仿生消化法评定猪饲料生物学效价的研究进展

在畜牧业生产中,客观、准确评定各种饲料原料的生物学效价是建立营养需要量标准、优化饲料配方的基础性科学决策依据,也是提高饲料利用率、降低饲料成本及节能减排的重要手段。从德国Weende试验站的Henneberg与Stohmann首倡的概略养分测定方法已沿用一个半世纪,传统的生物学效价评定手段也基本保持原体系未变。在此期间,许多动物营养学家、生物化学家和仪器分析专家们在改革这一体系方面进行了大量有益的尝试。特别是在饲料养分的生物学效价的涵义、测试评价手段及分析仪表的开发等方面取得了许多可喜的进展,支撑了现代畜禽养殖业和饲料工业的发展。但是由于饲料养分的生物学效价自身受控于日粮结构、畜禽品种、生理阶段、环境条件、饲养制度乃至健康状况等种种复杂因素。因此,许多学者对文献中报道的有关大量饲料养分生物学效价的测试评定结果的可比性提出了质疑。文章结合几十年来国内外在用仿生消化法评定猪饲料生物学效价方面的研究进展与存在问题进行讨论,并就作者等在开发以简捷、标准、可重复及可加为前提的单胃动物仿生酶水解系统的设计原理、重演性及可行性进行阶段性总结汇报。     

体外法评定饲料氨基酸营养价值

蛋白质饲料供应不足乃世界性问题,我国蛋白质饲料紧缺亦日趋严重,实现对饲料蛋白质营养价值的准确、客观评定是合理利用蛋白质饲料资源的先决条件。因此,如何客观评价饲料蛋白质氨基酸营养价值,是各国学者一直关注和研究的主要课题。近年的研究表明,满足畜禽蛋白质的需要实质上是满足其氨基酸的需要,蛋白质的营养实质是氨基酸的营养。在畜禽饲养及营养学中,评定蛋白质的生物学效价的方法已逐渐被摒弃,研究重点已转到蛋白质中各种必需氨基酸生物学效价评定方面,即以可利用氨基酸为基础评定饲料蛋白质的营养价值。1体外法测定氨基酸生物学效价…     

饲料级无机磷酸盐和饲料原料中磷的生物学效价的评定

磷(P)是日粮中不可缺少的重要营养元素。无论无机还是有机磷,他们的生物学效价都会不同。因此,了解生物学效价的知识和评定方法对选择饲料磷的来源,最大限度地发挥动物和家禽的生产性能,避免粪便过量的磷排泄具有极为重要的意义。本文的目的是对一些评定无机磷酸盐和有机饲料原料磷的生物学效价的常规方法做一介绍,并对他们的物理和化学特性加以描述。 磷是动物所必需的主要矿物元素之一。磷、钙,对于动物骨骼系统的生长和发育具有重要作     

猪对不同类型谷物饲料回肠末端氨基酸消化率比较测定

猪饲料营养价值的评定，是合理选择饲料原料，配制全价、平衡、适用日粮的基础，也是养猪生产取得效益的关键。饲料中氨基酸的可利用性的测定一直是动物营养学家的重要研究课题。近年来，国内外学者在猪饲料氨基酸生物学效价的评定方法上已取得重要进展，其中采用回－直肠吻合术的回肠末端氨基酸消化率测定法以其准确性、可操作性的优点，被认为是表征猪饲料氨基酸生物学效价的最适宜方法。据此，本研究采用该法评定了高蛋白糙米、普通玉米、普通糙米及普通稻谷的回肠末端氨基酸消化率，比较评价４类谷物类型饲料蛋白质营养价值优劣。１材料…     

饲料中磷的生物学效价评定方法

磷是动物机体必需的常量矿物质元素之一。准确评定饲料原料中磷的生物学效价是实现无机磷源合理添加,减少添加过量造成的经济损失,以及防止粪尿磷大量排泄的有效手段。本文就目前关于饲料中磷的生物学效价评定的方法即平衡试验法、斜率比法、估测法、三项指标综合法、体外溶解度法、体外透析法作一综述。     

饲料原料的研究进展及薯类饲料的开发价值

随着我国畜牧养殖产业的快速发展,畜禽饲料的需求量也有了巨大的增加,传统饲料原料短缺的情况逐渐凸显,这导致饲料原料价格飞涨,进而引起畜禽养殖经济效益下降,在一定程度上阻碍了我国畜牧养殖产业和饲料行业的发展.非常规饲料原料的开发可以有效缓解这种状况.本文对现阶段我国饲料原料和饲料行业的发展现状以及薯类非常规能量原料的开发价...     

体外透析法评定单胃动物饲料养分生物学效价

体外法能快速准确地进行饲料生物学效价评定,其中体外透析法具有将酶促反应和产物分离合二为一、消除产物抑制、类似于动物消化道吸收等特点。文章对国内外利用体外透析法评定单胃动物饲料养分生物学效价方面的研究进展与存在的问题进行讨论,侧重分析了蛋白质、氨基酸、淀粉、矿物元素等饲料养分的生物学效价体外评定发展现状与不足以及主要影响因素,并简要概述单胃动物仿生消化系统进行饲料评定的优势,旨在为建立我国便捷评定畜禽饲料养分生物学效价的方法提供参考。     

体内法评定鸡饲料原料中矿物元素生物学利用率的研究进展

动物营养研究的最终目标之一是实现以饲料养分的有效含量来满足动物对饲料养分的有效需要量。目前,无机和有机矿物元素添加剂中矿物元素的生物学利用率评定已受到人们的重视,但对动植物性饲料原料中矿物元素生物学利用率的评定还少见报道。本文综述了体内法评定鸡饲料原料中矿物元素生物学利用率的主要方法、研究进展及存在的问题,并提出了今后进一步的研究方向。     

不同蛋氨酸来源的相对生物学效价

贵刊 2 0 0 3年第九期登载的《液体蛋氨酸羟基类似物的生物学效价》一文 ,我们认为有必要对其中有关生物学效价评定方法的一些观点提出质疑 ,供大家进一步讨论。评定液体蛋氨酸羟基类似物 (MHA -FA)相对于蛋氨酸 (DLM)的生物学效价与评定其他任何营养物质一样 ,梯度添加效应试验并用线性或指数回归分析是最敏感 ,也是唯一能够准确反映动物生长与生产规律和评定营养物质生物学效价的方法。对此动物营养界已有定论。动物对限制性营养物质如蛋氨酸的生长反应呈曲线式并遵循报酬递减规律。在蛋氨酸缺乏的日粮中 ,随着梯度添加DLM或MHA -F…     

加强我国饲料生物学效价等基础研究工作意义重大

今年，大宗饲料原料和部分饲料添加剂价格的飞涨让饲料企业感受到了寻找新的替代原料和提高现有饲料资源利用效率的必要性。的确，我国还有大量非常规饲料资源尚未得到合理开发利用，不仅造成了资源浪费，还污染了自然环境。通过饲料营养价值或称生物学效价评定方法，可以提高这些饲料资源的利用效率，对有效缓解饲料资源短缺具有重要的现实意义。     

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.