水通道蛋白在调节肠道健康中的作用

水通道蛋白是一类可以高效选择性转运水分子的细胞膜通道蛋白,广泛分布于人和哺乳动物的胃肠道组织中,在机体液体转运和消化生理中发挥重要作用。本文总结了水通道蛋白的结构、分类及其在人、鼠类和仔猪胃肠道系统的表达和分布情况,并阐述了水通道蛋白与腹泻、肠上皮细胞迁移与修复、肠道屏障功能和肠道炎症相关疾病等过程的关系及其作用。     

反刍动物生产中碳、氮、磷、钾的减排问题

近年来,随着我国奶牛养殖数量和规模的不断扩大,大量的粪尿作为肥料被广泛地施用在农田里,奶牛正常的生理活动产生的大量气体（CO2和CH4）也被排放到了空气中,但是反刍动物生产中排放的这些废物却对土壤、空气和水造成了日益严重的污染,其中粪、尿和气体中的碳、氮、磷、钾元素引起的环境污染问题更是不容忽视。笔者就以上存在的问题综述了奶牛生产中碳、氮、磷和钾对环境的污染,并从营养和饲养管理上提出相应的减排技术措施。     

Dietary supplementation with Acanthopanax senticosus extract enhances gut health in weanling piglets

The present study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut health in weanling piglets by examining diarrhea frequency, intestinal microbiota and morphology. A total of 96 Duroc× (Landrace × Yorkshire) piglets weaned at 21 days of age with an average initial body weight (BW) of 5.6 ± 0.4 kg were randomly assigned to 3 treatment groups with 4 duplicates of 8 piglets each. The piglets were fed basal diet to which had been added 0 or 1 g/kg of ASE, or 0.7 g/kg antibiotics, respectively. Fecal consistence was monitored twice daily and the frequency of diarrhea was calculated. On day 21 after the initiation of supplementation, 8 piglets were randomly selected from each treatment group (2 piglets per pen) and slaughtered. The jejunum, ileum, colon and cecum were then excised and fixed in 10% neutral formalin solution to determine villus height and crypt depth, after their contents were collected to determine microbiota. The results showed that dietary supplementation with ASE increased (P < 0.05) the density of bacterial populations that co-migrated with Lactobacillus amylovorus, Lactobacillus salivarius, Bacillus subtilis, and Clostridium lituseburens, but decreased (P < 0.05) those co-migrating with Staphylococcus aureus, Salmonella typhimurium, Ruminococcus forques, and E. coli O157:H7 in the PCR-DGGE profiling analysis when compared with the control group. The villus height of the duodenum, jejunum and ileum increased (P < 0.05) by 14.8, 13.7 and 10.0%, while the crypt depth decreased (P < 0.05) by 17.9, 9.1 and 12.1%, respectively, in response to dietary ASE supplementation. Additionally dietary supplementation with ASE or an antibiotic decreased (P < 0.05) the frequency of diarrhea by 55.6 and 52.2%, respectively, compared with the control group. In conclusion, these findings suggest that dietary supplementation with ASE could regulate the microbiota composition and maintain a normal morphology of gut mucosa in weanling piglets, thereby decreasing diarrhea that resulted from weaning stress.     

Exploring the foundations of population health and preventive medicine as essential elements for veterinary education

The evolution of preventive medicine and public health training in professional veterinary medicine curricula is documented. Most veterinary colleges in the US began with a single course in meat hygiene or public health, with a focus on food hygiene issues. These courses laid the foundation for modern veterinary preventive medicine and public health training for veterinary students. Most graduates of veterinary colleges today have extensive training in population health, preventive medicine, and zoonotic diseases.     

不同日粮组成对断奶初期奶公犊瘤胃内环境指标的影响

选用3头三月龄左右装有瘤胃瘘管的荷斯坦奶公犊,按3×3完全拉丁方试验设计,喂给三种日粮。日粮组成按精粗比分别表示为:70:30;60:40;50:50,研究不同日粮组成对断奶初期奶公犊瘤胃内环境指标包括pH值、氨氮(NH3-N)浓度、纤毛虫数量及微生物蛋白的影响。试验结果表明:精粗比为70:30日粮条件下奶公犊瘤胃内pH值显著低于其它组(P<0.01),70:30日粮组瘤胃内NH3-N浓度显著高于精粗比为60:40和50:50日粮(P<0.01)。不同日粮组成下精粗比为60:40和50:50日粮的瘤胃纤毛虫数量和微生物蛋白显著高于高精料组70:30日粮(P<0.01)。     

