挤压组织蛋白作为水产饲料

制成颗粒是最普通的饲料加工方法,将近一半的猪、家禽和牛饲料以颗粒形式出售。颗粒饲料除了可以避免饲喂过程中的畜禽挑食,还可增强某些营养成分的利用效率,提高动物生产性能,减少粉尘和简化饲料操作方法。由于水产颗粒饲料必须具有良好的耐水性,因而使用挤压机可以提高水产颗粒饲料质量。挤压加工使饲料中的蛋白质和淀粉粘结变形,从而提高了颗粒饲料的耐水性。非挤压加工方法主要生产沉水颗粒料。挤压能使蛋白质的组织结构致密。因此,挤压成形的颗粒饲料其耐水性能更佳,并且具     

影响颗粒饲料耐久性指数的因素及其控制

<正>颗粒饲料耐久性指数(PDI,Pellet durability index)是反映颗粒饲料质量最主要的指标之一,它是用来衡量颗粒饲料成品在输送和搬运过程中饲料颗粒抗破碎的相对能力。其含义是把冷却、筛分后的颗粒饲料样品放在一个特制的回转箱中翻转一定时间,模拟饲料的输送和搬运过程,在样品翻转后通过筛分,最后     

影响饲料制粒工艺效果的因素

颗粒饲料是一种由全价混合粉料或单一原料（如牧草、饼粕等）经挤压作用而制成的粒状饲料.颗粒饲料虽然制造成本较高,但是经过大量的畜禽饲养试验,证明它的饲养效果好,经济效益明显.近年来,随着饲料工业的飞速发展,颗粒饲料已逐渐被广大养殖户所接受,用量有继续增长的趋势.颗粒饲料的质量受多种因素影响.早在1992年Reimer就曾报道了影响颗粒饲料质量的因素之间存在一定的比例关系,其中饲料配方占40%、粉碎粒度占20%、调质占20%、环模规格占15%、冷却干燥占5%.可见饲料原料的选择对颗粒饲料的质量影响最为重要.     

挤压膨化水产饲料的要点

近几年来,我国水产养殖发展比较快,而水产养殖的关键是提供能满足水产动物营养摄食习惯的各种形态的饲料,这种饲料应制成浮性（上层鱼类、蛙类）、慢沉性（中下层鱼类）、沉性（河蟹、虾类）三类,并且在水中能够完整地保持一定时间,以便动物有足够的摄食时间。要制出各种沉降速度的饲料,只有利用挤压膨化技术,这是其他制造技术难以实现的。为满足水产养殖者需求,盐城市浓缩蛋白饲料厂在１９９６年从美国Ｗｅｎｇｅｒ公司引进全套膨化饲料生产线,陆续开发生产了河蟹、虾类、蛙类、经济鱼类等沉浮颗粒饲料,其典型颗粒直径范围是１…     

制粒作业中蒸汽调制的基本原理

<正>颗粒饲料使动物(包括肉鸡、猪、牛、蛋鸡等)的生产表现总体提高5%～10%。颗粒饲料加工成本在美国是5～20美元/t,因饲料种类、加工设备及生产管理而异。鱼类颗粒饲料,特别是虾饲料,加工成本更高,但它带来的效益也更高,不论是水产养殖本身还是环境     

挤压技术在水产饲料中的应用

利用挤压技术生产的水产膨化饲料具有普通颗粒饲料无法比拟的优势。本文从技术角度对挤压生产中的原料、设备、工艺、操作等进行了理论阐述。     

主要加工条件对水产颗粒饲料耐水性的影响

进入90年代,我国水产养殖产量已逾500万吨,需要水产颗粒饲料600万吨以上。但目前我国水产饵料质量水平还不高,饵料系数徘徊在1.2- 3:1之间,究其原因,除了配方组成、饲养条件与方法有待改进外,水产颗粒饲料加工质量不高,在水中耐水性较差,饲料报酬低,也是重要原因之一。本文将着重探讨如何提高水产颗粒饲料在水中稳定性的问题。     

水产膨化颗粒饲料生产工艺特点及危害分析

随着水产养殖业的迅速发展,传统的饲料已经不能满足水产养殖发展的需求,市场需求的水产饲料不仅应营养均衡、水稳定性好,而且不会对水产动物生存的水体环境质量产生影响。膨化颗粒饲料可较好地满足上述要求。但与传统的畜禽饲料的生产工艺相比,水产膨化颗粒饲料的生产工艺复杂,     

水产膨化饲料的现状及展望

近年来,水产养殖规模不断扩大,养殖技术不断更新,养殖品种不断增加,尤其是网箱养鱼、流水养鱼、特种水产养殖的迅速崛起,传统的养殖技术已越来越不适应现代经济发展的需要.传统的粉状配合饲料和颗粒配合饲料由于存在着水中稳定性差,沉降速度快,易造成饲料散失浪费和水质污染等弊端,也正面临着严峻的挑战,而膨化饲料能较好地克服粉状和硬颗粒饲料的弊端,是现代水产养殖业的理想饲料品种,已显示出较好的市场前景,水产膨化饲料将是未来水产饲料发展的必然趋势.     

制粒和膨化加工技术在水产饲料生产上的应用分析

我国是世界第一水产大国，水产养殖年增１０％以上，由于水产养殖业的持续发展和颗粒饲料在水产养殖业中的应用，促进了水产养殖业向高密度、集约化方向发展。为了提高饲料的转化率、改善水体的环境，水产养殖业一直在通过优化饲料配方及选择最佳的机械设备去提高颗粒饲料的质量。实际上，根据鱼类有肠道短、饲料在肠道内的停留时间短的生理特点，只要采用适当的加工方法，同样可达到改善水质、减少鱼病、增强养殖业的可持续性、提高产量和产品质量、提高饲料转化率和经济效益的效果。本文就是从通过分析比较生产水产饲料的两种加工方法——…     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.