氨基酸对水禽羽毛发育的影响

羽毛是水禽重要的外貌特征,其形态发生、结构组成及换羽模式等与羽毛品质高度相关。随着水禽出栏日龄的不断缩短,水禽羽毛的早期发育和及时成熟显得尤为重要,试验研究表明,含硫氨基酸和支链氨基酸缺乏能够显著影响早期水禽羽毛的发育。     

家禽羽毛出现异常原因及防治

<正>一般家禽羽毛出现异常的原因是由于营养不良或管理不当造成的。1家禽羽毛的异常1.1营养因素(1)蛋白质含量不足或氨基酸不平衡:蛋白质是动物体内组织发育的主要营养成分,羽毛中蛋白质含量高于85%(角蛋白),而氨基酸则是羽毛生长最重要的营养物质,日粮中长期缺乏会出羽不良;赖氨酸缺乏可导致有色羽毛鸡羽毛色素沉积;生长鸡日粮中缺乏色氨酸、甘氨酸、精氨酸、缬氨酸、亮氨酸、异亮氨酸,苯丙氨酸和胳氨酸时,都会使鸡只羽毛多种异常症状。     

世界水禽的生产

水禽的肉和蛋具有营养高、风味美而独特的特点,尽管人类主要的禽肉和禽蛋来自鸡,但是在世界的某些地方,有很大一部分来自水禽(主要是鸭和鹅)。水禽的生产有利于世界人口营养水平的提高,尤其重要的是其价格便宜,适合低消费人群。此外,水禽还为羽毛和羽绒的生产提供广泛的来源。     

我国水禽业的技术创新与未来产业化格局

我国是水禽大国，现饲养的水禽主要包括家鸭，鹅、番鸭、野鸭与骡鸭等：水禽的肉、蛋别具风味，是其它家禽产品所不具备的。另外，水禽还可以进行肥肝生产，其羽毛、绒毛也是高附加值的副产品。水禽业是家禽生产中的一个重要组成部分。     

我国水禽业的技术创新与未来产业化格局

我国是水禽大国,现饲养的水禽主要包括家鸭、鹅、番鸭、野鸭与骡鸭等。水禽的肉、蛋别具风味,是其它家禽产品所不具备的。并且水禽还可以进行肥肝生产,其羽毛、绒毛也是高附加值的副产品,水禽业是家禽生产中的一个重要组成部分。但是,我国水禽产业参与国际竞争,要较快地提高经济效益、提高产业化程度,就必须在如下几个方面进行技术创新并形成产业化格局。1育种方法长期以来,传统育种理论一直是水禽育种技术核心,在经典育种理论的指导下,水禽业取得长足发展,如:绍兴鸭纯系和配套系选育;Z型北京鸭选育;褐色菜鸭的产蛋性能的改进;鸭的属间杂交…     

深加工工艺对羽毛粉和血粉品质的影响

用活化的H菌先发酵羽毛粉,与血粉按一定比例混合复配,调节氨基酸平衡,经酶解,水解,再与复合微生物(绿源生)厌氧发酵。结果显示:深加工工艺可以提高羽毛粉胃蛋白酶消化率,调节氨基酸平衡,提高羽毛粉蛋白质的品质与利用率,提高经济效益,降低饲料生产成本。     

鸽蛋白质缺乏症的诊断及防治

蛋白质对于鸽子的生物价值取决于氨基酸的组成种类,鸽子生长发育需12￣13种氨基酸。蛋白质缺乏会引起鸽子生长缓慢,发育停滞,畏寒、体温低于正常,食欲减退,消瘦疲劳,体重减轻,贫血,繁殖力减弱或完全丧失,抗病力降低,外伤不易愈合,流血不止、血液稀薄而凝固不良,皮下常有水肿,精神沉郁,无力,运动过后呼吸困难且心率快。如蛋氨酸缺乏,可使胆碱或维生素B1缺乏症恶化;赖氨酸缺乏,引起某些品种的鸽子羽毛色素沉着减少;精氨酸缺乏,使翅膀羽毛向上卷曲,鸽羽毛蓬乱。蛋白质缺乏症的诊断根据其临诊症状、日粮的蛋白质含量情况可以基本判定。判定时应…     

羽毛粉几种加工方法的比较

<正>随着动物食品和动物产品规模化和集约化的生产,大量废弃羽毛由于难以处理被丢弃,对环境造成很大污染。因此对羽毛粉的开发利用非常重要,研究者一直在寻找这一丰富资源的新用途,能使加工者有利可图的同时还能解决严重的废物处理问题。1羽毛的营养价值羽毛是有机物并可以转变为有用的资源。动物的羽毛中,含有种类丰富的氨基酸和蛋白质。比如鸡的羽毛中就含有17种氨基酸,其中有14%的丝氨酸,另外谷氨酸、亮氨酸、     

稳定和提高牛奶蛋白质含量的营养策略

乳腺是一个复杂的器官,组织和细胞类型繁杂,乳腺氨基酸代谢受到众多因素影响,如日粮组成、氨基酸成分、饲料添加剂、瘤胃功能等等。足量的比例平衡的氨基酸对奶牛营养具有重要意义,了解氨基酸的供应与平衡可以预测乳蛋白的产出。日粮蛋白质和氨基酸对乳蛋白含量与产量有重要影响。在大部分日粮条件下,蛋氨酸是第一限制性氨基酸,通过理化方法保护蛋氨酸过瘤胃可以改善蛋氨酸的生物有效性。此外,赖氨酸和支链氨基酸(异亮氨酸、亮氨酸、缬氨酸等)对于乳蛋白合成也很重要。当氨基酸不足以用于乳蛋白合成时,可从肽结合氨基酸库中释放。某些情况下,氨基酸平衡对乳蛋白合成的重要性更甚于日粮蛋白质的含量,适宜比例的必需氨基酸能增加乳蛋白合成,氨基酸平衡的改善可促进乳蛋白合成,提高奶产量。当日粮粗饲料质量较差时,可溶性碳水化合物可能成为瘤胃微生物蛋白质合成的限制因素,导致乳蛋白前体物数量下降。需要同时优化瘤胃内微生物蛋白质合成和适宜补充氨基酸,才能满足乳蛋白合成的需要。     

水解羽毛粉喂鹅试验

禽类羽毛由硬蛋白类中的角蛋白组成,含水极少,粗蛋白含量高达75～85%,但未经有效处理,其利用率极低。水解羽毛粉是经过高压水解后,加工成为易被消化吸收的氨基酸或短肽等水分子物质,利用率可提高到80.3%。然而,羽毛粉中蛋氨酸、赖氨酸和色氨酸的含量较少,在鸡上的研究表明,由于羽毛粉的氨基酸不平衡而影响其蛋白质的利用     

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。     

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。     

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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。 …