锌与公畜营养

锌作为动物营养中一种重要的必需微量元素,参与动物体内几乎所有的物质代谢过程。现已确认,有200多种酶的活性与锌有关。锌通过调节这些酶的活性来影响动物体内蛋白质和核酸的合成与代谢,糖类的吸     

微量元素锌与家畜繁殖性能

<正> 锌作为动物营养中重要的必需微量元素,参与动物体内几乎所有的物质代谢过程。现已确认,有200多种酶的活性与锌有关。锌通过调节这些酶的活性来影响体内蛋白质和核酸的代谢和合成,糖类的吸收,维生素A代谢,生殖机能和内分泌机能等生命活动。因此,锌又被称为“生命元素(The element of     

锌水平对鹅血液免疫功能的影响

锌作为动物体内必需的微量元素对免疫功能具有增强作用。以往学者对于哺乳动物和鸡与锌的关系有一定研究,然而关于锌对鹅免疫功能的影响则罕见报道。试验通过设置不同锌水平的饲粮,探讨雏鹅阶段能发挥最佳免疫力的锌需要量,为锌在雏鹅阶段应用提供依据。1材料与方法1.1试验动物选用1日龄雏鹅120只,雌雄兼有,随机分为4组,每组30只,平均体重70.4 g/只。前2周饲养于木笼中,15日龄后分组地面饲养,自由采食,保证充足的饮水。试验A、B、C、D组添加ZnSO4·H2O,使锌添加水平分别为0,40,110,2 000 mg/kg。试验期为55 d。1.2试验日粮采用以玉米-豆…     

不同锌源对仔猪生长性能的影响

锌是动物营养中的一种必需微量元素,是动物体内２００多种酶发挥作用的辅助因子,参与动物体内的多种生化代谢,对动物的生长与发育具有重要作用。本试验旨在探讨不同锌源对仔猪生长性能的影响。     

酵母锌对断奶仔猪生长性能及抗氧化作用的影响

1973年,世界卫生组织专家委员会确认锌是动物生长所必需的微量元素之一.已证明,锌参与体内120多种酶的生物合成,调节300多种酶促反应,合理的锌水平可以保证动物各组织、器官功能处于最佳的功能状态,促进动物生长,强化防御能力、免疫系统,增强动物对疾病的抵抗能力.目前为止,在畜牧生产中应用的锌有无机锌、有机锌和螯合锌.以酵母形态存在的锌现已用作儿童补锌试剂,为探索其在动物生产中的应用效果,笔者以不同浓度的酵母锌为锌源饲喂断奶仔猪,研究酵母锌与断奶仔猪生长性能及抗氧化作用之间的相互关系,以确定酵母锌在断奶仔猪饲料中合理的添加水平,为酵母锌在饲料生产中的广泛应用提供理论依据.     

锌与免疫的关系

一．前言　　公元前十五世纪，人们就开始用含锌的炉甘石治疗伤口，以加速其愈合。人类对于锌的营养作用却是由Raulin（1869）进行黑曲霉培养时发现的。此后经过100多年，特别是最近十几年来，锌对动物生命活动的重要性已被各国的研究所证实（杨文正,1994）。研究表明，动物体内200多种酶中含有锌，并有300多种酶的活性与锌有关，锌通过调节这些酶的活性来影响动物体内的物质合成与代谢及各种生命活动（杨文正,1994；Kidd,1996）。随着科技的发展和研究手段的提高，发现锌的营养功能是非常广泛和重要的，人们誉之为“生命的火花”，合理的…     

锌与畜禽免疫功能的关系

近年来，随着动物营养学的横向发展，已形成了营养与生理、营养与免疫、营养基因与调控等边缘学科，微量元素与免疫功能的关系也越来越受到人们的高度重视。锌是动物机体维持生命活动所必需的微量元素，动物体内有200多种酶含有锌，锌通过调节这些酶的活性来影响动物机体的代谢过程。本文就微量元素锌与动物细胞免疫、体液免疫和非特异性防循系统的关系进行综述。     

微量元素对动物繁殖机能的影响

随着动物营养科学的发展,微量元素在动物体内的作用不断地被揭示。本文综述了锌、锰、碘、硒、铜,钼和钴等微量元素对动物繁殖机能的影响。锌对动物繁殖机能的影响一些学者(Chesters,1978;Hidirog-lou,1979;Apagar,1985)就动物缺锌对繁殖性能的影响进行了广泛的研究。动物体内200多种酶含有锌,其中一些酶与繁殖有关,但锌如何影响繁殖还知之甚少。锌是一些酶的必需成分或激活因子,而这些酶参与固醇类激素的合成。锌可能通过垂体间接影     

硒锌联合应用对奶牛抗氧化功能的影响

为探讨元素硒锌联合应用对奶牛抗氧化系统的影响及锌硒在奶牛体内代谢的相互关系,选择１５头荷斯坦奶牛进行为期３个月的试验,实验以每组５头随机分为三组：对照组,饲喂基础日粮;加硒组,日粮添加亚硒酸钠０．２２ｍｇ／ｋｇ饲料;加硒加锌组,在加硒组基础上添加硫酸锌１２ｍｇ／ｋｇ饲料。结果显示,加硒组及加硒加锌组奶牛血清谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）及铜锌超氧化物歧化酶活性在实验期内大于对照组,差异显著;加     

微量元素锌对水貂繁殖性能的影响

<正>锌在动物体内广泛存在,是其必需的微量元素,且动物体内的锌组成了200多种酶,例如透明质酸酶、醇脱氨酶、苹果酸脱氨酶、乳酸脱氢酶等。而锌与精子中DNA聚合酶、碱性磷酸酶、腺苷酸环化酶、RNA聚合酶、甘露糖苷等的活性直接存在关系。这些酶在合成、激活以及催化过程中都有锌的直接参与,且蛋白质结构维持完整性的过程也离不开锌,因此锌对精子的生理功能维持或者生成精子的过程具有一定的调节作用。据有关研究表明,精子活性与锌浓度呈正相关,     

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.