗蛋白质、中性洗涤纤维、总能量消化率均显著高于对照组(P<0.05)。公兔回肠内芽孢杆菌和大肠杆菌数量均显著高于雌兔(P<0.05)。与对照组相比,BS组家兔肠道各节段的芽孢杆菌数量均高于对照组(P<0.05),而LA和BL组仔兔肠道乳酸杆菌数量显著高于对照组(P<0.05)。结论:日粮单独添加1×107 cfu/g乳杆菌或0.5×10^6 cfu/g枯草杆菌+0.5×10^7 cfu/g乳杆菌可以提高肠道有益菌群数量、营养物质消化率、盲肠发酵、饲料效率和生长性能。此外,仅添加乳杆菌的家兔肠道大肠菌群和粪便评分均有所下降。     

发酵五味子药渣对断奶仔猪小肠黏膜的形态及免疫的影响

选用90头DLY(杜×长×大)断奶仔猪(28日龄),随机分为5组:空白对照组,饲喂基础日粮;阳性对照组(0.5%SC组),饲喂基础日粮+0.5%北五味子;0.1%FSD组,饲喂基础日粮+0.1%发酵五味子药渣;0.3%FSD组,饲喂基础日粮+0.3%发酵五味子药渣;0.5%FSD组,饲喂基础日粮+0.5%发酵五味子药渣。每天记录5组猪的腹泻情况以及采食量,计算腹泻率和料肉比,并于试验第7、14、21天,分别采集空白对照组、0.5%SC组、5%FSD组仔猪的十二指肠、空肠、回肠中段组织以及空肠黏膜,测定肠绒毛高度,隐窝深度,肠上皮内杯状细胞、淋巴细胞数量,以及空肠黏膜分泌型免疫球蛋白A(SIgA)含量。结果表明:0.1%FSD组、0.3%FSD组、0.5%FSD组仔猪的腹泻率分别比空白对照组低13.87%、30.82%、41.72%;料肉比分别比空白对照组仔猪低1.7%、4.02%、8.6%;与空白对照组相比,0.5%SC和0.5%FSD组仔猪的小肠绒毛较完整;0.5%FSD组仔猪的十二指肠、空肠、回肠绒毛高度显著增加(P0.05),隐窝深度显著降低(P0.05),绒毛高度与隐窝深度比值(V/C)提高;0.5%FSD组仔猪肠上皮内杯状细胞及淋巴细胞数量均高于空白对照组,肠黏膜SIgA含量极显著高于空白对照组(P0.01),0.5%FSD组与0.5%SC组各项指标的差异均没有统计学意义。