基因型和环境及其互作对糜子主要农艺性状的影响

为了进一步了解基因型、环境及其互作对糜子主要农艺性状的影响,运用联合方差和AMMI模型对6个糜子新品种(粳性)在11个不同环境试点的生育期、株高、主茎节数、主穗长、穗粒重、千粒重和产量等7个主要农艺性状的表现及其品种稳定性与适应性进行了研究。结果表明,糜子主要农艺性状在不同基因型以及环境之间存在极显著差异,其中基因型对主茎节数、环境对株高、基因型与环境互作对穗粒重的影响较大。各品种7个农艺性状指标的变异系数中,最大的是产量,达42.72%,其次是穗粒重和株高,分别为37.90%和26.74%,变异系数最小的是生育期,为14.89%。各试点中产量最高的是甘9133-1-3-4-1,品种稳定性最好的是榆糜3号(CK)。宁夏彭阳和陕西延安试点产量较高,变异程度较小,对品种鉴别力较好。     

池塘内循环流水养殖模式对黄颡鱼生长性能、形体指标、血清生化指标及肌肉营养成分的影响

为了综合评价池塘内循环流水养殖(IPA)模式在黄颡鱼养殖中的应用效果,选取IPA模式、常规池塘养殖(UPA)模式和野生环境(WE)下的黄颡鱼各50尾为研究对象,在养殖322 d后对其生长性能、形体指标、血清生化指标及肌肉营养成分差异进行比较。结果显示:1) IPA组黄颡鱼的成活率显著高于UPA组(P<0.05),但增重率和特定生长率略低于UPA组(P>0.05)。2) IPA组和WE组黄颡鱼的肥满度、肝体指数和脏体指数显著低于UPA组(P <0.05); IPA组的肥满度显著高于WE组(P<0.05),而肝体指数和脏体指数2组间差异不显著(P>0.05)。3) IPA组和UPA组血清中总蛋白含量显著低于WE组(P<0.05); IPA组血清中总胆红素、碱性磷酸酶、总胆汁酸和总胆固醇含量显著低于UPA组(P<0.05); IPA组血清中γ-谷氨酰基转移酶和谷草转氨酶活性显著高于WE组(P<0.05); IPA组血清中肌酐、葡萄糖含量显著低于UPA组(P<0.05)。4) IPA组和WE组肌肉中粗脂肪含量显著低于UPA组(P<0.05),但粗蛋白质含量显著高于UPA组(P<0.05); IPA组肌肉中氨基酸总量显著高于UPA组(P<0.05),而显著低于WE组(P<0.05); IPA组必需氨基酸和鲜味氨基酸总量显著高于UPA组(P <0.05); 3组黄颡鱼肌肉中第一限制性氨基酸均为苯丙氨酸+酪氨酸,且IPA组和WE组的必需氨基酸指数显著高于UPA组(P<0.05); IPA组和WE组黄颡鱼肌肉中n-3多不饱和脂肪酸(PUFA)和二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)含量显著高于UPA组(P<0.05),且饱和脂肪酸总量显著低于UPA组(P<0.05)。由此得出,IPA组黄颡鱼具有较高的成活率,较好的体形,其肌肉营养品质优于UPA组黄颡鱼,且健康状况也优于UPA组黄颡鱼,但仍差于WE组黄颡鱼。因此,应进一步优化IPA的环境条件(如流速因子、养殖密度等)以及人工配合饲料配方以迎合消费者对于黄颡鱼营养和味道的需求。     

大蒜素对断奶仔猪生长发育及其周围环境的影响

选用 10 8头 2 0日龄健康无病的杜× (长×大 )三元杂交断奶仔猪 ,按血缘、体重、性别一致原则随机分为 2组 ,每组设 3个重复。各组试验猪基础日粮一致、饲养管理条件一致 ,并由同一饲养员饲养。对照组饲喂带有抗生素的饲料 ;试验组在饲料中添加 2 5%大蒜素 2 0 0g t,试验期18d。结果表明 ,与对照组比较 ,试验组日增重提高 16 5% (P <0 0 5) ,料重比降低 13% (P <0 0 5) ,采食量无显著差异 ,未有试验猪发病 ,粪便颜色比对照组浅 ,粪便表面蚊蝇量较少 ,说明大蒜素对仔猪具有促生长作用 ,同时还具有抑菌和杀菌、减少仔猪发病率、驱除蚊蝇、改善舍内外环境等功效 ,从而提高了经济效益 ,是一种极具有开发价值的中草药添加剂